INHIBITORY MECHANISM OF SERICYSTATIN, AN INTRACELLULAR PROTEINASE-INHIBITOR, REACTING WITH CYSTEINE PROTEINASES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 362  (10) , 1411-1414
Abstract
Studies are reported on the inhibitory mechanism of an endogenous inhibitor [from pig leukocytes], which has the ability of inhibiting cysteine and serine proteinases. On the basis of this unusual inhibitory property, the name sericystatin is proposed. The cysteine proteinases (cathepsin B [EC 3.4.22.1] and papain [EC 3.4.22.2] can be reactivated from their complexes with sericystatin by the action of oxidized glutathione or by chymotrypsin-like neutral proteinases. The inhibitory activity of sericystatin can be inactivated by treatment with oxidized glutathione. Sericystatin probably inhibits these enzymes by a reversible thiol-disulfide exchange mechanism.