title: Hydrolysis of plasma kallikrein by trypsin and plasmin and the formation of active fragments.
abstract: Active plasma kallikrein (Mr = 90,000) can be separated by reduction of the disulfide bridges into a heavy-chain (Mr = 45,000) and a light-chain (Mr = 36,000). A partially active fragment, corresponding to the light-chain, was isolated during the purification of active human plasma kallikrein. Bovine trypsin can form a fragment corresponding to the heavy-chain when incubated with plasma kallikrein; plasmin also causes the formation of the heavy-chain but at a slower rate. High molecular weight kininogen decreases the rate of cleavage of kallikrein by both enzymes. Light-chain does not accumulate during incubation with these proteases and the heavy-chain, after prolonged incubation is also digested. Incubation of labelled active kallikrein with plasma causes formation of fragments corresponding to the heavy- and the light-chain.
mesh_terms: D005341:Fibrinolysin / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007610:Kallikreins / Q000097:blood*; D046911:Macromolecular Substances; D008970:Molecular Weight; D010446:Peptide Fragments / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D010446:Peptide Fragments; D007610:Kallikreins; D014357:Trypsin; D005341:Fibrinolysin