Inhibition of cysteine proteinases by a protein inhibitor from potato

FEBS Letters

Brzin, Joze¹  Buttle, David J.²  Rowan, Andrew D.²  Barrett, Alan J.² 

[1]Department of Biochemistry, J. Stefan Institute, Jamova 39, 61000 Ljubljana, Yugoslavia

[2]Department of Biochemistry, Strangeways Research Laboratory, Worts Causeway, Cambridge CB1 4RN, U.K.

关键词: Cysteine proteinase;    Enzyme inhibition;    Potato;    Cystatin;    Boc;    f-butyloxycarbonyl;    Bz;    benzoyl;    E-64;    L-3-carboxy-2;    3-trans-epoxypropionyl-leucylamido(4-guanidino)butane;    K i(app);    apparent dissociation constant of inhibitor in the presence of substrate;    K i;    the inhibition constant;    K m;    the Michaelis constant;    NHMec;    7(4-methyl)-coumarylamide;    NHPhNO2;    p-nitroanilide;    [S];    total substrate concentration;    Z;    benzyloxycarbonyl;   

DOI  :  10.1016/0014-5793(90)81186-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The inhibitory specificity of a protein from potato tubers that inhibits cysteine proteinases (potato cysteine proteinase inhibitor, PCPI) has been compared with that of chicken egg-white cystatin. Most proteinases that are inhibited by cystatin were also inhibited by PCPI, but the potato inhibitor inhibited stem bromelain and fruit bromelain, which are not inhibited by cystatin, and for which no protein inhibitor of comparable potency has previously been described. In contrast, papaya proteinase IV was unaffected by PCPI as it is by the cystatins, and the exopeptidase, dipeptidyl peptidase I, is inhibited by cystatins, but was unaffected by PCPI. The differences in inhibitory specificity between these proteins may well reflect differences between superfamilies of cysteine proteinase inhibitors.

【 授权许可】

Unknown