TAU/NEUROFILAMENT PROTEIN KINASES PK40 AND PK36

Abstract: Novel TAU/neurofilament protein kinases, PK40 and PK36, are essentially purified and characterized. Novel immunoassays relating to the kinases and inhibitors for the kinases also are provided. Finally, DNA sequences encoding the kinases and cell lines relating to the kinases are provided.

Description: TAU/NEUROFILAMENT PROTEIN KINASES PK40 AND PK36 This invention relates to novel TAU/neurofilame t protein kinases, DNA sequences therefor and cell lines relating thereto, as well as inhibitors of the kinases and im unoassayε relating to the kinases. Background of the Invention Neurofilaments (NF) , the intermediate filaments (IF) specific for neurons, are an assembly of three subunits of apparent Mr on SDS-PAGE of 68 kD, 160 kD and 200 kD, termed F-L, NF-M and NF-^H, I respectively. All three subunits contain a highly conserved helical rod domain. The two heavier subunits also have extended C-terminal tail domains which are heavily phosphorylated. The cDNA-derived sequences of the two heavy NF-subunits have revealed the presence of 5, 12 and 40 Lys-Ser-Pro (Val,Ala,X) repeats in'the C-terminal domains of rat NF-M, human NF-M and human "NF-H, respectively (Napolitano et al. , 1987; Myers et al. , 1987 and Lees et al. , 1988). These sequences form the epitopes of several phosphoepitope-specific anti-NF-mAbs (Lee et al. , 1988). The physiological significance of NF and their phosphorylation is not very well understood yet (reviewed by Matus, 1988); correlative evidence suggests involvement in the regulation of axonal diameter (Hoffman et al.,. 1987; Pleasure et al., 1989) . Electron microscopic studies in conjunction with antibody decoration (Hirokawa wt al., 1984) and biochemical evidence (Minami et al., 1983) favor NF-H as a component in interactions of the NF and micrntubule networks. The phosphorylation status of NF and their ability to promote tubulin polymerization are correlated in vitro (Minami et al., 1985). The existence of NF-kinase(s) not activated by common second messengers and some of their expected properties were postulated from in vivo phosphorylation studies on extruded axoplasm of the giant axons of the squid (Pant et al., 1978, 1986) and of Myxicola (Shecket et al., 1982). In vitro characterization of purified NF-kinases has focused so far on activities that copurify with the NF-cytoskeleton and can be dissociated under high salt conditions ( unge et al., 1981; Toru-Delbauffe et al., 1983). There is currently no evidence of second messenger dependence of any of these activities. From a mixture of such kinases one 67 kD activity has been purified to apparent homogeneity ( ible et al., -1989). This kinase prefers NF-H as a substrate, but only if not completely dephosphoryl ed. A cAMP-dependent kinase copurifying with microtubuleε has been shown to phosphorylate preferentially NF-M in NF-triplets (Leterrier et al., 1981). In no case are the stoichiometry or the sites of phosphorylation known and no shift of apparent Mr of NF-M and NF-H on SDS-PAGE has been demonstrated. Such a shift is expected after incorporation of phosphate in high stoichiometric ratios into the dephosphorylated subunits. A smaller than expected gel shift associated with a heterogeneous state of KSP-phosphorylation of NF-M is induced by uncharacterized kinases in mouse L cells transfected with a human NF-M clone (Pleasure et al. , 1990). A possible pathological- role of aberrant NF-phosphorylation was considered when the anti-rat-NF mAb 07-5 (commercially available as SMI-34 from Sternberger-Meyer Immunochemicalε of Jarretsville, MD, U.S.A.) was found to stain neurofibrillary tangles in brain tissue from Alzheimer's patients (Sternberger et,al., 1985), but did not stain normal human brain tissue, except for cerebellar basket cell axons and certain motoneuron axons of patients 60 years of age (Blanchard & Ingram, 1989). On the other hand, there is a report that the localization of the SMI-34 epitope is exclusively perikaryonal, while most other mAbs reacting with NF-phosphoepitopes stain axons preferentially -(Sternberger et al. , 1983). However, i munochemical evidence (Grundke-lqbal et al., 1986; Kosik et al., 1986; Wood et al. , 1986; Nukina et al. , 1987) concerning the crossreactivities of a series of mAbs with NFs, microtubule associated protein TAU and the main component of tangles and paired helical filaments (PHF) point to TAU as a major constituent of PHFs. This deduction is reinforced by the isolation from PHFs of TAU-derived peptides (Wischik et al, , 1988), while no NF-derived peptides (Kondo et al., 1988) were obtained. A number of anti-JJTF mAbs crossreacting with TAU, among them SMI-31 (commercially available from Sternberger-Meyer Immunochemical) and RT97, recognize the phosphorylated KSP-sequence repeat in NF proteins (Lee et al., 1988). PHFs react strongly with RT97, but only after prolonged treatment with SDS, suggesting the presence of this phosphorylated epitope in PHF in a nonperipheral location (Rasool et al., 1984). Several lines of evidence indicate an abnormal level or an abnormal site of phosphorylation in the C-terminal portion of the TAU molecule in Alzheimer's Disease (AD) (Grundke-lqbal et al., 1986; Kondo et al., 1988; Iqbal et al., 19έ9) . If an abnormally phosphorylated form of TAU is responsible for or involved in the development of neurological conditions characterized by PHFs in neurofibrillary tangles, then it clearly would be extremely important to identify the factor(s) which cause that phosphory1ation. Summary of the Invention The invention provides preparations containing isolated, essentially pure, nonskeletal-associated kinases, the kinases capable of phosphorylating dephosphorylated NF-M to an extent sufficient to cause a shift on SDS-PAGE of the apparent M of dephosphorylated NF-M toward that of native NF-M. The kinaseε further are capable of phosphorylating both dephosphorylated and native Tau and are capable of phosphorylating and reconstituting phospho-epitopeε on completely dephosphorylated NF-triplet or purified dephosphorylated NF-M. The kinaseε alεo are inhibited by excess ATP. One kinase, PK40, has an apparent molecular weight of 40 kD and iε capable of phoεphorylating completely dephosphorylated NF-M to an extent sufficient to cause a complete shift of apparent molecular weight from that of completely dephosphorylated NF-M to that of native NF-M. This kinase also is capable of causing a complete shift for TAU and a partial shift for NF-H. It in particular can phosphorylate TAU to n extent that mimickε the alterations characteristic of human TAU proteins extracted from PHFs. It further can phosphorylate both KSP siteε of TAU and can aboliεh the TAU-1 epitope. Another kinaεe, PK36 haε an apparent molecular weight of 36 kD and iε capable of phosphorylating completely dephosphorylated NF-M to an extent sufficient to cause at least a partial shift of apparent molecular weight from that of completely dephosphorylated NF-M toward that of native NF-M. According to another aspect of the invention, novel assayε are provided. One assay involves a method for detecting a mammalian kinase. A fraction of biological material derived from a mammal is prepared, it being unknown whether the fraction contains the kinase of interest. The fraction is subεtantially free of epitopes characteristic of a phosphorylated protein and reactive with a test antibody. The fraction is contacted with a dephosphorylated protein free of the epitope under conditions so as to permit the phosphorylation of the protein if the kinase is present. The fraction then is tested for the presence of the epitope using the test antibody. Preferably the fraction is contacted with a completely dephosphorylated neuroprotein. The presence of the epitope can be detected using an antibody reactive with an epitope correlated with phosphorylated neuroproteins such as SMI-31 antibody or SMI-34 antibody, and reagents may be employed to produce a color in the presence of an immunoprecipitate complex between the antibodies and the epitope. The color produced then may be measured as a quantitative measure of the presence of the complex. In a similar immunoassay, the fraction of biological material derived from a mammal is prepared, being unknown whether the fraction contains the kinase of interest. The fraction is substantially free of epitopes that are characteristic of a protein in a particular state of phosphoralation and that are reactive with the test antibody. (Particular state of phosphoralation includes completely dephosphoralated. ) The fraction iε contacted with a protein that iε characterized by the epitope under conditions εo as to permit the phoεphoralation of the protein if the mammalian kinaεe is present. The presence of the epitope that is tested for uεing the antibody. If the epitope has dissappeared, -then the kinase iε preεent. Examples of useful antibodies include SMI-33 and TAU-1. Preferred substrateε include neuroproteins that are reactive with the foregoing antibodies, such as, for example, the phoεphoralated TAU. Another novel immunoaεεay according to the invention involves use of an antibody that is reactive with an epitope characteristic of a particular εtate of phosphoralation of a protein, and use of the protein in a state of phosphoralation that does not bind to the antibody. Such immunoassays may be in the form of a kit including a container with the first container containing the antibody and the second container containing the protein. Preferrably the protein is a neuroprotein and most preferrably the protein is desphosphoralated TAU. Yet another novel immunoassay according to the invention employs dephosphorylated NF. Preferred embodiments involve aεsays utilizing completely dephosphorylated NF-triplet, completely dephosphorylated NF-M and completely dephosphorylated NF-H. According to another aspect of the invention, antibodies to the novel kinase of the invention are provided. Monoclonal and polyclonal antibodies capable of binding to and, preferably selectively specific for PK40 and PK36 are provided. Most preferably the antibodies are capable of inhibiting the kinaεe activity of either PK40 or PK36. The antibodieε may be used among other things for detecting the -presence of PK40 or PK36. • The invention also provides methods for inhibiting neuroprotein phosphorylation activity in a cell by introducing into a cell an inhibitor of PK40 or PK36 in an amount sufficient to inhibit the phosphorylation activity of the PK40 or PK36. Preferred inhibitors include fragments of substrates of PK40 or PK36, antibodies selectively specific for PK40 or PK36 and ATP or analogs of ATP. Most preferably the inhibitor is administered in an amount sufficient to prevent the formation of neurofilament tangles. According to still another aspect of the invention, vectors are provided containing oligonucleotides encoding PK40 or unique fragments thereof and PK36 or unique fragments thereof. Likewise, cell lines are provided that are transformed or transfected with an oligonucleotide encoding PK40 or a unique fragment thereof or PK 36 or a unique fragment thereof. Productε of the cell line also are provided. These and other features of the invention are described in greater detail below in connection with the detailed description of the preferred embodiments. Brief Description of the Drawings FIG. 1 is a photograph of a stained gel (12% SDS-PAGE) indicating the presence of PK36 and PK40. Detailed Description of the Preferred Embodiment ■ The invention in one aspect involves the identification of novel kinaseε, PK40 and PK36. PK40 and PK36 have been iεolated from bovine brain as described in Example 4 and are essentially pure. By "esεentially pure" it iε meant that at least 40% of the material in a preparation is the kinase of interest. Preferably the kinase represents at least 80%, and most preferably the kinase represents at least 90%, of the material in the preparation. In any event, the preparations of the invention are sufficiently pure so as to permit amino acid sequencing by conventional methods, and further, can be made sufficiently pure to permit the generation and identification of antibodies to the kinases of interest. PK40 and PK36 have apparent molecular weights (M r ) of 40 kD and 36 kD on SDS-PAGE, respectively. A unique characteristic of PK40 is its slight shift (C < 1) in apparant molecular weight during the purification procedures of the invention. This is believed to be due to phosphorylation of PK40 during purification. The kinases are noncytoskeletal-aεεociated. "By noncytoskeletal-associated it is meant that the kinase does not co-purify with the NF-cytoskeleton under high-salt extraction conditions. " PK40, but not PK36, normally is isolated in a tyrosine phosphorylated form. The kinases are capable of phosphorylating a variety of dephosphorylated native substrates. The native substrates have characteristic mobilities on SDS-PAGE which change when the substrates are dephosphorylated. Treatment of these dephosphorylated subεtrates with the kinases of the invention under conditions permitting phosphorylation of the subεtrates, may result in a mobility shift on SDS-PAGE of the apparent M of the dephosphorylated substrate toward that of the native substrate, depending upon the particular substrate and kinase selected, and the conditions applied. A "shift" is any detectable change in mobility. By "complete shift" it is meant that the mobility of the previously dephosphorylated substrate, after treatment with the kinase of the invention, is the same as that of the native substrate. A "partial shift" means that the mobility has moved between that of the dephosphorylated substrate and that of the native substrate. "No shift" means no detectable change in mobility after treatment of the dephosphorylated substrate with the kinase of the invention. PK40 is capable of phosphorylating completely-dephosphorylated NF-M (cdNF-M) so as to cause a complete shift on SDS-PAGE of the apparent M of the cdNF-M to that of native NF-M. PK40 causes a partial shift of completely-dephosphorylated NF-H (cdNF-H). PK40 further is capable of causing a complete shift of completely-dephosphorylated native bovine TAU or pure human TAU isoform expressed in E.coli from the clone Htau 40 (Goedert et al. 1989). In this regard, under saturation phosphorylation conditions, PK40 causes a change in the isoform pattern that closely resembles the pattern of human TAU proteins extracted from PHF. This and other pattern changes are discuεεed in greater detail below. It alεo phoεphorylates both KSP sites of TAU and abolishes the TAU 1 epitope. PK36 iε capable of phoεphorylating cdNF-M so as to cause at least a partial shift on SDS-PAGE of the apparent M of the cdNF-M to that of native NF-M. It also can cause a partial shift with respect to TAU. Neither kinase iε activated by the uεual second messengers, i.e. , small molecules (such as cAMP, cGMP, Calcium, Ca + Phosphatidyl Serine and Ca/CAM) that are produced inside the cell when the outside of the cell membrane receives a signal or stimulus, such as a peptide hormone. The ATP dependence and inhibition of the activities of PK40 and PK36 were determined as described in Example 6. The apparent K value for ATP of PK40 is 93 - 12 μM and of PK36 is 50 μM. These values reflect a requirement for relatively high ATP concentrations. Both kinases, however, are strongly inhibited by an excess of ATP, i.e. , when ATP is in relatively small excess over Mg 2+* . In addition, PK36, but not PK40, is inhibited by the Walsh inhibitor. Identification of these novel kinases was made possible by the employment of a novel kinase im unoasεay described herein. This immunoassay required NF proteins devoid of immunoreactivity with mAbs SMI-31 and SMI-34, in that the asεay meaεureε kinase activity specific for epitopes recognized by these antibodies, i.e. , the repeated phosphorylated KSP sequences. In order to be devoid of such immunoreactivity, the NF proteins were completely dephosphorylated as described in Example 1. Thus, by "completely dephosphorylated", it is meant nonreactive with SMI-31 and SMI-34 antibodies. With such dephosphorylated substrates, it is possible to assay for kinase activity i.e. , the rephosphorylation of the KSP εequenceε, by measuring th'e reappearance of immunoreactivity with SMI-31 and SMI-34. Thus, the completely-dephosphorylated NF proteins were incubated with different ammonium sulfate fractions from bovine brain supernatants, and reconstitution of the SMI-31 and SMI-34 epitopes was assayed in the different fractions, as described in Example 2. A colorimetric immunoassay also described in Example 2, can be used to quantitatively measure levels of phosphorylating activity. In such an assay, the presence of the epitopes characteristic of phosphorylated NF proteins is tested using reagents that produce a color in the presence of an immunoprecipitate complex between antibodies such as SMI-31 or SMI-34 and the phosphorylated NF proteins. The amount of color produced is determined, thus providing a quantitative measurement of the amount of complex formed. Such a measurement correlates with the KSP-specific phoεphorylating activity preεent in the εample teεted. Again, completely-dephoεphorylated neuroprotein can be uεed aε a substrate, although there are instances that do not necessarily require completely-dephosphorylated material as a substrate. The invention also pertains to the nucleic acids encoding the human kinaseε correεponding to bovine PK40 and PK36, and to a method for cloning DNA sequences encoding the human kinaseε. The purified bovine kinases are sequenced as described in Example 11. With this sequence information, .oligonucleotide probes are constructed and used to identify the gene encoding the human kinase in a cDNA library. Due to degeneracy of the genetic code, most amino acids are represented by more than one codon. Therefore, in order to increase the proportion of codons on the probe that actually correspond to the codons in the genome, the amino acid sequence chosen from the bovine kinase that is used to synthesize the corresponding oligonucleotide probe will be from a region that has a minimal amount of degeneracy. Specifically, a radiolabeled synthetic oligonucleotide hybridization probe corresponding to the least degenerate codon sequence of a peptide sequence for each of kinase PK40 and PK36 is prepared and used to screen a cDNA library from human cells as described in Example 12. For PK40 it is preferred to use codon sequences corresponding to the unique fragments: Sequence I.D. Nos. 1 and 2. Clones are obtained whose codon order matches the -amino acid εequence of each of the kinaεeε. From overlapping partial cloneε, a full-length cDNA sequence for each of the human kinases, which correspond to bovine PK40 and PK36, is thus identified, and recombinant vector molecules containing the total cDNA sequences are obtained. Such a cloning method can be utilized because each of the corresponding human kinases is encoded by an oligonucleotide with substantial homology to either bovine PK40 or PK36. Thus, there is sufficient homology such that the human cDNA is.- capable of being identified by the hybridization technology described herein. A vector containing an oligonucleotide means a vector containing the cDNA sequence, but not necessarily expressing it. For expression of the cDNA sequence, it must be operably linked to a eukaryotic or prokaryotic expression control DNA sequence. Such recombinant molecules are easily prepared and identified by one of ordinary skill in the art using routine skill and without undue experimentation. Cells transformed or transfected with these recombinant vector molecules are capable of expressing the human kinase, or fragments thereof. Alternatively, the human kinases can be isolated according to the methodε deεcribed in the Exampleε that were uεed for iεolating bovine PK40 and PK36. The human PK40 and PK36 kinases are inhibited by excesε ATP, phosphorylate dephosphorylated neur filament and TAU proteins, and in particular, phosphorylate KSP sequences in these proteins. Human kinases herein mean those nonskeletal-aεsociated kinases identified as described in this invention, including human PK40 and human PK36. Except for the Examples, as uεed herein and in the claims, PK40 and PK36 mean mammalian PK40 and PK36, naturally occurring and cloned. In the Examples, unless specifically referred to otherwise, PK40 and PK36 mean bovine PK40 and PK36. By human PK40 and PK36, is meant the human kinases corresponding to bovine PK40 and PK36. ' According to another aspect of the invention, antibodies, both polyclonal and monoclonal, can be raised against the kinases of the invention, and then, if desired, selected on the basis of their ability to inhibit the phosphorylating activity of the kinaseε. Monoclonal antibodies are obtained by the method deεcribed by Milεtein and Kohler. Such a procedure involveε injecting an animal with an immunogen, removing cells from the animal's spleen and fusing them with myeloma cells to form a hybrid cell, called a hybridoma, that reproduces in vitro. The population of hybrido aε iε screened and individual clones are iεolated, each of which secretes a single antibody species to a specific antigenic site on the immunogen. The monoclonal antibodieε are uεeful for detecting the presence or absence of the PK40 or PK36 kinaseε. In addition, the monoclonal or polyclonal antibodies are useful as inhibitors of the PK4fl and PK36 kinases. Because PK40 has sequence homology with ERK kinases, it will be understood that certain preferred antibodies will be selected so as not to react with such ERK kinases. Preparing such antibodies is well within the level of skill in the art. The invention alεo involves the identification of inhibitors of PK40 and/or PK36. An inhibitor of PK40 or PK36 is a molecule that is capable of binding to PK40 or PK36 in a manner so as to inhibit the phosphorylating activity of PK40 or PK36. This invention discloseε that PK40 and PK δ are strongly inhibited by an excess of ATP. Other inhibitors may be identified by those of ordinary skill in the art using the aεεays as described herein, e.g. , adding the putative inhibitor to the kinase and subjecting the mixture to the quantitative colorimetric immunoassay described in Example 2. Thus, various analogs and conjugates of ATP may be screened for their ability to inhibit the phosphorylating activity of PK40 or PK36. Examples of analogs are readily available in the literature and can be accessed using variouε data-bases, including full-text patent data-bases. The inhibitors thus can resemble the molecular structure of ATP, especially in the diεtribution of charged groups. The inhibitors can be modified to enable them to enter neurons in a variety of ways. For example, the charged groups of ATP analogs can be modified by esterification by analogy with dibutyryl-cyclic-AMP. • Tens of thousands of putative inhibitors may be screened, first in mixtures containing, for example, 1000 candidates, and then, after inhibition by a mixture is established, in submixtures containing, for example, 100, then 10, and then one inhibitor. Other inhibitors may include, but are not limited to, KSP binding εite proteins, or proteinε which bind to one of the kinaεeε of thiε invention, e.g. , substrates, fragments of εubstrate, antibodies, fragments of antibodies, and peptides such as single chain antibody constructs or structural analogs of any of these. A substrate of PK40 or PK36 is a protein that is acted upon by PK40 and/or PK36 in vivo. An inhibiting fragment of a subεtrate of PK40 and/or PK36 aε used herein is a peptide that is a structural analog of at least a portion of the subεtrate and that is capable of binding to PK40 and/or PK36, so aε to titrate out the phosphorylating activity of PK40 and/or PK36 for the native substrate. Such fragments may be identified and prepared by cleaving substrates of PK40 and/or PK36, e.g. , neurofilament or TAU protein, and testing the ability of the fragmentε produced thereby to interfere with the phosphorylating activity of the kinase for native substrate. Alternatively, structural analogs of the PK40 or PK36 substrateε may be prepared which contain at least one KSP site and are resistant to degradation by cytoplasmic, proteolytic enzymes. Such fragments are easily prepared and identified by one of ordinary skill in the art using routine" skill and without undue experimentation. For example, they can be prepared from known sequence information of substrateε of the kinaεeε of the invention. A uεe of thiε invention, is to administer to a cell an inhibitor of one of the kinaseε of the invention. This can act to reduce the phosphorylation activity in the cell and also to reduce or prevent the formation of paired helical filaments or tangles. This permits the analysis, for example, of the contribution of such..phosphorylation activity to cell maintenance as well as to neurocellular states characteristic of neurodegenerative disease and aging. A therapeutic use of this invention is to administer to a subject in need of such treatment an inhibitor of one of the kinases of this invention in order to treat neurodegenerative conditions characteristic -of Alzheimer's diεease and normal aging. Such an inhibitor can reduce the formation of paired helical filaments. The inhibitor is administered to a subject in a therapeutically acceptable amount. The term "subject" iε intended to include mammals. The term "therapeutically acceptable amount" is that amount which is capable of ameliorating or delaying progression of the diseased or degenerative condition in the subject. A therapeutically acceptable amount can be determined on an individual basis and will be based, at least in part, on consideration of the subject'ε εize, εeverity of symptoms to be treated, results sought, and the specific inhibitor used. A therapeutically acceptable amount can be determined by one of ordinary skill in the art employing such factors and using no more than routine experimentation. As discussed herein, inhibitors include, but are not limited to, ATP, analogε of ATP, KSP binding site proteins, or proteins which bind to one of the kinases of this invention, e.g., subεtrateε, fragmentε of substrate, antibodies, fragments of antibodies, and peptides such as single chain antibody constructs. Administration of the inhibitor of this invention may be made by any method which allows the inhibitor to reach the target cells. Typical methods include oral, rectal, peritoneal, subcutaneous, intravenous and topical adminiεtration of the inhibitor. Other delivery εyεtemε can include εustained release delivery syεtemε. Preferred sustained release delivery systems are those which can provide for release of the inhibitor of the invention in sustained release pellets or capsuleε. Many typeε of εustained release delivery syεtemε are available. Theεe include, but are not limited to: (a) erosional systems in which the inhibitor is contained in a form within a matrix, found in U.S. Patent Nos. 4,452,775 (Kent) and 4,667,014 (Nestor et aJL.); and (b) diffusional syεtemε in which an active component permeateε at a controlled rate through a polymer, found in U.S. Patent Noε. 3,832,252 (Higuchi et al.) and 3,854,480 (Zaffaroni) . In addition, a pump-baεed hardware delivery εystem can be used, some of which are adapted for implantation directly into the brain. A particular problem which must be overcome for thoεe εystems which deliver inhibitor via the bloodstream is to cross the blood-brain barrier, which controls the exchange of materials between the plasma and the central nervous system. Many substances are unable to pass through this barrier. One way to accomplish transport of the inhibitor acroεs the blood—brain barrier iε to couple the inhibitor to a εecondary molecule, a carrier, which iε either a peptide or a non-proteinaceouε moiety. The carrier is selected such that it is able to penetrate the blood-brain barrier. Examples of carriers are fatty acids, inoεitol, cholesterol, and glucose derivatives. Alternatively, the carrier can be a compound which enters the brain through a specific transport system in brain endothelial cells, such aε transport systems for transferring insulin, or insulin-like growth factors I and II. This combination of inhibitor and carrier is called a prodrug. Upon entering the central nervous system, the prodrug may remain intact or the chemical linkage between the carrier and inhibitor may be hydrolyzed, thereby separating the carrier from the inhibitor. An alternative method for transporting the inhibitor acrosε the blood-brain barrier iε to uεe liposomes. Liposomes- are single or multi-compartmented bodies obtained when lipids are disperεed in aqueous suεpenεion. The wallε or membranes are composed of a continuous lipid bilayer which enclose an inner aqueous space. Such vesicles can be used to encapεulate and deliver therapeutic agentε. International Patent No. WO 91/04014 (Collinε et al. ) describes a liposome delivery syεtem in which the therapeutic agent is encapsulated within the liposome, and the outside layer of the liposome has added to it molecules that normally are transported acrosε the blood-brain barrier. Such lipoεomeε can target endogenouε brain tranεport systems that transport specific ligands across the blood-brain barrier, including but not limited to, transferring inεulin, and inεulin-like growth factorε I and II. Alternatively, antibodies to brain endothelial cell receptors for such ligands can be added to the outer liposome layer. U.S. Patent No. 4,704,355 (Bernstein) also describes methods for coupling antibodies to liposomes. In addition, Patent No. 4,704,355 describes preparing liposomes which encapsulate ATP The invention also describes a novel assay that can be used aε a diagnostic test for early Alzheimer's disease. The assay measures the level of neuroprotein phosphorylation activity in a human cell by human kinases corresponding to PK40 and PK36. Skin fibroblasts are grown in vitro from a normal and from a test subject. Varying concentrations of an uncoupler of oxidative phosphorylation from ATP production are added to the skin fibroblasts and the presence of immunological epitopes that are correlated with phosphorylated neuroproteins are determined. Fibroblasts from Alzheimer's patients show this effect at lower concentrations of uncoupling agent than fibroblasts from normal subjects. The appearance of such epitopes will indicate the release from inhibition of kinases PK40 and PK36. Antibodies selectively specific. for PK40 or PK36 also can be used to evaluate the level of neuroprotein phosphorylation activity, by quantifying the amount of PK40 or PK36 present in a tissue sample. It is believed that diseased states will be characterized by a higher level of kinaεe present. EXAMPLE 1 The novel kinase immunoassays required NF proteins devoid of immunoreactivity with mAbs SMI-31 and SMI-34. These immunoassays measure kinase activity specific for these epitopes, i.e. , the repeated KSP sequences. Such specificity was required because crude brain extracts contain a very large number of protein kinases. In order to be devoid of such immunoreactivity, the NF proteinε must be completely dephosphorylated. NF-triplet protein and individual NF-εubunits were prepared, and subsequently dephosphorylated, as follows. - NF-triplet protein was prepared by one of two methods: "native" or "reconstituted." The preparation of "native" NF-triplet was a modification of previously described procedures (Tokutake et al., 1983; Lee et al. , 1987). A freshly obtained bovine spinal cord (100-150g, Arena & Sons, Hopkinton, MA) waε desheathed, minced with a razor blade and left for 2 hours in 3 1 of 10 mM Triε, pH 7.0, 50 mM NaCl, 2 mM EGTA, 1 mM DTT, 0.1 mM PMSF at 4°C for swelling. The supernatant was decanted and the swollen tissue was homogenized for 1, minute in 200 ml of a similar buffer containing 150 πώ NaCl (isotonic buffer) with an Ultra-Turax at 2/3 speed. After 15 minutes centrifugation at 12,000xg the precipitate was twice rehomogenized in 200 ml isotonic buffer for l minute at full speed. Supernatants of the centrifugationε were combined and made 0.85 M in sucrose by adding solid sucrose (1 mole/1). Centrifugation-at 100,000xg for 4 hours yielded about 200 mg of gelatinous precipitate which waε dissolved (aided by slow Ultra Turax homogenization) in 100 ml adsorption buffer: 10 mM potassium phosphate, pH 7.4, 8 M urea (deionized for 1-2 hours over mixed bed ion exchanger AG 501-X8 (D), Bio-Rad) , 0.5% β-mercapto-ethanol (β-ME) . NFs were absorbed by εhaking this εolution for 10 minuteε at 4°C with hydroxyapatite (HTP, 40g, dry weight, Bio-Rad) , pree uilibrated in adεorption buffe . The adsorbent was εedimented for 10 minuteε at 15,000xg and waεhed (10 minutes each) subsequently with 100 ml adsorption buffer, 3 x 85 ml 130 mM KP0 4 , pH 7.0, 8 M urea, 0.5% β-ME and once each with 50 ml 300 mM and 250 mM KP0 4 , pH 7.0, 8 M Urea, 0.5% β-ME. The supernatants of the latter two washes contained the bulk amount of NF-L, NF-M and NF-H and were combined for reconstitution of the NF-triplet by dialysis into 3 changes of 1 liter of 10 mM MES, -pH 6.8, 100 mM NaCl, 1 mM MgCl 2 and 1 mM EGTA. After 30 minutes of incubation at 37°C and centrifugation for 6 hours at 120,000xg, 40-60 mg of NF-triplet proteins were obtained. The gelatinous precipitate was rehomogenized in 40% glycerol with a glass-teflon homogenizer to form suspenεions of 2.5-3 mg/ml and stored at -20°C_ For separation of the individual NF-subunitε a previously described procedure (Tokutake, 1984) was modified. The native NF-triplet precipitate was taken up (0.5-1 ml/mg NF protein) in 10 mM sodium phosphate, pH 6.8, 6 M urea, 0.5% β-ME (starting buffer), centrifuged at 100,000xg for 1 hour and loaded onto a 40 x 1.5 cm DEAE-Sephacel column (Pharmacia) . NF subunits were eluted at room temperature with 600 ml of a linear gradient formed by starting buffer and 400 mM sodium phosphate, pH 6.8, 6 M urea, 0.5% β-ME at 10-15 ml/hour. Fractions were collected (120 fractions, 5 ml each) and fractions 41-48, 71-80 and 85-94 were pooled; these contained pure NF-H, NF-M, and NF-L, respectively, according to analysis by SDS-PAGE. The three fractions were concentrated to 2-3 ml by vacuum dialysiε and dialyεed into water. NF-L waε obtained aε a clear gelatinouε precipitate after centrifugation for 1 hour at 100,000xg; NF-M and NF-H were precipitated by ammonium εulfate. For εtorage at -20°C the pure subunits were homogenized (NF-L) or disεolved (NF-M, NF-H) in 40% glycerol to form εtock concentrationε of about 1 mg/ml of protein. Alternatively, NF-subunits were separated by FPLC on a Mono Q 5/5 column (Karlsεon et al. , 1987). The "reconstituted" NF-triplet waε reconstituted from the three purified subunits after recombination of the appropriate column fractions, ' in a manner similar to that described above for reconstitution of "native" NF-triplet protein. Dephosphorylation of NF-triplet was accompliεhed with E. coli alkaline phoεphatase. One ml (2.5-3 mg) of NF-triplet stock solution was incubated for 5 days at 37°C with 10 units (about 400 μg) E. coli alkaline phosphataεe (type III-N, Sigma Chemicals) in a total volume of 2 ml, containing 50 mM Tris pH 8.5, 100 mM NaCl, 0.5 mM MgS0 4 , 0.5 mM ZnS0 4 , ImM PMSF and 5 μg leupeptin. The NF triplet protein waε separated from the phosphatase by centrifugation for 1 hour at 100,000xg, 4°C. The pellet was waεhed twice by rehomogenization in 2 ml water. The final pellet (yield 40-50%) was resuεpended by a glass-teflon homogenizer in 40% glycerol to form a stock solution of about 0.5 mg/ml, stored at -20°C. Dephosphorylated NF-triplet tended to aggregate over several weeks of storage. After analytical SDS-PAGE of dephosphorylation reactions, phosphatase and accompanying impurities were removed by subjecting the gel for 6 hours to a "Western-blot electrophoresis" in an SDS-free buffer prior to staining. Dephosphorylation of subunit NF-M was accomplished by incubating NF-M (0.5g) with 2 units (80 μg) E. coli alkaline phosphataεe for 5 dayε in a total volume of 1 ml under the same buffer conditions as used for the NF-triplet. The phosphatase was removed by gel filtration of the mixture on a 50 x 1N5 cm Sephadex G200 column (50-120 μm, 10 ml/hr flow rate), equilibrated with 10 mM BisTris, pH 7.0, 100 mM NaCl. Fractions were analyzed by SDS-PAGE. NF-M containing fractions around the exclusion volume were pooled (4 ml), dialyzed into water, concentrated in a SpeedVac and stored at -20°C aε a 0.3 mg/ml stock solution containing 40% -glycerol. The yield was 270 μg (54%). Dephosphorylation of subunit NF-H was accomplished by incubating NF-H (1.05 mg) with 120 μg calf intestinal- alkaline phosphatase for 6 days at 37°C in a total volume of 1.5 ml containing 50 mM Triε, pH 8.5, 1 mM MgS0 4 , 1 mM PMSF and 15 μg leupeptin. Separation from the phosphatase, concentration and storage were as described for NF-M. The yield waε 700 μg (67%). The dephoεphorylation reactions for both NF-subunits were monitored by εpotting 1-1.5 μg of NF-protein on nitrocellulose. Blocking, staining with SMI-31 and SMI-34 and development of the blots were performed as deεcribed for Immuno-dotblot aεεayε. The εhift of apparent M on SDS-PAGE (1.5 mm gels (Laemmli, 1970), 7.5% acrylamide, accompanying dephosphorylation of NF-M and NF-H in the "native" triplet waε virtually completed within minutes. Five days of incubation, however, was necesεary to completely abolish the SMI-31 and SMI-34 immunoreactivity and create substrates suitable for the immunoassays of the invention. The phosphatase was removed quantitatively by repeated sedimentation of the dephosphorylated triplet. Dephosphorylation of the NF-M and NF-H subunitε in the NF-triplet which had been "reconεtituted" from FPLC-purified subunits, occurred much more slowly as monitored by gel shift, removal of SMI-31 reactivity and generation of the SMI-33 epitope. mAb SMI-33 (Sternberger - Meyer Immunochemicals) iε εpecific for the non-phosphorylated KSP εequence, Lee et al. , 1988. Loεs of SMI-31 reactivity waε not complete even after five days of incubation. FPLC-purified NF-M, but not FPLC-purified NF-H, was dephosphorylated with E. coli alkaline phosphatase so as to be unreactive to SMI—31 and SMI-34 Tinder conditions similar to those used for the NF-triplet. For the FPLC-purified NF-H, the shift of apparent M on SDS-PAGE and the removal of SMI-31 and SMI-34 immunoreactivity remained incomplete even after five days of incubation with high concentrations of E. coli alkaline phosphatase. The immunoreactivity of FPLC-purified NF-H with SMI-31 and SMI-34, however, was removed with calf intestinal alkaline phosphataεe (special molecular biology grade, Boehringer Mannheim Biochemicalε) after five days of incubation. NF-M was completely dephosphorylated with either phosphatase. The phosphatases were removed by gel filtration. Heat treatment and freezing of the NF were avoided because the proteins tended to aggregate. I EXAMPLE 2 The preferred method for the immunoassay for detecting KSP-phosphorylating kinases is as follows. Dephosphorylated NF-triplet protein was incubated with the 35-45% ammonium sulfate fraction of the brain supernatant (see section B.). Immuno-dotblot assays were performed in 50 mM HEPES, pH 7.0, 2 mM MgCl 2 , 1 mM ATP, 2 mM DTT in a total volume of 30 μl with 5 μg of dephosphorylated native NF-triplet or 1.2 μg of dephosphorylated pure subunits NF-M or NF-H as substrates together with a control assay lacking NFs. After incubation at 37°C for 18 hours, assayε were diluted to 100 μl with 10 mM PBS, pH 7.2, and aliquots of 50 μl were spotted on nitrocellulose (0.22μm, Schleicher and Schiill). Blots were blocked by 1 hour incubation with 3% BSA in lOmM PBS, pH 7.2, and washed once in 0.5% Triton-XlOO/10 mM PBS. Antibodies were diluted in sterile 10 mM PBS, pH 7.2, 0.5% Triton-XlOO, 10% fetal calf serum. Blots were incubated with SMI mAbs for at least 2 hours. The blots were then waεhed five timeε. Mouεe mAbε were detected by reaction with horεeradiεh-peroxidaεe-1inked goat-anti-mouεe antibody (Cappel Co.) in 1:200 dilution and by staining with 0.05% 4-chloro-l-naphthol (Sigma) and 0.05% H 2 0 2 in 50 mM TBS, pH 7.5, 33% ethanol for 5-20 minutes. All incubations and washes were at room temperature. Incubations were sealed in plastic bags with 50 μl of solution/cm 2 membr'ane. The SMI-31 and SMI-34 epitopes were reconstituted. The activity was NF-specific, since control immunoassayε lacking dephoεphorylated NF-triplet were negative. These site specific kinase immunoassayε, while only εemiquantitative, nevertheleεε allowed for the eεtimation of εome of the propertieε -of the kinaεes while still in crude form. The foregoing procedure involved parameters that were optimized as follows. Immuno-dotblot-assays (0.5mM Mg 2+, 0.5mM ATP) were performed using various ammonium sulfate fractionε of whole brain εupernatant to determine the fraction containing the desired activity. The control assays did not contain NF proteins. A 35-45% fraction was found to contain the strongeεt activity for reconstituting SMI-31 and SMI-34 epitopes. This activity was NF-specific, since the corresponding control immunoasεay which lacked dephoεphorylated native NF-triplet waε almost negative for this fraction. An additional less permanent NF—specific activity was detected in the 40-55% and 55-70% AS-fractions of cytoskeletal extract with 0.8M KC1 where the main NF-kinase activity had been expected. The soluble nature of the kinases in the 35-45% fraction was confirmed when the activity did not cosediment under low salt conditions (lOmM HEPES Buffer pH7) after 15 minutes of incubation with the phosphorylated native NF-triplet at 37°C orassembled cold solubilized microtubuleε according to the method of Shelanski et al (1973) [4M glycerol, 1 mM GTP, 37°C, 30 minutes] , in the absence or presence of 5m Mg/ATP. The optimal incubation time, pH and NaCl concentration for conducting the assay was determined using the 35-45% fraction. The asεayε were performed with 0.5mM g 2+- (unless indicated otherwise). At an ATP concentration of ImM, an 18 hour incubation time was optimal; the assays for pH and NaCl were performed at the 18 hour incubation time. The asεay responses were optimal at pH 7.0, low salt conditions (50mM or less; 10, 20, 50, 75 and 100 mM tested) and ImM ATP. I muno-dotblot-aεsays were conducted to determme the optimal Mg 2+ and ATP concentrations using the SMI-31 and SMI-34 antibodies. The amount of enzyme was varied as follows: 0.04, 0.09, 0.13, 0.18, 0.22, 0.33 and 0.44 micrograms of crude enzyme. Control assays were without NFs using 0.4 micrograms crude enzyme. Mg 2+ and ATP concentrations were at 1.0, 2.0, and 4.0 mM. The optimal Mg 2+ and ATP concentrations were found to be 2mM and ImM, respectively. ATP [5mM] mhibited the kinase activity. Mn 2+ was about twice as effective as Mg 2+. GTP could not subεtitute for ATP. Concentrationε of NaCl greater than 20 mM diminished the assay responεe. Thiε effect waε attributable to ionic εtrength rather than specifically to sodium or chloride ionε, εince the εame decline was seen with (NH 4 ) 2 S0 4 at comparable ionic εtrength. Alternatively, a quantitative colorimetric immunoassay of PK40 and PK36 can be used. Such an assay measures binding of mAbs to dephosphorylated human or other specie neurofilaments, TAU protein, or recombinant TAU protein by kinases PK40 and PK36. The kinases PK40 and PK36, alone or together, were assayed by a quantitative ELISA-type assay based on the mAbs SMI-31, SMI-34 (Sternberger-Meyer Immunochemicals, Jarretsville, MD) aε primary antibody. The εecondary antibody waε horεeradiεh-peroxidaεe-linked goat anti-mouεe antibody (Cappel Co.), followed by color development with H 2 0 2 and "ABTS" (2,2'-Azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) «2NH.), and color extraction and measurement. Different amounts of PK40 and/or PK36 were incubated ith 6 μl 250 mM HEPES buffer, pH 7.0/10 mM MgS04, 1.2 μl 25 mM ATP and 40-160 ug of dephosphorylated bovine neurofilament triplet protein in a total volume of 30 μl. Incubation was for 18 hours at 37°C and waε followed by dilution to 150 μl with 10 mM PBS. Each assay (20 μl) was applied to a nitrocellulose membrane as a dot, the membrane was blocked with bovine serum albumin and individual dots were punched out. They were next incubated with SMI-31 mAb (1:500, 100 μl) for 6 hours at 25°C. Each dot was washed 5X with 1 ml of PBS containing Triton X-100. The second incubation waε with the goat anti-mouse Ab, 1:200 for 6 hours at 25°C, followed by washing 5X with 1 ml PBS/Triton X-100. Color development was carried out by shaking each dot individually with a 0.1% ABTS in citrate pH 4.0/0.03% H_0 2 at room temperature for 30 minutes. The reaction produced a soluble color in the supernatant which was measured at 415 nm. EXAMPLE 3 An alternative method for assaying the phosphorylating activity of the kinases was by 32P assays. Radioactive assays in the same buffer system as for immunoassays contained 5 μg of HTP-purified native NF-triplet as substrate (3μg of subεtrate proteins other than NFs) and 150-250 cpm/pmole gamma- 32P-ATP. Incubation times were 15 minutes at 37°C for activities up to about 1 pmole/min/assay, since the assay responseε were linear within these time intervals. Assays were stopped by cooling on ice, addition of 20 μl 25 mM EDTA and immediate transfer of the mixture onto glass filters (Whatman GF/A) wetted with 10% TCA/2% sodium pyrophosphate (PPA) . The glass filters were washed twice for 1 hour and once for at least 3 hours in 10% TCA/2% PPA and finally in ethanol and were air-dried. Radioactivity waε assessed by scintillation counting (Beckman LS 230) with 5 ml "Liquiscint" (National Diagnoεtics) for 20 minutes. Assayε were routinely carried out in triplicate except for,some duplicate assays in a few explicitly mentioned cases; a control assay lacking NFs waε εubtracted from the mean value. A preferred εubεtrate for this asεay is TAU, prepared as described in the procedure of Example 9, below. Assays to be analyzed on SDS-PAGE were stopped with an equivalent amount of sample buffer, boiled for 3 minutes and run on 7.5% gels. After staining with Coomassie Blue, destaining and drying on Whatman 3MM paper, autoradiography was performed with a DuPont Cronex screen intensifier at -70°C. For quantitative measurements, radioactive bands of individual NF-subunits were cut out, placed in an Eppendorf vial immersed in 20 ml water and the Cerenkov radiation of the sample was counted. Counting efficiency waε about 30%. EXAMPLE 4 The method for purifying the kinases was optimized by exposing the 35-45% AS-fraction to a variety of chromatography media at 4°C. The activity as assayed using the SMI antibodies was lost in almost every case. These losses occurred even in the presence of 4M NaCl, which by itεelf did not affect enzyme εurvival in controlled experiments. (NaCl was added to prevent binding of the kinase or posεible eεsential subunits to the chromatography media) . It was discovered, however, that inclusion of Mg-ATP in the solution stabilized the activity.-on some media. In order of decreasing survival of activity, Sephadex Agaroεe, CM-Sepharoεe and quarternary ammonium ion exchangerε were found to be useful chromatography media in the presence of Mg-ATP. The preferred method for purifying the KSP-phosphorylating kinases is aε followε. Step I: A fresh bovine brain (350-450 g wet weight) was cleared from meningeε and blood vessels and homogenized at 4°C in 350 ml homogenization buffer (10 mM Bis Triε, pH 7.0, 150 mM NaCl, 2 mM EGTA, 1 mM DTT, 0.1 mM PMSF, 5 μg/ml leupeptin) with an UltraTurax or a Sorvall Omni-Mixer for 3 minutes. The pellet after centrifugation at 20,000xg for 20 minutes was extracted twice with 300 ml homogenization buffer. The turbid supernatants were clarified by centrifugation at 100,000xg for 1 hour. Solid ammonium sulfate was added slowly over about 1 hour while keeping the pH at 8.0-8.5 with ammonia. The precipitate obtained between 35% and 45% saturation was -collected by centrifugation at 20,000xg for 20 minutes, rediεsolved in 20 ml 10 mM HEPES, pH 7.0, 1 mM MgCl 2 , 1 mM EGTA and 1 mM DTT, and dialyzed extenεively againεt this buffer to form a "crude enzyme" εtock solution of about 20 mg/ml protein, which could be stored for εeveral weekε at 4°C with little loss of activity. Step II: 20 ml of crude enzyme was dialyzed into CM-Sepharose starting buffer (5 mM magnesium acetate, 5 mM ATP, 1 mM DTT, 10% glycerol, 0.02% sodium azide, adjusted to pH 6.0 with BisTris) and- loaded onto a 3 x 2.5 cm CM-Sepharoεe column equilibrated with starting buffer. The column was washed with 60 ml starting buffer at about 50 ml/hr, then the kinaseε were eluted in one step with 85 mM magnesium acetate, 5 mM ATP, 1 mM DTT, 10% glycerol, 0.02% sodium azide, pH 6.0 as a fraction of 15 ml volume. Step III: The combined fractions of the CM-Sepharose chromatography containing the bulk of the activity were dialyzed into lOmM HEPES, pH 7, ImM EDTA and ImM DTT. The protein then was concentrated to about 3 ml in a SpeedVac and loaded onto a 95 x 2.5 cm column of Sephadex G200 Superfine (Pharmacia) and were eluted with a filtration buffer (48 mM BisTris, pH 7.0, 5 mM MgCl 2 , 5 mM ATP, 1 mM DTT, 0.02% sodium azide) . After elution of 155 ml at a flow rate of 1.5-2 ml/hr, fractions of 5 ml were collected. The collected 5ml fractions (10-28) were tested in immuno-dotblot-as ayε uεing SMI-31 and SMI—34 antibodies after 18 hours of incubation with NF-triplet. The fractions also were subjected to 32 P-assayε (30 minuteε of incubation with NF-triplet) to test for the presence of kinase activity. The kinase activity eluted as a very broad peak (Fractions 14-23). No significant NF-εpecific phosphatase activity could be detected in the relevant kinase fractions by monitoring the liberation of phosphate under asεay conditionε from 32 P-labeled dephosphorylated native NF-triplet, prepared by phosphorylation with partially purified NF-kinase. The fractions further were subjected to 12% SDS-PAGE gel electrophoresiε. The PK40 and PK36 bands are identifiable (arrows, Fig. 1), with the PK40 being most prominent in fraction 17-19 and PK36 being most prominent in fractions 21 and 22. These fractions then were used in the asεay method. Step IV: Gel filtration f actionε containing significant amounts of PK40 (17-19) and PK36 (21-22), according to SDS-PAGE analysis, were pooled, dialyzed into Mono Q starting buffer (20 mM Tris, pH 8.0, 20 mM MgCl 2 , 5mM ATP, 1 mM DTT, 0.02% sodium azide) and loaded on an HR 5/5 Mono Q FPLC-column (Pharmacia) equilibrated with starting buffe . Elution of PK40 at a flow rate of 1 ml/min started with 5 ml εtarting buffer followed by a linear gradient of 7 ml up to 60 mM MgCl 2 , 7 ml iεocratic elution at 60 mM MgCl 2 and finally a linear gradient up to 110 mM MgCl 2 formed with elution buffer (20 mM Tris, pH 8.0, 110 mM MgCl 2 , 5 mM ATP, 1 mM DTT, 0.02% sodium azide). The gradient profile for PK36 waε identical. The variouε fractionε were εubjected to a variety of assays, including: a dotblot aεεay; a 32 P-assay; and 12% SDS-PAGE gel electrophoresi . The activity within the fractions was demonstrated by the immuno-dotblot-aεεay and 32P-aεεay. The activity of the PK40 fractions in the dotblot assay and 32P-asεay were correlated with the particular fraction run on the SDS-PAGE gel and, importantly with the particular band., revealed by the SDS-PAGE. The activity of the fractionε correlated with presence of the gel electrophoresiε 40kD band. The aεεayε revealed relatively prominent phoεphorylation of NF-M and NF-H by PK40. The activity of the PK36 fractions in the dotblot asεay and 32P-assay correlated with the presence of the gel electrophoresiε 36kD band. The assayε revealed relatively prominent phoεphorylation of NF-M and NF-L by PK36. Peak fractions of the NF-kinases (PK40: 11-12; PK36: 12-13) were pooled, dialyzed into storage buffer (20 mM BisTris, pH 7.0, 2 mM MgCl 2 , 2 mM ATP, 1 mM DTT, 0.02% sodium azide) and concentrated about 10-fold in icroconcentrators (Amicon 10) for εtorage purpoεes. The enzyme is stable when frozen. Activity was retained for several dayε at 4°C and after 5 cycleε of freeze-thawing with little loss. These pooled fractions were used in the preparations described below. - A relatively pure mix of PK36 and PK40 as used for the identification of 36 kD and 40 kD proteins as kinaseε waε obtained after pooling of gel filtration fractions 16-23 and elution from Mono Q with an uninterrupted linear gradient of 17 ml from 20 mM to 110 mM MgCl . To further confirm the identity of PK40 and PK36 as protein kinaεeε, a highly enriched mixture of both kinaseε obtained aε described (refer to above procedure for elution f om Mono Q) was separated on polyacrylamide gels (PAGE) and the migration of both proteins was correlated with NF-kinase activity eluted from gel slices as follows: The PK40/36 mixture was electrophoresed on a 10% PAGE containing SDS, ImM DTT and 5mM MgATP. Gel slices of about 2mm size were eluted overnight into small amounts of water. Aliquots of the supernatants were assesεed for NF-kinaεe activity and activity by the P-assay followed by SDS-PAGE of NF and autoradiography. A comparatively weak NF-kinase activity correlated precisely with the presence of a 36kD protein in the respective gel sliceε (aε analyzed on 12% SDS-PAGE) while the 40kD kinase apparently could not be renatured successfully from SDS. To also prove the identity of the 40kD protein as a kinase a similar experiment waε performed whereby the PK40/36 mixture waε εeparated on a non-denaturing 7.5% PAGE. In this case the 40kD protein appeared as the dominating kinase very well correlated with activity. Step V: The best preparations of PK40 were obtained after PK40 was run preparatively on nondenaturing 7.5% PAGE and was eluted from gel sliceε in an electro-eluter .(model UEA, International Biotechnologieε, New Haven, CT) in two conεecutive 30 minute runε at 120 V and 4°C into a trapping buffer consisting of 7.5 M ammonium acetate, 10 mM Mg-ATP, 2 mM DTT and a trace of bromophenol blue. The elution buffer contained 25 mM Tris pH 8.3, 192 mM glycine, 2 mM Mg-ATP and 1 mM DTT. The kinase was dialyzed into a storage buffer of 20 mM BisTriε pH ! 7.0, 2 mM Mg-ATP, 1 mM DTT, and concentrated about 10-fold in a microconcentrator (Amicon 10) . Table 1, below, detailε the enrichment of PK40 and PK36. Table 1. Enrichment of PK40 and PK36 through various chromatographic steps step spec. total [mg] activity 0 activity*^ PK40 PK36 PK40 PK36 PK40 PK36 I) AS-Fractionation _a 290 II) CM-Sepharose 0.55 23.6 43 III) Sephadex G200 1.45 1. 15 3.80 2.27 2.6 2.0 IV) Mono Q FP C 3.8 2. 8 0 .73 0 .39 0.19 0. 14 V) Prep. Gel- electrophoresis 5.2 0 .67 0.13 not determined. NF-specific activity too low against background. Electroelution of PK36 from a preparative SDS-gel was unsuccessful . "nmoles 32P-P04 tranεferred/min/mg protein . nmoles 32P-P04 transferred/min. The Mono Q fractions containing PK40 was further subjected to a two-dimensional SDS-PAGE gel separation procedure (O 'Farrell procedure) . A Western Blot assay was performed using a polyclonal anti-ERK antibody. Anti-rat MAP Kinase R2 (Upstate Biotechnology, Inc. , N.Y. Cat #406-182) . Western SUBSTITUTE SHEET analysis revealed the presence of only one ERK protein, although three isoformε could be distinguished. EXAMPLE 5 The subεtrate εpecificity of PK40 and PK36 waε determined aε followε. Among neuronal proteins tested, the specificity of PK40 for dephosphorylated NF-M was most striking. Other subεtrateε were leεs efficient. The order of εpecificity was: dephosphorylated NF-M >> TAU > NF-M = NF-L > dephosphorylated NF-H > NF-H. PK36 had a lower specific activity than PK40, the subεtrate εpecificity being: NF-L = TAU = dephosphorylated NF-M > NF-M >> NF-H = dephosphorylated NF-H. Some microtubule-associated proteinε were, also good substrates for both kinases. MAP2 in a crude microtubule-preparation was a εubεtrate for PK40 and PK36 comparable to, or better than, TAU proteins, especially for PK40. MAP#2 is phosphorylated by both kinases above background level (PK40:2.5x; PK36:1.5x; determined by CERENKOV-c ' ounting) . Background labeling of MAP2 was due to a second messenger independent activity intrinsic to cycled microtubules. Lyεine-rich histone type III (calf thymus, Sigma Chemicals) was the most preferred substrate for both PK36 and PK40. This is a feature in stark contrast to all other known ERK kinaseε, which do not phosphorylate lysine-rich histone type III very well, and which phosphorylate microtubule associated proteins including TAU and MAP2 to a substantially greater extent than lysine-rich histone type III. The acidic protein phosvitin (Sigma Chemicals) and tubulin (from.calf brain, gift of Dr. F. Solomon, Dept. of Biology, MIT) were very poor subεtrateε for either PK36 or PK40. EXAMPLE 6 The ATP dependence and inhibition of the activitieε of PK40 and PK36 were determined at 2 mM Mg 2+ with soluble dephosphorylated NF-M as second substrate to avoid uncertainties arising from the aggregation state of NF-triplet in suspension. The optima were at 0.5 - 1 mM ATP for both kinases. Apparent K values for ATP of both kinases were estimated from Woolf-Hanes plots (Dixon and Webb, 1979) for a range of ATP concentrations sufficiently below the onset of inhibition. Three determinations of the Km of PK40 at three different concentrations of the second subεtrate, NF-M, gave similar values (mean + S.D.: 93 + 12 μM) , indicating little influence of the concentration of NF-M on ATP-affinity of PK40. The apparent K m of PK36 was approximately 50 μM. PK36 and particularly PK40 were strongly inhibited to 14% and 7%, respectively, of the control level in the presence of 5 mM ATP, amounting to 3 mM excess of free (uncomplexed) ATP over Mg 2+. In contrast, with excess Mg2+ (5 mM over 1 mM ATP or 5 mM over 5 mM ATP), little or no inhibition was observed for PK40, while the activity of PK36 was significantly reduced. The activity of the kinaεeε waε alεo reduced to 27%.(PK40) and 40% (PK36) in the preεence of 150 mM NaCl. Inhibition by the Walsh inhibitor was seen only for PK36, with an eεtimated IC 50 of 50 micromolar. The foregoing is εummarized in TABLE 2, below. Table 2. Effect of sodium chloride, excesε magneεium and ATP and of the Walεh inhibitor on the relative activity [%3 of PK40 and PK36 PK40 a PK36 a Control 100 b +6.9 100+1.12mM 14+0.5 40+0.2 38+2.2 40+0.8 103+0.5 87+0.6 58+3.3 The values represent the mean of 3 assays (+ S.D.); except for the Walsh inhibitor assayε, which were carried out in duplicate, preparations of PK40: see Table 1, step V; preparations of PK36: see Table 1, step IV. All values repreεent relative activitieε in % of the control. EXAMPLE 7 A comparison of the phosphorylating activity of PK40 and PK36 with other kinaseε was performed. Phosphorylation of the KSP sequence in dephosphorylated NF-triplet and dephosphorylated NF-M, using the SMI-31 immunoassay, i.e., measuring reconstitution of the SMI-epitopeε, waε achieved with a mixture of PK40 and PK36, but not with PKC, calcium/calmodulin dependent kinaεe II, cAMP-dependent kinaεe or εecond meεεenger-independent microtubule-aεεociated kinaεe. Phosphorylationε with Ca 2+/calmodulm-dependent kinaεe II and protein kinaεe C were performed at 37°C in 30 microliters of 50 mM HEPES, pH 7.5, 10 mM Mg 2+ , 5 mM Ca 2+ , 1 mM EGTA, 2mM DTT, 1 mM ATP and 50 micrograms/milliliter calmodulin and phosphatidylserine, respectively, and 5 micrograms NF-triplet protein. EXAMPLE 8 PK40 and PK36 induced mobility shifts of the heavy NF-subunits on SDS-PAGE and incorporated phosphate in high molar ratios. To determine the maximum number of phosphateε incorporated into the heavy NF-subunits by PK40 and PK36 the purified activities of step V and εtep IV above were incubated in increasing concentrations with dephoεphorylated NF-M and dephosphorylated NF-H. The stoichiometry of phosphorylation was determined by asεuming that the correct molecular maεses of NF-M and NF—H are 110 kD and 140 kD, respectively, as determined by Kaufmann et al- (1984), since SDS-PAGE considerably overestimates -their M . The saturation phoεphorylation of completely dephoεphorylated NF-M and dephoεphorylated NF-H by PK40 and PK36 waε meaεured by aεsaying: (i) increasing amounts of enzyme activity measured against extent of phosphorylation in 18 hour assays as monitored by 32 P-incorporation (mole PO. per mole NF-M); (ii) gel mobility shift on 7.5% SDS-PAGE; and (iii) SMI-31 and SMI—34 immunoassayε. A mixture of PK40 and 36 also was tested. PK40 incorporated up to 15 phosphate groups into NF-M which corresponds well to the number of phosphateε found in isolated bovine IsTF-M (Wong et al., 1984) and induced a complete shift of the NF-M band on SDS-PAGE to the higher apparent M of native NF-M. In contrast, only a partial shift of NF-H was achieved with a maximum of 7 phosphates introduced into a molecule with presumably about 40 KSP-sites. The phosphorylation of NF-M with PK36 appeared to be -saturated at 10 moles phosphate/mole NF-M with a substantial gel mobility shift; however, the NF-M band remained diffuse, posεibly due to a heterogeneous phosphorylation state. NF-H waε not pho phorylated very well by PK36 and εhowed virtually no gel shift, in correlation with its poor substrate properties for PK36. Both kinases reconstituted the SMI-epitopeε, but only weakly in the case of NF-H and PK36. The maximal phosphorylation of NF-M was not εignificantly higher with a mixture of the two kinaεes, indicating, that PK40 and PK36 might have a largely overlapping site-specificity on NF-M. After incorporation of 7-13 phosphates, NF-M had a gel mobility comparable to native NF-M. The SMI-immunoasεay reεponεes were correlated with the gel mobility shift, but did not respond at lower levels of phosphorylation, i.e., <5 moles PO Λ /mole NF-M. The SMI-34 immuno-assay required a higher level of phosphorylation than the SMI-31 asεay. EXAMPLE 9 PK40 can induce a variety of changeε in properties on both dephosphorylated and native TAU, which changes are of pathological interest. To further confirm the effect of PK40 on TAU, bovine TAU waε prepared. The procedure used is preferred as it can be carried out at 4°C and results in a product that is free of phosphorylation that ordinarily would occur at higher temperatures. TAU waε prepared from freεh bovine brain according to Baudier et al. (1987). Briefly, 1 kg of brain tissue was homogenized in 1 liter of lOOmM potasεium phoεphate (KPO.) buffer, pH 6.5, containing 2mM each of EDTA and EGTA, ImM DTT, 0. ImM PMSF and 5 mg/1 each of aprotinin, leupeptin, antipain, antichymotrypsin and pepstatin A. Tiεεue debriε waε removed by centrifugation at 15,000xg and reextracted with 1 liter of KPO 4. buffer. Supernatantε were made 45% in ammonium εulfate, the precipitate was collected after centrifugation at 20,000xg, rehomogenized and dialyzed extensively into KP0 4 buffer. The dialyεate was adsorbed onto 8 g of preswollen CM-Sephadex, unbound material was removed by washing with KPO. buffer, and the TAU containing fraction waε eluted with KPO./0.5 M NaCl, pH 6.5. HC10 4 waε added to 3%, precipitated material waε removed by centrifugation and crude TAU in the Tris-neutralized supernatant was precipitated by 45% ammonium sulfate. The pellet waε taken up in 5ml water, dialyzed into 50mM HEPES, ImM EDTA, ImM DTT, pH 6.9 (Mono S starting buffer),. FPLC was performed on a 5/5 Mono S column (Pharmacia) with a linear gradient of 30ml from 0 to 500mM NaCl, whereby TAU eluted aε a broad peak around 250mM NaCl. TAU containing fractions were dialyzed into water and minor contaminating protease activities were destroyed by boiling for 5 minutes. Dephosphorylated TAU protein was prepared by incubation of 300μg native bovine TAU with 60μg calf intestinal alkaline phosphataεe (Boehringer Mannheim) and 20μg E. coli alk. phoshpatase (Sigma type III-N) in 350μl of 50mM Tris, each 0.5mM MgS0 4 and ZnS0 4 , O.lmM PMSF, lOμg/ml each of aprotinin, leupeptin, antipain, pepstatin and antichymotrypsin (all Sigma), pH 8.0, for 3 days at 37°C. Phosphateε were removed by precipitation with lOμl HC10 4 at room temperature. The supernatant was neutralized with Tris and dialyzed into water. Gel mobility shiftε of bovine and human TAU proteinε induced by PK40 and PK36 phoεphorylation waε measured by incubating lOμg of native or dephosphorylated bovine TAU (prepared according to the above alternative procedure) and 3μg of bacterially expressed human TAU isoform hTau40 for 18hr at 37°C with about 25 pmole/min of PK40 or PK36. Analysis was performed by 10% SDS-PAGE and autoradiography. Similar reεultε were obtained with a pure 42 KD human TAU isoform expressed in E. coli from the clone Htau 40 (Goedert et al. , 1989), kindly supplied as protein by Dr. E.M. Mandelkow. Under saturating conditions as described above, PK40 incorporated up to 14 phosphates into the 42 kD TAU isoform. PK36 induced a partial mobility shift in TAU protein, aε in the caεe of NF-M. Saturating phoεphorylation by PK40 of dephosphorylated bovine TAU and of TAU native bovine TAU resulted in significantly reduced mobility on 10% SDS-PAGE as well as a characteristic change of the isoform patterns. The alterations produced jin vitro reεult in a pattern that very cloεely resembles the pattern of human TAU proteins extracted from PHF, whether native or dephosphorylated TAU was used. The shift in the pattern of human TAU proteins extracted from PHF relative to TAU from normal human brains is depicted clearly in (Goedert et al., 1992), which εhift waε shown to be entirely due to hyperphosphorylation. On 10% SDS PAGE, multiple isoformε of native bovine TAU are converted to a 3 iεoform pattern. This is the same 3 isoform apparent pattern produced when the six isoforms of native human TAU are phosphorylated. In some preparations of bovine TAU, the isoform with the least mobility waε leεs prominent after phosphorylation, essentially creating a pattern of two isoformε which haε been obεerved in εome PHF-extractε. The level of phoεphorylation and the concomitant conformational changes are approximately equal with partially phoεphorylated native TAU and dephoεphorylated TAU aε substrates. The bacterially expresεed 42kD, human TAU isoform from the clone hTau40 behaves in a way similar to bovine TAU upon PK40 phosphorylation. The gel mobility shift corresponds to about 15kD of increased apparent size. PK36 was not able to phosphorylate hTau40 to the same extent and consequently induced only a partial mobility shift. The heterogeneous appearance of HTau40 probably reflects the end state of PK36 phosphorylation εince the pattern waε not altered at threefold higher concentrationε of the kinaεe. Pretreatment with PK40 prior to PK36 phoεphorylation produced the same completely shifted band as PK40 alone (not shown) . Treatment of bovine TAU- with PK40, but not PK36, also resultε in phoεphorylation of TAU to an extent that yields a phosphorylated-TAU protein that is immunochemically similar to the hyperphosphorylated TAU of PHF-TAU. Dephosphorylated bovine TAU, and native bovine TAU were incubated with 25 pmole/min PK40 or 15 pmole/min PK36 for 18 hours and probed with monoclonal antibodies TAU-1 (SIGMA) (0.15μg TAU as antigen); SMI33 (0.5μg TAU as antigen); SMI31 (lμg TAU as antigen); and SMI34 (2μg TAU as antigen) . TAU-1 does not directly recognize a phosphorylated epitope but PHF-TAU protein treated with phosphateε, will bind to TAU-1 (Grundke-Iqbal et al. 1986). SMI-33 also does not directly recognize phoεphorylated epitopeε but doeε recognize an epitope on dephosphorylated TAU and on native TAU. This epitope is believed to be the unphosphorylated KSP sequence (Lee et al. , 1988), which occurs twice in the sequence of all bovine TAU isoforms (Himmler et al, 1989). Coverεely, the SMI-31 epitope iε not present in native or dephosphorylated TAU, in agreement with the KSP sites not normally being phosphorylated. As determined by Western blotting, treatment of native bovine TAU with PK40 completely abolished immunoreactivity towards TAU-1 and SMI-33, but resulted in very strong antibody binding reactions with SMI-31 and SMI-34, both of which detect phosphorylated epitopes. This indicates phosphorylation of the KSP siteε of TAU aε it occurs in PHF. (The reduction in electrophoetic mobility waε also detected on these Western blots. The effect of PK40 treatment on TAU-1 binding is of particular interest since the TAU-1 epitope is masked by phosphorylation in tangles in situ as well as in PHF-TAU on Western blots (Grundke-Iqbal et al. 1986) . In contrast, the only significant immunochemical alteration induced by PK36 treatment of TAU was a strongly reduced SMI 33 activity, the TAU-1 activity being substantially unchanged from diphosphorylated bouine TAU. PK36 is a less efficient phosphorylating kinase of TAU than PK40. Several kinaseε have previously been suggested to play a role in the conversion of TAU proteins into PHF-TAU. However, unlike PK40, none confer all the known pathological changes on TAU. Thus, by the criteria of conformational and immunochemical alterations as well as stoichiometry, of phosphorylation, PK40, a new member of the ERK-family, can perform abnormal TAU-hyperphosphorylationε characteristic of Alzheimer's Disease (AD), Down's Syndrome (DS) and normal aging. PK36 with a partly overlapping site-specificity could not induce TAU-changes to a similar extent. A variety of immunohistochemical and biochemical studies point to TAU-hyperphosphorylation as an event that precedes tangle formation. PK40 plays a key role in the hyperphosphorylation of TAU. Chronic upregulation of PK40 might cause neurite degeneration and interference with the functional integrity of neurons. EXAMPLE 10 Uncoupling of oxidative phosphorylation from ATP production by chemical means causes the appearance of■ immunological epitopes in fibroblast cellε from healthy patientε, cultured under εpecial conditions. (Blass et al. , 1990). This observation is used for the diagnosiε of early Alzheimer'ε diεeaεe by linking the appearance of theεe epitopes to the activity of kinaseε PK40 and PK36, which are releaεed from inhibition when ATP levels fall, as is the case when oxidative phosphorylation is uncoupled from ATP production. Uncoupling iε achieved by the uεe of an uncoupling reagent, e.g. , CCCP (carbonyl cyanide m-chlorophenylhydrazone) , or the deprivation of oxygen. The diagnoεtic test for .early neuronal degeneration is applicable for various conditions where neurons degenerate, e.g. , Alzheimer's disease, Parkinson's disease, Huntington's chorea, normal aging, and brain infarctε. A diagnoεtic test for early Alzheimer's diεeaεe iε deεcribed uεing kinaεeε PK40 and PK36. Primary cultures of skin fibroblastε are obtained from the patient to be teεted. These are grown in Dulbecco'ε modified Eagle"ε medium containing 0.1 mM dibutyryl cyclic-AMP, 0.1 ug/ml 7S nerve growth factor, 10 ug/ml mixed bovine ganglioεideε and 5% chick embryo extract. In the preεence of an uncoupler of oxidative phoεphorylation from ATP production, e.g. , CCCP (carbonyl cyanide m-chlorophenyl hydrazone), or with the deprivation of oxygen, the cells show i munological epitopes (Alz-50, PHF-epitopeε,SMI-31/SMI-34-positive TAU/neurofilament epitopes), indicating the release from inhibition of kinases PK40 and PK36. Cells from Alzheimer patients show this effect at lower concentrations of uncoupler, compared to normal cells. Thuε, cellε from patientε to be tested are "titrated" with increasing concentrations of uncoupling agent or with decreaεing oxygen concentrationε. They are diεtinguiεhed from cellε from normal individuals by their lower resistance to the effects of decreasing the ATP concentration. EXAMPLE 11 Protein Sequencing of PK40 To obtain pure PK40 approximately 150μg of total protein from the Mono Q FPLC fraction containing enriched kinase was loaded into a 50mm wide slot and was separated on a 1.5mm thick 12% SDS-PAGE. The major proteins were made visible by brief immersion into 1M KC1 at 4°C. The band corresponding to PK40 was cut out, minced and homogenized in 3ml of water containing ImM DTT with a Mini-Turax. The suspenεion was sealed into a dialysis bag and shaken with water, ImM DTT overnight. The gel fragments were removed by centrifugation and the supernatant was lyophilized. Peptide Mapping of Kinase The lyophilisate, containing 20μg of an apparently homogeneous 40kD protein on SDS-PAGE. 20μg kinase was diεεolved in 500μL reduction buffer (6M guangidine hydrochloride/0.5M triε-(hydroxymethyl)-aminomethane pH 8.6). The pH was adjusted to 8.6 with ammonia. 15μL 1M dithiothetreitol waε added. The reduction waε performed for 2h at 52°C under nitrogen. Then 30μL μL 1M εodium iodoacetate solution was added and the sample waε incubated for 30 min. at room temperature in the dark. Excess reagents were removed by dialysiε (cut off IkD) against 500mL 0.5M urea/0.1M NH.HCO g pH 8.6 overnight (complete buffer change after 4h) . After dialysis, sequence grade trypsin (Boehringer Mannheim) was added in the ratio 1:20. The protein was cleaved for 18h at 37°C. The solution waε then concentrated to about 250μL. The reaction waε εtopped by cooling to 4°C. After concentration the peptideε were εeparated HPLC. Separation of Tryptic Peptideε by HPLC A εample waε injected onto an HP 1090 HPLC-system equipped with an Nucleosil RP-18 HPLC-column (CS-Chromatographie Service) 250mm x 4.6mm; 5μ material; 300 Angstrom), and samples were collected at 0.7ml/min., 40 C with 0.1% TFA and a gradient from 0 to 70% acetonitrile. The single peptideε were collected aε 0.5 min. fractionε uεing a fraction collector from LKB/Pharmacia Superrac model 2211. Elution of peptides was monitored at 210, 280 and 295nm and 0.35ml fractions were collected. The single fractions were lyophilized after separation. Chromatographic conditions: flow 0.7mL/min, column temperature 40°C, detection 210nm, 280nm and 295nm, solvent A 0.1% TFA, solvent B 60% acetonitril/0.1% TFA, gradient 5min 0%B, 120 min 70%B, 125 min 100%B, 130min 0%B, 140min 0%B. All chemicals used were of biochemical or analytical quality and were purchased from Bio-Rad (D-8000 Munich), Pharacia/LKB (D-7800 Freiburg), Merck (D-6100 Darmstadt), Serva (D-6900 Heidelberg), Applied Biosystems (sequencer chemicals; D-6108) Weiterstadt or Pierce (PTH-amino acid * standard; Rockford, IL 61105 U.S.A.), Boehringer (D-6800 Mannheim) for sequence grade trypsin. The dialyεis tube was from Reichelt Chemietechnik (D-6900 Heidelberg) . The gas phase protein sequencer model 470A was purchased from Applied Biosystems. A slightly modified standard sequencer program was used. The sequencer is described in detail in the respective instrument manual. For detection of phenylthiohydantion amino acids (PTH-aa) a HPLC syεtem from Hewlett Packard PH 1082 and an autosampler from Waters (D-5090 Leverkusen) WISP 7208 equipped with a Kontron (D-4000 Duεεeldorf) dataεyεtem MT 450 were uεed. The HPLC-columns used for PTH-detection (250mmx4.6mm) filled with Superspher™ material from Merck were purchaεed from CS-Chromatographie Service (D-5163 Langerwehe) . Peptide mapε were run on an HPLC-syεtem from Hewlett Packard HP 1090 equipped with a diode array detector HP1040A and a chemstation with the integration software. The HPLC-column for peptide mapping was purchased from CS-Chromatrographie Service (Nucleioεil RP-19; 250mmx4.6mm; 5μ material; 300 Angεtrom) . N-Terminal sequence analysis N-terminal sequence analysiε waε performed uεing the gaε phaεe protein εequencer 470A from Applied Biosystems. The standard sequencer program was used with a slight modification instead of 20% trifluoro acetic acid (TFA) 1M methanolic HC1 was taken for conversion of PTH-amino acids. 50-100pmol of kinase peptides were used for sequencing. For the identification of PTH-amino acids a HPLC-system based on a Merck Superspher'" column was uεed (Lottspeich F. 1985. "Microscale isocratic separation of phenylthiohydantoin amino acid derivatives", J. Chromatography 326: 321-327). The syεtem waε run iεocratically. Conditions: flow 1.5mL/min, detection 269nm, oven temperature 61°C, mobile phase 68.5% lOmM sodium acetate, pH 4.9 / 31.5% acetonitril supplemented with 5mL dichloromethane per L. The calibration was performed with a 25 pmol standard of all PTH-amino acids before each sequencer run. The purified tryptic digests are given as Sequence I.D. Nos. 1-15. The sequences of these tryptic digestε (Seq. I.D. Nos. 1-15) were compared to the known amino acid sequenceε of the ERK1 and ERK2 proteinε derived from rat brain cDNA clones (Boulton et al. , 1991). Sequence I.D. Noε. 3-15 matched very closely the ERK-kinase family proteins. ERK's have the highest homology (about 40%) to cell cycle-associated cdc2 kinase and thus PK40 can be considered to be a member of the cell cycle-associated ERK kinase family. Sequence I.D. Number 6 contains the consenεes site of serine/threonine kinaεes for nucleotide binding, Gly Glu Gly Ala Tyr Gly (Hanks et al. , 1988) . Sequence I.D. Numbers 1 and 2 were not homologous to any of the ERK proteins. EXAMPLE 12 A cloning procedure for cDNAs encoding kinases PK40 and PK36 is described. A radiolabeled synthetic oligonucleotide hybridization probe corresponding to the most unique codons of the peptide sequence for each of the PK40 and PK36 kinaεeε iε prepared. Specifically, probes corresponding to Sequence I.D. Numbers 1 and 2 are most suitable for the cloning procedure for cDNA encoding PK40. The oligonucleotide probes (e.g. Sequence I.D. Nos. 1 and 2) for PK40 and oligonucleotide probes for PK36 are used to screen lambda gtll cDNA libraries prepared from poly(A) RNA from human fetal brain cells, commercially available from a variety of sources. Hybridization conditions are as described by Cate et al. (1986), except that the final wash in tetramethyl ammonium chloride is omitted. DNA inserts from positive plaques are subcloned directly into the plasmid vector pBlue-script SKM13+ (Stratagene, Inc. San Diego, CA) . Poεitive plaεmid subclones are identified by colony hybridization, with the use of the same oligonucleotide hybridization probe. Minipreparationε of plasmid DNA are prepared from positive colonies. The nucleotide sequence immediately upstream from the oligonucleotide binding site is determined by double strand sequencing (Chen and Seeburg, 1985), using 32P end-labeled oligonucleotide as sequencing primer and non-radioactive nucleotides in the extenεion reactions. Subclones whoεe codon order upstream from the priming site match the known amino acid sequence are εequenced in their entirety by the dideoxy chain termination method, with either the Klenow fragment of Eεcherichia coli DNA polymeraεe I or modified bacteriophage T7 DNA polymeraεe (Sequenaεe; United Stateε Biochemicalε) in the extenεion reactions. Subcloneε are εequenced from their termini, from both directions from a set of reεtriction εiteε. Cloneε are obtained whose codon order matcheε he amino acid εequence of each of the kinases. A full-length cDNA sequence iε aεεembled from the overlapping partial cloneε for each of the kinases. 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Wible BA, Smith KE, Angelideε KJ (1989) Resolution and purification of a neurofilament-specific kinase. Proc Natl Acad Sci USA 86:720-724. Wischik CM, Novak M, Edwardε PC, Klug A, Tichelaar W, Crowther RA (1988) Structural characterization of the core of the paired helical filament of Alzheimer diεeaεe (1988). Proc Natl Acad Sci USA 85:4884-4888. Wong J. Hutchison SB, Liem RKH (1984) An isoelectric variant of the 150,000-Dalton neurofilament polypeptide. J Biol Chem 259:10867-10874. Wood, JG, Mirra SS, Pollock NJ, Binder LI (1986) Neurofibrillary tangles of Alzheimer diεeaεe share antigenic determinants with the axonal microtubule-associated protein TAU (t) . Proc. Natl Acad. Sci. USA 83:4040-4043. SEQUENCE LISTING (1) GENERAL INFORMATION: (i) APPLICANT: Ingram, Vernon M. , Roder, Hanno M. (ii) TITLE OF INVENTION: Novel Tau/Neurofilament Protein Kinases (iii) NUMBER OF SEQUENCES: 15 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: Massachusetts Institute of Technology (B) STREET: 28 Carleton Street (C) CITY: Cambridge (D) STATE: Massachusetts (E) COUNTRY: United States of America (F) ZIP: 02142 (v) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Diskette, 5.25 inch (B. COMPUTER: IBM-compatible (C) OPERATING SYSTEM: MS-DOS Version 3.3 (D) SOFTWARE: WordPerfect 5.1 SUBSTITUTESHEET (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: Unknown (B) FILING DATE: July 10, 1992 (C) CLASSIFICATION: (vii) PRIOR APPLICATION DATA: (A) APPLICATION NUMBER: 07/742,880 (B) FILING DATE: 9-AUG-1991 (viii) ATTORNEY/AGENT INFORMATION: (A) NAME: Gates, Edward R. (B) REGISTRATION NUMBER: 31,616 (C) REFERENCE/DOCKET NUMBER: M0656/7008 (2) INFORMATION FOR SEQ ID NO: 1: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear ( ii ) MOLECULE TYPE : peptide SUBSTITUTE SHEET (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1 Gly Gin Val Phe Asp Val Gly Pro Val Gly Leu Ala Gly Pro 1 5 10 (2) INFORMATION FOR SEQ ID NO: 2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 12 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2 Gin Thr Gly Pro lie Gly Pro His Gly Pro Gin Gly 1 5 10 (2) INFORMATION FOR SEQ ID NO: 3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3 Xaa lie Glu Val Glu Gin Ala Leu Ala Thr Pro Tyr Xaa Glu 1 5 10 SUBSTITUTE SHEET - 71 - (2) INFORMATION FOR SEQ ID NO: 4. (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 amino acids (B) TYPE-: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4 Xaa He Glu Val Glu Gin Ala Leu Ala His Pro Tyr Xaa Glu 1 5 10 (2) INFORMATION FOR SEQ ID NO: 5: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 15 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE-DESCRIPTION: SEQ ID NO: 5 He Glu Val Glu Gin Ala Leu Ala His Pro Tyr Xaa Glu Gin Tyr 1 5 10 15 SUBSTITUTE SHEET (2) INFORMATION FOR SEQ ID NO: 6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 15 amino acids (B) TYPE: amino acid . (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 6 Tyr Thr Asn Leu Ser Tyr He Gly Glu Gly Ala Xaa Gly Met Val 1 5 10 15 (2) INFORMATION FOR SEQ ID NO: 7: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE -DESCRIPTION: SEQ ID NO: 7 Asp Val Tyr He Val Gin Asp Leu Met Glu Thr Asp Leu Tyr 1 5 10 SUBSTITUTESHEET (2) INFORMATION FOR SEQ ID NO: 8: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 8 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 8 Asn Tyr Leu Leu Ser Leu Pro Xaa 1 5 (2) INFORMATION FOR SEQ ID NO: 9: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 9 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 9 Glu Leu lie Phe Glu Glu Thr Ala Xaa 1 5 SUBSTITUTE SHEET (2) INFORMATION FOR SEQ ID NO: 10: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 8 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 10 Met Leu Thr Phe Asn Pro Xaa Lys 1 5 (2) INFORMATION FOR SEQ ID NO: 11: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 8 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 11 lie Cys Asp Phe Gly Leu Ala Xaa 1 5 SUBSTITU TESHEET (2) INFORMATION FOR SEQ ID NO: 12: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 7 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 12 Ala Leu Asp Leu Leu Asp Xaa 1 5 (2) INFORMATION FOR SEQ ID NO: 13: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 7 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 13 Asp Val Tyr lie Val Gin Asp 1 5 S U BSTI TUTE S HEET (2) INFORMATION FOR SEQ ID NO: 14: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 14 Ala Pro Glu lie Met Leu 1 5 (2) INFORMATION FOR SEQ ID NO: 15: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 15 Ser lie Asp lie Xaa Ser 1 5 5UBSTVTUTE SHEET

Claims: Claimε 1. A preparation containing an isolated, esεentially pure, nonεkeletal-associated kinase, the kinase capable of phosphorylating dephosphorylated NF-M to an extent sufficient to cause a shift on SDS-PAGE of the apparent of dephosphorylated NF-M toward that of native NF-M. 2. A preparation as claimed in claim 1 wherein the kinase is capable of phosphorylating both KSP siteε of TAU and iε capable of aboliεhing the TAU epitope on TAU. 3. A preparation as claimed in claim 1 wherein the kinase is capable of phosphorylating and I reconstituting phospho-epitopes on completely dephosphorylated NF-triplet or purified dephosphorylated NF-M. 4. A preparation as claimed in claim 1 wherein the kinase is capable of being inhibited by excess ATP. 5. A preparation as claimed in claim 1 wherein the kinaεe haε a Km of about 93 for ATP. 6. A preparation aε claimed in claim 1 wherein the kinase iε capable of phosphorylating completely dephoεphorylated NF-M to an extent sufficient to cauεe a complete εhift and wherein the kinaεe iε capable of phoεphorylating completely dephosphorylated NF—H to an extent sufficient to cause a partial shift on SDS-PAGE of the apparent M of completely dephosphorylated NF-H toward that of native NF-H. 7. A preparation aε claimed in claim 1 wherein the kinaεe iε capable of phoεphorylating completely dephoεphorylated TAU to an extent sufficient to cause a complete shift on SDS-PAGE of the apparent M of completely dephosphorylated TAU to that of native TAU. 8. A prepartion as claimed in claim 1 wherein the kinase is capable of phosphorylating TAU to an extent sufficient to result in an SDS-PAGE pattern characteristic of human TAU proteins extracted from PHF. 9. A preparation as claimed in claim 1 wherein the kinase has a sequence characterized by εequence numbers 1 and 2. 10. A preparation as claimed in any one of claims 1-9 wherein the kinase has an apparent molecular weight of 40 kD. 11. A preparation as claimed in claim 1 wherein the kinase is capable of phosphorylating completely dephosphorylated NF-M to an extent sufficient to cause at leaεt a partial shift on SDS-PAGE of the aappppaarreenntt MM ooff ccoommpplleetteellyy cdephosphorylated NF-M toward that of native NF-M. 12. A preparation as claimed in claim 11 wherein the kinase has a Km of about 50 for ATP. 13. A preparation as claimed in claimε 1 and 11-13 wherein the kinaεe haε an apparent M of 36 kD. 14. A method for detecting a mammalian kinaεe comprising, preparing a fraction of biological material derived from a mammal, it being unknown whether the fraction contains the kinase, the fraction being subεtantially free of epitopes that are characteristic of a protein in a particular state of phosphorylation and that are reactive with a test antibody, contacting the fraction with a protein free of the epitope under conditions so as to permit the phosphorylation of the neuroprotein if the mammalian kinase is present, and testing for the presence of the epitope using the test antibody. 15. A method for detecting a mammalian kinaεe compriεing: preparing a fraction of biological material derived from a mammal, it being unknown whether the fraction containε the kinaεe, the fraction being substantially free of epitopes that are characteristic of a protein in a particular state of phosphorylation and that are reactive with a test antibody, contacting the fraction with a protein that includes the epitope under conditions so as to permit the phosphorylation of the protein if the mammalian kinase is preεent, and testing for the presence of the epitope using the test antibody. 16. A method aε claimed in claim 15 further characterized by contacting the fraction with a neuroprotein. 17. A method aε claimed in claimε 14 or 15 further characterized by contacting the fraction with a completely dephoεphorylated neuroprotein. 18. A method aε claimed in claimε 14 or 15 further characterized by contacting the fraction with a completely dephoεphorylated NF-H. 19. A method as claimed in claims 14 or 15 further characterized by contacting the fraction with a completely dephosphorylated TAU. 20. A method as claimed in claims 14-15 wherein the teεt antibody iε a teεt antibody εelected from the group conεisting of SMI-31, SMI 33 and SMI-34. 21. An i munoasεay compriεing: an antibody that iε reactive with an epitope characteriεtic of a particular εtate of phoεphorylation of a protein, and the protein in a εtate of phosphorylation that does not bind to the antibody. 22. An immunoassay as claimed in claim 21 wherein the protein is a neuroprotein. 23. An immunoassay as claimed in claim 21 wherein the protein is dephosphorylated relative to the native protein. 24. An immunoasεay aε claimed in claim 21 wherein the protein iε TAU. 25. An immunoassay as claimed in claim 23 wherein the protein is TAU. 26. An immunoassay employing dephosphorylated NF. 27. An immunoassay aε claimed in claim 26 wherein the assay employs completely dephosphorylated NF-triplet. 28. An immunoassay as claimed in claim 26 wherein the assay employε completely dephoεphorylated NF-M. 29. An immunoassay as claimed in claim 26 wherein the assay employε completely dephosphorylated NF-H. 30. A monoclonal antibody selectively specific for PK40. 31. A monoclonal antibody capable of binding to and inhibiting the kinase activity of PK40. 32. An immunoassay for detecting PK40 employing the monoclonal antibody of claim 30., I 33. A polyclonal antibody selectively specific for PK40. 34. A polyclonal antibody as claimed in claim 33 wherein the antibody is capable of inhibiting the kinase activity of PK40. 35. An immunoassay for detecting PK40 employing the polyclonal antibody of claim 33. 36. A monoclonal antibody selectively specific for PK36. 37. A monoclonal antibody capable of binding to and inhibiting the kinase activity of PK36. 38. An immunoasεay for detecting PK36 employing the monoclonal antibody of claim 36. 39. A polyclonal antibody selectively specific for PK36. 40. A polyclonal antibody as claimed in claim 39 wherein the antibody is capable of inhibiting the kinase activity of PK36. 41. An immunoasεay for detecting PK36 employing the polyclonal antibody of claim 39. I 42. A method for inhibiting neuroprotein phoεphorylation activity in a cell compriεing, introducing into a cell an inhibitor of PK40 or PK36 in an amount εufficient to inhibit phoεphorylating activity of the PK40 or PK36. 43. A method aε claimed in claim 42 wherein a fragment of a subεtrate of PK40 or PK36 iε introduced into the cell. 44. A method aε claimed in claim 42 wherein an antibody capable of binding to PK40 iε introduced into the cell. 45. A method as claimed in claim 42 wherein an antibody capable of binding to PK36 is introduced into the cell. 46. A method as claimed in c ' .aim 42 wherein ATP or an analog thereof is introduced into the cell. 47. A method as claimed in claim 42 wherein the inhibitor iε administered in a εufficient amount to prevent the formation of neurofilament tangleε. 48. A vector containing an oligonucleotide encoding PK40 or a unique fragment thereof. 4 . A vector aε claimed in claim 48 wherein the oligonucleotide is a cDNA. I 50. A vector as claimed in claim 48 wherein the oligonucleotide corresponds to human PK40 or a unique fragment thereof. 51. A vector containing an oligonucleotide encoding PK36 or a unique fragment thereof. 52. A vector aε claimed in claim 51 wherein the oligonucleotide is cDNA. 53. A vector aε claimed in claim 51 wherein the oligonucleotide correεpondε to human PK36 or a unique fragment thereof. 54. A cell line tranεformed or transfected with an oligonucleotide encoding PK40 or a unique fragment thereof. • 55. A cell line transformed or tranεfected with an oligonucleotide encoding PK36 or a unique fragment thereof. 56. A kinase produced by the cell line of either of claimε 54 or 55.

Inventors: INGRAM VERNON M, RODER HANNO M, INGRAM, VERNON, M., RODER, HANNO, M.
Applicants: MASSACHUSETTS INST TECHNOLOGY, MASSACHUSETTS INSTITUTE OF TECHNOLOGY
Application year: 1992
Main classification: C12N9
IPC codes: A61K38, A61K39, A61P25, C07K16, C12N9, C12N15, C12P21, G01N33