Abstract:
The invention provides compounds having formulae comprising 
     X 1 -Ser-Met-Arg-Glu-Arg-X 2   
     in which X 1  and X 2  are up to 30 amino acid residues and the formula represents a reverse-order sequence corresponding to amino acid residues 332 to 328 of human APP and from zero to 30 successive amino acid residues of human APP extending in each direction therefrom, The invention also provides the pentapeptide Ser-Met-Arg-Glu-Arg, corresponding to residues 332 to 328 of human amyloid precursor protein in reverse order, and the tripeptide Arg-Glu-Arg which corresponds residues 328 to 330 of human amyloid precursor protein, the tripeptide and pentapeptide being provided as pharmaceutical compositions. The invention further provides conjugates of the foregoing compounds which can cross the blood-brain barrier and pharmaceutical compositions containing such conjugates. The compounds and compositions of the invention are believed to be useful in the treatment of Alzheimer&#39;s disease and as cognitive enhancers and appropriate methods of medical treatment are disclosed.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to polypeptide compounds and to their use in medicine. Compounds according to the invention are believed to be potentially useful as cognitive enhancers and in the treatment of neurodegenerative diseases such as Alzheimer&#39;s disease.  
         BACKGROUND TO THE INVENTION  
         [0002]    Alzheimer&#39;s disease is a degenerative brain disease which is characterised by progressive loss of memory and subsequently most other cognitive functions in an irreversible decline over a period of years. It represents a substantial health problem, particularly in an ageing population.  
           [0003]    The amyloid precursor protein (“APP”) is a multifunctional transmembrane protein and is known to have important functions in normal brain tissue. The human form of APP is known to consist of 695 amino acid residues (SEQ ID No: 1) in a sequence which is also known (see Kang et al, Nature 325, 733-736 (1987), the contents of which are incorporated herein by reference). The chick form of APP is known to consist of 534 amino acid residues (SEQ ID No: 2) and to resemble the human form closely, being approximately 95% homologous therewith (see the paper by Kang et al just mentioned and Barnes et al, J Neurosci, 18 (15) 5869-5880 (1998), contents of which are also incorporated herein by reference). The amino acid sequences of the human and chick forms of APP are reproduced in FIG. 1 of the drawings of this specification.  
           [0004]    Two effects which have been noted to take place in the brain of a person suffering from Alzheimer&#39;s disease are he build up outside the nerve cells of the brain of tangled masses of protein and the build up inside the brain cells of a different protein. The extracellular proteins are known to be aggregates of polypeptides having amino acid sequences corresponding to portions of the extracellular part of APP. The tangled masses of these proteins are known as amyloid plaques. The intracellular proteins are known as tau proteins. It is however not known whether either or both of the extracellular accumulation of amyloid plaques and the intracellular accumulation of tau proteins are the causes or the symptoms of Alzheimer&#39;s and related neurodegenerative diseases of the Alzheimer type.  
           [0005]    The amino acid sequence of the β-amyloid polypeptide fragment (1-42) is identical in the human and chick forms of APP and consists of amino acid residues 597 to 638 in the human form and residues 436 to 477 in the chick form, (see the papers by Kang et al and Barnes et al referred to hereinbefore).  
           [0006]    Definitions  
           [0007]    The following expressions are used in this specification and have the following meanings:  
                                       APP   means “amyloid precursor protein”;       human APP   means the human form of APP;       chick APP   means the chick form of APP;       RERMS   means the pentapeptide Arg-Glu-           Arg-Met-Ser (SEQ ID No: 3);       APP 328-332   also means the pentapeptide Arg-           Glu-Arg-Met-Ser (SEQ ID No: 3)           which corresponds to amino acid.           residues 328 to 332 of human APP;       SMRER   means the pentapeptide Ser-Met-           Arg-Glu-Arg (SEQ ID No: 4);       Aβ domain   means the domain of APP which           forms β-amyloid plagues;       β-amyloid 12-28   means the sequence of amino acid           residues which constitute part of           the Aβ domain of human APP, the           sequence being Val-His-His-Gln-           Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-           Val-Gly-Ser-Asn-Lys (SEQ ID No: 8)           which corresponds to amino acid           residues 608 to 624 of human APP           and amino acids 447 to 463 of           chick APP;       RSAER   means the pentapeptide Arg-Ser-           Ala-Glu-Arg (SEQ ID No: 5); and       APP 319-335   means the polypeptide Ala-Lys-Glu-           Arg-Leu-Glu-Ala-Lys-His-Arg-Glu-           Arg-Met-Ser-Gln-Val-Met           (AKERLEAKHRERMSQVM) (SEQ ID No:           6).       RER   means the tripeptide Arg-Glu-Arg           (SEQ ID No: 9).       RERM   means the tetrapeptide Arg-Glu-           Arg-Met (SEQ ID No: 10).       MRER   means the tetrapeptide Met-Arg-           Glu-Arg (SEQ ID No: 11).       Amino acid   as used herein is meant to include           both natural and synthetic amino           acids, and both D and L amino           acids.       Standard amino acid   means any of the twenty standard           L-amino acids commonly found in           naturally occurring peptides.       Nonstandard amino acid   means any amino acid, other than           the standard amino acids,           regardless of whether it is           prepared synthetically or derived           from a natural source. As used           herein, “synthetic amino acid”           also encompasses chemically           modified amino acids, including           but not limited to salts, amino           acid derivatives (such as amides),           and substitutions. Amino acids           contained within the peptides of           the present invention, and           particularly at the carboxy- or           amino-terminus, can be modified by           methylation, amidation,           acetylation or substitution with           other chemical groups which can           change the peptide&#39;s circulating           half life without adversely           affecting their activity.           Additionally, a disulfide linkage           may be present or absent in the           peptides of the invention.       Derivative   includes any purposefully           generated peptide which in its           entirety, or in part, has a           substantially similar amino acid           sequence to the present compounds.           Derivatives of the present           compounds may be characterized by           single or multiple amino acid           substitutions, deletions,           additions, or replacements. These           derivatives may include (a)           derivatives in which one or more           amino acid residues of the present           compounds are substituted with           conservative or non-conservative           amino acids; (b) derivatives in           which one or more amino acids are           added to the present compounds;           (c) derivatives in which one or           more of the amino acids of the           present compounds include a           substituent group; (d) derivatives           in which the present compounds or           a portion thereof is fused to           another peptide (e.g., serum           albumin or protein transduction           domain); (e) derivatives in which           one or more nonstandard amino acid           residues (i.e., those other than           the 20 standard L-amino acids           found in naturally occurring           proteins) are incorporated or           substituted into the present           compounds sequence; and (f)           derivatives in which one or more           nonamino acid linking groups are           incorporated into or replace a           portion of the present compounds.                  
 
           [0008]    Throughout this specification and its claims amino acid sequences are written using the standard one-letter or three-letter abbreviations. All sequences are written from left to right in the direction from the N-terminal to the C-terminal.  
           [0009]    The following term is defined as follows:  
           [0010]    reverse order sequence as used herein, the reverse order sequence of a given sequence is a sequence in which the order of amino acid residues is reversed compared with the given sequence when reading in the direction from the N-terminal to the C-terminal and vice versa. Thus, for example, SMRER is the reverse order sequence of RERMS, each being read as stated above from left to right in the N-terminal to C-terminal direction. Further, MVQSMRERHKAELREKA (SEQ ID No: 7) is the reverse order sequence of APP 319-335 defined above.  
         SUMMARY OF THE INVENTION  
         [0011]    The present invention provides a compound having a formula comprising: 
           X 1 -Arg-Xaa-Arg-X 2   (I) 
           [0012]    wherein X 1  and X 2 , which may be the same or different, each represents from zero to 30 natural or synthetic amino acid residues or derivatives thereof and Xaa represents a natural or synthetic amino acid or a derivative thereof. Xaa is preferably glutamic acid.  
           [0013]    The present invention also provides a compound having a formula comprising: 
           X 1 -Arg-Xaa 1 -Arg-Xaa 2 -Xaa 3 -X 2   (II) 
           [0014]    wherein X 1  and X 2 , which may be the same or different, each represents from zero to 30 natural or synthetic amino acid residues or derivatives thereof and Xaa 1 , Xaa 2  and Xaa 3 , which may be the same or different, each represents a natural or synthetic amino acid or a derivative thereof.  
           [0015]    In both compound (I) and compound (II), amino acid derivatives include, for example, substituted amino acids.  
           [0016]    In both compound (I) and compound (II), X 1  and X 2  are each preferably from zero to 20, more preferably from zero to 10.  
           [0017]    When X 1  and X 2  are both zero in formula (I), formula (I) is that of a tripeptide which is Arg-Glu-Arg (RER) when Xaa is glutamic acid. When X 1  and X 2  are both zero in formula (II), formula (II) is that of a pentapeptide which is RERMS when Xaa 1  is glutamic acid, Xaa 2  is methionine and Xaa 3  is serine  
           [0018]    In a compound according to formula (II) Xaa 1  is preferably glutamic acid, Xaa 2  is preferably methionine and Xaa 3  is preferably serine.  
           [0019]    Preferably, compounds according to the invention are compounds in which X 1  and X 2  are such that (I) or (II) represents an amino acid sequence which is identical or closely homologous to amino acid residues 328 to 332 of human APP and up to 30 successive amino acid residues of human APP extending in each direction therefrom.  
           [0020]    It is also preferred that compound (I) is one in which X 1  and X 2  are such that the formula represents a reverse-order amino acid sequence which is identical or closely homologous to amino acid residues 330 to 328 of human APP and up to 30 successive amino acid residues of human APP extending in each direction therefrom.  
           [0021]    As used herein, a peptide or a portion of a peptide which is “closely homologous” means the peptide, or the portion thereof, has an amino acid homology of greater than about 80% with respect to a reference peptide, preferably greater than about 90% and, more preferably, greater than about 95%.  
           [0022]    Amino acid sequence homology may be computed by using the BLASTP and TBLASTN programs which employ the BLAST (basic local alignment search tool) 2.0.14 algorithm; BLASTP and TBLASTN settings to be used in such computations are indicated in Table 1 below. Amino acid sequence identity (complete homology) is reported under “Identities” by the BLASTP and TBLASTN programs. Amino acid sequence similarity (degree of homology) is reported under “Positives” by the BLASTP and TBLASTN programs. Techniques for computing amino acid sequence homology are well known to those skilled in the art, and the use of the BLAST algorithm is described in Altschul et al. (1990),  J. Mol. Biol.  215: 403-10 and Altschul et al. (1997),  Nucleic Acids Res.  25:3389-3402, the disclosures of which are herein incorporated by reference in their entirety. BLASTP and TBLASTN programs utilizing the BLAST 2.0.14 algorithm and may be accessed at http.//www.ncbi.nlm.nih.gov/.  
                             TABLE 1                           Settings to be used for the computation of amino       acid sequence similarity or identity with BLASTP and       TBLASTN programs utilizing the BLAST 2.0.14 algorithm                    10           Expect Value   Low complexity filtering           Filter   using SEG program*                       Substitution Matrix   BLOSUM62           Gap existence cost   11           Per residue gap cost   1           Lambda ratio   0.85           Word size   3                                  
 
           [0023]    The invention also provides compounds having a formula comprising: 
           X 1 -Xaa 3 -Xaa 2 -Arg-Xaa 1 -Arg-X 2   (III) 
           [0024]    wherein X 1 , X 2 , Xaa 1 , Xaa 2  and Xaa 3  are as stated hereinbefore.  
           [0025]    When X 1  and X 2  are both zero, the formula is that of a pentapeptide which is SMRER when Xaa 1  is glutamic acid, Xaa 2  is methionine and Xaa 3  is serine.  
           [0026]    Such formulae represent the reverse-order sequences of the formulae mentioned hereinbefore.  
           [0027]    Preferably, the compound is one in which X 1  and X 2  are such that the formula represents a reverse-order amino acid sequence which is identical or closely homologous to amino acid residues 332 to 328 of human APP and up to 30 successive amino acid residues of human APP extending in each direction therefrom.  
           [0028]    As used herein, a peptide or a portion of a peptide which is “closely homologous” means the peptide, or the portion thereof, has an amino acid homology of greater than about 80% with respect to a reference peptide, preferably greater than about 90% and, more preferably, greater than about 95%.  
           [0029]    Preferably, X 1  in (I) represents: 
           X 3 -Ala-Lys-Glu-Arg-Leu-Glu-Ala-Lys-His 
           [0030]    and/or X 2  represents 
           Met-Ser-Gln-Val-Met-X 4   
           [0031]    X 3  and X 4  being the same or different and representing from zero to 30 natural or synthetic amino acid residues or derivatives thereof.  
           [0032]    X 3  and X 4  are again preferably each from zero to 20, more preferably from zero to 10.  
           [0033]    When X 3  and X 4  are both zero and Xaa is glutamic acid, the formula corresponds to the sequence of amino acid residues 319 to 335 of human APP.  
           [0034]    It is also preferred that X 1  in (I) represents: 
           X 3 -Met-Val-Gln-Ser-Met 
           [0035]    and/or X 2  represents: 
           His-Lys-Ala-Glu-Leu-Arg-Glu-Lys-Ala-X 4   
           [0036]    wherein X 3  and X 4 , which may be the same or different, each represents from zero to 30 natural or synthetic amino acid residues or derivatives thereof.  
           [0037]    X 3  and X 4  are again preferably each from zero to 20, more preferably from zero to 10.  
           [0038]    When X 3  and X 4  are both zero and Xaa is glutamic acid, the formula corresponds to the reverse-order sequence of amino acid residues 335 to 319 of human APP.  
           [0039]    Preferably, X 1  in (II) represents: 
           X 3 -Ala-Lys-Glu-Arg-Leu-Glu-Ala-Lys-His 
           [0040]    and/or X 2  represents 
           Gln-Val-Met-X 4   
           [0041]    X 3  and X 4  being the same or different and representing from zero to 30 natural or synthetic amino acid residues or derivatives thereof.  
           [0042]    X 3  and X 4  are again preferably each from zero to 20, more preferably from zero to 10.  
           [0043]    When X 3  and X 4  are both zero and Xaa 1 , Xaa 2  and Xaa 3  are glutamic acid, methionine and serine, respectively, the formula corresponds to the sequence of amino acid residues 319 to 335 of human APP.  
           [0044]    Preferably, X 1  in (III) represents: 
           X 3 -Met-Val-Gln 
           [0045]    and/or X 2  represents: 
           His-Lys-Ala-Glu-Leu-Arg-Glu-Lys-Ala-X 4   
           [0046]    wherein X 3  and X 4 , which may be the same or different, each represents from zero to 30 natural or synthetic amino acid residues or derivatives thereof.  
           [0047]    X 3  and X 4  are again preferably each from zero to 20, ore preferably from zero to 10.  
           [0048]    When X 3  and X 4  are both zero and Xaa 1 , Xaa 2  and Xaa 3  are glutamic acid, methionine and serine, respectively, the formula corresponds to the reverse-order sequence of amino acid residues 335 to 319 of human APP.  
           [0049]    The invention also provides compounds having the formula (I) in which Xaa is glutamic acid and either X 1  is methionine and X 2  is zero, or X 1  is zero and X 2  is methionine. These are the compounds Met-Arg-Glu-Arg (MRER) (SEQ ID No: 11) and Arg-Glu-Arg-Met (RERM) (SEQ ID No: 10), respectively.  
           [0050]    In addition to the compounds mentioned hereinbefore, the present invention also provides the compounds (including RER, RERMS and SMRER) for use in medicine and their use in the preparation of medicaments for the treatment of neurodegenerative diseases, including Alzheimer&#39;s disease, and as cognitive enhancers.  
           [0051]    The invention further provides pharmaceutical compositions comprising the compounds (including RER, RERMS and SMRER) and a pharmaceutically-acceptable carrier and also compositions in which a compound according to the invention (including RER, RERMS and SMRER) is chemically or physically linked to a further molecule or vehicle to form a complex for pharmaceutical delivery of the compound.  
           [0052]    The compounds which are most preferred in the medical uses and pharmaceutical compositions are the following: 
           Arg-Glu-Arg  (SEQ ID No: 9) 
           [0053]    which corresponds to amino acid residues 328-330 of human APP, 
           Arg-Glu-Arg-Met-Ser  (SEQ ID No: 3) 
           [0054]    which corresponds to amino acid residues 328-332 of human APP, 
           Ser-Met-Arg-Glu-Arg  (SEQ ID No: 4) 
           [0055]    which is the reverse-order polypeptide of the above, 
           Ala-Lys-Glu-Arg-Leu-Glu-Ala-Lys-His-Arg-Glu-Arg-Met-Ser-Gln-Val-Met  (SEQ ID No: 6) 
           [0056]    which corresponds to amino acid residues 319-335 of human APP, and 
           Met-Val-Gln-Ser-Met-Arg-Glu-Arg-His-Lys-Ala-Glu-Leu-Arg-Glu-Lys-Ala  (SEQ ID No: 7) 
           [0057]    which is the reverse-order polypeptide of the above.  
           [0058]    The invention further provides a compound having a formula comprising 
           X 1 -Ser-Met-Arg-Glu-Arg-X 2   (IV) 
           [0059]    wherein X 1  and X 2 , which may be the same or different, each represents from zero to 30 amino acid residues, the amino acid residues of X 1  and X 2  being such that, when X 1  and X 2  are not both zero, the formula represents a reverse-order sequence corresponding to amino acid residues 332 to 328 of human APP and from zero to 30 successive amino acid residues of human APP extending in each direction therefrom, the formula also comprising sequences closely homologous to said reverse-order sequence and sequences in which said amino acids thereof are replaced by nonstandard amino acids and/or by derivatives of said amino acids, provided always that the compound is not 
           Met-Val-Gln-Ser-Met-Arg-Glu-Arg-His-Lys-Ala-Glu-Leu-Arg-Glu-Lys-Ala  (SEQ ID No: 7) 
           [0060]    Subject to the above proviso, formula (IV) thus includes within its scope polypeptides which consist of a core sequence of the five amino acid residues 332 to 328 of human APP in reverse order relative to human APP and, extending therefrom in the N-terminal direction, up to 30 of amino acid residues 333 to 362 of human APP and, in the C-terminal direction, up to 30 of amino acid residues 327 to 328 of human APP, the whole forming a reverse-order sequence relative to human APP.  
           [0061]    In formula (IV), X 1  is preferably from zero to 20 and/or X 2  is from zero to 20. More preferably, X 1  is from zero to 10 and/or X 2  is from zero to 10. Still more preferably, X 1  and/or X 2  is zero.  
           [0062]    In other preferred compounds of formula (IV), X 1  is 2 or less and X 2  is 8 or less.  
           [0063]    When X 1  and X 2  are both zero formula (IV) represents the polypeptide 
           Ser-Met-Arg-Glu-Arg  (SEQ ID No: 4) 
           [0064]    which may also be represented as SMRER and is the reverse-order sequence of the polypeptide RERMS (SEQ ID No. 3).  
           [0065]    The invention also provides a pharmaceutical composition containing as an active ingredient a compound according to formula (IV), together with a pharmaceutically acceptable carrier, filler or excipient.  
           [0066]    Further, the invention provides a compound according to formula (IV) which is chemically or physically linked or conjugated to a further molecule or vehicle whereby the compound can be delivered across the blood-brain barrier.  
           [0067]    The invention also provides pharmaceutical compositions containing such compounds together with a pharmaceutically acceptable carrier, filler or excipient.  
           [0068]    In each case, the preferred compound according to formula (IV) is 
           Ser-Met-Arg-Glu-Arg  (SEQ ID No: 4) 
           [0069]    The invention moreover provides a pharmaceutical composition containing as an active ingredient the polypeptide 
           Arg-Glu-Arg  (SEQ ID No: 9) 
           [0070]    together with a pharmaceutically acceptable carrier, filler or excipient. This polypeptide may also be represented as RER. The polypeptide RER is preferably chemically or physically linked or conjugated to a further molecule or vehicle whereby the compound can be delivered across the blood-brain barrier. The invention also provides a pharmaceutical composition containing such a compound together with a pharmaceutically acceptable carrier, filler or excipient.  
           [0071]    Also provided by the invention are methods of treating or preventing a neurodegenerative disease, for example Alzheimer&#39;s disease, in an animal, preferably a human, the method comprising:  
           [0072]    identifying an animal suffering or potentially suffering from a neurodegenerative disease; and  
           [0073]    administering to the animal an amount of at least one of the following compounds effective to treat or at least partially prevent the neurodegenerative disease,  
           [0074]    the said compounds being:  
           [0075]    a compound according to formula (IV), including all preferred forms thereof, particularly Ser-Met-Arg-Glu-Arg (SEQ ID No. 4);  
           [0076]    Arg-Glu-Arg (SEQ ID No: 9);  
           [0077]    any of the foregoing compounds chemically or physically linked or conjugated to a further molecule or vehicle whereby the compound can be delivered across the blood-brain barrier; and  
           [0078]    pharmaceutical compositions containing as an active ingredient any of the foregoing compounds, including such compounds linked or conjugated as stated, together with a pharmaceutically acceptable carrier, filler or excipient.  
           [0079]    Further, the invention provides a method of producing a cognitive enhancement effect in an animal, preferably a human, the method comprising:  
           [0080]    providing an animal in which such an effect is to be produced; and  
           [0081]    administering to the animal an amount of at least one of the following compounds effective to produce the cognitive enhancement,  
           [0082]    the said compounds being:  
           [0083]    a compound according to formula (IV), including all preferred forms thereof, particularly Ser-Met-Arg-Glu-Arg (SEQ ID No: 4);  
           [0084]    Arg-Glu-Arg (SEQ ID No: 9);  
           [0085]    any of the foregoing compounds chemically or physically linked or conjugated to a further molecule or vehicle whereby the compound can be delivered across the blood-brain barrier; and  
           [0086]    pharmaceutical compositions containing as an active ingredient any of the foregoing compounds, including such compounds linked or conjugated as stated, together with a pharmaceutically acceptable carrier, filler or excipient. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0087]    The drawings of this specification consist of the following:  
         [0088]    [0088]FIG. 1 which shows the amino acid sequence of human APP and chick APP, as referred to hereinbefore;  
         [0089]    [0089]FIG. 2 shows the effect of β-amyloid 12-28 polypeptide on memory formation;  
         [0090]    [0090]FIG. 3 shows the effect of RERMS on β-amyloid 12-28 induced amnesia;  
         [0091]    [0091]FIG. 4 shows the effect of RERMS on anti-APP induced amnesia;  
         [0092]    [0092]FIG. 5 shows the effect of RERMS, SMRER and RSAER on APP-antisense induced amnesia;  
         [0093]    [0093]FIG. 6 shows the effect of APP 319-335 on APP-antisense induced amnesia;  
         [0094]    [0094]FIG. 7 shows the effect of RERMS on weak training;  
         [0095]    [0095]FIG. 8 shows the effect of APP 319-335 on weak training; and  
         [0096]    [0096]FIG. 9 shows the effect of RER on weak training. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0097]    The invention will now be described further by way of example with reference to the following experimental procedures and results.  
         [0098]    Materials and Methods  
         [0099]    Animals and Training  
         [0100]    Commercially obtained Ross Chunky eggs were incubated and hatched in brooders and held until 16±6 hours old. Chicks were placed in pairs in small aluminium pens. Following an equilibration period of an hour, the chicks were pretrained and trained essentially as described by Lossner and Rose (J. Neurochem. 41, 1357-1363 (1983), the contents of which are incorporated herein by reference). Pretraining involved three 10 s presentations of a small (2 mm diameter) white bead, at approximately 5 minute intervals. Chicks, which failed to peck the bead at least twice in three presentations (less than 5%), were not used subsequently, but remained in their pens for the duration of the experiment. Two training techniques were used: “strong” and “weak” training. In both, 5 to 10 minutes after the last pre-training trial, chicks were trained by a 10 s presentation of a 4 mm diameter chrome bead, which had been dipped in the bitter-tasting methylanthranilate. Control chicks pecked at a water-coated or dry bead. In the “strong” version of the task, 100% methylanthranilate was used. In the “weak” version, 10% methylanthranilate was used. Chicks spontaneously pecked at the training or control beads within 20 s. Chicks that peck at the bitter bead evinced a disgust reaction and would not normally peck at a similar, but dry bead for some hours subsequently. At various times following training chicks were tested, by offering them a dry 4 mm diameter chrome bead, followed 10 minutes later by a small (2 mm diameter) white bead, each for 20 to 30 s. Animals were tested by an experimenter blind as to which treatment each chick had received. Chicks are considered to remember the task if they avoid the chrome bead at test but peck at the white bead (discriminate), and to have forgotten it if they peck at both beads. Recall is calculated as a percent avoidance score(percentage of chicks which avoid the chrome bead) and as a discrimination score (percentage of chicks which avoid the chrome but peck at the white bead). The use of the discrimination score ensures that chicks can indeed see and peck accurately at the bead; and hence that the avoidance of the chrome bead is not due to non-specific factors such as lack of visuo-motor coordination, motivation, attention, arousal, etc. but is a positive act, demonstrating memory for the distasteful stimulus. Each chick was trained and tested only once and differences between groups tested for statistical significance by g-test described by Sokal and Rohlf (Biometry: the Principles and Practice of Statistics in Biological Research (2nd edition), W H Freeman, New York (1981)), the contents of which are incorporated herein by reference. The validity of this particular training task used to assess memory formation is extensively discussed by Andrew (Neural and Behavioural Plasticity: the Use of the Domestic Chick as a Model, Oxford University Press, Oxford, UK (1991), the contents of which are incorporated herein by reference.  
         [0101]    Chicks trained on the strong version of the task were found to recall the avoidance for at least 48 hours, and more than 80% were found normally to avoid and discriminate on test at 24 hours. Therefore if agents that are amnesic—that is, cause the chick not to remember—are administered, chicks will demonstrate forgetting by pecking rather than avoiding the chrome bead on test. By contrast, chicks were found normally to remember the “weak” version of the task for only a few hours—some 6 to 8 hours in all; retention at 24 hours was normally reduced to some 20 to 30%. Thus the learning experience is not committed to long-term memory. Agents that are memory enhancers can thus be tested. A memory enhancing agent, administered to a chick trained on the weak-learning task, produces an increase in retention—increased avoidance of the chrome bead—at 24 hours. That is, such memory enhancers help convert weak to strong learning by enabling the transition from shorter to longer-term memory.  
         [0102]    Peptide Injections  
         [0103]    Bilateral intracranial injections (2 μg/hemisphere) of either saline, or solutions in saline of different peptides (0.5 to 5 μg/hemisphere) homologous to different regions of the external domain of human APP were injected intracerebrally into a specific brain region, known to be required for memory formation (the intermediate hyperstriatum ventrale) at different time-points pre- or post-training using a 5 μg Hamilton syringe fitted with a plastic sleeve to allow a penetration of 3 mm. After completion of the injection, the needle was kept in place for 5 s. Correct placement was ensured by using a specially designed headholder described by Davis et al (Physiol. Behav. 22, 177-184 (1979), the contents of which are incorporated herein by reference) and was routinely visually monitored postmortem. Peptides or other substances were administered at various times either before or after the training protocol. Chicks were tested at different time points post-training as described above. The general behaviour of the chicks following injections was observed to detect any potential non-specific or adverse reactions to the injections.  
         [0104]    Peptide Materials  
         [0105]    The polypeptides administered were synthesised using a conventional peptide synthesiser in a manner which is well-known to those skilled in the art, The synthesised polypeptides were purified by use of RP-HPLC and purity further checked by mass spectrometry (MALDI-TOF), both techniques being well known to those skilled in the art. The polypeptides after synthesis were kept under argon in a lyophilised state, the argon preventing oxidation of cysteine, methionine and tryptophan in particular.  
         [0106]    Polypeptide synthesis as just mentioned is carried out by MWC-Biotech UK Limited of Milton Keynes, UK.  
         [0107]    RERMS is also available from Sachem Limited of St. Helens, Merseyside, UK.  
         [0108]    Experimental Results  
         [0109]    It is well known in many animal model systems for the study of memory that injection of β-amyloid and β-amyloid peptides, such as β-amyloid 12-28, results in a failure of animals to retain recently acquired memories. FIG. 2 shows this result for a chick; injection of β-amyloid 12-28 into the brain 30 minutes prior to training chicks on the passive avoidance task results in amnesia in animals tested 30 minutes subsequently.  
         [0110]    [0110]FIG. 2 shows in the left-hand half the percent avoidance measured in terms of total avoidance and discrimination for a saline control and in the right-hand half the percent avoidance measured when β-amyloid 12-28 is injected as described above 30 minutes pretraining and memory is tested 30 minutes posttraining.  
         [0111]    However, if amnesia is induced by injection of β-amyloid 12-28 30 minutes pretraining, and RERMS is injected 20 minutes pretraining, memory retention is restored. FIG. 3 shows that in this case memory is normal at 24 hours post-training.  
         [0112]    [0112]FIG. 3 shows on the left the percent avoidance measured in terms of total avoidance and discrimination for a saline control, in the centre the corresponding results when β-amyloid 12-28 is injected 30 minutes pretraining and memory tested 24 hours posttraining, and on the right the results when the pretraining injection of β-amyloid 12-28 is followed 10 minutes later by RERMS and memory is again tested 24 hours posttraining.  
         [0113]    It is thus shown that RERMS can prevent the memory loss produced by β-amyloid 12-28, a component of the amyloid plaques characteristic of Alzheimer&#39;s disease.  
         [0114]    It is known that disrupting the normal function of APP by blocking its external domain with a specific monoclonal antibody (mb22C11) around the time of training, whilst without effect on the ability of chicks to learn the passive avoidance response, prevents the transition to long term memory. The monoclonal antibody mb22C11, available from Boehringer-Mannheim, specifically recognises an epitope consisting of part of the external domain of APP.  
         [0115]    [0115]FIG. 4 shows on the left the percent avoidance measured for chicks injected with a saline control, in the centre the percent avoidance measured when mb22C11 is injected (1-5 μg in 2 μl) intracerebrally as described hereinbefore for peptide injections 30 minutes pretraining and, on the right, the percent avoidance measured when RERMS is also injected 25 minutes after mb22C11 (5 minutes pretraining). In all cases, memory was tested 24 hours posttraining.  
         [0116]    The results shown in FIG. 4 demonstrate that RERMS injected 5 minutes before training will prevent antibody induced memory loss and that the peptide RERMS can prevent anti-APP induced memory loss. Thus, RERMS can prevent the memory loss resulting from disrupting the normal function of APP.  
         [0117]    [0117]FIGS. 5 and 6 show the effect of inducing memory loss by injection of a 16-mer end-protected phosphodiester oligodeoxynucleotide designed to correspond to the transcription start sites 146 and AUG 1786  of the APP mRNA, immediately upstream of a ribozyme binding site. The oligodeoxynucleotide, 5′-CCC GAG GAC TGA GCC A-3′ (SEQ ID No:9) was further modified on the 2nd and 13th nucleotides to prevent internal looping and is available from King&#39;s College Molecular Medicine Unit, London, UK. The oligodeoxynucleotide was used in scrambled (SC) and antisense (AS) forms and administered as described hereinbefore for peptide administration in an amount of 0.6 to 1.0 μg in 2 μl.  
         [0118]    In a first experiment, chicks were injected with saline, RERMS, SMRER and RSAER in various combinations in the amounts stated hereinbefore.  
         [0119]    The results are shown in FIG. 5 which shows the percent avoidances measured on the “strong” learning task described hereinbefore. FIG. 5 a  shows the effect compared with a saline control of administration separately of SC oligodeoxynucleotide 12 hours pretraining and AS oligodeoxynucleotide 12 hours pretraining, together with the effect of administration of RERMS following the AS oligodeoxynucleotide 30 minutes pretraining.  
         [0120]    [0120]FIG. 5 a  shows that the SC oligodeoxynucleotide had no effect on memory but the AS compound had a significant effect of memory loss which was avoided to a substantial extent when RERMS was administered.  
         [0121]    [0121]FIG. 5 b  shows that similar results were obtained with the reverse-order pentapeptide SMRER.  
         [0122]    [0122]FIG. 5 c  shows that the effect obtained with RERMS and SMRER is absent with the pentapeptide RSAER.  
         [0123]    In a second experiment, SC and AS oligodeoxynucleotides were administered 12 hours pretraining. A polypeptide (APP 319-335) corresponding to amino acid residues 319 to 335 of human APP was injected 30 minutes pretraining. Chicks were tested for memory according to the “strong” version of the test described hereinbefore 30 minutes posttraining.  
         [0124]    [0124]FIG. 6 shows successively from the left: the percent avoidance measured for a saline control; the percent avoidance measured when SC oligodeoxynucleotide was administered; the percent avoidance measured when AS oligodeoxynucleotide was administered; and the percent avoidance measured when APP 319-335 was administered 30 minutes pretraining following administration of AS oligodeoxynucleotide 12 hours pretraining. Each result is shown both in terms of total avoidance (left-hand column) and discrimination (right-hand column).  
         [0125]    The results shown in FIG. 6 demonstrate that APP319-335 can prevent antisense induced memory loss.  
         [0126]    [0126]FIGS. 7 and 8 show the effects of RERMS and APP 319-335 on memory in chicks trained on the “weak” memory test described hereinbefore.  
         [0127]    As stated hereinbefore, weakly trained chicks (trained on 10% methylanthranilate) retain memory for the avoidance for only some 6 hours, and thereafter forget. FIG. 7 shows, on the left, the percent avoidance results (in terms of total avoidance and discrimination) for chicks trained on the “strong” version of the training, in the centre the corresponding results for “weak” training and, on the right, the effect of administration of RERMS following “weak” training. The chicks were tested for memory 24 hours posttraining; RERMS was administered in accordance with the procedure described hereinbefore 30 minutes pretraining.  
         [0128]    [0128]FIG. 8 shows the corresponding results obtained when the APP 319-335 polypeptide was used instead of RERMS.  
         [0129]    [0129]FIGS. 7 and 8 show that RERMS and APP 319-335 if injected prior to training chicks on the weak task, enhance memory at 24 hours. They thus function as cognitive enhancers (nootropic agents). Thus, RERMS and APP 319-335 both enhance normal memory in weakly trained animals.  
         [0130]    [0130]FIG. 9 shows the effect of RER on memory in chicks trained on the “weak” memory test described hereinbefore.  
         [0131]    As stated hereinbefore, weakly trained chicks (trained on 10% methylanthranilate) retain memory for the avoidance for only some 6 hours, and thereafter forget.  
         [0132]    [0132]FIG. 9 shows, in the three columns on the left, on the left the percent avoidance results (in terms of total avoidance) for chicks trained on the “strong” version of the training, in the centre the corresponding results for “weak” training and, on the right, the effect of administration of RER following “weak” training. The chicks were tested for memory 24 hours posttraining; RER was administered in accordance with the procedure described hereinbefore 30 minutes pretraining.  
         [0133]    [0133]FIG. 9 shows, on the right, the corresponding data in terms of discrimination.  
         [0134]    [0134]FIG. 9 shows that RER, if injected prior to training chicks on the weak task, enhances memory at 24 hours. It thus functions as a cognitive enhancer (nootropic agent). Thus, RER enhances normal memory in weakly trained animals.  
         [0135]    The role of APP in memory formation has been attributed to its involvement in cell-to-substrate adhesion processes. The data reported suggests that the APP involvement in memory formation most probably involves change in signal transduction events. The post-training time within which the antibody and antisense-induced amnesia, and within which RERMS and SMRER prevents amnesia, corresponds to that during which memory formation is vulnerable to disruption of the putative signal-transduction functions of APP.  
         [0136]    The chick system is a good one for exploring these issues, because the learning task is precise and sharply timed, and permits one also to be sure that any observed effect of an injected substance is specific to retention and not either to acquisition or to concomitant processes such as visual acuity, arousal or motor activity. Further, the role of other cell adhesion molecules in the cascade leading to synaptic modulation has been well mapped, so that the effects of either blocking or attempting to rescue functional APP activity can be set into an established context: see Rose, Learn. Memory 7, 1-17 (2000) the contents of which are fully incorporated herein by reference.  
         [0137]    It is therefore indicated by the experimental results reported above that compounds of the present invention are effective for the treatment and/or prevention of neurological diseases and disorders and as cognitive enhancers (nootropic agents) in other animals, including human and non-human mammals. The compounds are therefore effective in the treatment and/or prevention of Alzheimer&#39;s disease in humans and other neurodegenerative diseases and disorders in animals generally, including humans. Such animals include transgenic and other animal models for Alzheimer&#39;s disease.  
         [0138]    As used herein, except where the context indicates otherwise, the terms “treatment”, “treat” and analogous expressions used in relation to neurodegenerative diseases include within their scope not only treatment when symptoms are apparent but also the partial or total prevention of such diseases and delay in their onset in patients or animals who are subjected to treatment before onset of the disease or its symptoms become apparent.  
         [0139]    The compounds may be administered intracerebally as described above, or may be administered peripherally, for example intramuscularly, intravenously, transdermally or orally, preferably after complexation as described above. Instead or in addition, the compounds may be protected against alteration between administration and effectiveness, for example by addition of protective groups.  
         [0140]    The compounds may also be formulated as pharmaceutical compositions as referred to hereinbefore, particularly such compositions as are capable of crossing the blood-brain barrier and thereby suitable for peripheral administration.  
         [0141]    In all events a suitable dose of peptide compounds according to the invention is from 10 to 100 μg/kg body weight of the animal being treated.  
         [0142]    As used herein, the term “effective to treat” in the context of a neurodegenerative disease means that amount of the compound(s) used in the treatment which causes a reduction or stabilisation or, as the case may be, prevents or delays the appearance of such symptoms as measured by standard medical or psychological criteria, for example as disclosed in Handbook of Memory Disorders (eds: A D Baddeley, B A Wilson and F N Watts), Wiley (1995), the disclosure of which is herein incorporated by reference.  
         [0143]    As used herein, the term “effective to treat” in relation to a cognitive enhancement means an amount of the compound(s) used in the treatment which causes an improvement in cognitive power as measured by psychological criteria, for example as disclosed in Handbook of Memory Disorders (eds: A D Baddeley, B A Wilson and F N Watts), Wiley (1995), the disclosure of which is herein incorporated by reference.  
     
       
       
         1 
         
           
             11  
           
           
             1  
             695  
             PRT  
             Homo sapiens  
           
            1 

Met Leu Pro Gly Leu Ala Leu Leu Leu Leu Ala Ala Trp Thr Ala Arg 
 1               5                  10                  15 

Ala Leu Glu Val Pro Thr Asp Gly Asn Ala Gly Leu Leu Ala Glu Pro 
            20                  25                  30 

Gln Ile Ala Met Phe Cys Gly Arg Leu Asn Met His Met Asn Val Gln 
        35                  40                  45 

Asn Gly Lys Trp Asp Ser Asp Pro Ser Gly Thr Lys Thr Cys Ile Asp 
    50                  55                  60 

Thr Lys Glu Gly Ile Leu Gln Tyr Cys Gln Glu Val Tyr Pro Glu Leu 
65                  70                  75                  80 

Gln Ile Thr Asn Val Val Glu Ala Asn Gln Pro Val Thr Ile Gln Asn 
                85                  90                  95 

Trp Cys Lys Arg Gly Arg Lys Gln Cys Lys Thr His Pro His Phe Val 
            100                 105                 110 

Ile Pro Tyr Arg Cys Leu Val Gly Glu Phe Val Ser Asp Ala Leu Leu 
        115                 120                 125 

Val Pro Asp Lys Cys Lys Phe Leu His Gln Glu Arg Met Asp Val Cys 
    130                 135                 140 

Glu Thr His Leu His Trp His Thr Val Ala Lys Glu Thr Cys Ser Glu 
145                 150                 155                 160 

Lys Ser Thr Asn Leu His Asp Tyr Gly Met Leu Leu Pro Cys Gly Ile 
                165                 170                 175 

Asp Lys Phe Arg Gly Val Glu Phe Val Cys Cys Pro Leu Ala Glu Glu 
            180                 185                 190 

Ser Asp Asn Val Asp Ser Ala Asp Ala Glu Glu Asp Asp Ser Asp Val 
        195                 200                 205 

Trp Trp Gly Gly Ala Asp Thr Asp Tyr Ala Asp Gly Ser Glu Asp Lys 
    210                 215                 220 

Val Val Glu Val Ala Glu Glu Glu Glu Val Ala Glu Val Glu Glu Glu 
225                 230                 235                 240 

Glu Ala Asp Asp Asp Glu Asp Asp Glu Asp Gly Asp Glu Val Glu Glu 
                245                 250                 255 

Glu Ala Glu Glu Pro Tyr Glu Glu Ala Thr Glu Arg Thr Thr Ser Ile 
            260                 265                 270 

Ala Thr Thr Thr Thr Thr Thr Thr Glu Ser Val Glu Glu Val Val Arg 
        275                 280                 285 

Val Pro Thr Thr Ala Ala Ser Thr Pro Asp Ala Val Asp Lys Tyr Leu 
    290                 295                 300 

Glu Thr Pro Gly Asp Glu Asn Glu His Ala His Phe Gln Lys Ala Lys 
305                 310                 315                 320 

Glu Arg Leu Glu Ala Lys His Arg Glu Arg Met Ser Gln Val Met Arg 
                325                 330                 335 

Glu Trp Glu Glu Ala Glu Arg Gln Ala Lys Asn Leu Pro Lys Ala Asp 
            340                 345                 350 

Lys Lys Ala Val Ile Gln His Phe Gln Glu Lys Val Glu Ser Leu Glu 
        355                 360                 365 

Gln Glu Ala Ala Asn Glu Arg Gln Gln Leu Val Glu Thr His Met Ala 
    370                 375                 380 

Arg Val Glu Ala Met Leu Asn Asp Arg Arg Arg Leu Ala Leu Glu Asn 
385                 390                 395                 400 

Tyr Ile Thr Ala Leu Gln Ala Val Pro Pro Arg Pro Arg His Val Phe 
                405                 410                 415 

Asn Met Leu Lys Lys Tyr Val Arg Ala Glu Gln Lys Asp Arg Gln His 
            420                 425                 430 

Thr Leu Lys His Phe Glu His Val Arg Met Val Asp Pro Lys Lys Ala 
        435                 440                 445 

Ala Gln Ile Arg Ser Gln Val Met Thr His Leu Arg Val Ile Tyr Glu 
    450                 455                 460 

Arg Met Asn Gln Ser Leu Ser Leu Leu Tyr Asn Val Pro Ala Val Ala 
465                 470                 475                 480 

Glu Glu Ile Gln Asp Glu Val Asp Glu Leu Leu Gln Lys Glu Gln Asn 
                485                 490                 495 

Tyr Ser Asp Asp Val Leu Ala Asn Met Ile Ser Glu Pro Arg Ile Ser 
            500                 505                 510 

Tyr Gly Asn Asp Ala Leu Met Pro Ser Leu Thr Glu Thr Lys Thr Thr 
        515                 520                 525 

Val Glu Leu Leu Pro Val Asn Gly Glu Phe Ser Leu Asp Asp Leu Gln 
    530                 535                 540 

Pro Trp His Ser Phe Gly Ala Asp Ser Val Pro Ala Asn Thr Glu Asn 
545                 550                 555                 560 

Glu Val Glu Pro Val Asp Ala Arg Pro Ala Ala Asp Arg Gly Leu Thr 
                565                 570                 575 

Thr Arg Pro Gly Ser Gly Leu Thr Asn Ile Lys Thr Glu Glu Ile Ser 
            580                 585                 590 

Glu Val Lys Met Asp Ala Glu Phe Arg His Asp Ser Gly Tyr Glu Val 
        595                 600                 605 

His His Gln Lys Leu Val Phe Phe Ala Glu Asp Val Gly Ser Asn Lys 
    610                 615                 620 

Gly Ala Ile Ile Gly Leu Met Val Gly Gly Val Val Ile Ala Thr Val 
625                 630                 635                 640 

Ile Val Ile Thr Leu Val Met Leu Lys Lys Lys Gln Tyr Thr Ser Ile 
                645                 650                 655 

His His Gly Val Val Glu Val Asp Ala Ala Val Thr Pro Glu Glu Arg 
            660                 665                 670 

His Leu Ser Lys Met Gln Gln Asn Gly Tyr Glu Asn Pro Thr Tyr Lys 
        675                 680                 685 

Phe Phe Glu Gln Met Gln Asn 
    690                 695 

 
           
             2  
             534  
             PRT  
             Chick  
           
            2 

Gly Met Asn Leu His Asp Tyr Gly Met Leu Leu Pro Cys Gly Ile Asp 
 1               5                  10                  15 

Lys Phe Arg Gly Val Glu Phe Val Cys Cys Pro Leu Ala Glu Glu Ser 
            20                  25                  30 

Asp Asn Leu Asp Ser Ala Asp Ala Glu Asp Asp Asp Ser Asp Val Trp 
        35                  40                  45 

Trp Gly Gly Ala Asp Ala Asp Tyr Ala Asp Gly Ser Asp Asp Lys Val 
    50                  55                  60 

Val Glu Glu Gln Pro Glu Glu Asp Glu Glu Leu Thr Val Val Glu Asp 
65                  70                  75                  80 

Glu Asp Ala Asp Asp Asp Asp Asp Asp Asp Gly Asp Glu Ile Glu Glu 
                85                  90                  95 

Thr Glu Glu Glu Tyr Glu Glu Ala Thr Glu Arg Thr Thr Ser Ile Ala 
            100                 105                 110 

Thr Thr Thr Thr Thr Thr Thr Glu Ser Val Glu Glu Val Val Arg Val 
        115                 120                 125 

Pro Thr Thr Ala Ala Ser Thr Pro Asp Ala Val Asp Lys Tyr Leu Glu 
    130                 135                 140 

Thr Pro Gly Asp Glu Asn Glu His Ala His Phe Gln Lys Ala Lys Glu 
145                 150                 155                 160 

Arg Leu Glu Ala Lys His Arg Glu Arg Met Ser Gln Val Met Arg Glu 
                165                 170                 175 

Trp Glu Glu Ala Glu Arg Gln Ala Lys Asn Leu Pro Lys Ala Asp Lys 
            180                 185                 190 

Lys Ala Val Ile Gln His Phe Gln Glu Lys Val Glu Ser Leu Glu Gln 
        195                 200                 205 

Glu Ala Ala Asn Glu Arg Gln Gln Leu Val Glu Thr His Met Ala Arg 
    210                 215                 220 

Val Glu Ala Met Leu Asn Asp Arg Arg Arg Ile Ala Leu Glu Asn Tyr 
225                 230                 235                 240 

Ile Thr Ala Leu Gln Thr Val Pro Pro Arg Pro Arg His Val Phe Asn 
                245                 250                 255 

Met Leu Lys Lys Tyr Val Arg Ala Glu Gln Lys Asp Arg Gln His Thr 
            260                 265                 270 

Leu Lys His Phe Glu His Val Arg Met Val Asp Pro Lys Lys Ala Ala 
        275                 280                 285 

Gln Ile Arg Ser Gln Val Met Thr His Leu Arg Val Ile Tyr Glu Arg 
    290                 295                 300 

Met Asn Gln Ser Leu Ser Phe Leu Tyr Asn Val Pro Ala Val Ala Glu 
305                 310                 315                 320 

Glu Ile Gln Asp Glu Val Asp Glu Leu Leu Gln Lys Glu Gln Asn Tyr 
                325                 330                 335 

Ser Asp Asp Val Leu Ala Asn Met Ile Ser Glu Pro Arg Ile Ser Tyr 
            340                 345                 350 

Gly Asn Asp Ala Leu Met Pro Ser Leu Thr Glu Thr Lys Thr Thr Val 
        355                 360                 365 

Glu Leu Leu Pro Val Asp Gly Glu Phe Ser Leu Asp Asp Leu Gln Pro 
    370                 375                 380 

Trp His Pro Phe Gly Val Asp Ser Val Pro Ala Asn Thr Glu Asn Glu 
385                 390                 395                 400 

Val Glu Pro Val Asp Ala Arg Pro Ala Ala Asp Arg Gly Leu Thr Thr 
                405                 410                 415 

Arg Pro Gly Ser Gly Leu Thr Asn Val Lys Thr Glu Glu Val Ser Glu 
            420                 425                 430 

Val Lys Met Asp Ala Glu Phe Arg His Asp Ser Gly Tyr Glu Val His 
        435                 440                 445 

His Gln Lys Leu Val Phe Phe Ala Glu Asp Val Gly Ser Asn Lys Gly 
    450                 455                 460 

Ala Ile Ile Gly Leu Met Val Gly Gly Val Val Ile Ala Thr Val Ile 
465                 470                 475                 480 

Val Ile Thr Leu Val Met Leu Lys Lys Lys Gln Tyr Thr Ser Ile His 
                485                 490                 495 

His Gly Val Val Glu Val Asp Ala Ala Val Thr Pro Glu Glu Arg His 
            500                 505                 510 

Leu Ser Lys Met Gln Gln Asn Gly Tyr Glu Asn Pro Thr Tyr Lys Phe 
        515                 520                 525 

Phe Glu Gln Met Gln Asn 
    530 

 
           
             3  
             5  
             PRT  
             Artificial Sequence  
             
               5-mer polypeptide  
             
           
            3 

Arg Glu Arg Met Ser 
 1               5 

 
           
             4  
             5  
             PRT  
             Artificial Sequence  
             
               5-mer polypeptide  
             
           
            4 

Ser Met Arg Glu Arg 
 1               5 

 
           
             5  
             5  
             PRT  
             Artificial Sequence  
             
               5-mer polypeptide  
             
           
            5 

Arg Ser Ala Glu Arg 
 1               5 

 
           
             6  
             17  
             PRT  
             Artificial Sequence  
             
               16-mer polypeptide  
             
           
            6 

Ala Lys Glu Arg Leu Glu Ala Lys His Arg Glu Arg Met Ser Gln Val 
 1               5                  10                  15 

Met 

 
           
             7  
             17  
             PRT  
             Artificial Sequence  
             
               16-mer polypeptide  
             
           
            7 

Met Val Gln Ser Met Arg Glu Arg His Lys Ala Glu Leu Arg Glu Lys 
 1               5                  10                  15 

Ala 

 
           
             8  
             17  
             PRT  
             Artificial Sequence  
             
               17-mer polypeptide  
             
           
            8 

Val His His Gln Lys Leu Val Phe Phe Ala Glu Asp Val Gly Ser Asn 
 1               5                  10                  15 

Lys 

 
           
             9  
             3  
             PRT  
             Artificial Sequence  
             
               3-mer polypeptide  
             
           
            9 

Arg Glu Arg 
 1 

 
           
             10  
             4  
             PRT  
             Artificial Sequence  
             
               4-mer polypeptide  
             
           
            10 

Arg Glu Arg Met 
 1 

 
           
             11  
             4  
             PRT  
             Artificial Sequence  
             
               4-mer polypeptide  
             
           
            11 

Met Arg Glu Arg 
 1