title: Purification and properties of a thiol protease from lung fluke adult Paragonimus ohirai.
abstract: The thiol protease was purified from adult Paragonimus ohirai by alpha 1-antitrypsin-Sepharose, Sephadex G-75 and CM-cellulose, measuring its activities to hydrolyze hemoglobin and tosyl-L-lysine alpha-naphthyl-ester. The purified protease showed a single band on polyacrylamide disc gel isoelectrophoresis as zymogram with Tos-Lys-NE and also by protein staining, and its pI was found to be 6.4. The molecular weight was calculated to be 29,000 by gel filtration and 27,000 by SDS-polyacrylamide gel electrophoresis as a single polypeptide. The protease hydrolyzed hemoglobin and Tos-Lys-NE optimally at pH 4.0 and 5.0, respectively. The both hydrolyzing activities were inhibited by alpha 1-AT and soybean trypsin inhibitor as well as thiol protease inhibitors such as antipain, E-64 and p-hydroxymercuriphenylsulfonate. These results indicate that this enzyme is a new type thiol protease.
mesh_terms: D000818:Animals; D002413:Cations, Divalent; D002846:Chromatography, Affinity; D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D010238:Paragonimus / Q000201:enzymology*
chemical_list: D002413:Cations, Divalent; D010450:Endopeptidases; D003546:Cysteine Endopeptidases