title: Characterization of proline endopeptidase from skeletal muscle.
abstract: Proline endopeptidase was purified from human muscle by anion-exchange chromatography, thiol-affinity chromatography and chromatography on hydroxyapatite. The enzyme gave a single band on polyacrylamide gel electrophoresis. Activity was maximum at pH 7.0-7.5. The molecular weight (by gel filtration) was 69,000. The enzyme hydrolysed benzyloxycarbonyl-Gly-Pro-7-amido-4-methylcoumarin with Km 32 microM. It was inhibited by di-isopropyl phosphofluoridate and 4-hydroxymercuriphenyl sulphate. Bacitracin inhibited at higher concentrations but lower concentrations stimulated the activity. The enzyme activity appeared largely in the soluble fraction following fractionation of rat muscles. Proline endopeptidase activity in rat muscle was unaltered by treatment of the animals with compound 48/80, a mast cell degranulator.
mesh_terms: D000818:Animals; D002845:Chromatography; D010450:Endopeptidases / Q000378:metabolism*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008970:Molecular Weight; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D000085822:Prolyl Oligopeptidases; D011480:Protease Inhibitors / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012697:Serine Endopeptidases; D013379:Substrate Specificity; D014018:Tissue Distribution; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D011480:Protease Inhibitors; D003189:p-Methoxy-N-methylphenethylamine; D010450:Endopeptidases; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases