Pig leukocyte cysteine proteinase inhibitor (PLCPI), a new member of the stefin family

FEBS Letters

Dolenc, Iztok¹  Pungerc̆ar, Joz̆e¹  Štrukelj, Borut¹  Berbic̆, Selma¹  Ritonja, Anka¹  Turk, Vito¹  Lenarc̆ic̆, Brigita¹  Stoka, Veronika¹ 

[1] Department of Biochemistry and Molecular Biology, J. Stefan Institute, Jamova 39, 61111 Ljubljana, Slovenia

关键词: Stefin;    Papain;    Cathepsin;    Cathelin;    Amino acid sequence;    Kinetics;    PLCPI;    pig leukocyte cysteine proteinase inhibitor;    Bz-;    benzoyl;    Cm-;    carboxymethyl-;    EDTA;    ethylenediamine tetraacetic acid;    Ep-475;    l-3-carboxy-trans-2;    3-epoxypropyl-leucylamido-(3-guanidino)butane;    -AMC;    4-methyl-7-coumarylamide;    HPLC;    high performance liquid chromatography;    PAGE;    polyacrylamide gelelectrophoresis;    PITC;    phenylisothiocyanate;    PTH;    phenylthiohydantoin;    Z-;    benzyloxycarbonyl;   

DOI  :  10.1016/0014-5793(93)80822-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A new stefin type low-M _r, cysteine proteinase inhibitor (PLCPI) was isolated from pig polymorphonuclear leukocytes as a contaminant of the cathelin sample. The inhibitor consists of 103 amino acids, and its M _r, was calculated to be 11,768. The inhibitor exhibits considerable sequence identity with inhibitors from the stefin family, particularly with human stefin A. The PLCPI is a fast acting inhibitor of papain and cathepsins L and S (k _ass ⩾ 1 × 10⁶ M⁻¹ · s⁻¹) and forms very tight complexes with these enzymes (K _i, ⩽ 190 pM). The affinity for cathepsins B and H (K _i ⩾ 125 nM) was lower. These results also show that the inhibitory activity previously ascribed to cathelin was due to the presence of PLCPI.

【 授权许可】

Unknown