title: Properties of the acid thiol proteinase from Schistosoma mansoni adults.
abstract: Seven beta-naphthylamine-linked peptides were tested as substrates for a previously described thiol proteinase of adult Schistosoma mansoni. The enzyme was not active on carbobenoxy-arginyl-arginyl-4-methoxy-2-naphthylamide and carbobenzoxy-alanyl-arginyl-arginyl-4-methoxy-2-naphthylamide. Enzyme activity was maximal at acidic pH (4.9-5.5) with similar optima for both macromolecular and peptide substrates. Activity of partially purified enzyme preparations against carbobenzoxy-arginyl-arginyl-4-methoxy-2-naphthylamide was stimulated more than 10-fold by thiols. The properties of this proteinase differ from those of proteolytic enzymes from the cercariae ad eggs of S. mansoni.
mesh_terms: D000818:Animals; D003546:Cysteine Endopeptidases; D004226:Dithioerythritol / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010455:Peptides / Q000378:metabolism; D012550:Schistosoma mansoni / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D010455:Peptides; D004226:Dithioerythritol; D010450:Endopeptidases; D003546:Cysteine Endopeptidases