Identification of bovine stefin A, a novel protein inhibitor of cysteine proteinases

FEBS Letters

Dolenc, Iztok²  Björk, Ingemar¹  Turk, Boris²  Ritonja, Anka²  Turk, Vito²  Stoka, Veronika² 

[1] Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, The Biomedical Center, Uppsala, Sweden;Department of Biochemistry and Molecular Biology, J. Stefan Institute, Janova 39, 61000 Ljubljana, Slovenia

关键词: Stefin;    Cystatin;    Cysteine proteinase;    Cathepsin;    Amino acid sequence;    -AMC;    4-methyl-7-coumarylamide;    Brij 35;    polyoxyethylenelaurylether;    Bz-;    benzoyl;    CNBr;    cyanogen bromide;    Cm-;    carboxymethyl-;    CPI;    cysteine proteinase inhibitor;    Ep-475;    L-3-carboxytrans-2;    3-epoxypropyl-leucylamido-4-(guanidino) butane;    HPLC;    high performance liquid chromatography;    PAGE;    polyacrylamide gel-electrophoresis;    Z-;    benzyloxycarbonyl-;   

DOI  :  10.1016/0014-5793(95)00060-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

For the first time, three different stefins, A, B and C, have been isolated from a single species. The complete amino acid sequence of bovine stefin A was determined. The inhibitor, with a calculated M _r of 11,123, consists of 98 amino acid residues. Although it exhibits considerable similarity to human and rat stefin A, some significant differences in inhibition kinetics were found. Bovine stefin A bound tightly and rapidly to cathepsin L (k _ass = 9.6·10⁶ M ⁻¹·s ⁻¹, K _i = 29 pM). The binding to cathepsin H was also rapid (k _ass = 2.1·10⁶ M ⁻¹·s ⁻¹), but weaker (K _i = 0.4 nM) due to a higher dissociation rate constant. In contrast, the binding to cathepsin B was much slower (k _ass = 1.4·10⁵ M ⁻¹·s ⁻¹), but still tight (K _i = 1.9 nM).

【 授权许可】

Unknown