Differences in specificity for the interactions of stefins A, B and D with cysteine proteinases

FEBS Letters

Lenarčič, Brigita¹  Žunec, Petra¹  Križaj, Igor¹  Turk, Vito¹ 

[1] Department of Biochemistry and Molecular Biology, J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia

关键词: Cysteine proteinase inhibitor;    Papain;    Cathepsin;    Amino acid sequence;    Kinetics;    -AMC;    4-methyl-7-coumarylamide;    Bz-;    benzoyl;    Cm-;    carboxymethyl-;    CNBr;    cyanogen bromide;    Ep-475;    l-3-carboxy-trans-2;    3-epoxypropylleucylamido(3-guanidino)butane;    HPLC;    high-performance liquid chromatography;    PAGE;    polyacrylamide gel electrophoresis;    PITC;    phenylisothiocyanate;    PLCPI;    pig leukocyte cysteine proteinase inhibitor;    PTH;    phenylthiohydantoin;    Z-;    benzyloxycarbonyl-;   

DOI  :  10.1016/0014-5793(96)00984-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Four different stefin-type cysteine proteinase inhibitors have been isolated from porcine thymus and skin. Amino acid sequence determination revealed the presence of stefin A and stefin B type inhibitors and two new inhibitors, designated as porcine stefin D1 and stefin D2. Stefin D1 was identified as PLCPI, an inhibitor recently characterized from porcine polymorphonuclear leukocytes [Lenarčič et al. (1993) FEBS Lett. 336, 289–292]. Stefin A is composed of 101 amino acids and has an M _r of 11391 while stefin B contains 98 amino acids, has an M _r of 11174 and is N-terminally blocked. All inhibitors were found to be fast-acting inhibitors of papain, cathepsin L and cathepsin S (K _i = 0.009–0.161 nM). Stefins A and B also bind tightly and rapidly to cathepsin H (K _i = 0.027 and 0.069 nM, respectively), while stefins D1 and D2 have been shown to be very poor inhibitors of cathepsin H (K _i = 102–150 nM). he decreased affinity of these inhibitors toward cathepsin B (K _i = 2–1700 nM) was shown to be mainly due to the low second order association rate constants. The presence of a highly negatively charged N-terminus on stefin D1 constitutes a likely structural determinant of inhibitor specificity.

【 授权许可】

Unknown