ACTIVE STREPTOKINASE FROM THE CLONED GENE IN STREPTOCOCCUS-SANGUIS IS WITHOUT THE CARBOXYL-TERMINAL-32 RESIDUES

被引:40
作者
JACKSON, KW
MALKE, H
GERLACH, D
FERRETTI, JJ
TANG, J
机构
[1] OKLAHOMA MED RES FDN, PROT STUDIES LAB, OKLAHOMA CITY, OK 73103 USA
[2] UNIV OKLAHOMA, HLTH SCI CTR, DEPT MICROBIOL & IMMUNOL, OKLAHOMA CITY, OK 73190 USA
[3] UNIV OKLAHOMA, HLTH SCI CTR, DEPT BIOCHEM, OKLAHOMA CITY, OK 73190 USA
[4] ACAD SCI GDR, CENT INST MICROBIOL & EXPTL THERAPY, DDR-6900 JENA, GER DEM REP
关键词
D O I
10.1021/bi00349a016
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The streptokinase expressed by the cloned gene in Streptococcus sanguis has a molecular weight of about 44000 [Malke, H., Gerlach, D., Kohler, W., and Ferretti, J.J. (1984) MGG, Mol. Gen. Genet. 196, 360-365] while the molecular weight of the native streptokinase is 47000. The structural and activity differences of the cloned streptokinase (cSK) as expressed by S. sanguis and the native streptokinase (nSK) were investigated. From a partially purified cSK, two active fractions were obtained by reversed-phase HPLC. The minor fraction cSKL was nearly as active as SK in plasminogen activation. The major fraction cSKs had only about one-fourth of the specific activity. The structures of cSKL and cSKs were studied and compared to the known amino acid sequence of SK [Jackson, K. W., and Tang, J. (1982) Biochemistry 21, 6620-6625]. From the NH2- and COOH-terminal sequences and amino acid composition of the cyanogen bromide (CNBr) fragments, it could be deduced that cSKL and cSKs are without 31 and 32 residues, respectively, from the COOH-terminal end of SK. Since the cloned gene contained the full SK structure, the missing structures must have been due to posttranslational proteolysis. An SK fragment similar in size to cSK was observed from a chymotryptic digest of SK.
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页码:108 / 114
页数:7
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