Properties of the major carboxypeptidase in the larvae of the webbing clothes moth, Tineola bisselliella.
The larvae of the webbing clothes moth, Tineola bisselliella contain two carboxypeptidases (EC 3.4.12-) and one of these has been purified by preparative polyacrylamide gel electrophoresis. Its pH optimum for the hydrolysis of N-benzyloxycarbonyl-glycyl-leucine was pH 7.5-7.7 and its molecular weight as judged by gel filtration was 72 000. It is strongly inhibited by disopropylfluorophosphate, thiol reagents and some metal cations and also by 1:10 phenanthroline but not EDTA. Km and V values for the hydrolysis of 13 N-acyl dipeptides were determined. The enzyme has a strong preference for neutral aliphatic amino acid residues and does not hydrolyse C-terminal proline, arginine or lysine. It is a true carboxypeptidase, requiring an L-amino acid in the C-terminal position, with a free carboxyl group and hydrolysing peptide substrates consecutively from the C-terminal end. Dipeptides are cleaved much more slosly than tripeptides or N-acyl dipeptides.
D000818:Animals; D002268:Carboxypeptidases / Q000378:metabolism*; D002413:Cations, Divalent; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007461:Iodoacetates / Q000494:pharmacology; D007700:Kinetics; D007814:Larva / Q000201:enzymology; D007915:Lepidoptera / Q000201:enzymology*; D009036:Moths / Q000201:enzymology*; D010618:Phenanthrolines / Q000494:pharmacology; D013329:Structure-Activity Relationship
D002413:Cations, Divalent; D002729:Chloromercuribenzoates; D007461:Iodoacetates; D010618:Phenanthrolines; D004492:Edetic Acid; D004237:Diuron; D002268:Carboxypeptidases