title: Specificity of the acid protease from Monascus kaoliang towards the B-chain of oxidized insulin.
abstract: The proteolytic specificity of the acid protease from Monascus kaoliang has been investigated using the B-chain of performic acid-oxidized insulin as peptide substrate. Six splittings were detected after 1 h digestion and 12 splittings were found after 12 h incubation at 37 degrees C, pH 4.8. The bonds most susceptible to the acton of M. kaoliang acid protease were Phe(24)-Phe(25), Leu(15)-Tyr(16) and Tyr(16)-Leu(17). Among the acid proteases compared, the specificity of M. kaoliang acid protease on the B-chain of oxidized insulin is more closely related to that of penicillopepsin with which it has ten cleavage sites in common. N-Acetyl-L-phenylalanyl-L-3,5-diiodotyrosine, a synthetic substrate for pepsin, was resistant to the hydrolysis of M. kaoliang acid protease.
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D016282:Aspartic Acid Endopeptidases; D010450:Endopeptidases / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000032:analysis; D013379:Substrate Specificity
chemical_list: D007328:Insulin; D010446:Peptide Fragments; D010450:Endopeptidases; C022325:aspartic proteinase A; D016282:Aspartic Acid Endopeptidases