HUMAN PROUROKINASE-LIKE POLYPEPTIDES AND THEIR PREPARATION METHODS

Abstract: Human prourokinase derivatives in which oligopeptides capable of forming a covalent bond with a blood clot (thrombus) through enzymatic action of human blood coagulation factor XIII are attached to the NH2-terminal.

Description: Description Human prourokinase-like polypeptides and their preparation methods Technical Field : This invention rel ates to methods f or the preparation of human prourokinase-like polypeptides with binding ability through covalent bonds with blood clots, by means of gene engineering. The said peptides have a function as a thrombolytic agent. Background Art: Human urokinase is an enzyme present in human urine in a trace amount, and can convert the inactive plasminogen to the active plas in. The formed plasmin can lyse blood clots. Owing to this fact, human urokinase is clinically used widely as a thrombolytic agent. However, human urokinase has low affinity with blood clot and is of the active form. Therefore it activates not only plasminogen at or in the vicinity of the blood clot but also plasminogen in the circulation, resulting in formation of a large amount of plasmin in the circulation. The extensive plasmin formation in the circulation modifies platlet function (Blood: Vol.68, p275, 1986) and degrades circulating fibrinogen and clotting factors V and VIII (Blood: Vol.68, pl280, 1986), also carried the risk of grave side effect of systemic hemorrhage, which often results in death (Journal of American Colleague Cardiology: Vol.10, p970, 1987). The ideal thrombolytic agent should be capable of attacking the components of a thrombus while sparing the circulating clotting proteins and platlets and have an appropriate half life in vivo. In recent years, human prourokinase and tissue plasminogen activator (hereinafter referred to as tPA) are under development as the second generation thrombolytic agents. These agents activate the plasminogen specially in close proximity to a thrombus. Therefore, excessive administration of the agent carries less risk of grave side effect of systemic hemorrhage. However, human prourokinase has better affinity with thrombus than human urokinase, but not enough yet. The tPA has such defects as a large amount of inhibitor (plasminogen activator inhibitor " I) present in the blood, a short half life so that therapeutic effects are not expected unless a large amount is administered, and occurrence of reocclusion after artery recanalization by thrombolysis in many cases (Circulation: Vol.73, p347, 1986; New England Journal of Medicine: Vol.317, p581, 1987). Substances which are not inactivated irreversibly by plasminogen activator inhibitor I and which have better affinity with blood clot than human prourokinase does are imagined as ideal thrombolytic agents. Attempts have been made to produce such substances. A first of such substances is a chimeric substance in which the NH 2 - terminal region of tPA is fused with the COOH-terminal region of human prourokinase having an enzymatic activity to activate the plasminogen, and produced by recorπbinant DNA technology, with recognition that the Hz -terminal region of tPA has high affimity with the blood clot (The Journal of Biological Chemistry, Vol.268, pl0855, 1987; Thrombosis and Haemostasis, Vol.54, p893, 1985). However, contrary to the expectation, this sunstance has not affinity to blood clot so much as that of tPA. A second of the substances is a chimeric substance in which about 560 amino acids at the NH2-terminal side which has affinity to the blood clot is combined chemically with the COOH-terminal region of human prourokinase, same as that described above (Biochemistry, Vol.25, p3603, 1986). A third is a chimeric substance made by chemically combining an antibody against fibrin which is a major component of blood clot, with the COOH-terminal region of human prourokinase, same as that described above (Clinical Research Abstract, Vol.36, p265A, 1989). The second and third substacnes have improved affinity to blood clot, being as a result expected to improve the thrombolytic effect. Economical manufacturing of these second and third substances is however difficult. Further, urokinase derivatives are reported (PCT/SU84/00008: O84/04536) and such derivatives bind with fibrin through fibrinogen chemically linked to urokinase beforehand. Further more, it is reported that an oligopeptide forms covalent bonds with fibrin enzymatically due to the action of blood coagulation factor XIII and it is suggested that affinity of urokinase with blood clot is improved by bonding such oligopeptide with urokinase (PCT/US88/0227 : WO89/00051). However the inventors of this application recognized in their study that affinity of urokinase with blood clot is scarcely improved by bonding such oligopeptide with urokinase. The purpose of this invention is human prourokinase-like polypeptides with better affinity to blood clot than that of human prourokinase, and is to provide a method to prepare the said polypeptides economically. Disclosure of Invention : This invention is human prourokinase-like polypeptides (which hereinafter may be referred to as the human prourokinase-like polypeptides of this invention) made by adding an oligopeptide having a structure to form a covalent bonds with blood clot through enzymatic action of the human blood coagulation factor XIII (which hereinafter may be referred to as the oligopeptide(s) ) , to the NH2 -terminal side of a human prourokinase derivative (which hereinafter may be referred to as the human prourokinase derivative(s) ). Best Mode for Carrying Out The Invention : This invention is described in detail. (A) The oligopeptides There are substances capable of forming covalent bonds with fibrin, a major component in the blood clot, in a human body. The inventors studied the details of the a ino acid sequences of a ~ .antiplasmin, fibronectin and fibrinogen -chain, which are representatives of the said substances, and found that the structure of the sequence of several 10 amino acids at the NH2 - terminal side is ... Gl QO V l (° r Leu)QPro(or Gly)... (where O stands for an amino acid) and that a peptide with such an amino acid sequence has capability of forming covalent bonds with such components as fibrin through the enzymatic action of human blood coagulation factor XIII (active form). Thus this invention has been completed. The oligopeptide may be an oligomer with a structure allowing to form covalent bonds with blood clot through the enzymatic action of blood coagulation factor XIII (active form). Concrete examples are those with the structure of ... Gin 00 Vai (° r Leu)0Pro(or Gly)... The oligopeptide is not limited to oligopeptides at the NH 2 -terminal side of each of fibrinogen 7 -chain, a 2.antiplasmin and fibronectin, from the object of this invention. The following are preferable concrete examples of the oligopeptides. Name of the oligopeptide Amino acid sequence A (Met. )Asn.Gln.Glu.Gln.Val.Ser.Pro.Leu.Thr.Leu.Leu.Lys. F (Met. )Gln.Ala.Gln.Gln.Met.Val.Gln.Pro.Gln.Ser.Pro.Val. Ala.Val.Lys. Vi (Met. )Ala.Gln.Lys.Met.Val.Gln.Pro.Leu.Thr.Leu.Leu.Lys. V 2 (Met. )Ala.Gln.Lys.Met.Val.Gln.Pro.Gln.Thr.Leu.Leu.Lys. V 3 (Met. )Gln.Glu.Gln.Val.Ser.Pro.Gln.Thr.Leu.Leu.Lys. V« (Met. )Asn.Gln.Asp.Gln.Val.Ser.Pro.Gln.Thr.Leu.Leu.Lys. V 5 (Met.)Asn.Gln.Glu.Asn.Val.Ser.Pro.Gln.Thr.Leu.Leu.Lys. Ve (Met. )Asn.Gln.Ser.Met.Val.Ser.Pro.Gln.Thr.Leu.Leu.Lys. where (Met) is methionine which may be present in some cases. (B) The human prourokinase derivatives The human prourokinase derivatives include those that do not contain the whole amino acid sequences of human prourokinase, those containing amino acid sequences of the region necessary and sufficient to exhibit the enzymatic action for activating plasminogen (for instance, those with defect of from the first serine to the third glutamic acid or from the first serine to the 143th glutamic acid of the amino acid sequence of human prourokinase) or those of which part of amino acids is changed to a desirable form [for instance, those of which one or both of the 135th lysine and 156th arginine are changed to an amino acid other than basic amino acid (e.g. glutamic acid); and those whose 157th phenylalanine is changed to an acidic amino acid (e.g. aspartic acid)] . (C) The human prourokinase-like polypeptides of this invention The human prourokinase-like polypeptides of this invention can be produced in a wide variety by combining the human prourokinase derivatives and the oligopeptides. Preferable concrete examples are shown in parallel to the amino acid sequence of natural human prourokinase. The amino acid sequence is illustrated only by portions different from the amino acid sequence of natrural human prourokinase and the amino acid sequence in their neighborhood by one letter abbreviation. amino acid sequence 1 135 144 human prourokinase SNELHQVP ••• GKKPSSPPEELKFQC 156 ••• RPRFKIIGG ••• human prourokinase-like polypeptides of this invention AHUK(q,q) (M)NQEQVSPLTLLKLSNEI_HQVP ••• GQKPSSPPEELKFQC ••• RPQFKIIGG ••• APUK(q,q) (M)NQEQVSPLTLLKLHQVP ••• GQKPSSPPEELKFQC ••• RPQFKIIGG ••• APUK(k,q) (M)NQEQVSPLTLLKLHQVP ••• GKKPSSPPEELKFQC ••• RPQFKIIGG*•• APϋK(k,d) (M)NQEQVSPLT______KLHQVP ••• GKKPSSPPEELKFQC ••• RPRDKIIGG««« APUK(k,k) (M)NQEQVSPLTLLKLHQVP ••• GKKPSSPPEELKFQC ••• RPRFKIIGG ••• FPUK(q,q) (M)QAQQMVQPQSPVAVKLHQVP ••• GQKPSSPEELKFQC ••• RPQFKIIGG ••• Vi PUK(k,q) (M)AQKMVGPLTLLKLHQVP ••• GKKPSSPPEELKFQC ••• RPQFKIIGG ••• V 2 PUK(k,q) (M)AQKMVGPQTLLKLHQVP ••• GKKPSSPPEELKFQC ••• RPQFKIIGG ••• ACUK(-,q) (M)NQEQVSPLTLLKLKFQC ••• RPQFKIIGG ••• FCϋK(-,q) (M)QAQQMVQPQSPVAVKLKFQC ••• RPQFKIIGG ••• where (M) is methionine which may be present in some cases. (D) Gene system of the human prourokinase-like polypeptides of this invention and their preparation method The DNA segment encoding the human prourokinase-like polypeptides of this invention consists of the product formed by linking a DNA encoding the amino acid sequence of oligopeptide with a structure allowing to form covalent bond with blood clot (such as fibrin of a major component) through the enzymatic action of human blood coagulation factor XIII (active form) (hereinafter referred to the oligopeptide), with a DNA encoding the amino acid sequence of the human prourokinase derivative. The DNA encoding the amino acid sequence of the oligopeptide is a DNA of continuously bound codons, each of which encodes an amino acid. All amino acid codons are applicable as the codons. Codons which are easily expressed in a host cell used are preferably used, and also use of codons which do not form a folded structure at the level of messenger RNA due to the series of these codons is preferable. Such DNA segments designed to a desirable form can be easily prepared by chemical synthesis. Examples of preferable DNA segments encoding the oligopeptides are described below. A Amino acid sequence: (Met)Asn.Gln.Glu.Gln.Val .Ser.Pro.Leu.Thr.Leu.Leu.Lys. DNA ATC.MC. CAG.GM. CAG.GTG.TCT .C(_G.TTC.ACT.TTC. CTT.M F Amino acid sequence: (Met)Gin. la.Gin.Gin.Met.Val.Gin.Pro.Gin.Ser.Pro.Val. DNA ATG.CAG.GC^.CM.CAG.ATG.GTT.CM.CCT.CAG.TCA.CCG.GTT. Ala.Val.Lys. GCT.GTT.AAG. Vi Amino acid sequence: (Met) la.Gin.Lys.Met.Val.Gin.Pro. eu.Thr.Leu.Leu.Lys. DNA ATG.GC_A.CM.AM.ATG.GTT.CAG.CCG.CTG.ACC.TTG.CTT.AAG. V. Amino acid sequence: (Met)Ala.Gin.Lys.Met.Val.Gin.Pro.Gin.Thr.Leu.Leu.Lys. DNA ATG.GC^.O^.AM.ATC.GTT.CAG.CCG.CM.ACT.COT.CTT.MG. V 3 Amino acid sequence: (Met) .Gin.Glu.Gin.Val.Ser. ro. DNA ATG CAG GM CAG GTG TCT CCG Gin.Thr.Leu.Leu.Lys. CAG ACT TTG CTT MG V 4 Amino acid sequence: (Met) .Asn.Gin. sp.Gin.Val.Ser. DNA ATG MC CAG GAC CAG GTG TCT Pro.Gin.Thr.Le .Leu.Lys. CCG CAG ACT TTG CTT MG V 5 Amino acid sequence: (Met).Asn.Gin.Glu.Asn.Val.Ser. DNA ATG AAC CAG GM MC GTG TCT Pro.Gin.Thr. eu.Leu.Lys. CCG CAG ACT TTG CTT MG V 6 Amino acid sequence: (Met) .Asn.Gin.Ser.Met.Val.Ser. DNA ATG MC CM TCT ATG GTG TCT Pro.Gin.Thr.Leu.Leu.Lys. CCG CAG ACT TTG CTT MG where (Met) is methionine which may be present in some cases. A DNA segment encoding the human prourokinase derivative is obtained from a DNA encoding natural human prourokinase. In this case, more " preferable results are obtained if a DNA encoding natural human prourokinase is changed to a codon which is easily expressed in the host cell used or to a codon which does not form a folded structure at the level of messenger RNA, though the DNA can be used as it is. A human prourokinase-like polypeptide from which the first serine to the third glutamic acid are deleted is accumulated in E.coli cells in larger amount than human prourokinase with no amino acids deleted. Preferable concrete examples of the human prourokinase derivatives are described. (1) Derivatives of which the codon encoding the second to eighth amino acids from the NH 2 -terminal side of the amino acid sequence of natural human prourokinase is a codon described in 1 below (in the case of human prourokinase with defect of the first to third amino acids, the codon encoding the amino acids of the fourth Leu to the eighth Pro). 1. Asn 2 .Glu 3 .Leu 4 .His 5 .Gin 6 .Val 7 .Pro 8 AAC. GAG. CTC. CAC. CAG. GTT. CCG (2) In the case of human prourokinase derivatives with defect from the first serine to 143th glutamic acid, derivatives of which the codon encoding leucine and lysine corresponding to the 144th and 145th is a codon described in 2 below. 2. Leu 141 .Lys 1 5 CTC. AAG (3) In the case of human prourokinase derivatives whose 156th arginine is changed to glutamine, derivatives of which the codon encoding the amino acids from the 156th glutamine to 162th glycine is a codon described in 3. 3. Gin 15β .Phe 157 .Lys 1 8 .lie 159 .He 1 G0 .Gly I(il .Gly 1 β2 CAG. TTT. AM. ATC. ATT. GGC. GGC The DNA fragment encoding the human prourokinase-like polypeptides of this invention can be inserted to the expression plasmid. Concrete DNA base sequence and corresponding amino acid sequence are shown in Fig. 5 (FCUK(-,q)), Fig. 6 (AHUK(q,q)), Fig.7 (APUK(k,k)) and Fig. 8 (APUK(k,q) ) . The intended product is accumulated in the host cell or in the culture solution by culturing the transformant (host cell) transformed by the transduction of the expression plasmid. When E. coli is used as a host cell, the intended product is usually obtained as insoluble precipitate after cell disruption by such a means as ultrasonication or Gaulin homogenizer. The precipitate is dissolved in an aqueous solution such as of guanidine hydrochloride or urea, and treated in such a way as oxidation by air in the presence of thiol compound in order to reconstruct the original steric structure of the intended product. It is then purified using such a method as fractional precipitation by salting out with ammonium sulfate, hydrophobic chromatography, or metal chelate chromatography. Generally employed biochemical purification technologies other than the above can be applied. The human prourokinase-like polypeptides of this invention are thus prepared with economical advantage. [Example ] This invention is further described in detail by reference to the following examples. The using conditions of restriction enzymes, isolation methods of DNA fragments and synthesized double strand DNAs used, in the examples are described below. (1) Reaction of each restriction enzyme Into 50 1 of each of the following reaction solutions containing l μ g of DNA (plasmid or DNA fragment) was added 10 units of each restriction enzyme, and the solutions were incubated at a relevant temperature described below for two hours. When partial digestion was carried out, 1 to 2 units of restriction enzyme was added and the solutions were incubated for 0.5 to an hour. restriction Composition of reaction solution (m mole) reaction enzyme Tris-hydrochloric NaCl MgC mercapto- bovine temperature name acid buffer (pH) (KC1) ethanol serum (°C (dithio albumin -threitol] (%_ AatI 10 (7.5) (50) 10 1 37 Ace 1 10 (8.5) 200 7 7 60 Axy I 10 (7.5) 100 7 7 37 Afl I 10 (8.0) (40) 7 7 0.01 37 Bal I 20 (8.5) 7 7 0.01 37 BamHl 6 (7.9) 150 6 30 Ban 1 6 (7.4) 50 6 10 37 BspHl 10 (7.4) (100) 10 0.01 37 Dra I 10 (8.0) (40) 7 37 EcoRI 100 (7.5) 50 5 37 Eco47 M 10 (8.5) (80) 7 0.01 37 HindM 10 (7.5) 60 7 37 Kpn I 10 (7.5) 7 7 37 Nar I 6 (7.4) 6 6 37 Nae I 10 (8.0) 20 1 6 0.01 37 Nco I 10 (8.5) 80 7 0.01 37 Pst I 10 (7.5) 100 10 37 Sea I 6 (7.4) 100 6 (i; 37 (2) Blunting reaction of DNA with T DNA polymerase Into 50 μ 1 of the following reaction solution containing 1 to 2 μ g of linear DNA was added 0.5 to 1 unit of T < DNA polymerase to incubate at 37 °C for an hour. [Composition of reaction solution] 67mM of Tris hydrochloric acid (pH 8.8), 6.7mM of MgCl 2 , 16.6 / M of (NHU ) SO , lOmM of β -mercaptoethanol, 6.7 μ M of ethylenediaminetetraacetic acid, 0.0167% of bovine serum albumin, 330/ M of dCTP, 330// M of dATP, 330/ M of dGTP and 330/ M of dTTP. (3) Blunting reaction of DNA with Klenow fragment Into 50/ 1 of the following reaction solution containing 1 to 2// g of linear DNA was added 0.5 to 1 unit of Klenow fragment to incubate at 25°C for an hour. [Composition of reaction solution] 67mM of potassium phosphate buffer (pH 7.4), 6.7mM of MgCL 2 , ImM of/S- mercaptoethanol, 33 M of dATP, 33u/ / M of dTTP, 33 / M of dGTP and 33 M of dCTP. (4) Ligation reaction of DNA by T 4 DNA ligase Into 7.5/ 1 of DNA solution containing (about 0.1 μ g of) DNA fragment to be ligated were mixed 60 / 1 of Solution A of "DNA ligation kit" made by Takara Shuzo Co. and 7.5/ 1 of Solution B of the same (containing T < DNA ligase) to incubate at 16 °C for 30 minutes. (5) Isolation of DNA fragment and others After each plasmid was digested with restriction enzyme, the intended DNA fragment was isolated by agarose electrophoresis. The DNA fragment obtained by electric elution was extracted with phenol and chloroform, and purified by precipitation with ethanol . E . coli JM103 strain was transformed by each plasmid prepared . The transformant was investigated by quick isolation method by alkaline lysis , and a clone with the intended plasmid was obtained . ( 6 ) Synthesized double herical DNA used The synthesized double strand DNAs used to prepare an intended plasmid were produced according to the following procedure : Each single chain DNA oligomer was synthesized by amidite method , purified by OPC cartridge (Applied Biosystem Co. ) , and dried . Each pair of isolated DNA was dissolved in a buffer (pH 7.6 ) of 20mM of Tris-hydrochloric acid and lOmM of MgCl 2 , heated at 95 °C for 2 minutes, gradually cooled down to room temperature, and then kept at 12°C for over night to anneal . The double strand DNAs described below were thus obtained. Name of the Synthesized double herical DNA HL-A 5 ' - TTAAGCTGAGCMCGAGCT - 3 ' HL-B 3 ' - CGACTCGTTGC - 5 ' CUK-A 5 ' - CAAG]_TTCAGTG__GG - 3 ' CUK-B 3 ' - TCGAGTTCAMGTCACACC - 5 ' AP-A 5 ' - CATXSMCCAGGMCAGGTCTCTCCGTTGACTTTGCTTMGCT - 3 ' AP-B 3 ' -TG»GTACT^3GTCC rCTCCACAGAGGCMCTGMACGAAT - 5 ' FN-A 5 ' -CATGCAGGCACM(^GATX3GTTCMCCTCAGTCACCGGTTGCTG - 3 ' FN-B 3 ' -GTCCGTGTTGTCTACCAAGTTX^AGTCAGTGGCCAACGACMTT - 5 ' V. -A 5 ' -CATGGC_ACAAAAMTC_G__TCAGCCGCI_GACCTTGC- 3 ' Vi -B 3 ' - CCTGTiTi IACCAAGTCGGCGACTGGAACGMTr - 5 ' V 2 -A 5 ' -CATGGC_AαW^AMTGGTTCAGCCGCAMCTCTTC- 3 ' V 2 -B 3 ' - CGTG]_ I __TACCMCTCGGCGTTTGAGAAGMTT-- 5 ' V 3 -A 5 ' - C_ATGCAGGM(__AGGTGTCTCCGCAGACTTTGCTTMGCT - 3 ' V 3 _B 3 ' - TGCACTACGTCC3_TCTCCACAGAGGCGTCTGAMCGMT - 5 ' V« -A 5 ' - CATGΛACCAGGACCAGGTGTCTCCGCAGACTTTGCTTAAGCT - 3 ' V 4 -B 3 ' - TGC_AGTACTTGGTCCTGGTCCACAGAGGCGTCTGAMCGMT 5 ' V 5 -A 5 ' - CATGMCCAGGAAMCGTCTCTCCGCAGACTTTGCTTAAGCT 3 ' V 5 -B 3 ' - TGCAGTACTTGGTCCTTTTGCACAGAGGCGTCTGAMCGMT 5 ' V 6 -A 5 ' - CATGMCCAATCTATGGTGTCTCCGCAGACTTTGCTTAAGCT 3 ' V 6 -B 3 ' - TGCAGTACTT∞TTAGATACCACAGAGGCGTCTGAAACGMT 5 ' TUK1-A 5 ' - G :CTCAGTTTAAMTCATTGGCGGCG- 3 ' TUK1-B 3 ' - ACTCAMTTΓΓAGTMCCGCCGCTTA -5 ' TUK2-A 5 ' -GCCTCGCGATAAMTCATTGGCGGCG - 3 ' TUK2-B 3 ' - AGCGCTATTTTAGTMCCGCCGCTTM- 5 CROSD-A 5 ' - CTAGATMGGAGGTGAAMCCATG- 3 ' CROSD-B 3 ' - TATTCCTCCACTTTTGGTAC- 5 ' Example 1 Preparation of plasmid pACUK (-,q)/5, plasmid pFCUK (-,q)/5, plasmid pVjPUK (k,q)/5 and plasmid pV 2 PUK (k,q)/5 About 3.9kb of DNA fragment isolated after plasmid pHUK (q,q)/0 was digested with restriction enzymes Bal I and Sac I and synthesized oligomer CUK- A/B were linked by T 4 DNA ligase to give plasmid pCUK (-,q)/0. About 3.9kb of DNA fragment isolated after plasmid pCUK (-,q)/0 was digested with restriction enzymes Aat II and Sac I and synthesized oligomer AP- A/B were linked by T 4 DNA ligase to give plasmid pACUK (-,q)/0. Plasmid p9420 was digested with restriction enzyme Nco I and treated with alkaline phosphatase and a DNA fragment containing urokinase gene which was isolated after plasmid pACUK (-,q)/0 was digested with restriction enzyme BspH I were linked by T 4 DNA ligase to give plasmid pACUK (-,q)/5. About 5.4kb of DNA fragment isolated after plasmid pACUK (-,q)/5 was digested with restriction enzymes Aat II and Afl II, about 0.5kb of DNA fragment isolated after plasmid p9410 was digested with restriction enzymes Aat II and Nco I, and synthesized oligomer FN-A/B were linked by T 4 DNA ligase to give plasmid pFCUK (-,q)/5. About 5.8kb of DNA fragment isolated after plasmid pAPUK (k,q)/5 was digested with restriction enzymes Aat II and Afl II, about 0.5kb of DNA fragment isolated after plasmid p9410 was digested with restriction enzymes Aat II and Nco I, and synthesized oligomer Vi -A/B were linked by T DNA ligase to give plasmid pViPϋK (k,q)/5. About 5.8kb of DNA fragment isolated after plasmid pAPUK (k,q)/5 was digested with restriction enzymes Aat II and Afl II, about 0.5kb of DNA fragment isolated after plasmid p9410 was digested with restriction enzymes Aat II and Nco I, and synthesized oligomer V 2 -A/B were linked by T 4 DNA ligase to give plasmid pV 2 PϋK (k,q)/5. Example 2 Preparation of plasmid pAPUK (q,q)/5 and plasmid pFPUK (q,q)/5 About 4.3kb of DNA fragment isolated after plasmid pHUK (q,q)/0 was digested with restriction enzymes Aat II and Sac I and synthesized oligomer AP- A/B were linked by T 4 DNA ligase to give plasmid pAPUK (q,q)/0. About 1.2kb of DNA fragment isolated after plasmid pAPUK (q,q)/0 was digested with restriction enzymes Afl II and BamH I and about 5.1kb of DNA fragment isolated after plasmid pACUK (-,q)/5 was digested with restriction enzymes Afl II and BamH I were linked by T 4 DNA ligase to give plasmid pAPUK (q.q)/5. About 5.8kb of DNA fragment isolated after plasmid pAPUK (q,q)/5 was digested with restriction enzymes Aat II and Afl II, about 0.5kb of DNA fragment isolated after plasmid p9410 was digested with restriction enzymes Aat II and Nco I and synthesized oligomer FN-A/B were linked by T 4 DNA ligase to give plasmid pFPUK (q,q)/5. Example 3 Preparation of plasmid pAHUK (q,q)/5, plasmid pAPUK (k,k)/5, plasmid pAPUK (k,q)/5 and plasmid pAPUK (k,d)/5 About 4.9kb of DNA fragment isolated after plasmid pAPUK (q,q)/5 was digested with restriction enzymes Afl II and BamH I, about 1.4kb of DNA fragment isolated after plasmid pHUK (q,q)/0 was digested with restriction enzymes BamH I and Sac I and synthesized oligomer HL-A/B were linked by T 4 DNA ligase to give plasmid pAHUK (q,q)/5. E. coli HB101 containing plasmid pAHUK (q,q)/5 is deposited as FERM BP-2467 to the Fermentation Research Institute, Agency of Industrial Science & Technology, Ministry of International Trade and Industry. About 5.2kb of DNA fragment isolated after plasmid pAPUK (q,q)/5 was digested with restriction enzymes Hind III and Pst I and about l.lkb of DNA fragment isolated after plasmid pMUT4H was digested with restriction enzymes Hind III and Pst I were linked by T 4 DNA ligase to give plasmid pAPUK (k,k)/5. E. coli HB101 containing plasmid pAPUK (k,k)/5 is deposited as FERM BP-2465 to the Fermentation Research Institute, Agency of Industrial Science & Technology, Ministry of International Trade and Industry. About 5.5kb of DNA fragment isolated after plasmid pAPUK (k,k)/5 was digested with restriction enzymes Bal I and BamH I and about 0.75kb of DNA fragment isolated after plasmid pCUK (-,q)/0 was digested with restriction enzymes Bal I and BamH I were linked by T 4 DNA ligase to give plasmid pAPUK (k,q) l ~ . E. coli HB101 containing plasmid pAPUK (k,q)/5 is deposited as FERM BP-2466 to the Fermentation Research Institute, Agency of Industrial Science & Technology, Ministry of International Trade and Industry. About 5.5kb of DNA fragment isolated after plasmid pAPUK (k,k)/5 was digested with restriction enzymes Bal I and BamH I and about 0.75kb of DNA fragment isolated after plasmid pHUK (q,d)/0 was digested with restriction enzymes Bal I and BamH I were linked by T 4 DNA ligase to give plasmid pAPUK (k,d) l ~ . Example 4 Expression of human prourokinase-like polypeptides gene by E. coli Plasmids pAHUK (q,q)/5, pAPUK (q,q)/5, pAPUK (k,q)/5, pAPUK (k,d)/5, pAPUK (k,k)/5, pFPUK (q,q)/5, pACUK (-,q)/5, pFCUK (-,q)/5, pVjPUK (k,q)/5 and pV 2 PϋK (k,q)/5, which were obtained in Exanples 1, 2 and 3, were each transformed to E. coli JM103 strain according to a usual method. Each of the obtained transfor ants was cultured aerobically in 50- m of L-broth at 37 °C . When the absorbance at 600nm became about 1.0, 0.5 mi of lOOmM isopropyl thiogalactopyranoside (IPTG) was added, and culture was continued for another 4 hours to express each human prourokinase-like polypeptide gene. Example 5 Extraction and purification of gene products from E. coli lOg of each of wet cells obtained in Example 4 was suspended in 100m of lOmM glycine-NaOH buffer (pH 9.0, and containing 0.1M of NaCl and 5mM of EDTA), to which 50mg of lysozyme was added and stirred for an hour while cooled with ice. Then the cells were disrupted by ultrasonication. Immediately after the disruption, the cells were centrifuged at 4°C and 12,000 rpm for 30 minutes to give precipitate. The obtained precipitate was washed with lOmM glycine-NaOH buffer (pH 9.0) several times, and dissolved with stirring in a solution of 500 ■π£ of 0.1M glycine-NaOH buffer (pH 9.0) to which 500m of 8M guanidine hydrochloride was added. Deionized water, 1M glycine-NaOH buffer (pH 9.0), EDTA and reduced glutathione were added to the resulting solution to make 4L (final concentration: 1.0M of guanidine hydrochloride, 0.04M of glycine, l M of EDTA and 0.2mM of reduced glutathione). The obtained solution was let stand at room temperature over night for refolding. The solution was concentrated by ultrafiltration (exclusion molecular weight: 6000). A crude product was obtained from the solution by salting out with 25% to 55% saturation of ammonium sulfate. The crude product was dissolved in 50mM phosphate buffer (pH 7.5, and containing 0.5M of guanidine hydrochloride and 0.6M of ammonium sulfate), and insoluble matter was removed by centrif gation. The supernatant was adsorbed in a phenyl Sepharose (Pharmacia Co.) column which was equilibrated with the same buffer, and sufficiently washed with the same buffer, then eluted with the same buffer but not containing ammonium sulfate to collect the elution fraction containing the intended product. This fraction was adsorbed on a Zn-chelate (Cu chelate for ACUK (-,q) and FCUK (-,q)) Sepharose (Pharmacia Co.) column, sufficiently washed with 50mM phosphate buffer (pH 6.0, and containing 0.5M of NaCl), and eluted with 20mM acetic acid buffer (pH 5.4, and containing 5M of NaCl) . The elution fraction containing the intended product was concentrated and desalted using a ultrafiltration membrane PM-10 (Amicon Co.) (if necessary, it was passed through a .benzamidine Sepharose column to remove the active form). Thus a purified product corresponding to each of the human prourokinase-like polypeptides of this invention, AHUK (q,q), APUK (q,q), APUK (k,q), APUK (k,d), APUK (k,k), FPUK (q,q), ACUK (-,q), FCUK (-,q), Vi PϋK (k,q) and V 2 PUK (k,q), was obtained. Reference Example 1 Preparation of plasmids pMUT90pml and p9420 A DNA fragment containing prelilac p/o, which was isolated after plasmid pPLL was digested with restriction enzymes Aat II and Xba I, and about 3.4kb of DNA fragnent containing laql" gene, which was isolated after plasmid pMJR1560 (Amersham co. ) was digested with restriction enzyme Pst I, followed by treatment with T 4 DNA polymerase and digestion with restriction enzyme Aat II, and synthesized oligomer CroS/D-A/B were linked with T 4 DNA ligase to give plasmid p9410. DNA fragment containing vector fragment, which was isolated after pMUTδL harboring natural human prourokinase gene was digested with restriction enzyme Nco I, was linked by T 4 DNA ligase to give plasmid p6514. Plasmid p6514 was digested with restriction enzyme EcoR I and followed by treatment with Klenow fragment to fill in the restriction site, then linked by T 4 DNA ligase to give plasmid p6516. About 4.2kb of DNA fragment isolated after plasmid p6516 was digested with restriction enzyme BamH I was treated with Klenow fragment to fill in the restriction site, then linked by T 4 DNA ligase to give plasmid p6610. About 3.7kb of DNA fragment isolated after plasmid pMUT9Lpml (with a human prourokinase derivatives gene of which lysine at the 135th position of the amino acid sequence of natural human prourokinase was substituted by glutamine) , which was produced by deriving from plasmid pMUTβL, was digested with restriction enzymes Nar I and Nco I, and about 0.6kb of DNA fragment isolated after plasmid p6610 was digested with restriction enzymes Nar I and Nco I were linked by T 4 DNA ligase to give plasmid pMUT90pml. A DNA fragment containing prelilac p/o, which was isolated after plasmid p9410 was digested with restriction enzyme Kpn I, treated with T 4 DNA polymerase and further digested with restriction enzyme Aat II, and about 3.5kb of DNA fragment containing tac p/o, which was isolated after plasmid pMUT90pml was digested with restriction enzyme Pst I, treated with T 4 DNA polymerase and further digested with restriction enzyme Aat II were linked by T DNA ligase to give plasmid p9420. Reference Example 2 Preparation of plasmids pHUK (q,d)/0 and pHUK (q,q)/0 About 4.4kb of DNA fragment isolated after plasmid pMUTδL harboring human prourokinase gene was digested with restriction enzymes Axy I and Hind III was treated with Klenow fragment to fill in the restriction site, then linked by T 4 DNA ligase to give plasmid pMUT4H. About 3.1kb of DNA fragment isolated after plasmid pMUT4H was digested with restriction enzymes Ace III and Nar I and about 1.3kb of DNA fragment isolated after plasmid pMUT90pml was digested with restriction enzymes Ace III and Nar I were linked by T 4 DNA ligase to give plasmid p6028. About 3.7kb of DNA fragment isolated after plasmid p6028 was digested with restriction enzymes Eco47 III and Hind III was treated with Klenow fragment to fill in the restriction site, then linked by T 4 DNA ligase to give plasmid p6N17. About 3.7kb of DNA fragment isolated after plasmid p6Nl7 was digested with restriction enzymes Dra II and EcoR I, and each of synthesized oligomers TUK1- A/B and TUK2-A/B were linked by T 4 DNA ligase to give plasmid p7214 and plasmid p7224, respectively. About 3.8kb of DNA fragment isolated after plasmid pMUT90pml was digested with restriction enzyme Ban II, and each of about 0.5kb of DNA fragments isolated after plasmids p7214 and p7224 were each digested with restriction enzyme Ban II were linked by T 4 DNA ligase to give plasmids pHUK (q,q)/0 and pHUK (q,d)/0, respectively. Reference Examaple 3 Preparation of urokinase-like polypeptide ATUK (q,q) of which a peptide with ability to form bond with fibrin is added to the NH∑ terminal side 100,000 units of purified sample of human prourokinase-like polypeptide AHUK (q,q) obtained in Example 5 was dissolved in lOOul of 50mM Tris hydrochloric acid buffer (pH 7.5) containing 0.1M NaCl, to which 0.015cu of serum plasmin (Green Cross Co.) was added to incubate at 37 °C for an hour. Then 10 / g of trypsin inhibitor (Sigma Chemical Co.) was added to stop the reaction. The product was adsorbed in benzamidine Sepharose column, and eluted with 20mM acetic acid buffer (pH 4.5) containing 0.5M NaCl. The eluted fractions were concentrated and desalted using ultrafiltration membrane PM-10 (AMICON Co.) to give urokinase-like polypeptide ATUK (q,q). Analysis of the amino acid sequence in the neighborhood of the NH 2 terminal confirmed that the purified sample was urokinase-like polypeptide with the same sequence as that in the neighborhood of the NH 2 terminal of prourokinase-like polypeptide AHUK (q,q) . [Effect of the Invention ] It is inferred that the human prourokinase-like polypeptides of this invention bind with blood clots through covalent bond through the enzymatic action of the blood coagulation factor XIII (active form) which appears at the region where blood clots are formed, and then are converted to activated form which does not leave from the blood clot. Therefore the polypeptides can be an ideal thrambolytic agent which is very clot-specific, has less side effects such as systemic hemorrhage, and is not inhibited by plasminogen activator inhibitor I. They can be economically manufactured by gene engineering methods. Test Example 1 Fibrin binding ability test. The binding ability of each of purified human prourokinase-like polypeptides of this invention (hereinafter referred to as test sample) to a fibrin clot was compared with that of tPA,human prourokinase and urokinase-like polypeptide ATUK(q,q). The binding test was carried out according to the following two methods. (Reagents) 1) Tris-hydrochloric acid buffer; 50mM of Tris, 38mM of NaCl, 0.01% of Triton X- 100, pH 7.5 2) Fibrinogen solution; lOmg of plasminogen free human fibrinogen of Sigma Chemical Co./ml of Tris-hydrochloric acid buffer 3) Thrombin solution; 100 units of human thrombin of Sigma Chemical Co./ml of Tris-hydrochloric acid buffer 4) Plasmin solution; 15cu of serum plasmin of Green Cross Co./ml of H.0 5) Trypsin inhibitor solution; 5mg of trypsin inhibitor of Sigma Chemical Co./ml 6) Hirudin; Hirudin of Sigma Chemical Co. 7) Test sample solution; 5000 international units of test sample/ml of Tris- hydrochloric acid buffer I. Testing method of binding ability in fibrin clotting process Into a 1.5-ml eppendorf tube, while cooled with ice, were placed 75 1 of fibrinogen solution, 5// 1 of 0.1M CaCl 2 aqueous solution and 100 1 of each test sample, to which the Tris-hydrochloric acid buffer was added to make 297// 1 to mix well. 3 μ 1 of thrombin solution was added to the resulting solution to mix to treated for 60 minutes in a water bath of 37 °C . Fibrin clots were thus formed. Immediately the clots were centrifuged at 4°C (16,000- rpm, 10 minutes). The precipitate was washed with Tris-hydrochloric acid buffer. 1 NIH of hirudin and 5 to 15/ / 1 of plasmin solution were added to dissolve the precipitate and simultaneously the test sample was activated. A trypsin inhibitor of volume of 5 fold-weight of plasmin was added to inhibit the plasmin activity. An amount of test sample was measured from the degradation activity of synthesized substrate S-2444 of Kabi Co., being the amount of test sample bound. II. Testing method of binding ability after fibrin clots are formed Method I was repeated except that fibrin clots were formed with no addition of test sample, then 100 μ 1 of test sample solution and 200 1 of Tris- hydrochloric acid buffer were added to keep for 60 minutes in a water bath of 37 °C . An amount of test sample in the centrifuged precipitate obtained by the same treatment as that in I was measured. (Supplementary) In the above testing method, if the test samples were human prourokinase and APUK (k,k), the test was carried out in the presence of hirudin in order to prevent the test sample from losing activity by degradation by thrombin. The binding ability of each of test samples to fibrin clots are shown in the following table by Amount of test sample bound binding ratio = x 100 Amount of test sample used * human urokinase:urokinase exracted from human urine * HUK : human prourokinase The tPA and APUK (q,q), which were bound in the fibrin clotting process, left from the fibrin clots after bound were estimated at an hourly interval. It was recognized that tPA was left 23% after 2 hours and gradually was being left after it. To contrast, 8% of APUK (q,q) was left after 2 hours and no leaving was recognized after it. Test Example 2 Fibrin lysis activity test The lysis activity of each of purified human prourokinase-like polypeptides of this invention (hereinafter referred to as test sample) to fibrin was measured using the standard urokinase (distributed by the National Institute of Hygiene Science) as a reference. Testing method Into 5 r of 0.1M phosphate buffer (pH 7.4) containing 2% of bovine fibrinogen (Seikagaku Kogyo Co.) and lOmM of CaCl 2 were added 5mi of 0.25% aqueous solution of agarose which was heated to dissolve and 0.1-j of bovine thrombin (Mochida Pharmaceutical Co.) solution (100 active units/ 77 ^). After mixing, the mixture was poured in a Petri dish of 9.0cm in diameter to make a fibrin plate. On the fibrin plate was spotted each of 5 1 of test samples, each of which contained one unit of hirudin, and incubated at 37 °C for 18 hours. An activity value was calculated from the lysis circle. The lysis activity of each test sample per unit absorbance at 280nm is shown in the following table in international unit. Fibrin lysis activity Test sample name International unit/O.D.280 AHUK (q,q) 8.8 x 10* APUK (q,q) 10.9 x 10* APUK (k,q) 10.4 x 10* APUK (k,d) 8.7 x 10 4 APUK (k,k) 9.2 x 10 4 FPUK (q,q) 10.9 x 10 4 ACUK (-,q) 15.7 x 10 4 FCUK (-,q) 16.8 x 10 4 V 2 P (k,q) 10.4 x 10 4 Brief Description of Drawings : Fig. 1 is systematic diagrams of Examples 1 and 2, Fig. 2 is of Example 3, Fig. 3 is of Reference Example 1, and Fig. 4 is of Reference Example 2. Figs. 5, 6, 7 and 8 are the base sequence of DNA encoding each of the human prourokinase-like polypeptides of this invention, FCUK (-,q), AHUK (q,q), APUK (k,k) and APUK (k,q) and corresponding amino acid sequence (one letter abbreviation) .

Claims: Claims 1. Human prourokinase-like polypeptides of which oligopeptides having a structure to form a covalent bond with blood clot (thrombus) through enzymatic action of human blood coagulation factor XIII are attached to the NH 2 -terminal sides of human prourokinase derivatives. 2. DNA segments encoding polypeptides with the amino acid sequence, or with practically the same amino acid sequence us the said, of human prourokinase- like polypeptides with oligopeptides having a structure to form a covalent bond with blood clot, according to Claim (1). 3. Plasmid containing the DNA segment according to Claim (2) , control regions for expression thereof, and a DNA sequence necessary for replication in Escherichia coli. 4. A method for the preparation of human prourokinase-like polypeptides which comprises culturing the E. coli transformed with the plasmid according to Claim (3) and producing the said human prourokinase-like polypeptides from the cells.

Inventors: KOBAYASHI YOHICHI, MUKOHARA YUKUO, NAKAMURA HIROAKI, SATOH MASAYUKI, WATABE KEN, KOBAYASHI, YOHICHI, MUKOHARA, YUKUO, NAKAMURA, HIROAKI, SATOH, MASAYUKI, WATABE, KEN
Applicants: NIPPON SODA CO, NIPPON SODA CO., LTD.
Application year: 1990
Main classification: C12N15
IPC codes: A61K38, C07K14, C12N9, C12N15