Human plasma kallikrein. Preliminary studies on hydrolysis of proteins and peptides.
Acid-activated human plasma kallikrein (HuPK) was purified from human Cohn fraction IV by affinity chromatography, using a ligand soybean trypsin inhibitor and aminobenzamidine. The purified enzyme does not inactivate bradykinin and lysyl-bradykinin by cleavage of their peptide bonds. Methionyl-lysyl-bradykinin is converted to the more potent peptide, bradykinin, by incubation with plasma kallikrein. The enzyme does not show aminopeptidase activity when assayed with amino-acyl-naphthylamides. Arginine-rich polypeptides and proteins, such as polyarginine, salmine, and histones were cleaved by the enzyme. HuPK does not show any detectable caseinolytic activity. A kinin is released from a non-homologous plasma (horse) by this kallikrein. The enzyme is not affected by calcium or EDTA, and it is strongly inhibited by copper ion.
D000626:Aminopeptidases / Q000378:metabolism; D000818:Animals; D002417:Cattle; D004950:Esterases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007610:Kallikreins / Q000097:blood* / Q000378:metabolism; D007705:Kinins / Q000378:metabolism; D001121:Lysine Carboxypeptidase / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism
D006657:Histones; D007705:Kinins; D004950:Esterases; D010447:Peptide Hydrolases; D000626:Aminopeptidases; D001121:Lysine Carboxypeptidase; D007610:Kallikreins