title: Inhibitory mechanism of sericystatin, an intracellular proteinase inhibitor, reacting with cysteine proteinases.
abstract: Studies are reported on the inhibitory mechanism of an endogenous inhibitor, which has the ability of inhibiting both cysteine and serine proteinases. On the basis of this unusual inhibitory property, we propose the name "sericystatin". The cysteine proteinases (cathepsin B and papain) can be reactivated from their complex 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. The results indicate that sericystatin inhibits these enzymes by a reversible thiol-disulphide exchange mechanism.
mesh_terms: D000818:Animals; D010450:Endopeptidases; D005978:Glutathione / Q000494:pharmacology; D007700:Kinetics; D007962:Leukocytes / Q000032:analysis; D011480:Protease Inhibitors / Q000037:antagonists & inhibitors*; D011506:Proteins / Q000378:metabolism*; D012697:Serine Endopeptidases; D013552:Swine
chemical_list: D011480:Protease Inhibitors; D011506:Proteins; D010450:Endopeptidases; D012697:Serine Endopeptidases; D005978:Glutathione