KINETICS OF INHIBITION OF BOVINE CATHEPSIN-S BY BOVINE STEFIN-B

被引：31

作者：

TURK, B ^{[1
]}

COLIC, A ^{[1
]}

STOKA, V ^{[1
]}

TURK, V ^{[1
]}

机构：

[1] CTR GENET ENGN & BIOTECHNOL, SARAJEVO, BOSNIA & HERCEG

来源：

FEBS LETTERS | 1994年 / 339卷 / 1-2期

关键词：

STEFIN B; CATHEPSIN S; CYSTATIN; CYSTEINE PROTEINASE; STOPPED-FLOW; KINETICS;

D O I：

10.1016/0014-5793(94)80405-2

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 kinetics of the complex formation between bovine cathepsin S and bovine stefin B was studied by conventional and stopped-flow techniques. The inhibition at low inhibitor concentrations was tight and reversible (k(ass) = 5.8 x 10(7) M(-1) . s(-1), k(diss) = 4.9 x 10(-4) s(-1) at pH 6.0 and 25 degrees C), whereas at higher inhibitor concentrations it was pseudo-irreversible (k(ass) = 6.14x 10(7) M(-1) . s(-1)). The complex was formed directly lacking the fast pre equilibrium step with the dissociation equilibrium constant of similar to 8 pM. The competitive nature of inhibition was confirmed. The k(ass) was found to be pH-independent between pH 6.0 and 7.5 and decreased at lower or higher pH values in a way that strongly suggests involvement of two ionizable groups in the interaction (pK(1) = 5.2, pK(2) = 8.3). The enzyme-substrate interaction seems to be influenced by different ionizable groups (pK(1) = 4.4, PK2 = 7.8).

引用

页码：155 / 159

页数：5

共 37 条

[1] HUMAN CYSTATIN-C - ROLE OF THE N-TERMINAL SEGMENT IN THE INHIBITION OF HUMAN CYSTEINE PROTEINASES AND IN ITS INACTIVATION BY LEUKOCYTE ELASTASE [J].