MODIFIED TCF

Abstract: Modified TCF in which amino-acid residue(s) of the wild-type TCF responsible for glycosylation is (are) substituted or deleted so that at least one N-linked oligosaccharide chain is removed. The modified TCF have longer biological half-lives without loss of its biological activities. The modified TCFs are therapeutically important as agents for liver diseases or as anti-cancer drugs.

Description: DESCRIPTION MODIFIED TCF FIELD OF THE INVENTION This invention is related to genetically engineered modified TCFs which contain different number of N-linked oligosaccharide chains compared with wild type TCF, and have new amino-acid sequences. These modified TCFs obtained in this invention have longer serum half-lives, have growth stimulating activities for hepatocytes and cy to toxic activities against tumor cells. Therefore, the modified TCFs are useful as therapeutic agents against liver diseases and as anti-cancer drugs. BACKGROUND OF THE INVENTION TCF- 11, tumor cy to toxic factor derived form human fibroblast, is a novel anti -tumor protein which is different from any other proteins so far reported. The inventors succeeded in cDNA cloning of this protein, deduced its entire amino-acid sequence and confirmed the usefulness. This novel anti- tumor protein and its cDNA were disclosed in W090/10651. They were designated as TCF-II. In this invention, the glycoprotein which has the amino-acid sequence disclosed in W090/10651 is called TCF. TCF is a substance which has been called TCF-II. TCF has both strong cytotoxic activity against tumor cells and growth stimulating activity for normal cells. And it has been confirmed that TCF is a member of a family including HGF, a growth factor for hepatocytes. The molecular weight of TCF is 78000 ± 2000 daltons and/or 74000 ± 2000 daltons on SDS polyacryl amide gel electrophoreisis. Under reducing conditions, it showed a polypeptide band called A chain with a molecular mass of 52000 2000 daltons and two polypeptide bands called B chain and/or C chain with molecular masses of 30000 ± 2000 daltons and/or 26000 ± 2000 daltons, respectively. Because TCF is a growth factor for hepatocytes, application to liver regeneration after hepatecto y has been examined. Since biological half-life of TCF is very short, attempts have been made to obtain more effective modified TCFs with prolonged biological half-lives. Relationship between oligosaccharide chains and serum half-lives has been investigated in some glycoproteins including erythropoietin. The investigations have demonstrated that glycoproteins with slightly different structure in oligosaccharide chains and with different biological activities can be synthesized from same gene. It was known that glycosylated erythropoietin is different in the biological activities from non-glycosylated one. However, about the relationship between oligosaccharide chains and biological activities of TCF little has been known. DISCLOSURE OF THE INVENTION The present inventors took notice of the usefulness of TCF, and investigated application of TCF to the treatment of tumors or liver diseases and utilization as diagnostic markers of diseases. TCF has a very short half-life of approximately 2 minutes. To obtain modified proteins with prolonged biological half-lives, the inventors constructed several genetically engineered TCFs with mutations in the polypeptide moiety and analyzed them. However, most, of the modified proteins appeared to lose the biological activities. Then, to prolong the biological half-life without loss of the biological activity, the inventors paid attention to the four N-linked oligosaccharide chains attached to TCF and attempted to construct the new modified TCFs which have a deletion of one or more oligosaccharide chains. The theme of this invention is to present the new modified TCFs which have different amino-acid sequences compared to the wild- type TCF, and decreased number of N-linked oligosaccharide chains and longer biological half-lives than the wild-type TCF. These modified TCFs can be obtained by altering the nucleotide sequence of TCF cDNA encoding the amino-acd residues responsible for N-glycosylation and by expressing the genetically utagenized TCF cDNAs. Modified TCFs presented by the invention have one or more deletionCs) of the four N-linked oligosaccharide chains present in the wild- type TCF. These are the first modified TCFs with prolonged biological half- lives without any loss of the biological activities, obtained by altering the amino-acid residues of the wild- type TCF. Fig. 1 shows the entire amino-acid sequence of the wild- type TCF deduced from its cDNA sequence (Seq. Id No. 1). Amino-acid residues responsible for N- glycosylation are underlined. It is speculated that the signal sequence is removed and the glutamine residue at position 32nd results in the N- terminal amino acid of TCF. Four N-linked oligosaccharide chains bind to asparagine residues at positions 258th, 366th, 530th, and 617th relative to the N- terminal amino acid. These asparagine residues correspond to those at positions 289th, 397th, 561st, and 648th in Fig.l. Fig. 2 shows cDNA sequence encoding the amino-acid sequence. The coding region starts at the ATG codon marked with a circle in the figure. Amino-acid residues responsible for N-glycosylation are Asn-X-Thr or Asn-X-Ser (amino-acid residues are indicated by the three- letter code and the X represents any amino-acid residues). Modified TCF lacking specific oligosaccharide chain(s) can be obtained by expressing the nucleotide sequence in which the codons for Asn, Ser or Thr are deleted or substituted with those for one of the other amino acids, in eukaryotic cells, preferably mammal iap cells. Modified TCF which lacks specific oligosaccharide chains can be obtained by replacing the codons for Asn with those for other amino acids such as Gin, a substitution with little effects on the conformation of TCF. Gin is the most preferable amino acid which substitutes for Asn. Asp, Glu, His, Ser or Thr are also acceptable. Modified TCF lacking specific oligosaccharide chain (s) can be obtained by replacing the codons for Ser with those for other amino acids such as Ala, a substitution with little effects on the conformation of TCF. Ala is the most preferable amino acid which substitute for Ser. Pro, Gly or Asn are also acceptable. Modified TCF lacking specific oligosaccharide chain (s) can be obtained by deleting or replacing the codens for Thr to other amino acids. Al.i is the most preferable amino acid which substitutes for Thr. Val, His or Asn are also acceptable. N-glycosylation sites are indicated in a schematic structure of TCF in Fig. 3. The N-glycosylation sites are designated as numbers 1, 2, 3 and 4 from N-terminal. These numbers specify the positions of the N-glycosylation sites. To alter the amino-acid sequences responsible for N-glycosylation into those for non-glycosylation, the cDNA can be site-specifically mutagenized by PCR(polymerase chain reaction). The reactions are performed by cDNA for the wild- type TCF as the template and synthetic oligonucleotides as the primers. The sequences of primers are designed to delete or substitute the DNA sequences as described above. Other methods for mutagenesis are also applicable. The cell lines producing the modified TCFs can be established by transforming host cells with expression vectors containing these mutant cDNAs. The modified TCFs can be recovered from the cultured broth of the transformed cell lines. For example, to substitute Asn at position 289th (Fig. 1), binding site for oligosaccharide chain 1, cDNA was mutagenized by in vitro mutagenesis or mutagenesis by PCR. These mutagenesis reactions are performed by cDNA coding the wild- type TCF disclosed in WO 90/10651 as the template and synthetic oligonucleotide TCF-1R 5' -TCAGTGTCCTGCATAGTAT-3' as the primer. An expression vector containing the mutagenized cDNA can be transfected into eukaryotic cell lines including mammalian cell lines. The modified TCFs can be recovered from the cultured supernatan s of the transfected cells. Any types of host-vector systems for eukaryotic cells are acceptable for expression of the modified TCFs. The most preferable is a combination of cytomegalovirus promoter and Namalwa cells, which was disclosed in WO 92/1053. Commonly used systems including a gene amplification system using a combination of SV 40 promoter, DHFR gene and CHO cell line or an expression system using a combination of the replication origin of bovine papiloma virus and mouse C127 cell line can be enumerated. Any commonly used methods for purification of biologically active proteins, can be used for purification of the modified TCFs, for example, precipitation by organic solvent, salting out, gel exclusion chromatography, affinity chromatography using monoclonal antibody or electrophoresis. Monoclonal antibodies against the wild-type TCF disclosed in Japanese Patent application number, 3-177236 can be used for affinity chromatography of modified TCF. The modified TCFs can be stored lyophilized or frozen. Fifteen modified TCFs can be obtained by combinations of the removal of the oligosaccharide chains. The modified TCFs are identified by numbers of removed oligosaccharide chains. For example, the modified TCF which lacks oligosaccharide chain 1 is named TCF- 1 , the modified TCF which lacks all four oligosaccharide chains is named TCF- 1234, and the modified TCF which lacks oligosaccharide chains 2 and 3 is named TCF-23. Figure 4 schematically represents the N-linked oligosaccharides bound to the modified TCF. All the modified TCFs have different molecular masses according to the removal of the oligosaccharide chains. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the entire amino-acid sequence of the wild- type TCF deduced from its cDNA sequence. Amino-acid residues responsible for binding of N-linked oligosaccharide chains are underlined. Figure 2 shows the cDNA sequence for the wild- type TCF. Codons to be substituted in the present invention are underlined. The coding sequence starts at the ATG codon marked with a circle. Figure 3 schematically represents the primary structure of the wild-type TCF. Circles represent the N-glycosylation sites and the arrow shows the cleavage site between A chain and B chain. Figure 4 schematically represents the oligosaccharide chains attached to TCF and the modified TCF. The horizontal lines represent the polypeptides and the vertical bars represents the oligosaccharide chains. Figure 5 shows the construction of the plas ids containing cDNAs for the modified TCF. Figure 6 shows the construction of the expression vectors for TCF and the modified TCF. Figure 7 shows the analysis of the representative modified TCF by SDS polyacryla ide gel electrophoresis. Figure 8 shows the stimulating activities of the modified TCF for growth of hepatocytes. Each figure shows the activity of the modified TCF described below. (1) TCF, TCF-1, TCF-2, TCF-3 and TCF-4 (2) TCF-12, TCF-13, TCF-14, TCF-23, TCF-24 and TCF-34 (3) TCF-123, TCF-124, TCF-1234, TCF-134 and TCF-234 Figure 9 shows the tumor cytotoxic activities of the modified TCF. Figure 10 shows the plasma concentrations of the modified TCF in the rats into which said modif ied TCFs were intravenously injected. The novel mod i f i ed TCFs are obta i ned by opera ti ng the presen t inventions. The modified TCFs obtained by the present invention can be prepared by express ing the cDNAs in whi ch the codons f or the amino- acid residues responsible for N-glycosylation are substi tuted wi th those for other amino acids or are deleted. The modif ied TCFs have longer biological half - lives due to the control of the numbers and the binding si tes of the N- l inked ol igosaccharide chains. BEST MODE FOR PRACTICE OF THE INVENTION In the examples herein, the present invention is described in more detail. Example 1 Preparation of the modified TCFs. DNAs were manipulated essentially as described in Molecular Cloning, A Laboratory Manual, Second Edition, J. Sambrook, E.F. Fritsch, T. Maniatis, Cold Spring Habor Laboratory Press, New York, 1989 to prepare modified TCFs as described below. ® Cloning of TCF cDNA. Site-specific mutations were introduced into TCF cDNA as described below by a 6.3-kb TCF expression plas id, pcDTCF II, prepared by the method disclosed in W092/01053. The E. coli strain containing pcDTCF II has been deposited to National Institute of Bioscience and Human-Technology as FERM BP-3479. (2) Methods for introducing site-specific mutations. 1) Method 1 i) Cloning of TCF cDNA into M13mpl8. The plasmid pcDTCFII (6.3 kb) was prepared by introducing the entire coding region of human TCF cDNA into plasmid pcDNA I (Invitrogen Co.) digested with restriction enzymes BamHI and SphI (Takara Co.). (All the restriction enzymes and the modifying enzymes were purchased from Takara Co..) pcDTCFII was digested with BamHI and SphI for 1 hour at 37 * C , precipitated with ethanol, and electrophoresed on 1% agarose gel. The 2.3 kb of TCF cDNA fragment was purified from the gel by Gene Clean (BiolOl Co.). On the other hand, replicative-form of phage DNA, M13mpl8 (Takara Co.) was digested with BamHI and SphI, precipitated with ethanol, and dissolved in water to make the vector DNA solution. The vector DNA solution and TCF cDNA were mixed and ligated by the DNA Ligation Kit (Takara Co.). A part of the ligation mixture was used for transformation of E. coli, DH5cr. The transformants were mixed with E. coli, NM522,an indicator strain, (Invitrogen Co.) and poured onto the LB soft agar plates containing 1% of bacto- tryptone, 0.5% of bacto-yeast extract, 1% of sodium chloride, 1% of IPTG (isopropyl- ?-D- thiogalactoside, Takara Co.), and 1% of Xgal (5-bromo- 4-chloro-3-indolyl-/9 -D-galactoside, Takara Co.) in order to make plaques. The double- stranded phage DNA was prepared from a clear plaque and the single-stranded DNA was prepared and used as a template for introducing site-specific mutations. ii) Introduction of site-specific mutation. The codon for the 289th amino acid, Asn, in a consensus amino acid sequence for N-glycosylation, Asn-X-Thr, was replaced with a codon for Gin that does not make the consensus amino-acid sequence for N-glycosylation, The definition of the number of amino acid is based on Met at the N- terminal of the wild- type TCF as the first amino acid. The oligonucleotide TCF- 1R, 5'-TCAGTGTCCTGCATAGTAT-3' , was synthesized by a DNA synthesizer (Applied Biosyste s Co.). All the oligonucleotides were synthesized by the synthesizer unless otherwise noted. Introduction of site-speci ic mutation was carried out by the oligonucleotide-directed in vitro mutagenesis system (Amersham Co.) according to the manufacture's instruction. E. coli, NM522 was transformed with the reaction mixture and screened with TCF 1 primer by the plaque hybridization teachnique. The single-stranded DNA was prepared from a positive plaque and the sequence was determined by the dideoxy chain termination method described by Sanger et al. to confirm that the codon, AAT, for Asn at 289th, was replaced with the codon, CAG, for Gin. The 1.4-kb Pstl-Hindlll DNA fragment was prepared from the double-stranded DNA from the positive clone, ligated to Pstl-Hindlll- digested pBluescript SK+ (Stratagene Co.) to produce plasmid, pSKTCFPH-1. 2) Method 2 Introduction of site-specific mutations in the codons for the 399th, 563rd, and 650th amino acids were carried out essentially as described by R.Higuchi (R.Higuchi, PCR protocols, p.177-183, Academic Press, 1990) using polymerase chain reaction (PCR). A codon for Ser in a consensus amino acid sequence for N-glycosylation, Asn-X-Ser, was replaced with a codon for Ala in each mutagenesis. To mutagenize the codon for Ser at 399th, 25 cycles of PCR were carried out by a mutant primer, TCF-2R 5' -CCAGATCTTGTTTGAGCTAAGTTGCCC-3' , a wild type primer, TCF701F 5'-GCTGGGATCATCAGACACCAC-3' , AmpliTaq polymerase (Takara Co.), and 4 ng of the plasmid pcDTCF II as a template. The PCR products were purified by centricon 100 (Amicon Co.) to remove primers, digested with restriction enzymes, Bglll and EcoRI (Takara Co.), and ligated to the 4.1 kb DNA fragment of Bglll-EcoRI-digested pSKTCFPH, plasmid previously produced by ligating Pstl- Hindl 11 -digested pBluescript SK+ and 1.4 kb fragment of the Pstl-Hindlll- digested pcDTCF II. A part of the ligation mixture was used for transformation of E. coli,DH5 a. The plasmid DNAs were prepared from ampicillin resistant transformants and the DNA sequences were determined to screen for plasmid ρSKTCFPH-2 in which the codon, TCC, for Ser at 399th was replaced with the codon, GCT, for Ala. Plasmid pSKTCFPH- 12 was produced by ligating PCR products and the 4.1 kb DNA fragment of the Bglll-EcoRI digested plasmid, pSKTCFPH- 1 in a similar way. The DNA sequences of the portion of DNAs derived from PCR products in all plasmids were determined to confirm their sequences. Ampicillin was purchased from Sigma Co.. To mutagenize the codon for Ser at 563rd, 25 cycles of PCR were carried out by a mutant primer, TCF-3R 5'-ATACCAGCTGGGCAACATTGAGAAC-3' , a wild type primer, TCF1202F 5'-GGCAACTTATCCCAAACAAGATCTGG-3' , AmpliTaq polymerase (Takara Co.), and 4 ng of the plasmid pcDTCF II as a template. The PCR products were purified by centricon 100 (Amicon Co.) to remove primers, digested with restriction enzymes, Xhol and PvuII (Takara Co.). pcDTCF II was digested with Xhol and ligated to generate pcDTCF ΔXho, which lacks the 1.1 kb Xhol DNA fragment. pcDTCF ΔXho was digested with SphI and PvuII and the 4.8 kb of Xhol- Sphl DNA fragment and the 0.5 kb of PvuII-SphI fragment were purified and ligated to XhoI-PvuII-digested PCR products described above by the DNA Ligation Kit. A part of the ligation mixture was used for transformation of E. coli, MC1061/P3 (Invitrogen Co.). The plasmid DNAs were prepared from ampicillin- and tetracycline- resistant transformants and plasmid, pcDTCF ΔXhoI-3 in which the codon, TCC, for Ser at 563rd was replaced with the codon, GCC, for Ala, was selected in a similar way. Tetracycline was purchased from Sigma Co. . Two rounds of PCR were carried out to utagenize the codon for Ser at 650th. The first PCRs were carried out independently by AmpliTaq polymerase (Takara Co.), 4 ng of the plasmid pcDTCF II as a template, and a pair of a mutant primer, TCF-4F 5' -ACTCTGAATGAGGCTGAAATATGTG-3' and a wild type primer, TCF2203R 5'-GGCATGCACAGTTGTATTGGTGGGTGCTTCAG-3' or a pair of a mutant primer, TCF-4R 5'-CACATATTTCAGCCTCATTCAGAGT-3' and a wild type primer, TCF1685F 5'- AACAGGTTCTCAATGTTTCCCAG-3'. The PCR products were purified by DE81 paper (Whattman Co.) and one tenth of them was used for the second PCR by the primers, TCF2203R and TCF1685F. The PCR product was separated in an agarose gel, purified by DE81 paper and digested with Bglll and SphI. On the other hand, pcDTCFΔXhoI and pcDTCF ΔXhoI-3 were digested with Bglll and SphI and the 4.9 kb of DNA fragments were purified, ligated to the Bglll-Sphl-digested PCR fragment described above by the DNA Ligation Kit. One tenth of the ligation mixtures was used to transform E. coli, MC1061/P3. The plasmid DNAs were prepared from ampicillin- and tetracycline-resistant transformants and plasmid, ρcDTCFΔXhoI-4 in which the codon, TCT, for Ser at 650th, was replaced with the codon, GCT, for Ala and plasmid, pcDTCF ΔXhoI-34 in which both codons for Ser at 563rd and at 650th were replaced with the codons for Ala, were selected, in a similar way. (D Construction of expression vectors. 1) Construction of vectors for transient expression. Plasmids, pSKTCFPH, pSKTCFPH 1, pSKTCFPH-2, and pSKTCFPH-12 were digested with Xhol and 1.1 kb of DNA fragments were purified. Plasmids, pcDTCF ΔXhoI, pcDTCFΔXhoI-3, pcDTCFΔXhoI-4, and pcDTCF ΔXho I -34 were digested with Xhol and ligated to four kinds of 1.1 kb of DNA fragments described above. Fifteen ligation mixtures except the combination of 1.1 kb of pSKTCFPH and pcDTCF ΔXhoI were used to transform E. coli, MC1061/P3. Fifteen expression vectors, pcDTCF-1, pcDTCF-2, pcDTCF-3, pcDTCF-4, pcDTCF-12, pcDTCF- 13, pcDTCF- 14, pcDTCF-23, pcDTCF-24, pcDTCF-34, pcDTCF-123, pcDTCF-124, pcDTCF-134, pcDTCF-234, and pcDTCF-1234 were selected. Analysis by restriction enzymes is confirmed the structures of these vectors. When these plasmids are transfected into mammalian cells, for instance COS cells, genes for TCF and the modified TCF are expressed under the control of cytomegalovirus (CMV) promoter. The construction of these plasmids are shown in Figure 5. 2) Construction of vectors for stable expression. Plasmid pHSG396 (Takara Co.) was digested with Hindi I T , blunt-ended with the DNA Blunting Kit (Takara Co.), purified with Gene Clean, ligated to Notl linker, 8mer 5'-GCGGCCGC-3' (Takara Co.), and used to transform E. coli, DH5αr. The plasmid DNAs were prepared from chloramphenicol resistant transformants and plasmid, pHSG Notl, which did not contain Hindi 11 site but contain Notl site was selected. pHSG Notl, was digested with Sail and SphI and ligated to the 2.3 kb of full-length TCF cDNA digested with Sail and SphI to produce plasmid, pHSG N- TCF. The 1.1 kb of Xhol-Xhol fragment was deleted from the plasmid, pHSG N-TCF, to produce plasmid, pHSG N-TCFII ΔX. pHSG N-TCFII ΔX, was digested with BstPl and SphI and the 2.3 kb of DNA fragment was purified, ligated to the BstPI- Sphl-digested 15 plasmids, pcDTCF- 1, pcDTCF-2, pcDTCF-3, pcDTCF-4, pcDTCF-12, pcDTCF-13, pcDTCF -14, pcDTCF- 23, pcDTCF-24, pcDTCF-34, pcDTCF-123, pcDTCF-124, pcDTCF- 134, pcDTCF-234, and pcDTCF-1234, and the BstPI-Sphl-digested pcDTCF that contained the wild type TCF cDNA by DNA Ligation Kit, and used to transform E. coli,DH5αr. The plasmid DNAs were prepared from chloramphenicol-resistanl transformants and the 16 plasmids that contained 2.3 kb of the wild-type TCF or each of the mutant TCF cDNAs in the plasmid, pHSG Notl, were selected. These plasmids were designated as pHSGN-TCF, pHSGN-TCF-1, pHSGN-TCF-2, P HSGN-TCF-3,pHSGN-TCF-4, pHSGN-TCF-12, pHSGN-TCF-13, pHSGN-TCF-14, pHSGN-TCF- 23,pHSGN-TCF-24, pHSGN-TCF-34, pHSGN-TCF-123, pHSGN-TCF-124, pHSGN-TCF- 134,pHSGN-TCF-234, and pHSGN-TCF-1234. These 16 plasmids were digested with Sail and Notl, ligated to the XhoI-Notl-digested expression vector, BCMGSneo, and used to transform E. coli, DH5 ex. BCMGSneo is a plasmid that contains the replication origin of bovine papiloma virus and cytomegalovirus promoter, and is capable of replicating in E. coli. BCMGSneo is provided by Dr. H. Karasuyama in Basel Immunology Institute and is described in Idenshikohgaku hand book, ρ297- 299, Yohdo Co., 1991. The plasmid DNAs were prepared from ampicillin resistant transformants and the 16 expression vectors that contained 2.3 kb of wild- type TCF or each of the mutant TCF cDNAs in BCMGSneo were selected. These plasmids were designated as, pBPV-TCF,pBPV-TCF-l, pBPV-TCF-2, pBPV-TCF-3, pRPV-TCF-4, pBPV-TCF-12, pBPV-TCF-13, pBPV-TCF-14, pBPV-TCF-23, pBPV-TCF-24, pBPV-TCF-34, pBPV-TCF-123, pBPV-TCF-124, pBPV-TCF-134, pBPV-TCF-234. and pBPV-TCF-1234. Antibiotics, chloramphenicol was purchased from Sigma Co.. E. coli strains containing ρBPV-TCF-3 or pBPV-TCF-13 were deposited to National Institute of Bioscience and Human Technology as FERM BP-4454 and FERM BP-4455. ® Preparation and purification of the TCF or the modified TCFs expression plasmids. The 16 E.coli strains containing each of the expression vectors, pBPV- TCF,pBPV-TCF-l, pBPV-TCF-2, pBPV-TCF-3, pBPV-TCF-4, pBPV-TCF-12, pBPV-TCF-13, pBPV-TCF-14, pBPV-TCF-23, pBPV-TCF-24, pBPV-TCF-34, pBPV-TCF-123, pBPV-TCF-124, pBPV-TCF-134, pBPV-TCF-234, and pBPV- TCF- 1234, were cultured in 400 ml of medium containing 50//g/ml of ampicillin at 37°C . When the absorbance at 600nm of each culture broth reached 0.8, chloramphenicol was added to the broth at a final concentration of 170 / g/ml and each broth was cultured overnight. These 16 plasmids were prepared by the alkali-SDS method and purified by cesium chloride density gradient ultra centi f ugation as described by Maniatis et. al. (Molecular Cloning 2nd ed.). © Transfection of the TCF- and the modified TCF- expression plasmids into the cultured animal cell lines. The 16 expression plasmids were transfected into a mouse cell line, C 127 by TRANSFECTAM (IBF Co. Maryland, USA), DNA transfection reagent for cultured mammalian cell lines, as described below. One day prior to transfection, approximately 10 6 cells of mouse C127 were suspended in DME medium (GIBCO Co.) containing 10 % of fetal calf serum and incubated at 37°C overnight in a COz incubator (a humidified incubator in an atmosphere of 5-7. of CO2), in 25 cm 2 tissue culture flasks (Sumitomo Bakelite, for adherent cells). (Cells were cultured at 37 * C in a humidified incubator in an atmosphere of 5-7% C0 Z , unless otherwise noted.). The cells were washed twice with Opti . MEM medium (GIBCO Co.) before transfection. After adding 2ml of Opti. MEM to the monolayer of the cells, transfection was carried out by 10 fig of the plasmid DNA as described in the manufacturer's protocol. After incubated for 6 hours, 7.5 ml of DME medium was added to the flasks. Then, the cells were incubated for two more days at 37 * C. The medium was replaced with fresh DME medium on the first day. The cells were trypsinized, washed once with DME medium and suspended in 50 mL of DME medium containing 100 μg/ml of G418. One hundred micro- liter of the suspension was added to each well in a 96-well flat-bottomed plates and incubated at 37'C . One week later, 100 L of DME medium containing 100-/g/ml of G418 was added to each well, and the plates were incubated at 37°C . Another week later, expression of the TCF or the modified TCFs was detected by measuring the concentration of TCF or the modified TCFs in 100// L of the cultured media by an enzyme immuno assay employing anti-TCF monoclonal antibodies (N. Shima et.al. Gastroenterologia Japonica 26 (4) 477-482, 1991). The cell lines expressing TCF or the modified TCFs were cultured at 37°C in a 12-well tissue culture plate or in a 25 cm 2 flask according to the cell numbers.Cell lines which express the modified TCFs (a total of 15 modified TCFs designated as TCF-1, TCF-2, TCF-3, TCF-4, TCF-12, TCF-13, TCF-14, TCF-23, TCF 24, TCF-34, TCF-123, TCF-124, TCF-134, TCF-234, and TCF-1234) were thus obtained. © Large-scale cultivation of the cell lines which produce TCF or the modified TCFs. The confluent cells producing TCF or the modified TCFs in 75 cm 2 tissue culture flasks were harvested by trypsinization, followed by inoculating into three 225 cm 2 tissue culture flasks. One hundred milliliters of DME medium was added to each flask and the culture was incubated at 37 * C. Four days later, the confluent cells were trypsinized and suspended in the DME medium. The cell suspension was diluted 10-fold with DME medium (a total volume of 3 L) . One hundred milliliters of the diluted cell suspension was inoculated into a new 225 cm 2 tissue culture flask. The cells were cultured at 37 * C for 5 days in thirty 225 cm 2 tissue culture flasks. The cultured supernatant (a total volume of 3 L) was collected. Cells were harvested from 6 flasks, followed by inoculating into sixty 225cm 2 tissue culture flasks. To each flask, 100 ml of the medium was added and incubated at 37 * C for 5 days. The cultured supernatant (a total volume of 6 L) was collected. Thus, 9 L of the cultured supernatant which contains the TCF or the modified TCFs was obtained. © Purification of the TCF and the modified TCFs. A three-step purification was performed as described below. 1) Heparin-sepharose CL-6B Nine liters of the cultured supernatant which contains each of the modified TCF centrifuged at 6,000 rpm for 30 min. to remove insoluble materials. The supernatant was applied at an approximate flow rate of 200ml per hour to a heparin-sepharose CL-6B column (2.5 X 12 cm) (Pharmacia Co. ) which had been equi l i brated wi th 300 mL of the equi l i bration buf fer, 10 mM Tris-HCl buffer (pH 7.5) containing 0.5 M of NaCl and 0.01% of Tween 20. The column was then washed wi th approximately 700 mL of the equi l i bration buf fer. The TCF or the modif ied TCFs were eluted wi th lOmM Tris-HCl buffer (pH 7.5) containing 2 M NaCl and 0.01% of Tween 20 and the fractions of 3 mL were col lected. The f ract i ons were mon i tored by the absorbance a t 280 nm and the frac ti ons containing TCF or the modified TCFs (approximatel 100 L) were obtained. 2) Mono S-FPLC The eluate which contains TCF or the modified TCFs was dialyzed against 10 mM of phosphate buffer (pH 6.5) containing 0.15 M of NaCl and centrifuged at 12,000 rpm for 90 min. to remove insoluble materials. The supernatant was applied at a flow rate of 1 mL/min. to a Mono S column ( 0.5 X 5 cm, Pharmacia, FPLC) which had been equilibrated with approximately 20 ml of 10 mM phosphate buffer (pH 7.0) containing 0.15 M NaCl and 0.01 % Tween 20 (buffer A). The column was washed once with approximately 30 mL of buffer A. Then the TCF or the modified TCFs were eluted at a flow rate of 0.5 mL/min. from the column with a linear gradient of NaCl (up to 1.0 M) and fractions of 0.5 ml were collected. The fractions containing TCF or the modified TCFs (an approximate volume of 4mL) which were eluted with 0.7-0.8 M NaCl were obtained. 3) Heparin 5-PW-FPLC Two volumes (8 mDof 10 mM Tris-HCl (pH 7.5) containing 0.01 % Tween 20 were added to the eluate which contains TCF or the modified TCFs. This diluted solution was applied at a flow rate of 1 mL/min. to a heparin 5-PW column (0.5 X 7.5 cm, T0S0 Co.,FPLC) which had been equilibrated with approximately 20 mL of 10 mM Tris-HCl buffer (pH 7.5) containing 0.3 M NaCl and 0.01 % Tween 20 (buffer B). The column was washed with approximately 30 ml of buffer B. Then TCF or the modified TCFs were eluted at a flow rate of 0.5 mL/min. with a linear gradient of NaCl (up to 2.0 M) and fractions of 0.5 mL were collected. The fractions containing TCF or the modified TCFs (those eluted with approximately 1.3 M NaCl, a total volume of 3 mL) were obtained. These fractions were dialyzed against deionized water, lyophilized and reconstituted with phosphate- buffered saline (PBS) containing 0.001% Tween 20. The yield and the recovery of each of the final purified modified TCFs are shown in Table 1. The yields were determined with polyclonal EIA described in the following section. Table 1 : The yield and the recovery of each of the final purified modified TCFs © Quantitation of the purified modified TCFs. 1) Preparation of polyclonal antibodies and labeling of the antibodies. Anti-TCF antiserum was obtained from rabbits which were immunized with TCF. The anti -TCF IgG was purified from the antiserum by an Af f -Gel protein A Sepharose (Bio Rad Co.) according to the manufacturer's protocol. The purified IgG was dialyzed overnight against PBS, and applied at a flow rate of 0.5 mL/min. to a TCF affinity column in which TCF was immobilized to affigel 10 (Bio Rad Co.). The immobilized column was washed with PBS and the anti-TCF IgG was eluted with 0.1 M Glycine-HCl buffer (pH 2.5). The eluate was dialyzed against PBS and the purified anti-TCF polyclonal antibodies were thus obtained. The peroxydase labeled antibodies were prepared as described by Ishikawa et al. (J. I munoassay, vol. 4, 209-327, 1983). 2) Quantitation of the purified modified TCFs. Anti-TCF antibodies were dissolved at a concentration of 10 g/mL in 0.1 M NaHC0 3 . The antibody solution was added (100// L/wel 1) to 96-well microtiter plates (NUNC Co.) and left overnight at room temperature. This step allowed the antibodies to attach to the plates. Block Ace (Snow Brand Milk Products Co. Ltd.) diluted two-fold with deionized water was added to the anti body- coated microtiter-well plates (200 //L/ml) and left for an hour at room temperature for blocking each well. The plates were then washed three times with PBS containing 0.1% Tween 20 (washing buffer). The modified TCF were diluted with appropriate volume of the first buffer (0.2 M Tris-HCl pH 7.4 containing 40% Block Ace and 0.1% Tween 20) to prepare modified TCF samples. Standard TCF solution was prepared by sequentially diluting 10 ng/mL of TCF solution with the first buffer. One hundred micro liters of the modified TCF samples were added to each well, left for 3 hours at 37 °C and washed three times with the washing buffer. The Peroxydase-conjuga ed antibody solution was diluted 400-fold with the second buffer ( 0.1 M Tris-HCl buffer pH 7.4 containing 20% Block Ace, 0.1% Tween 20 and 0.5 mg/mL of mouse IgG). One hundred microliters of the diluted peroxydase- labeled antibody solution was added to each well, left for 2 hours at 37 TJ and washed three times with the washing buffer. Subsequently, 100// L of substrate solution (0.4 mg/mL of o-phenylene dia ine dihydrochloride and 0.006% H Z 0 Z in 0.1 M citrate-phosphatte buffer, pH 4.5) was added to each well and incubated at 37VJ for 30 minutes in a dark place. The enzyme reaction was stopped by addition of 50// L of 6N H2SO4. The absorbance at 492 nm was measured on an im uno reader (Corona Co.). © Analysis of the purified TCF or the modified TCFs on SDS- polyacryl amide gel electrophoresis. Five micrograms of each of purified modified TCF was subjected to an SDS-polyacrylamide gel. Modified TCFs (TCF-3 and TCF-13) with prolonged biological half-lives as described later, and the wild-type TCF were applied to an SDS-polyacrylamide gel electrophoresis. The results are shown in Fig. 7. Electrophoresis was performed either in the presence (reducing conditions) or absence (non-reducing conditions) of β-mercaptoethanol. As indicated in Fig.7 TCF showed two adjacent bands with approximate molecular masses of 78,000 and 74,000 under non-reducing conditions. The two bands of TCF-3 migrated faster than those of TCF, and the two bands of TCF- 13 migrated faster than those of TCF-3, under non-reducing conditions. Under the reducing conditions, three protein bands with approximate molecular masses of 52,000, 30,000 and 26,000 were observed for TCF. Similarly, three bands with 52,000, 26,000 and 22,000 for TCF-3, and three bands with 48,000, 26,000 and 22,000 for TCF-13 were observed. The decrease in molecular mass of these modified TCFs was probably due to the removal of oligosaccharide chains. The results suggested that the desired modified TCFs were obtained. No other protein bands were detected except those deduced from the structure of the two modified proteins. Example 2 Biological activities of the TCF and the modified TCFs in vitro. Growth stimulating activity for hepatocytes. Growth stimulating activity for hepatocytes were determined as follows. Rat hepatocytes were isolated from a Wister rat (body weight was approximately 200 g) by the method of Seglen (Methods in cell biology Vol.13, p.29 .Academic Press, New York). The basal medium, Williams E (Flow laboratories Co.), containing 10% fetal bovine serum and 10 /M dexamethasone) was used for the growth of the cells. One hundred microliters of the basal medium containing 1.0 X 10 4 cells was added to each well in a 96-well flat-bottomed plate (Falcon Co.) and incubated at 37 * C . After 24 hours of incubation, 100 /L of the basal medium containing TCF or the modified TCFs was added to each well and incubated for 22 hours at 37 ° C. Each well was supplemented with 1 /Ci of 3 H-thimidine (Amersham Co.) and further incubated at 37 ° C for 2 hours. After washing twice with cold PBS, cells were trypsinized with 0.5% trypsine and harvested on a sheet of glass filter by a cell harvester. Radioactivities incorporated into the cells in each well were counted by Matrix 96 (Packard Co.). As shown in Fig. 8, all the modified TCFs were shown to maintain growth stimulating activities for rat hepatocytes. © Tumor cytotoxic activity. Tumor cytotoxic activities of TCF, TCF-3 and TCF-13 were measured. Meth A sarcoma was used as a target cell line. The cells were suspended in RPMI medium (GIBCO Co.) supplemented with 10% FCS at a final cell density of 2 X 10" cells per mL. Fifty microliters of the cell suspension was inoculated into each well in 96-well flat-bottomed microtiter plates. The purified TCF, TCF-3 and TCF- 13 were serially diluted with RPMI medium from the concentration of 50 ng/mL, and the 50 //L of each diluted sample was added to each test well. After incubation at 37 * C for 5 days, MTT was added at a final concentration of 0.5 mg/ml and the plates were incubated at 37°C . Four hours later, 100 pi of the solution containing 10% SDS and 0.01 M NH 4 C1 was added to each well and left overnight at room temperature. Next day, the absorbance at 620 nm was measured as a parameter of the viable cell numbers in each well. Fig. 9 shows the results of the assay. TCF, TCF-3 and TCF-13 having cytotoxic activities to Meth A cells in a dose- dependent manner. Example 3 Measurement of biological half-lives of the TCF and the modified TCFs in vivo. Anti-TCF polyclonal antibody was dissolved in 0.1 M NaHC0 3 solution to a final concentration of 10μg/mL. One hundred microliters of the antibody solution was added to each well and the plates were left overnight at room temperature. The wells were filled with 50% solution of Block Ace in H 2 0, incubated for 1 hour at room temperature and washed three times with washing solution (PBS containing 0.1% Tween 20). Plasma samples periodically collected from the rats which were intravenously injected with TCF or the modified TCFs were diluted with normal rat serum, when necessary. TCF solutions serially diluted with normal rat serum (from 10 ng/mL) was used as the standard TCF solution. Fifty microliters of the sample solution and 50 L of the first buffer (0.2 M Tris HC1 pH 7.3 containing 50% Block Ace, 0.2 M NaCl, 0.1% Tween 20, 0.2% CHAPS, 20 mM Benza idine hydrochloride, and 10 M EDTA) was mixed and added to each well. The plates were left for 3 hours at 37 * C and washed three times with the washing buffer. One hundred microliters of the peroxidase- labeled anti-TCF antibody solution, which was 400-fold diluted with 0.1 M phosphate buffer pH7.0 containing 10 % Block Ace, 0.15 M NaCl, 0.1% Tween 20, 4% rat serum and 0.5% mouse IgG, was added to each well. Plates were incubated for 2 hours at 37 * C and washed three times with the washing buffer. Subsequently, 100 //L of substrate solution (0.4 mg/mL of o-phenylene diamine dihydrochloride and 0.006% Hzθ2 in 0.1 M citrate-phosphatte buffer, pH 4.5) was added to each well and incubated at 37°C for 30 minutes in a dark place. The enzyme reaction was stopped by addition of 50 //L of 6N H2SO4. The absorbance at 492 nm was measured on an immuno reader (Corona Co.). Thus concentrations of the TCF or the modified TCFs in rat serum were determined. Time course of plasma levels were examined by El A in rats after the single intravenous injection of TCF and the modified TCFs. Male Wister rats weigning about 200 g were used. After the intravenous injection of TCF to the rats, the plasma level declined biexponentially, well described by a two- compartment model. Plasma half-lives of rapid phase and slower phase were 2.4± 2.5 min.(tVzQ.) and 15.6±4.6 min. (t'/z β) in rats after the TCF injection at a dose of 50 //g/kg, respectively. Plasma level profiles of modified TCF were similar to that of the wild- type TCF, but their plasma levels declined slower than that of the wild- type TCF after the intravenous injection at the same dose. As shown in Table 2, plasma half-lives of TCF-3 and TCF-13 were prolonged and their total clearance were decreased. TCF-3 and TCF- 13 had larger AUC(the area under the plasma concentration - time curve) compared to the wild- type TCF. Table 2 : Pharmacokinetics parameters of the modified TCFs Mean ± SD Significantly difference from Wild-type TCF ( *P<0.05, ** P<0.01) Table 3 : Pharmacokinetics parameters of the modif ied TCFs Mean ± SD Significantly difference from Wild-type TCF ( *P<0.05, ** P<0.01) These results indicated that TCF-3 and TCF-13 had slower metabolic fates and have larger bioavailabilities than those of the wild-type TCF. The amino acid sequence of TCF-3 discloses in Seq. Id No.2, and the sequence of TCF- 13 discloses in Seq. Id No. 3. The modified TCFs in the present invention have longer biological half-lives, maintaining growth stimulating activities for hepatocytes and cytotoxic activities to tumor cells, and are therefore useful as therapeutic agents for liver diseases or as anti -cancer drugs. REFERENCE OF MICROORGANISM (1) P cTCF(S)/MC1061/P3 Organization of Deposition: National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry Address: 1-3, Higashi 1 chome, Tsukuba-shi, Ibaraki-ken, Japan Deposition Number: FERM BP-3479 (2) pBPV-TCF-3 Organization of Deposition: National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry Address: 1-3, Higashi 1 chome, Tsukuba-shi, Ibaraki-ken, Japan Deposition Number: FERM BP-4454 (3) pBPV-TCF-13 Organization of Deposition: National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry Address: 1-3, Higashi 1 chome, Tsukuba-shi, Ibaraki-ken, Japan Deposition Number: FERM BP-4455 SEQUENCE LISTING Seq Id No. 1 Length: 723 Type: amino acid Molecule Type: protein Sequence Met Trp Val Thr Lys Leu Leu Pro Ala Leu Leu Leu Gin His Val Leu 1 5 10 15 Leu His Leu Leu Leu Leu Pro He Ala He Pro Tyr Ala Glu Gly Gin 20 25 30 Arg Lys Arg Arg Asn Thr He His Glu Phe Lys Lys Ser Ala Lys Thr 35 40 45 Thr Leu He Lys He Asp Pro Ala Leu Lys He Lys Thr Lys Lys Val 50 55 60 Asn Thr Ala Asp Gin Cys Ala Asn Arg Cys Thr Arg Asn Lys Gly Leu 65 70 75 80 Pro Phe Thr Cys Lys Ala Phe Val Phe Asp Lys Ala Arg Lys Gin Cys 85 90 95 Leu Trp Phe Pro Phe Asn Ser Met Ser Ser Gly Val Lys Lys Glu Phe 100 105 110 Gly His Glu Phe Asp Leu Tyr Glu Asn Lys Asp Tyr He Arg Asn Cys 115 120 125 He He Gly Lys Gly Arg Ser Tyr Lys Gly Thr Val Ser He Thr Lys 130 135 140 Ser Gly He Lys Cys Gin Pro Trp Ser Ser Met He Pro His Glu His 145 150 155 160 Ser Tyr Arg Gly Lys Asp Leu Gin Glu Asn Tyr Cys Arg Asn Pro Arg 165 170 175 Gly Glu Glu Gly Gly Pro Trp Cys Phe Thr Ser Asn Pro Glu Val Arg 180 185 190 Tyr Glu Val Cys Asp He Pro Gin Cys Ser Glu Val Glu Cys Met Thr 195 200 205 Cys Asn Gly Glu Ser Tyr Arg Gly Leu Met Asp His Thr Glu Ser Gly 210 215 220 Lys He Cys Gin Arg Trp Asp His Gin Thr Pro His Arg His Lys Phe 225 230 235 240 Leu Pro Glu Arg Tyr Pro Asp Lys Gly Phe Asp Asp Asn Tyr Cys Arg 245 ' 250 255 Asn Pro Asp Gly Gin Pro Arg Pro Trp Cys Tyr Thr Leu Asp Pro His 260 265 270 Thr Arg Trp Glu Tyr Cys Ala He Lys Thr Cys Ala Asp Asn Thr Met 275 280 285 Asn Asp Thr Asp Val Pro Leu Glu Thr Thr Glu Cys He Gin Gly Gin 290 295 300 Gly Glu Gly Tyr Arg Gly Thr Val Asn Thr He Trp Asn Gly He Pro 305 310 315 320 Cys Gin Arg Trp Asp Ser Gin Tyr Pro His Glu His Asp Met Thr Pro 325 330 335 Glu Asn Phe Lys Cys Lys Asp Leu Arg Glu Asn Tyr Cys Arg Asn Pro 340 345 350 Asp Gly Ser Glu Ser Pro Trp Cys Phe Thr Thr Asp Pro Asn He Arg 355 360 365 Val Gly Tyr Cys Ser Gin He Pro Asn Cys Asp Met Ser His Gly Gin 370 375 380 Asp Cys Tyr Arg Gly Asn Gly Lys Asn Tyr Met Gly Asn Leu Ser Gin 385 390 395 400 Thr Arg Ser Gly Leu Thr Cys Ser Met Trp Asp Lys Asn Met Glu Asp 405 410 415 Leu His Arg His He Phe Trp Glu Pro Asp Ala Ser Lys Leu Asn Glu 420 425 430 Asn Tyr Cys Arg Asn Pro Asp Asp Asp Ala His Gly Pro Trp Cys Tyr 435 440 445 Thr Gly Asn Pro Leu He Pro Trp Asp Tyr Cys Pro He Ser Arg Cys 450 455 460 Glu Gly Asp Thr Thr Pro Thr He Val Asn Leu Asp His Pro Val He 465 470 475 480 Ser Cys Ala Lys Thr Lys Gin Leu Arg Val Val Asn Gly He Pro Thr 485 490 495 Arg Thr Asn He Gly Trp Met Val Ser Leu Arg Tyr Arg Asn Lys His 500 505 510 He Cys Gly Gly Ser Leu He Lys Glu Ser Trp Val Leu Thr Ala Arg 515 520 525 Gin Cys Phe Pro Ser Arg Asp Leu Lys Asp Tyr Glu Ala Trp Leu Gly 530 535 540 He His Asp Val His Gly Arg Gly Asp Glu Lys Cys Lys Gin Val Leu 545 550 555 560 Asn Val Ser Gin Leu Val Tyr Gly Pro Glu Gly Ser Asp Leu Val Leu 565 570 575 Met Lys Leu Ala Arg Pro Ala Val Leu Asp Asp Phe Val Ser Thr He 580 585 590 Asp Leu Pro Asn Tyr Gly Cys Thr He Pro Glu Lys Thr Ser Cys Ser 595 600 605 Val Tyr Gly Trp Gly Tyr Thr Gly Leu He Asn Tyr Asp Gly Leu Leu 610 615 620 Arg Val Ala His Leu Tyr He Met Gly Asn Glu Lys Cys Ser Gin His 625 630 635 640 His Arg Gly Lys Val Thr Leu Asn Glu Ser Glu He Cys Ala Gly Ala 645 650 655 Glu Lys He Gly Ser Gly Pro Cys Glu Gly Asp Tyr Gly Gly Pro Leu 660 665 670 Val Cys Glu Gin His Lys Met Arg Met Val Leu Gly Val He Val Pro 675 680 685 Gly Arg Gly Cys Ala He Pro Asn Arg Pro Gly He Phe Val Arg Val 690 695 ' 700 Ala Tyr Tyr Ala Lys Trp He His Lys He He Leu Thr Tyr Lys Val 705 710 715 720 Pro Gin Ser Seq Id No.2 Length: 723 Type: amino acid Molecule Type: protein Sequence Met Trp Val Thr Lys Leu Leu Pro Ala Leu Leu Leu Gin His Val Leu 1 5 10 15 Leu His Leu Leu Leu Leu Pro He Ala He Pro Tyr Ala Glu Gly Gin 20 25 30 Arg Lys Arg Arg Asn Thr He His Glu Phe Lys Lys Ser Ala Lys Thr 35 40 45 Thr Leu He Lys He Asp Pro Ala Leu Lys He Lys Thr Lys Lys Val 50 55 60 Asn Thr Ala Asp Gin Cys Ala Asn Arg Cys Thr Arg Asn Lys Gly Leu 65 70 75 80 Pro Phe Thr Cys Lys Ala Phe Val Phe Asp Lys Ala Arg Lys Gin Cys 85 90 95 Leu Trp Phe Pro Phe Asn Ser Met Ser Ser Gly Val Lys Lys Glu Phe 100 105 110 Gly His Glu Phe Asp Leu Tyr Glu Asn Lys Asp Tyr He Arg Asn Cys 115 120 125 He He Gly Lys Gly Arg Ser Tyr Lys Gly Thr Val Ser He Thr Lys 130 135 140 Ser Gly He Lys Cys Gin Pro Trp Ser Ser Met He Pro His Glu His 145 150 155 160 Ser Tyr Arg Gly Lys Asp Leu Gin Glu Asn Tyr Cys Arg Asn Pro Arg 165 170 175 Gly Glu Glu Gly Gly Pro Trp Cys Phe Thr Ser Asn Pro Glu Val Arg 180 185 190 Tyr Glu Val Cys Asp He Pro Gin Cys Ser Glu Val Glu Cys Met Thr 195 200 205 Cys Asn Gly Glu Ser Tyr Arg Gly Leu Met Asp His Thr Glu Ser Gly 210 215 220 Lys He Cys Gin Arg Trp Asp His Gin Thr Pro His Arg His Lys Phe 225 230 235 240 Leu Pro Glu Arg Tyr Pro Asp Lys Gly Phe Asp Asp Asn Tyr Cys Arg 245 250 255 Asn Pro Asp Gly Gin Pro Arg Pro Trp Cys Tyr Thr Leu Asp Pro His 260 265 270 Thr Arg Trp Glu Tyr Cys Ala He Lys Thr Cys Ala Asp Asn Thr Met 275 280 285 Asn Asp Thr Asp Val Pro Leu Glu Thr Thr Glu Cys He Gin Gly Gin 290 295 300 Gly Glu Gly Tyr Arg Gly Thr Val Asn Thr He Trp Asn Gly He Pro 305 310 315 320 Cys Gin Arg Trp Asp Ser Gin Tyr Pro His Glu His Asp Met Thr Pro 325 330 335 Glu Asn Phe Lys Cys Lys Asp Leu Arg Glu Asn Tyr Cys Arg Asn Pro 340 345 350 Asp Gly Ser Glu Ser Pro Trp Cys Phe Thr Thr Asp Pro Asn He Arg 355 360 365 Val Gly Tyr Cys Ser Gin He Pro Asn Cys Asp Met Ser His Gly Gin 370 375 380 Asp Cys Tyr Arg Gly Asn Gly Lys Asn Tyr Met Gly Asn Leu Ser Gin 385 390 395 400 Thr Arg Ser Gly Leu Thr Cys Ser Met Trp Asp Lys Asn Met Glu Asp 405 410 415 Leu His Arg His He Phe Trp Glu Pro Asp Ala Ser Lys Leu Asn Glu 420 425 430 Asn Tyr Cys Arg Asn Pro Asp Asp Asp Ala His Gly Pro Trp Cys Tyr 435 440 445 Thr Gly Asn Pro Leu He Pro Trp Asp Tyr Cys Pro He Ser Arg Cys 450 455 460 Glu Gly Asp Thr Thr Pro Thr He Val Asn Leu Asp His Pro Val He 465 470 475 480 Ser Cys Ala Lys Thr Lys Gin Leu Arg Val Val Asn Gly He Pro Thr 485 490 495 Arg Thr Asn He Gly Trp Met Val Ser Leu Arg Tyr Arg Asn Lys His 500 505 510 He Cys Gly Gly Ser Leu He Lys Glu Ser Trp Val Leu Thr Ala Arg 515 520 525 Gin Cys Phe Pro Ser Arg Asp Leu Lys Asp Tyr Glu Ala Trp Leu Gly 530 535 540 He His Asp Val His Gly Arg Gly Asp Glu Lys Cys Lys Gin Val Leu 545 550 555 560 Asn Val Ala Gin Leu Val Tyr Gly Pro Glu Gly Ser Asp Leu Val Leu 565 570 575 Met Lys Leu Ala Arg Pro Ala Val Leu Asp Asp Phe Val Ser Thr He 580 585 590 Asp Leu Pro Asn Tyr Gly Cys Thr He Pro Glu Lys Thr Ser Cys Ser 595 600 605 Val Tyr Gly Trp Gly Tyr Thr Gly Leu He Asn Tyr Asp Gly Leu Leu 610 615 620 Arg Val Ala His Leu Tyr. He Met Gly Asn Glu Lys Cys Ser Gin His 625 630 635 640 His Arg Gly Lys Val Thr Leu Asn Glu Ser Glu He Cys Ala Gly Ala 645 650 655 Glu Lys He Gly Ser Gly Pro Cys Glu Gly Asp Tyr Gly Gly Pro Leu 660 665 670 Val Cys Glu Gin His Lys Met Arg Met Val Leu Gly Val He Val Pro 675 680 685 Gly Arg Gly Cys Ala He Pro Asn Arg Pro Gly He Phe Val Arg Val 690 695 700 Ala Tyr Tyr Ala Lys Trp He His Lys He He Leu Thr Tyr Lys Val 705 710 ' 715 720 Pro Gin Ser Seq Id No.3 Length: 723 Type: amino acid Molecule Type: protein Sequence Met Trp Val Thr Lys Leu Leu Pro Ala Leu Leu Leu Gin His Val Leu 1 5 10 15 Leu His Leu Leu Leu Leu Pro He Ala He Pro Tyr Ala Glu Gly Gin 20 25 30 Arg Lys Arg Arg Asn Thr He His Glu Phe Lys Lys Ser Ala Lys Thr 35 40 45 Thr Leu He Lys He Asp Pro Ala Leu Lys He Lys Thr Lys Lys Val 50 55 60 Asn Thr Ala Asp Gin Cys Ala Asn Arg Cys Thr Arg Asn Lys Gly Leu 65 70 75 80 Pro Phe Thr Cys Lys Ala Phe Val Phe Asp Lys Ala Arg Lys Gin Cys 85 90 95 Leu Trp Phe Pro Phe Asn Ser Met Ser Ser Gly Val Lys Lys Glu Phe 100 105 110 Gly His Glu Phe Asp Leu Tyr Glu Asn Lys Asp Tyr He Arg Asn Cys 115 120 125 He He Gly Lys Gly Arg Ser Tyr Lys Gly Thr Val Ser He Thr Lys 130 135 140 Ser Gly He Lys Cys Gin Pro Trp Ser Ser Met He Pro His Glu His 145 150 155 160 Ser Tyr Arg Gly Lys Asp Leu Gin Glu Asn Tyr Cys Arg Asn Pro Arg 165 170 175 Gly Glu Glu Gly Gly Pro Trp Cys Phe Thr Ser Asn Pro Glu Val Arg 180 185 190 Tyr Glu Val Cys Asp He Pro Gin Cys Ser Glu Val Glu Cys Met Thr 195 200 205 Cys Asn Gly Glu Ser Tyr Arg Gly Leu Met Asp His Thr Glu Ser Gly 210 215 220 Lys He Cys Gin Arg Trp Asp His Gin Thr Pro His Arg His Lys Phe 225 230 235 240 Leu Pro Glu Arg Tyr Pro Asp Lys Gly Phe Asp Asp Asn Tyr Cys Arg 245 250 255 Asn Pro Asp Gly Gin Pro Arg Pro Trp Cys Tyr Thr Leu Asp Pro His 260 265 270 Thr Arg Trp Glu Tyr Cys Ala He Lys Thr Cys Ala Asp Asn Thr Met 275 280 285 Gin ASP Thr Asp Val Pro Leu Glu Thr Thr Glu Cys He Gin Gly Gin 290 295 300 Gly Glu Gly Tyr Arg Gly Thr Val Asn Thr He Trp Asn Gly He Pro 305 310 315 320 Cys Gin Arg Trp Asp Ser Gin Tyr Pro His Glu His Asp Met Thr Pro 325 330 335 Glu Asn Phe Lys Cys Lys Asp Leu Arg Glu Asn Tyr Cys Arg Asn Pro 340 345 350 Asp Gly Ser Glu Ser Pro Trp Cys Phe Thr Thr Asp Pro Asn He Arg 355 360 365 Val Gly Tyr Cys Ser Gin He Pro Asn Cys Asp Met Ser His Gly Gin 370 375 380 Asp Cys Tyr Arg Gly Asn Gly Lys Asn Tyr Met Gly Asn Leu Ser Gin 385 390 395 400 Thr Arg Ser Gly Leu Thr Cys Ser Met Trp Asp Lys Asn Met Glu Asp 405 410 415 Leu His Arg His He Phe Trp Glu Pro Asp Ala Ser Lys Leu Asn Glu 420 425 430 Asn Tyr Cys Arg Asn Pro Asp Asp Asp Ala His Gly Pro Trp Cys Tyr 435 440 445 Thr Gly Asn Pro Leu He Pro Trp Asp Tyr Cys Pro He Ser Arg Cys 450 455 460 Glu Gly Asp Thr Thr Pro Thr He Val Asn Leu Asp His Pro Val He 465 470 475 480 Ser Cys Ala Lys Thr Lys Gin Leu Arg Val Val Asn Gly He Pro Thr 485 490 495 Arg Thr Asn He Gly Trp Met Val Ser Leu Arg Tyr Arg Asn Lys His 500 505 510 He Cys Gly Gly Ser Leu He Lys Glu Ser Trp Val Leu Thr Ala Arg 515 520 525 Gin Cys Phe Pro Ser Arg Asp Leu Lys Asp Tyr Glu Ala Trp Leu Gly 530 535 540 He His Asp Val His Gly Arg Gly Asp Glu Lys Cys Lys Gin Val Leu 545 550 555 560 Asn Val Ala Gin Leu Val Tyr Gly Pro Glu Gly Ser Asp Leu Val Leu 565 570 575 Met Lys Leu Ala Arg Pro Ala Val Leu Asp Asp Phe Val Ser Thr He 580 585 590 Asp Leu Pro Asn Tyr Gly Cys Thr He Pro Glu Lys Thr Ser Cys Ser 595 600 605 Val Tyr Gly Trp Gly Tyr Thr Gly Leu He Asn Tyr Asp Gly Leu Leu 610 615 620 Arg Val Ala His Leu Tyr He Met Gly Asn Glu Lys Cys Ser Gin His 625 630 635 640 His Arg Gly Lys Val Thr Leu Asn Glu Ser Glu He Cys Ala Gly Ala 645 650 655 Glu Lys He Gly Ser Gly Pro Cys Glu Gly Asp Tyr Gly Gly Pro Leu 660 665 670 Val Cys Glu Gin His Lys Met Arg Met Val Leu Gly Val He Val Pro 675 680 685 Gly Arg Gly Cys Ala He Pro Asn Arg Pro Gly He Phe Val Arg Val 690 695 700 Ala Tyr Tyr Ala Lys Trp He His Lys He He Leu Thr Tyr Lys Val 705 710 715 720 Pro Gin Ser

Claims: CLAIMS 1. The modified TCFs which are characterized by that the amino-acid residues responsible for binding of N-linked oligosaccharide chains are modified so that at least one of the N-linked oligosaccharide chains is prevented from binding to TCF. 2. The modified TCFs according to claim 1, in which one of the residues responsible for N-glycosylation is substituted with other amino-acid residues so that the N-linked oligosaccharide chain(s) are prevented from binding to Asn residue(s) at positions 289th, 397th, 561stst and/or 648th from N-terminal in its amino-acid sequence described in Sequence 1. 3. The modified TCF according to claim 1, in which Ser at position 563rd is substituted with Ala. 4. The modified TCF according to claim 1, in which Asn at position 289th is substituted with Gin, and Ser at position 563rd is substituted with Ala. 5. Modified TCF, a glycoprotein to which DNA sequence encoding the amino-acid sequence described in Sequence 2 is expressed. 6. Modified TCF, a glycoprotein to which DNA sequence encoding the amino-acid sequence described in Sequence 3 is expressed.

Inventors: GOTO MASAAKI, HIGASHIO KANJI, MASUNAGA HIROAKI, MURAKAMI AKIHIKO, OOGAKI FUMIKO, SHIMA NOBUYUKI, TAKAHIRA REIKO, TSUDA EISUKE, UEDA MASATSUGU, YAMAGUCHI KYOJI, GOTO, MASAAKI, HIGASHIO, KANJI, MASUNAGA, HIROAKI, MURAKAMI, AKIHIKO, OOGAKI, FUMIKO, SHIMA, NOBUYUKI, TAKAHIRA, REIKO, TSUDA, EISUKE, UEDA, MASATSUGU, YAMAGUCHI, KYOJI
Applicants: GOTO MASAAKI, HIGASHIO KANJI, MASUNAGA HIROAKI, MURAKAMI AKIHIKO, OGAKI FUMIKO, SHIMA NOBUYUKI, SNOW BRAND MILK PROD CO LTD, TAKAHIRA REIKO, TSUDA EISUKE, UEDA MASATSUGU, YAMAGUCHI KYOJI, GOTO, MASAAKI, HIGASHIO, KANJI, MASUNAGA, HIROAKI, MURAKAMI, AKIHIKO, OOGAKI, FUMIKO, SHIMA, NOBUYUKI, SNOW BRAND MILK PRODUCTS CO., LTD., TAKAHIRA, REIKO, TSUDA, EISUKE, UEDA, MASATSUGU, YAMAGUCHI, KYOJI
Application year: 1993
Main classification: C07K15
IPC codes: A61K38, A61P35, C07K14, C12N1, C12N15, C12P21, C12R1