title: The catalytic properties of a proteinase isolated from sheep abomasal mucosal mast cells.
abstract: The catalytic properties of a sheep mast cell proteinase (SMCP), isolated from abomasal mucosal mast cells, were investigated. The enzyme was shown to have chymotrypsin-like esterase activity, with no detectable amide activity, using a range of low molecular weight substrates. Maximal activity, against Benzyloxycarbonyl-L-tyrosine-4-nitrophenol ester, was determined to be in the range pH 7.6-8.0. Inhibitor studies showed that, unlike chymotrypsin, a serine proteinase, SMCP was found to be susceptible to the action of thiol blocking agents and chelating agents, but to be unaffected by diisopropylphosphofluoridate, a serine proteinase inhibitor.
mesh_terms: D000018:Abomasum / Q000201:enzymology*; D000818:Animals; D002614:Chelating Agents / Q000494:pharmacology; D053818:Chymases; D002918:Chymotrypsin / Q000378:metabolism; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008407:Mast Cells / Q000201:enzymology*; D009092:Mucous Membrane / Q000201:enzymology; D011480:Protease Inhibitors; D012697:Serine Endopeptidases; D013379:Substrate Specificity
chemical_list: D002614:Chelating Agents; D011480:Protease Inhibitors; D010450:Endopeptidases; D012697:Serine Endopeptidases; D002918:Chymotrypsin; D053818:Chymases