Drug-immobilized particles and a process of purifying proteins

Abstract: The invention includes a microsphere comprising styrene-glycidyl methacrylate polymer, and methods for isolation, purification and identification of receptors to a specific compound possessing physiological activity. In addition, the invention provides proteins isolated and purified using the microspheres of the invention.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microsphere which is prepared by coupling a substance possessing physiological activity to a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon through a spacer as well as a process of isolating an objective or targeted substance by using the microsphere of the invention. 2. Background Cells constituting a living body are exposed to various kinds of stimulation from the external environment all the time. To respond to such stimulation the cells lead some gene groups to expression. As a result, various living phenomena can occur, such as induction of cell growth and/or cell differentiation and maintenance of physiological homeostasis. Extracellular stimulation is transformed into an intracellular signal, which activates a specific proteinous transcription factor. The functionally activated transcription factor binds to a specific base sequence on a chromosome to induce a gene group under its regulation to expression. The product of the induced gene expression primarily functions to respond to the stimulation in some cases. In the other cases, the product of the induced gene expression further activates another transcription factor that induces another gene group under its regulation to expression to secondarily respond to the stimulation. In either case, cellular response to the stimulation from the external environment is concluded to be a functional transformation of transcription factors. In recent years, an extremely interesting fact was revealed. That is, mechanisms of action of cyclosporin A (CysA) and FK506, immunosuppressive drugs, have been revealed. See J. Lin et al., Cell , 66 :807-815 (1991); S.J. O'Keefe et al., Nature , 357 :692 (1992); and N.A. Clipstone et al., Nature, 357 :695 (1992). The first opportunity for revealing the mechanisms is the identification of intracellular receptors to these drugs. See R. E. Handschumacher et al., Science , 226, 544 (1984); and J.J. Sekierka et al., J. Immunol ., 143 :1580-1583 (1989). On the basis of these findings, a series of signaling pathways following stimulation by antigen was revealed in T-cells that are immunocompetent cells. Accordingly, investigation and identification of intracellular receptors to drugs, as well as elucidation of signaling pathways, are expected to be further developed into developmental research of new drugs targeting the signaling pathway and research for novel drug designs. Conventional methods of isolation and purification of intracellular receptors to drugs are fractionation of crude cell extracts by using various columns, followed by detection of factors binding to labeled drugs in each fraction. Therefore, two steps of procedure, the first one was the isolation and purification using columns and the second one was the assay for binding activity against drugs, have been necessarily performed until now. Accordingly, for the purpose of purification, identification and functional analysis of receptors to a specific drug, located within cells or on cellular membrane, certain drug-immobilized microspheres have been designed and constituted. JP 04218772 A describes a reagent for diagnosis which utilizes an antigen-antibody reaction. The reagent consists of a polymer such as styrene / glycidyl methacrylate which is bound to an immunoactive substance via an organic compound having a hydroxyl group. JP 63017692 A describes a method to sustain activity of an enzyme for a long period of time by linking the enzyme at one end to a spacer consisting of a diglycidyl ether and immobilizing the enzyme at the other end by covalent bonds. DERWENT ABSTRAT (1992-102210) describes a DNA immobilized microsphere made of a styrene-glycidyl methacrylate polymer which is used for isolating a DNA transcriptional factor. SUMMARY OF THE INVENTION According to the conventional methods of purification, it can take an exceedingly long time to purify drug-binding factors from crude cell extracts and moreover, the yield of factors is quite low due to repeated fractionation using various columns. Therefore, a huge amount of starting material is necessary for the determination of an amino acid sequence of drug-binding factors. It also can be most difficult to establish an assay method for binding activity of receptors against drugs. because obtained drug receptors are usually not identified. Conventional methods of determination of binding of receptors to drugs are the filter binding method and gel filtration method which utilize the fact that drug receptors (proteins) bind to filters and that sizes of drugs binding to receptors become larger than free drugs and receptors. However, some receptors do not bind to filters or other receptors change their conformation after binding to filters and discharge drugs. Therefore, properties of drug receptors should be preliminarily investigated in the conventional methods. The present invention aims at solving the above mentioned problems to provide drug-immobilized particles and a process of purifying proteins. According to the present invention, a microsphere comprising a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon is provided, and isolation, purification and identification of receptors to a specific compound possessing physiological activity are easily performed. In addition, the present invention is concerned with microspheres prepared by coupling substances and processes for the purification of proteins using the microspheres of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a scheme for the preparation method of a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon and a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon connected with a spacer. Figure 2 is a scheme for the isolation method of a protein using microspheres of the present invention. Figure 3(A) shows the effects of E3330 on AP endonuclease activity of Ref-1. Figure 3(B) shows the effects of NH 2 -E3330 on AP endonuclease activity of Ref-1. Figure 4 shows the enhancement of the DNA-binding activity of NF-κB by recombinant rRef-1 and the repression of the recombinant rRef-1 activity by E3330. Figure 5 shows the effects of recombinant rRef-1 on the DNA-binding activities of r-p65 and/or r-p50. Figure 6 shows the procedure and the results of the GST pull-down assay. Figure 7 is a scheme for the structure of each recombinant protein of Ref-1 expressed by various deletion mutants. Figure 8 shows the results of binding assays against E3330 using the recombinant proteins of Ref-1 expressed in E . coli by various deletion mutants. Figure 9 shows the results of binding assays against E3330 using the recombinant proteins of Ref-1 expressed in E . coli by various deletion mutants. Figure 10 shows the results of identification of E3330-binding domain using the recombinant proteins of Ref-1 expressed by various deletion mutants. Figure 11 shows the results of identification of E3330-binding domain using the recombinant proteins of Ref-1 expressed by various deletion mutants. Figure 12 shows the summary of E3330-binding domain in Ref-1 identified using the recombinant proteins of Ref-1 expressed by various deletion mutants. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a microsphere prepared by coupling a compound possessing physiological activity to a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon through a spacer. In addition, the present invention provides a process of isolating a substance by using a microsphere prepared by coupling a compound possessing physiological activity to a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon through a spacer. More particularly, the present invention is concerned with a process of isolating an objective substance that can adhere to a substance possessing physiological activity from a mixture containing the objective substance by using a microsphere prepared by coupling the substance possessing physiological activity to a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon through a spacer. In more detail, the process of isolating a substance according to the present invention includes mixing crude cell extracts and microspheres prepared by coupling compounds possessing physiological activity to styrene-glycidyl methacrylate polymers covered with glycidyl methacrylate thereon through spacers, followed by isolation of microspheres, and then, eluting the objective substance adhering to the substances possessing physiological activity on the microspheres, to provide a useful process of isolating an objective or targeted substance. As the substance forming particles of microspheres in the present invention, styrene-glycidyl methacrylate polymers covered with glycidyl methacrylate thereon are employed. There is no special restriction on their states of polymerization or morphological properties in the preparation method in which formed particles should be isolated from a liquid phase. However, it is preferable that particles are prepared by soap-free emulsion polymerization according to the method developed by Inomata et al. such as described in Y. Inomata et al., Anal . Biochem ., 206 :109 (1992). The spacer in the present invention is a chemical compound interposed between the above particle and a compound possessing physiological activity as discussed in more detail herein. A preferable spacer is a compound possessing one or more functional groups, such as an amino group, carboxyl group and epoxy group, on both its ends before binding to a particle and a substance possessing physiological activity. As for the selection of a spacer in the present invention, there is no special restriction but the spacer should be a substance connecting the above styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon with a substance possessing physiological activity at an appropriate distance. A particularly preferred spacer is an ethylene glycol diglycidyl ether derivative. As for the selection of a substance possessing physiological activity (which will be occasionally abbreviated as physiologically active substance, hereinafter) in the present invention, there is no special restriction but the substance should possess activity in a living body and interaction and/or affinity to another substance of intra- or extra-living body. It is further preferable to employ a compound that specifically binds to a receptor located within cells or on cellular membrane. In a case where the substance possessing physiological activity has functional groups in its molecular structure which are connectable with the above spacer, such as an amino group and hydroxyl group, the functional group is utilized as a group connected with the spacer. In the other case where the substance possessing physiological activity has no functional group in its molecular structure which is connectable with the above spacer, a functional group connectable with the above spacer is additionally introduced into the concerned physiologically active substance and then, it is connected with the spacer. In either cases it is necessary to pay attention not to inactivate the physiological activity of the concerned physiologically active substance by connecting the physiologically active substance with a spacer. Namely, it is important to confirm that an objective or desired physiological activity is not inactivated by connecting the physiological active substance with a spacer. As the substance possessing physiological activities in the present invention, for example, 3-[ (5-(2,3-dimethoxy-6-methyl-1,4-benzoquinonyl)]-2-nonyl-2-propionic acid (which will be occasionally abbreviated as E3330, hereinafter or derivative thereof) may be suitably employed. A preparation method of a microsphere consisting of a compound possessing physiological activity coupled to a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon through a spacer according to the present invention is as follows. A particle composed of a styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon (which will be occasionally abbreviated as a SG-particle, hereinafter) is prepared according to an ordinary method. However, for the purpose of the SG-particle easily binding to a spacer, it is especially preferable that the glycidyl group on the SG-particle is ring-opened with appropriate reagents, such as ammonium hydroxide, followed by the introduction of a preferable functional group for binding to a spacer, if necessary. Subsequently, a spacer is bound to the SG-particle, followed by reaction with a substance possessing physiological activity or its derivatives. Thus, a microsphere of the present invention is prepared. In these reactions, various solvents, such as dioxane, DMSO and water, are suitably employed, if necessary. Figure 1 shows an example for the preparation of a microsphere of the present invention. Appropriate compounds, such as styrene and glycidyl methacrylate, are polymerized according to an ordinary method, such as emulsion polymerization, to prepare a SG-particle with a functional glycidyl group projecting on its surface. Sizes of particles, are selectively varied according to circumstances. However, the sizes (lengths) are ordinarily about 0.05 to 0.5 µm and preferably they are about 0.1 to 0.3 µm. The prepared SG-particle is reacted with a compound employed as a spacer, such as ethylene glycol diglycidyl ether (EDGE), to bind a spacer to the SG-particle. Thus, a spacer-binding SG-particle (SG-EGDE particle) is obtained. Then, the obtained particle is reacted with a physiological active substance possessing a reactive functional group, such as amino group, preferably in an organic solvent, such as dioxane. Thereby, a microsphere of the present invention, that is a physiologically active substance-immobilized latex particle, is prepared. As for the selection of a mixture containing an objective substance for isolation according to the present invention, there is no special restriction but the mixture should contain a substance possessing an affinity for and selective binding ability to a physiologically active substance employed in the preparation of a microsphere. It is ordinarily preferable that cell extracts, especially the cell extracts from the concerned physiological active substance-acting sites are employed as a mixture. The isolation procedure in the present invention is conducted as follows. Physiologically active substance-binding microspheres and a mixture containing proteins, such as cell extracts, are mixed and stirred, if necessary, for several minutes to several hours. The microspheres to which proteins are adhering are separated and rinsed with a buffer solution, if necessary. Then, adhering proteins are eluted from the microspheres by using an appropriate solution, such as a potassium chloride solution. There is no special restriction on the conditions under which the objective substance which is to be isolated adheres to a physiological active substance employed in the preparation of a microsphere. Any kinds of adhering, such as chemical bonds (hydrogen bond, etc.) and chemical or physical adsorption, may be suitably employed. Figure 2 shows an example for the isolation of a protein according to the process of the present invention. In this example, E3330 is employed as the physiologically active substance. An obtained protein is detected by using SDS-PAGE or other suitable methods. In addition, an obtained protein is purified according to an ordinary method, such as chromatography, if necessary. Proteins isolated according to a process of the present invention are considered to be receptors to the physiologically active substance of microspheres. However, proteins isolated according to a process of the present invention are not limited to the receptors to the physiological active substance employed in the preparation of microspheres. Any kinds of substances possessing chemical, physical or biological affinities to the physiological active substance employed in the preparation of microspheres are able to be isolated according to a process of the present invention. An obtained protein is purified, if necessary, and can be subjected to determination of its amino acid sequence. In addition, genes coding for the concerned protein can be cloned according to an ordinary biotechnological procedure, and their base sequences can be determined. Furthermore, according to an ordinary gene-technology procedure, proteins or peptides composed of partial amino acid sequences of the concerned protein are expressed and an active moiety of the receptor protein can be determined. These procedures are also described in the working examples which follow, giving examples in which E3330 is employed as the physiologically active substance. Structures of obtained receptors or domains composed of active moieties of the receptors can be elucidated through NMR analysis, X-ray crystal analysis or simulation analysis using computers on the basis of their amino acid sequences. For example, the protein. Ref-1, which is isolated according to a process of the present invention in which E3330 is employed as the physiologically active substance in the preparation of microspheres, is suggested to possess such structures as β-sheet/α-helix/β-sheet in the domain of 82 a.a. to 106 a.a. through the above structural analyses. The amino sequence of Ref-1 (SEQ ID NO:4) is set forth in Example 9 which follows, Regions of 72 to 88 amino acid residues (SEQ ID NO:13) of Ref-1 are of particular interest and set forth in Example 14 which follows. Further, in the processes of the invention the substance that can adhere to the substance possessing physiological activity may be a protein or peptide which has a sequence that is partially deleted, added or substituted with respect to SEQ ID NO:4 (the sequence of which is set forth in Example 9 which follows), and such peptides preferably comprise at least about 10 amino acids, more preferably at least about 15 to 50 amino acids, still more preferably at least about 40 to about 100 amino acids. Such peptides preferably have at least about 70 percent homology (sequence identity) to SEQ ID NO:4, more preferably at least about 80 or 90 percent sequence homology to SEQ ID NO:4. Also, such preferred peptides preferably will contain a region that has substantial sequence identity (e.g. about 80, 90 or 95 percent or more sequence identity) to SEQ ID NO:13 (which seqnece is set forth in Example 14 which follows). On the basis of the results of such stereochemical structural analyses and genetic analyses, one can readily determine which amino acid residue binds to a physiologically active substance employed in the preparation of microspheres among amino acids of the proteins or active moieties isolated according to a process of the present invention. In addition, one can investigate the interaction between the concerned physiologically active substance employed in the preparation of microspheres and amino acids of the isolated protein at molecular and/or atomic levels. Furthermore, it will be practicable to analyze chemical kinetics of the binding reactions. Many findings obtained from the above studies will not only identify the protein that is the receptor to the physiologically active substance employed in the preparation of microspheres but also reveal the mechanism of action of the concerned physiologically active substance in a living body. Moreover, it will be practicable to conduct a novel drug design by accurately controlling a new drug at an atomic level, the binding mechanism of which is different from that of the physiological active substance employed in the preparation of microspheres concerning the interaction with the protein of the receptor. Various drugs designed according to the above method reasonably possess different functions from those of the physiological active substance employed in the preparation of microspheres. Therefore, the drugs will be utilized more properly for various purposes. Thus, the process of the present invention is extremely important for a novel procedure of the drug designs. In addition, the present invention provides a process for isolation and detection of substances possessing affinity to a receptor by employing a protein with an ability of the concerned receptor as a substance possessing physiological activity coupled with microspheres. As a substance with an ability of a receptor, a whole receptor protein may be employed, but it is preferable to employ a domain that is obtained by trimming the receptor protein to an active domain of several tens (e.g. about 20 to 60) of amino acid residues as an active moiety of the concerned receptor. Therefore, screening examinations on drugs specifically binding to the concerned receptor or its active domain will be practicably performed, according to the above methods. Thus, chemical synthetic substances expected to be useful drugs are easily isolated and detected among various drug libraries by conducting the screening examinations. The substance isolated and detected through the above screening examinations should possess affinity for the protein which has an ability of a receptor and is coupled with microspheres. Therefore, the substance will be developed to be an effective ingredient of a medicine for promotion or inhibition of the activity of the concerned receptor. According to the present invention, a microsphere composed of styrene-glycidyl methacrylate polymer covered with glycidyl methacrylate thereon is provided, and purification and identification of receptors to which a specific compound possesses physiological activity and which is located within cells or on 'cellular membrane, are easily performed. Particles coupled with a substance possessing physiological activity specified in the present invention provide epoch-making and significant effects, that is, the isolation and purification of a receptor to a drug are able to be conducted simultaneously with the evaluation of its binding activity to the drug, the time required for isolation and purification of drugs is remarkably shortened and the recovery ratio is extremely improved, and the investigation on the assay method for binding activity against a drug is not necessarily performed anymore. In addition, the present invention provides that an intracellular receptor to a drug or a compound can be isolated and purified by using the drug- or the compound-immobilized particles and then the structure and functions of the receptor can be determined. Furthermore, the present invention is extremely useful for the development of novel drugs with superior functions on the basis of many findings obtained from the structural and functional analyses on receptors to drugs according to the process of the present invention. The present invention is further illustrated by the following Examples. These Examples are provided to aid in the understanding of the invention and are not to be construed as limitations thereof. Example 1 (Preparation of styrene-glycidyl methacrylate polymers) Styrene (St; Wako Pure Chemicals. It was used after distillation under reduced pressure of 21.5 mmHg at 46°C), glycidyl methacrylate (GMA; Wako Pure Chemicals. It was used after distillation under reduced pressure of 2 mmHg at 33°C), divinyl-benzene (DVB; Tokyo Kasei), 2,2'-azobis (2-amidinopropane dihydrochloride) (V-50; Wako Pure Chemicals) and water were used according to the following compositional formula: St/GMA/DVB/V-50/H 2 O = 1.2/1.8+0.3/0.04/0.06/110 (g) After substituting the gas in the mixture with nitrogen gas polymerization was conducted at 70°C for 24 hours. To polymerize the mixture, the soap-free emulsion polymerization was conducted according to the method developed by Inomata et al. (Y. Inomata et al., Anal . Biochem ., 206 :109 (1992)). Two hours after the initiation of polymerization, 0.3 g of GMA was added to the mixture to thoroughly cover the whole surface of the obtained polymers with GMA. The obtained polymers (SG-particles) were settled by centrifugation (15,000 rpm for 15 minutes at 4°C), followed by decantation, and then re-suspended in 200 ml of water. The above procedure was repeated three times to wash the SG particles and finally they were suspended in water. In order to introduce amino groups into the washed SG-particles (0.25 g), NH 4 OH (55.3 mmol; corresponding to a fifty times larger amount compared with the GMA unit) was added to the particles, followed by adjustment of the pH value to 11 with 1N HCl. The mixture was stirred using a stirrer at 70°C for 24 hours so that the epoxy group of GMA was ring-opened. Example 2 (Immobilization of a spacer) Next, an example for immobilization of ethylene glycol diglycidyl ether (EGDE; Wako Pure Chemicals), which was employed as a spacer, onto the SG-particles obtained in the working example 1 is shown in the following. An excess amount of EGDE, that was hundred times larger than the amount (mol) of amino groups on the surface of about 62.5 mg of SG-particles prepared in Example 1 above, was added to the SG-particles and then, the mixture was stirred at 30°C for 24 hours at pH 11 (adjusted with 1N NaOH) so that an epoxy group of EGDE was covalently bound to an amino group on the surface of the SG-particle. In order to avoid simultaneous immobilization of two epoxy groups at both ends of an EGDE molecule onto SG-particles, an excess amount of EGDE was added. Under these reaction conditions about 1 mmol of EGDE was immobilized onto 1 g of the particles. After the reaction was finished, the SG-particles were washed three times with water using a centrifugation procedure. Thus, the obtained spacer-immobilized particles, that are SG-EGDE particles, were used as particles to which a physiologically active compound is immobilized. Example 3 (Immobilization of an amino derivative of E3330 with a spacer) (a) (Introduction of an amino group into E3330) As E3330 does not possess an appropriate functional group, it is difficult to immobilize E3330 onto SG-EGDE particles. Therefore, NH 2 -E3330 was synthesized by introducing an amino group into E3330. (b) (Confirmation of the functions of NH 2 -E3330) The functions of NH 2 -E3330 were compared with those of E3330 with respect to the transcriptional activation ability of NF-κB. In order to examine their functions transfection experiments were conducted by introducing the recombinant plasmid DNA possessing luciferase genes regulated by NF-κB into Jurkat cells. As a result, it was ascertained that NH 2 -E3330 reduced not so strongly as E3330 but certainly reduced the transcriptional activation ability of NF-κB. Thus, it was confirmed that the amino group induced into E3330 did not inhibit the binding of E3330 to intracellular receptors. (c) (Immobilization of NH 2 -E3330 to SG-EGDE particles) Ten mg of SG-EGDE particles obtained in the working Example 2 above was washed three times with 1 ml of 1,4-dioxane using a centrifugation procedure. After washing, 500 µl of 1,4-dioxane solution containing 10 µmol of NH 2 -E3330 was added to the packed SG-EGDE particles to disperse the SG-EGDE particles in the above solution, followed by reaction at 37°C for 24 hours, in order to immobilize NH 2 -E3330 to epoxy groups of EGDE on the surfaces of the SG-EGDE particles. After the reaction was finished, the particles were washed three times with 20 µl of 1,4-dioxane using a centrifugation procedure. Then, the particles were dispersed in I ml of 1M Tris-HCl buffer solution (pH 7.4), allowed to stand still at 4°C for at least 24 hours, in order to thoroughly mask the intact epoxy groups on the surfaces of SG-EGDE particles. The drug-immobilized particles were stored at 4°C at a dark place. The centrifugation procedure for washing was conducted at 15,000 x g for 5 minutes at room temperature. Under these reaction conditions about 0.15 mmol of NH 2 -E3330 was immobilized onto 1 g of the SG-EGDE particles. The above immobilized amount of NH 2 -E3330 was obtained by subtracting the amount of NH 2 -E3330 not bound to the SG-EGDE particles from the starting amount of NH 2 -E3330. NH 2 -E3330 shows the maximum absorption at a wavelength of 254.5 nm, so that each amount of NH 2 -E3330 can be determined by measuring the absorbance at a wavelength of 254.5 nm on each sample, such as the starting solution, not-binding fraction and washing fractions. The measurement of the absorbance was conducted with a DU-64 Spectrophotometer (BECKMAN). Example 4 (Preparation of a crude nuclear extract and a cytoplasmic fraction) The culture medium suspension of Jurkat cells (2 x 10 10 cells), which were cultured in a suspension scale of 8 liters, was centrifuged using 500-ml-centrifugation tubes (NARGEN) at 500 x g for 10 minutes at 4°C for the purpose of collecting the cells. The collected cells were washed two times with PBS(-). The washing procedure was conducted using 50-ml-centrifugation tubes and the centrifugation conditions were 700 x g for 5 minutes at 4°C. Then, the final packed cell volume (PCV) was measured. Buffer A (10 mM Hepes pH 7.9, 1.5 mM MgCl 2 , 10 mM KCl, 0.5 mM DTT), at a four times larger volume than that of the PCV, was added to the packed cells to suspend the cells. The cell suspension was allowed to stand still on ice for 20 minutes so that the cells were swollen. The cell membranes of the swollen cells were broken by 20 strokes using a 40-ml-B-type Dounce homogenizer (WHEATON), transferred to a 50-ml-centrifugation tube (NARGEN) and centrifuged at 4,200 x g for 6 minutes at 4°C to separate the nuclear fraction (pellet) from the cytoplasmic fraction (supernatant). Buffer A, at a five times larger volume than that of the PCV, was added to the isolated nuclear fraction to re-suspend the nuclei. The nuclear suspension was centrifuged at 4,200 x g for 6 minutes at 4°C to remove the contaminated cytoplasmic fraction. The obtained nuclear pellet was dispersed in Buffer C (20 mM Hepes pH 7.9, 25% (v/v) glycerol, 0.42 M NaCl, 1.5 mM MgCl 2 , 0.2 mM EDTA, 0.5 mM PMSF, 1 mM, DTT), at the same volume as that of the PCV, and thoroughly suspended by 10 strokes using a B-type Dounce homogenizer. The suspension was slowly stirred for 30 minutes at 4°C to extract nuclear components. The extract was transferred to a 50-ml-centrifugation tube and centrifuged at 16,000 x g for 30 minutes at 4°C. The obtained supernatant was dialyzed two times against one liter of Buffer D (20 mM Hepes pH 7.9, 20% (v/v) glycerol, 0.1 M KCl, 0.2 mM EDTA, 0.5 mM PMSF. 1 mM DTT) for 2.5 hours at 4°C. On the other hand, the cytoplasmic fraction was transferred to another 50-ml-centrifugation tube and centrifuged again at 4,200 x g for 6 minutes at 4°C. The obtained supernatant was transferred to an ultra-centrifugation tube (BECKMAN: No. 355620) and ultracentrifuged at 35 krpm for one hour at 4°C (BECKMAN: Rotor Type 35). The obtained supernatant was dialyzed in the same manner as described above for the nuclear extract. After the completion of the dialyses, the nuclear extract and the cytoplasmic fraction were centrifuged at 14,000 x g for 30 minutes at 4°C. The obtained supernatants were used as the samples of a nuclear extract and a cytoplasmic fraction, respectively. These samples were subdivided into appropriate aliquots and stored at -80°C until use. In usual preparations, about 20 ml each of the nuclear extract and the cytoplasmic fraction at a protein concentration of 5 mg/ml and 10 mg/ml, respectively, were obtained in the scale of this working example. Example 5 (Fractionation of a nuclear fraction and cytoplasmic fraction using phosphocellulose) Cationic-ion exchange phosphocellulose (P11: Whatman) was employed for the fractionation of cell extract. Procedures for the fractionation were always conducted at 4°C. Distilled water was added to 10 g of dried phosphocellulose to obtain 500 ml of a phosphocellulose suspension. The suspension was well stirred and allowed to stand still for 30 minutes. To remove phosphocellulose with smaller particle sizes the supernatant of the suspension was removed and distilled water of the same volume as the removed supernatant was added to the remaining phosphocellulose. These procedures were repeated several times in order to obtain the phosphocellulose with a uniform particle size. Next, in order to activate the phosphocellulose, each one gram of the phosphocellulose with a uniform particle size on the basis of the dried weight was suspended in 50 ml of 0.5 N HCl solution and the suspension was allowed to stand for 5 minutes. The phosphocellulose was collected on two sheets of filter paper (Whatman: 3MM Chr) placed in a Buchner funnel and washed with an excess amount of distilled water until the pH value recovered to a neutral range. The pH value of the filtrate was measured using BTB pH test paper to confirm the pH value. The phosphocellulose on the filter paper was transferred into a beaker and resuspended in 0.5 N NaOH solution. The suspension was allowed to stand for 5 minutes. The phosphocellulose was washed in the same manner as described above. Finally, the phosphocellulose was suspended in 0.5 N HCl solution once more and washed again. As a result, activated phosphocellulose was obtained. The activated phosphocellulose was filled into a column (BIORAD: 731-1550), so that the column volume became 10 ml. The filled column was washed with 100 ml of Buffer D (20 mM HEPES (pH 7.9), 20% (v/v) glycerol, 1 M KCl, 1.2 mM EDTA, 0.5 mM PMSF, 1 mM DTT) containing 1 N KCl and then equilibrated with 100 ml of Buffer D containing 0.1 M KCl. Each 5 ml of a nuclear extract and a cytoplasmic fraction from Jarkat cells was applied on the column. The column was eluted stepwise with Buffer D at various salt concentrations of KCl, that is, the elution was conducted stepwise with Buffer D containing 0.1 M KCl, 0.32 M KCl, 0.35 M KCl or 1 M KCl. Each eluted fraction was dialyzed against Buffer D, subdivided into appropriate aliquots and stored at -80°C until use. The flow rate was adjusted to 8 ml/minute. To confirm the completion of each step of protein-elution with each salt concentration buffer, absorbance at a wave-length of 280 nm was measured with an UV detector (GILSON: MODEL 111B) during the fractionation. First, 5 ml of a cytoplasmic fraction (protein concentration: 12 mg/ml) was applied on the above column. As a result, 30 ml of 0.1 M fraction (P.1; protein concentration: 1.12 mg/ml), 39 ml of 0.3 M fraction (P.3; protein concentration: 0.23 mg/ml), 37 ml of 0.5 M fraction (P.5; protein concentration: 0.07 mg/ml), and 53 ml of 1.0 M fraction (P1.0; protein concentration: 0.02 mg/ml) were obtained. Next, a nuclear extract fraction was also fractionated using the phosphocellulose column in the same manner. Example 6 (Isolation of proteins using microspheres) A process of isolation and purification of E3330-binding proteins using E3330-immobilized particles is illustrated in Figure 2 and described below. (a) Microspheres and a fraction obtained through the fractionation using a phosphocellulose column in working Example 5 above were mixed and centrifuged to separate substances binding to E3330 which was immobilized on particles from the mixture. The centrifugation procedure for separation was conducted at 15,000 x g for 5 minutes at 4°C. All above procedures were conducted at 4°C. (b) First, 1 mg each of E3330-not-immobilized SG-EGDE particles and E3330-immobilized SG-EGDE particles were washed three times with 400 µl of Buffer D' (20 mM HEPES (pH 7.9), 10% (v/v) glycerol, 0.1 M KCl, 0.2 mM EDTA, 1 mM DTT) in which glycerol concentration was 10% instead of 20% in Buffer D. The E3330-not-immobilized SG-EGDE particles were dispersed in 1 ml of 1 M Tris-HCl buffer solution (pH 7.4) and allowed to stand still at 4°C for at least 24 hours in order to mask epoxy groups of EGDE. These particles were used as a reference control against E3330-immobilized SG-EGDE particles. To these washed E3330-not-immobilized SG-EGDE particles and E3330-immobilized SG-EGDE particles, 200 µl each of P.1, P.3, P.5 or P1.0, which were obtained through the fractionation of a cytoplasmic fraction using a phosphocellulose column, was added and mixed. These mixtures were allowed to stand still for 30 minutes with intermittently stirring at intervals of 10 minutes in order to bind proteins possessing E3330-binding ability to E3330 which was immobilized on the particles. The mixture was centrifuged and the supernatant was discarded. The pellet was washed three times with 500 µl of Buffer D' to remove non-specific binding substances as much as possible. Subsequently, the washed pellet was eluted three times with Buffer D' containing 50 µl of 1 M KCl, so that the proteins possessing E3330-binding ability were dissociated and eluted from E3330 immobilized on the particles. The wash solution and eluate solutions were stored at -80°C. (c) The detection of the proteins possessing E3330-binding ability was conducted by electrophoresis on a 10% SDS-polyacrylamide gel (SDS-PAGE) using 25 µl each of the first, second or third eluate solution obtained from the E3330-immobilized SG-EGDE particles and E3330-not-immobilized SG-EGDE particles used as a reference control. The proteins possessing E3330-binding ability were collected with more than 70% yield in the first elution and further collected with more than 90% yield in the first and second elutions. In this experiment, 4 x SDS sample dye (200 mM Tris-HCl (pH 6.8), 500 mM β-mercaptoethanol (β-ME), 8% SDS, 0.4% BPB) was used instead of 4 x SDS sample dye in order to prevent the electrophoresis from being disordered due to such high concentration of the salts. The electrophoresed gel was subjected to silver staining and the proteins specifically binding to E3330 were identified by comparison with the results of the reference control. As a result, in the P.5 fraction a protein band with a molecular weight of about 38 kDa which was not observed in the reference control was clearly observed, suggesting that the protein was specifically bound to E3330. Concerning the other fractions, there were no significant differences in the protein bands of the eluate solution with 1 M KCl, compared with the results of the reference control. The above procedure was repeated and finally 5 µg of E3330-binding protein was obtained. Example 7 (Evaluation of specific-binding abilities against E3330) Two kinds of experiments were conducted to confirm that the protein with a molecular weight of about 38 kDa in the P.5 fractions from cytoplasmic fractions and nuclear extracts of Jurkat cells was specifically bound to E3330. The first one was a competitive binding-inhibitory experiment. When upon the addition of the P.5 fraction of the cytoplasmic fraction (fractionated using the phosphocellulose (200 µl)) to SG-EGDE particles free E3330 at the same molar amount as that of the NH 2 -E3330 immobilized on the particles or free NH 2 -E3330 at a ten times larger molar amount than that of the immobilized NH 2 -E3330 were added simultaneously, the protein possessing specific binding ability to E3330 immobilized on the particles would be bound to free E3330 or free NH 2 -E3330, resulting in a lower yield in the isolation using the particles. As E3330 was insoluble in water, E3330 was dissolved in EtOH, diluted with Buffer D and then added to the particles (the final concentration of EtOH was 2%). As a result, it was confirmed that the yield of the protein with a molecular weight of about 38 kDa was lowered, indicating that the protein was specifically bound to E3330. Example 8 Next, an experiment was conducted wherein the amount of NH 2 -E3330 immobilized on the SG-EGDE particles was varied. In the present study the maximum amount of the immobilized E3330 derivatives is 0.4 µmol per 1 mg of SG-EGDE particles. Under these conditions, about 5 to 6 molecules of E3330 derivatives are immobilized on 1 mm 2 of the surface of the particles. This experimental study was conducted with an amount of the immobilized E3330 derivatives of 0.2 µmol or 0.4 µmol per 1 mg of SG-EGDE particles. However, in the present invention, amounts of compounds immobilized on the particles are varied depending on the properties of the immobilized compounds, conditions of immobilization and so on. The amounts are not defined and generally vary between a few molecules and hundred molecules. As a result, it was confirmed that the yield of the protein with a molecular weight of about 38 kDa increased as the immobilized amount increased. The identification of the specific protein was conducted by electrophoresis using SDS-PAGE. Example 9 (Determination of the amino acid sequence of the E3330-binding protein) The obtained E3330-binding protein was dialyzed two times against one liter of Buffer D for 2.5 hours at 4°C in order to remove the KCl that was used as an eluent solution of such a high concentration as 1.0 M of KCl. In order to concentrate the sample, after the dialysis was completed, the dialyzed sample was transferred into an ultra-centrifugation tube (BECKMAN: No. 331372) to which trichloroacetic acid (TCA: MERCK) and deoxycholic acid (DOC: Sigma) were added so that the final concentrations were 10% and 0.8 mg/ml, respectively. The mixture was stirred well and allowed to stand still for 30 minutes on ice. Then, the mixed sample was ultra-centrifuged at 28 krpm, for 15 minutes at 4°C (BECKMAN: Rotor SW 41 Ti). The obtained precipitate was dissolved in 10 ml of acetone. After standing still for 10 minutes at room temperature, the solution was ultra-centrifuged again. The obtained precipitate was allowed to stand still for 10 minutes on ice to be dried. Thus, the sample was concentrated. Finally, the concentrated sample was dissolved in 50 µl of 1 x SDS sample dye and transferred into a sample tube (Eppendorf: No. 0030 102.002). In this procedure, the remaining sample in the ultracentrifugation tube was rinsed with additional 10 µl of 1 x SDS sample dye and pooled in order to collect the remaining sample. As TCA and DOC remained in the sample, 3 µl of 1 M Tris-HCl (pH 7.9) was added for the purpose of neutralization. Then, the sample was stored at -80°C. To analyze the amino acid sequence of the E3330-binding protein, the protein was subjected to peptide-fragmentation. First, the sample was electrophoresed with pre-stained SDS-PAGE standard (BIO-RAD) on a 10% SDS-polyacrylamide gel and the protein was transferred onto a PVDF membrane (MILLIPORE: immobilon transfer membrane) from the polyacrylamide gel using a Mini trans blott module kit (BIO-RAD). Prior to the blotting, the PVDF membrane was soaked in methanol for 15 seconds and subsequently it was soaked in a blotting buffer solution (10 mM CAPS-NaOH (pH 11), 10% methanol) for more than 5 minutes. The blotting apparatus was placed on the anode side down and two sheets of fiber pad, two sheets of 3 MM paper, PVDF membrane, the gel, two sheets of 3 MM paper and two sheets of fiber pad were laid in the blotting apparatus in that order, avoiding bubbles. The apparatus was placed in an electrophoretic bath filled with a blotting buffer solution. The bath was chilled with ice and 0.3 A of electric current was turned on for 30 minutes to blot the protein onto the PVDF membrane. In case where the proteins blotted onto the membrane were enzymatically digested, Lysil Endopeptidase (Wako Pure Chemicals) was employed as the digestive enzyme. As a buffer solution for the digestive reaction 20 mM Tris-HCl (pH 8.8) with 8% acetonitrile was used. The amount of the enzyme was one tenth of the protein for the digestion (g/g). First, a half amount of the enzyme was added, followed by stirring with shaking for several seconds. Then, the other half of the enzyme was added to the above, followed by stirring with shaking at 37°C for about 24 hours under prevention of light-transmittance. After completion of the reaction, the digested fluid was carefully collected, paying attention to the PVDF membrane not to be sucked up. The remaining PVDF membrane was washed with 100 µl of 8% acetonitrile. The washing fluid was collected in the same manner as described above and pooled. These fluids were centrifuged at 15,000 x g for 2 minutes at room temperature in order to completely separate the contaminated PVDF membrane pieces and remove them. In case where the supernatant is directly applied on high performance liquid chromatography (HPLC), highly hydrophilic peptides are eluted in a passing through fraction. Therefore, the supernatant was concentrated by decompression so that the concentration of acetonitrile was reduced. To the concentrated supernatant 0.1% trifluoroacetic acid (TFA) was added so that the volume became 205 µl, which was applied on reversed phase HPLC (ABI: model 130A). A C8 column (PERKIN ELMER: 0711-0056) was employed. The flow rate was 50 µl/min and the column temperature was 35°C. Elution was conducted as follows; the mobile phase was 0.1% TFA and the concentration gradient of acetonitrile in the mobile phase was 0% for the first 5 minutes, 0 to 35% for the next 30 minutes and 35 to 70% for the last 20 minutes. Monitoring protein was conducted using ultraviolet absorption at a wave-length of 215 nm. Each eluted peptide fraction was collected at each time and stored at -80°C. A gas phase protein sequencer (ABI: model 477A protein sequencer) was used for amino acid sequence analysis of the peptides. Polybrene (ABI) was used as the carrier. As a result, three amino acid sequences of peptides were determined. The obtained sequences were GLDWVK (SEQ ID NO: 1)/AAGEGPALYEDPPD (SEQ ID NO: 2)/GAVAEDGDEL (SEQ ID NO: 3). These amino acid sequences were analyzed using a computer and determined to be completely identical with the amino acid sequences of the N-terminal flanking region of the redox protein Ref-1 which participates in oxidation-reduction reactions. Ref-1 has been reported to possess 318 amino acid residues with a molecular weight of 38 kDa. The protein obtained through the isolation and purification in this working example possesses the same molecular weight. Therefore, the E3330-binding protein is probably identical with Ref-1. the amino acid sequence of Ref-1 is as follows (SEQ ID NO:4; length of the sequence:318 amino acids): Example 10 (Production of the E3330-binding protein by genetic recombination) (a) The procedures for preparation of cDNA clones of the E3330-binding protein and analysis of the binding activity of the protein produced through gene expression of recombinant cDNA clones in Escherichia coli (E . coli) against E3330 were conducted as follows. On the basis of the determined amino acid sequences the E3330-binding factor is considered most probably to be Ref-1. Therefore, cDNA clones of Ref-1 were prepared and the recombinant cDNA clones were expressed in E.coli to obtain recombinant proteins, Then, the binding activity of the protein against E3330 was investigated. (b) First, RNA was prepared. When RNA was prepared, ultra-centrifugation tubes (BECKMAN: 331372), bucket (BECKMAN: for SW 41Ti) and bucket cap (BECKMAN: for SW 41Ti) were preliminarily soaked in 2% absolve solution (DUPONT; 20 ml of absolve was diluted with distilled water to 1000 ml) on the day before the preparation to remove contaminating RNase activity as much as possible. They were thoroughly rinsed with distilled water just before use. cultivation medium of Jurkat cells cultured up to 4.2 liter (7.6 x 10 9 cells) was transferred to 500-ml-centrifugation tubes and centrifuged at 500 x g for 5 minutes at 4°C to collect the cells. The collected cells were washed two times with PBS(-). The centrifugation conditions for washing were 700 x g for 5 minutes at 4°C using 50-ml-centrifugation tubes. At that time the packed cell volume (PCV) was simultaneously measured. These cells were thoroughly suspended in 10-fold PCV of guanidium solution (4 M guanidium thiocyauate, 0.1 M Tris-HCI pH 7.5, 1% (v/v) β-ME). The suspension was passed through an injection needle of 18G (1.2 mm) (TERUMO: NN-1838R) twenty times and further through an injection needle of 25G (0.5 mm) (TERUMO: SS-20ES) to cut DNA strands into fragments. To the resultant suspension 10% N-lauroylsarcosine was added and thoroughly stirred, so that the final concentration of lauroylsarcosine became 0.5%. Then, 3 ml of each aliquot of the mixture was carefully placed over the phase of 9 ml of CsCl/EDTA solution (5.7 M CsCl, 0.01 M EDTA pH 7.5) which was preliminarily poured into an ultra-centrifugation tube. The ultracentrifugation tubes were placed in the bucket and bucket cap was fastened. Then, the bucket was fixed in a rotor (SW 41Ti) and ultra-centrifuged at 32 krpm for 24 hours at 20°C. The supernatant was carefully discarded thoroughly and the upper part of the ultra-centrifugation tube was cut off by a cutter. The obtained precipitate was washed with 70% ethanol. Then, the pellet was rinsed three times with 150 µl of TE/SDS solution (10 mM Tris-HCl pH 7.6, 1 mM EDTA, 0.1% SDS) to dissolve the precipitate in TE/SDS solution. The solution was extracted two times with phenol/chloroform, followed by addition of 900 µl of ethanol and 30 µl of 3 M sodium acetate (pH 5.2). The mixture was stored at -80°C until use. When the concentration was measured, an aliquot of the above stock solution was taken out and centrifuged (15,000 x g for 5 minutes at 4°C). After washing with 70% ethanol (15,000 x g for 5 minutes at 4°C), the precipitate was dissolved in water that was pretreated with diethyl pyrocarbonate (DEPC) (DEPC was added to distilled water so that the final concentration of DEPC became 0.1 %, followed by stirring, standing still for about 24 hours and autoclaving. The pretreated water was stored at room temperature.). Absorbance of the solution was determined at a wave-length of 260 nm using a DU-64 Spectrophotometer and the amount of RNA was estimated. (c) Next, complementary single-stranded cDNA was prepared by reverse transcription. An aliquot of RNA (10 µg) obtained in the above procedure was taken out and centrifuged (15,000 x g for 5 minutes at 4°C). The obtained precipitate was washed with 70% ethanol (15,000 x g for 5 minutes at 4°C) and dissolved in 9.8 µl of DEPC-treated water. To the solution 160 ng of 0.5 µg/µl Oligo(dT) 15 primer (Promega: 5'-TTTTTTTTTTTTTTT-3') was added and heated at 70°C for 5 minutes. After the heating for 5 minutes, the sample was promptly placed on ice and 28 µl of preliminarily ice-chilled reaction buffer (a mixture of Reverse Transcriptase attachments, that is, 8 µl of 5 x RT Buffer, 4 µl of 0.1 M DTT, 2 µl of 10 mM dNTPs, and 13 µl of distilled water), 1 µl of Ribonuclease inhibitor (TaKaRa: Ribonuclease inhibitor) and 2 µl of Reverse transcriptase (GIBCO BRL: Super ScriptTM RNase H-Reverse Transcriptase) were added to the sample in this order. Then, the mixed sample was promptly subjected to a one-hour reaction at 37°C to elongate the complementary single-stranded cDNA by reverse transcription. At the end of the reaction, the sample was heated at 95°C for 5 minutes to stop the reaction by heat blocking. The obtained complementary single-stranded cDNA was stored at -30°C until use. (d) Subsequently, oligonucleotides were synthesized for the purpose of amplification of the Ref-1 translational region by Long-PCR method. Each base sequence of the synthesized oligonucleotides is shown in the following. Each oligonucleotide possesses an individual digestive region recognized by the restriction enzyme from which each oligonucleotide takes its name. The synthesized oligonucleotides were heated at 55°C for 8 hours to be deprotected. The deprotected oligonucleotides were subdivided into aliquots, dried under vacuum and dissolved in diluted (1 in 10) TE buffer (10 mM Tris-HCl pH 7.9, 1 mM EDTA). PCR was conducted with the above two kinds of oligonucleotides, employing the prepared single-stranded cDNA as templates. A PCR kit (XL PCR kit: PERKINELMER) was employed for the PCR procedures. There are two kinds of reaction solutions (Lower Layer and Upper Layer). The Lower Layer contains 40 pmol each of S'-terminal primer and 3'-terminal primer, dNTPs at a final concentration of 0.8 mM, Mg(OAc)2 at a final concentration of 1.4 mM and 12 µl of 3.3 x XL Buffer II. The final volume was adjusted to 40 µl. On the other hand, the Upper Layer contains 1 µl of the single-stranded cDNA templates, rTth DNA Polymerase, XL 4U and 18 µl of 3.3 x XL Buffer II. The final volume was adjusted to 60 µl. First, GEM 100 WAX (PERKIN ELMER) was placed on the Lower Layer of a sample tube and heated at 80°C for 5 minutes using a gene amplification apparatus, followed by cooling at 25°C for one minute, so that the WAX was solidified on the Lower Layer. Thereon the Upper Layer was placed and subjected to the reaction using a gene amplification apparatus according to the following scheme: 94°C for one minute, 16 cycles of (94°C for 15 seconds, 60°C for 10 minutes), 12 cycles of (94°C for 15 seconds, 60°C for 10 minutes (elongated by 15 seconds in every cycle)), and 72°C for 10 minutes. After the completion of the reaction, the WAX which was solidified on the Upper Layer was holed through and the reaction solution was transferred, followed by chloroform extraction and ethanol precipitation. The amplified DNA fragments were digested by XhoI and BamHI (TOYOBO) and directly subjected to agarose gel electrophoresis. A part of the agarose gel containing the DNA fragments was isolated, followed by phenol/chloroform extraction and ethanol precipitation to purify the DNA fragments. (e) As the E . coli expression vector, pET14b (Novagen) was employed. The DNA fragments purified in the above procedure were ligated with the isolated and purified pET14b XhoI/BamHI-digested fragments in order to construct the E . coli expression plasmids (pET/Ref) which would express the recombinant Ref-1 wild type protein. The E . coli possessing pET14b-derived E . coli expression plasmids expresses a His-Tag fused recombinant protein the N-terminal region of which is a peptide consisting of six histidines. Example 11 (Confirmation of the binding ability of Ref-1 against E3330) (a) The binding ability of the recombinant protein obtained in the above procedure against E3330 was investigated using E3330-immobilized particles. As a result, it was confirmed that the recombinant Ref-1 protein specifically bound to E3330. Furthermore, it was confirmed that E3330 bound to Ref-1 in a Far Western method using 14 C-labeled E3330. Therefore, Ref-1 is regarded as an intracellular receptor to E3330. (b) Ref-1 consists of a domain possessing redox activity in its N-terminal region and consists of another domain possessing AP nuclease activity, that severs apurinic/apyrimidinic single-stranded DNA and inserts nicks, in its C-terminal region. Therefore, it was investigated in the next experiment whether E3330 would inhibit these activities or not. First, concerning AP nuclease activity, the plasmid pBluescript SK+DNA (50 µg) was treated with 50 mM sodium citrate (pH 3.5) at 60°C for 15 minutes, followed by dialysis in 50 mM Tris-HCl (pH 7.4) at 4°C for about 24 hours. This AP plasmid DNA possesses a supercoiled circular DNA structure. This DNA was suspended in nuclease buffer solution (10 mM Tris-HCl (pH 8.0), 5 mM MgCl 2 , 1 mM EDTA, 0.01 % NP-40), to which the recombinant Ref-1 was added, resulting in insertion of nicks and an open circular DNA structure. However, as shown in Figure 3, the AP nuclease activity of the Ref-1 was not inhibited by E3330. (c) Next, effects of Ref-1 on the redox activity were investigated. The obtained results are shown in Figure 4. Prior to the conduction of the investigation, there are some considerations. Transcription factor NF-κB possesses plural cystine residues in its amino acid sequence. There are two conditions; one is an oxidized condition where these cystine residues are bound to each other through an S-S bond; and the other one is a reduced condition where they are individually existing with an SH-group. Therefore, NF-κB was treated with dithiothreitol (DTT) that is known as a reductant to transform NF-κB into the reduced state. As a result, the DNA-binding ability of the reduced NF-κB was increased, that was confirmed by a gel-shift assay. Ref-1 possessing redox activity was added to NF-κB which was partially purified from Jurkat cells, resulting in an increase in DNA-binding ability, that was confirmed by a gel-shift assay. Furthermore, the enhancement of the DNA-binding activity of NF-κB by Ref-1 was reduced by the addition of E3330 to the reaction mixture. However, E3330 did not inhibit the increase in the DNA-binding activity of NF-κB by DTT. Therefore, it was revealed that E3330 specifically inhibits the DNA-binding activity of NF-κB. (d) NF-κB is a hetero-dimer consisting of two subunits (p65 and p50). The molecular weights of those two subunits p65 and p50 are 65 kDa and 50 kDa, respectively. The His-tag recombinant proteins of those p65 and p50 subunits were prepared using the baculovirus expression system. Then, it was investigated by gel-shift assay whether E3330 bad effects on p65 or on p50. The obtained results are shown in Figure 5. The DNA-binding ability of the p65/p65 homo-dimer under reduced conditions by the addition of DTT was significantly enhanced, but the enhancement was not observed by the addition of Ref-1. On the other hand, DNA-binding ability of the p50/p50 homo-dimer and p65/p50 hetero-dimer was enhanced by the addition of either DTT or recombinant Ref-1. Therefore, it was revealed that Ref-1 had effects on p50, one of the subunits of NF-κB. The enhancement of the DNA-binding ability of the p50/p50 homo-dimer or the p65/p50 hetero-dimer by the addition of Ref-1 was reduced by the addition of E3330. As NF-κB recognizes a specific base sequence and binds to the specific DNA sequence, binding to DNA is the minimum requirement for NF-κB to function as a transcriptional factor. This binding step is regulated by Ref-1, indicating that Ref-1 is at least an intracellular factor activating the transcription factor NF-κB with respect to the DNA-binding step. Moreover, it was revealed that E3330 inhibits the activation induced by Ref-1. (e) In addition, a GST pull down assay was conducted to confirm that Ref-1 specifically bound to the p50 subunit of NF-κB. The obtained results show that Ref-1 really binds to p50 of GST-tag (GST-p50), as indicated in Figure 6. Example 12 (Preparation of mutational recombinant proteins of Ref-1) (a) In order to confirm that Ref-1 bound to E3330, a series of different quantities of N-terminal and C-terminal flanking regions of Ref-1 deletion mutant strains were prepared using pET/Ref, as described in the following. Then, these recombinant proteins were expressed in E . coli and purified using a nickel column and a glutathione column to investigate whether they bound to E3330-immobilized particles or not. These mutational recombinant proteins of Ref-1 including a wild type are schematically shown in Figure 7. (b) Preparation of pET/RefdC76, pET/RefdC91, pET/RefdC163 and pET/RefdC182 The prepared pET/Ref, 10 µg, was digested with BamHI and AatII (TOYOBO), extracted with phenol/chloroform and precipitated with ethanol. These pET/Ref BamHI/AatII digested fragments were dissolved in 100 µl of a buffer solution which was prepared by diluting (1 in 10) 10 x ExoIII Buffer (500 mM Tris-HCl (pH 8), 50 mM MgCl 2 , 100 mM β-ME) attached to Exonuclease III (ExoIII: TaKaRa). Subsequently, 180 U of ExoIII was added to the above solution, followed by incubation at 25°C for 5, 10, 15, 20, 25, 30, 40, 50, or 60 minutes, to degrade the pET/Ref BamHI/AatII digested fragments in 3' to 5' direction. Since ExoIII is inhibited by the addition of Zn2+, 100 µl of the buffer solution which was prepared by diluting (1 in 10) 10 x Mung Bean Buffer (300 mM CH 3 COONa (pH 4.6), 1 M NaCl, 10 mM (CH 3 COO) 2 Zn, 50% Glycerol) attached to Mung Bean Nuclease (TaKaRa) was added to each of the reaction mixtures to stop the degradation. The resultant reaction mixtures were incubated at 65°C for 5 minutes to inactivate the enzyme completely. Subsequently, 50 U of Mung Bean Nuclease was added to the above solutions, followed by incubation at 37°C for 30 minutes, to degrade portions of single-stranded DNA by ExoIII. Then, the resultant solutions were subjected to extraction with phenol/chloroform and precipitation with ethanol. The DNA termini were repaired with Klenow Fragment (terminal smoothing of DNA) to make the DNA termini completely smooth. Then, the resultant solutions were subjected to extraction with phenol/chloroform and precipitation with ethanol, followed by digestion with XhoI. Through the above procedures, translational regions of Ref-1 with deletions of various lengths in its C-terminal region, wherein the N-terminus was the XhoI-digested terminus and the C-terminus was the smooth terminus, were obtained. Three fragments, that is, one of these various DNA fragments, the isolated and purified pET14b XhoI/BamHI-digested fragment and a BamHI Linker, were ligated to each other in order to construct plasmids expressing recombinant Ref-1 deletion mutants in E . coli . The base sequences of the BamHI Linker are shown in the following. Every frame of the Linker was designed to contain a termination codon. The preparation method for the Linker is the same as the above method by which various kinds of double-stranded DNA with ligation sequences for each transcriptional factor were prepared. Names for plasmids expressing recombinant Ref-1 deletion mutants in E . coli were taken from the number of deleted amino acid residues from their C-termini after the translation. The names are described in the following in numerical order: pET/RefdC76 (76 amino acid residues from the C-terminus were deleted), pET/RefdC91 (91 amino acid residues from the C-terminus were deleted), pET/RefdC163 (163 amino acid residues from the C-terminus were deleted) and pET/RefdC182 (182 amino acid residues from the C-terminus were deleted). (c) Preparation of pET/RefdC230, pET/RefdC247 and pET/RefdC278 using the same method as described above, pET/RefdC23O (230 amino acid residues from the C-terminus were deleted), pET/RefdC247 (247 amino acid residues from the C-terminus were deleted) and pET/RefdC278 (278 amino acid residues from the C-terminus were deleted) were constructed. (d) Preparation of pET/RefdN41, pET/RefdN81, pET/RefdN121 and pET/RefdN161 A series of these recombinant Ref-1 N-terminal deletion mutants expressing in E . coli were amplified by Long-PCR method using synthesized oligonucleotides. Each base sequence of the synthesized oligonucleotides is shown in the following. Each oligonucleotide possesses an individual digestible region recognized by the restriction enzyme from which each oligonucleotide takes its name. The synthesized oligonucleotides were heated at 55°C for 8 hours for deprotection. The deprotected oligonucleotides were subdivided into aliquots, dried under vacuum and dissolved in diluted (1 in 10) TE buffer (10 mM Tris-HCl (pH 7.9), 1 mM EDTA). One of the above four kinds of oligonucleotides and a 3'Ref-1 BamHI primer were combined and the subsequent procedures were the same as previously described for conducting PCR. The amplified DNA fragments were individually digested by XhoI and BamHI (TOYOBO) and directly subjected to agarose gel electrophoresis. A part of the agarose gel containing the DNA fragments was isolated, followed by phenol/chloroform extraction and ethanol precipitation to purify the DNA fragments. One of these various DNA fragments, the isolated and purified pET14b XhoI/BaHI-digested fragment and a BamHI Linker, were ligated to each other in order to construct pET/RefdN41 (41 amino acid residues from the N-terminus were deleted), pET/RefdN81 (81 amino acid residues from the N-terminus were deleted), pET/RefdN121 (121 amino acid residues from the N-terminus were deleted) and pET/RefdN161 (161 amino acid residues from the N-terminus were deleted), respectively. (e) Preparation of pET/RefdN41dC163, pET/RefdN41dC182 and pET/RefdN41dC213 First, pET/RefdN41 was digested with PvuII and XhoI, and subjected to agarose gel electrophoresis. A part of the agarose gel containing only the translational region was isolated. On the other hand, pET/RefdC163, pET/RefdC182 and pET/RefdC213 were digested with PvuII and BamHI, and subjected to agarose gel electrophoresis. Each part of the agarose gel containing only the translational region was individually isolated and prepared. The same procedures, as described above, were conducted to construct pET/RefdN41dC163 (41 amino acid residues from the N-terminus were deleted and 163 amino acid residues from the C-terminus were deleted), pET/RefdN841dC182 (41 amino acid residues from the N-terminus were deleted and 182 amino acid residues from the C-terminus were deleted) and pET/RefdN41dC213 (41 amino acid residues from the N-terminus were deleted and 213 amino acid residues from the C-terminus were deleted), respectively. (f) Preparation of pET/RefdN51dC182, pET/RefdN61dC182, pET/RefdN71dC182, pET/RefdN81dC163 and pET/RefdN81dC182 The same procedures, as described above, were conducted to construct each deletion mutant. Example 13 (Binding assay of mutational recombinant proteins of Ref-1 expressed in E . coli against E3330) First, wild-type recombinant proteins of Ref-1 and mutational recombinant proteins of Ref-1 were expressed in E . coli and purified using His Bind Resin or Glutathione Sepharose 4B. Then, each purified protein was subjected to SDS-PAGE and stained using Rapid Stain CBB. The obtained results are shown in Figures 8 and 9. A series of C-terminal deletion mutants are shown in Figure 8. A series of N-terminal deletion mutants and a series of both-sided C-terminal and N-tetminal deletion mutants are shown in Figure 9. In Figure 8, Lanes from Lane 1 to Lane 9 were loaded with wild-type (WT), dC50, dC76, dC91, dC157, dC163, dC182, dC213 and GST-dC213 in this order, when electrophoresis was conducted. Their molecular weights were about 40kDa, 37kDa, 36kDa, 35kDa, 28kDa, 26kDa, 23kDa, 19kDa and 42kDa, respectively. In Figure 9, Lanes from Lane 1 to Lane 9 were loaded with wild-type (WT), dN41, dN81, dN121, dN161, GST-dN81dC182, GSTdN41dC213, GST-dN81dC213 and GST in this order, when electrophoresis was conducted. Their molecular weights are about 40kDa, 36kDa, 32kDa, 28kDa, 22kDa, 36kDa (a band appearing just left side of Lane 7), 37kDa, 33kDa and 28kDa, respectively. Example 14 (Identification of the E3330-binding domain using mutational recombinant proteins of Ref-1) Which kinds of Ref-1 deletion mutant proteins were bound to E3330 was investigated to identify the E3330-binding domain. Therefore, binding assays were performed using E3330-immobilized SG particles. The experimental scheme was the same as illustrated in Figure 2. Concerning the elution procedure, two kinds of processes were conducted in this experiment. In one procedure 2 µg of each purified Ref-1 deletion mutant protein was mixed with E3330-immobilized SG particles, followed by standing still for 30 minutes in an ice-water bath; the protein binding to the particles was eluted with an elution buffer containing 1 M KCl; and then, each eluate was subjected to 12.5% SDS-PAGE and proteins were detected by silver staining. In the other procedure 2 µg of each purified Ref-1 deletion mutant protein was mixed with E3330-immobilized SG particles, followed by standing still for 30 minutes in an ice-water bath; 1 x SDS sample dye was added to the particles to which each kind of proteins was bound; and the resultant suspension was directly boiled so that the protein binding to the particles was eluted; and then, each eluate was subjected to 12.5% SDS-PAGE and proteins were detected by CBB staining. As a result, it was suggested that the following recombinant deletion mutant proteins of Ref-1 were bound to E3330-immobilized SG particles. In the process using an elution buffer containing 1 M KCl, the binding proteins were wild-type (about 40kDa), dC76 (about 36kDa), dC91 (about 35kDa), dC163 (about 26kDa), dC182 (about 23kDa), dC213 (about 19kDa) and GST-dC213 (about 42kDa). In the other process using a direct boiling method, the binding proteins were wild-type (about 40kDa), dN41 (about 36kDa), dN81 (about 32kDa), GST-dN81dC182 (about 36kDa) and GST-dN81dC213 (about 33kDa). The results are shown in Figures 10 and 11. From the above results, Ref-1, that is a protein consisting of a total of 318 amino acid residues, does not bind to E3330 in case where 231 or more amino acid residues front its C-terminus are deleted or in case where 72 or more amino acid residues from its N-terminus are deleted. Therefore, it was revealed that the amino acid sequence of at least 72 a.a. to 88 a.a. participated in the binding activity of Ref-1 against E3330, as shown in Figure 12. A recombinant protein possessing only the concerned amino acid sequence (72 a.a. to 88 a.a.) was synthesized and investigated with respect to its binding properties using E3330-immobilized particles, resulting in confirmation of its binding ability against E3330. The amino acid sequence of 72 a.a. to 88 a.a. is as follows (length of the sequence: 17 amino acids): LRAWIKKKGLDWVKEEA. [SEQ ID NO:13]. These results indicated that the intracellular receptor to E3330 was isolated and purified using E3330-immobilized particles and it is clear that the present invention is extremely useful for isolation and purification of proteins. SEQUENCE LISTING (1) GENERAL INFORMATION (i) APPLICANT: HANDA, Hiroshi KAWAGUCHI, Haruma (ii) TITLE OF THE INVENTION: DRUG-IMMOBILIZED PARTICLES AND A PROCESS OF PURIFYING PROTEINS (iii) NUMBER OF SEQUENCES: 13 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: Dike, Bronstein, Roberts & Cushman, LLP (B) STREET: 130 Water Street (C) CITY: Boston (D) STATE: MA (E) COUNTRY: USA (F) ZIP: 02109 (v) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Diskette (B) COMPUTER: IBM Compatible (C) OPERATING SYSTEM: DOS (D) SOFTWARE: FastSEQ Version 1.5 (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: (B) FILING DATE: (C) CLASSIFICATION: (vii) PRIOR APPLICATION DATA: (A) APPLICATION NUMBER: (B) FILING DATE: (viii) ATTORNEY/AGENT INFORMATION: (A) NAME: Corless, Peter F (B) REGISTRATION NUMBER: 33,860 (C) REFERENCE/DOCKET NUMBER: 47115 (ix) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: 617-523-3400 (B) TELEFAX: 617-523-6440 (C) TELEX: (2) INFORMATION FOR SEQ ID NO: 1: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: N-terminal (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: (2) INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: N-terminal (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: (2) INFORMATION FOR SEQ ID NO:3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 10 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: N-terminal (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: (2) INFORMATION FOR SEQ ID NO:4: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 319 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: N-terminal (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: (2) INFORMATION FOR SEQ ID NO:5: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 31 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: (2) INFORMATION FOR SEQ ID NO:6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 31 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: (2) INFORMATION FOR SEQ ID NO:7: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 11 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: (2) INFORMATION FOR SEQ ID NO:8: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 15 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: (2) INFORMATION FOR SEQ ID NO:9: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: (2) INFORMATION FOR SEQ ID NO:10: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 34 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10: (2) INFORMATION FOR SEQ ID NO:11: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 11: (2) INFORMATION FOR SEQ ID NO:12: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 34 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: (2) INFORMATION FOR SEQ ID NO:13: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 17 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO (v) FRAGMENT TYPE: N-terminal (vi) ORIGINAL SOURCE: (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:

Claims: A process of isolating a substance that can adhere to a substance possessing physiological activity from a mixture containing the substance, comprising contacting the mixture with a microsphere prepared by coupling the substance possessing physiological activity to a styrene-glycidyl methyacrylate polymer covered with glycidyl methacrylate thereon through a spacer. A process of claim 1, wherein a mixture containing the substance for isolation is a cell extract. A process of claim 1 or claim 2, wherein the spacer is an ethylene glycol diglycidyl ether derivative. A process of any one of claims 1 to 3 wherein the substance possessing physiological activity is a 3-[(5-(2,3-dimethoxy-6-methyl-1,4-benzoquinonyl)]-2-nonyl-2-propionic acid or derivative thereof. A process of claim 4 wherein the substance that can adhere to the substance possessing physiological activity is a protein comprising an amino acid sequence represented by SEQ ID NO:4 in which one or more amino acids are deleted, added or substituted. A process of claim 4 wherein the substance that can adhere to the substance possessing physiological activity is a peptide comprising an amino acid sequence that has at least 70 percent sequence homology to SEQ ID NO:4. A process of claim 4 wherein the substance that can adhere to the substance possessing physiological activity is a peptide comprising an amino acid sequence that has at least about 80 percent sequence homology to SEQ ID NO:13. A styrene-glycidyl methacrylate polymer covered with glycidyl-methacrylate thereon, which is bound to a substance possessing physiological activity through a spacer. The polymer according to claim 8, wherein the polymer is a microsphere. The microspheres according to claim 9 in which a spacer is an ethylene glycol diglycidyl ether derivative. A microsphere according to claim 9 or claim 10 in which a substance possessing physiological activity is a 3-[(5-(2,3-dimethoxy-6-methyl-1,4-benzoquinonyl)]-2-nonyl-2-propionic acid derivative. A process of screening for a substance which binds to a substance possessing physiological activity, wherein the substance possessing physiological activity is bound through a spacer to a polymer comprising styrene-glycidyl methacrylate covered with glycidyl-methacrylate thereon.

Inventors: HANDA HIROSHI PROF, KAWAGUCHI HARUMA PROF, HANDA, HIROSHI, PROF., KAWAGUCHI, HARUMA, PROF.
Applicants: HANDA HIROSHI PROF, KAWAGUCHI HARUMA PROF, HANDA, HIROSHI, PROF., KAWAGUCHI, HARUMA, PROF.
Application year: 1997
Main classification: G01N33
IPC codes: C07K14, G01N33, C07K1, C08F8, C08F220, C12R1, C12N15, C08F212, C12P21