title: Purification and characterization of the chymotrypsin-like enzyme of the bovine granulocyte.
abstract: A chymotrypsin-like enzyme (EC 3.4.21.20) was isolated from bovine granulocytes, and purified 14-fold by affinity chromatography on 4-phenylbutylamine Affi-gel. The molecular weights of the isoenzymes were estimated as 16 000, 19 300 and 24 000 by SDS-polyacrylamide gel electrophoresis. A Michaelis constant of 2 mM and a catalytic constant of 34.6 s-1 were determined with Bz-Tyr-OEt. The esterolytic activity of the enzyme could be inhibited both by PMSF and by TPCK. It was also inhibited by chymostatin (Ki = 0.11 microgram/ml) and by the cytosol inhibitor of the bovine granulocyte (K'i = 1 microM). The chymotrypsin-like enzyme of the bovine granulocyte shares a number of the kinetic properties common to the chymotrypsin-like enzyme of the human granulocyte. The two granulocytes showed nearly identical chymotrypsin-like enzyme activities per cell.
mesh_terms: D000818:Animals; D002417:Cattle; D002846:Chromatography, Affinity; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D006098:Granulocytes / Q000201:enzymology*; D007527:Isoenzymes / Q000302:isolation & purification; D008970:Molecular Weight; D009842:Oligopeptides / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D009842:Oligopeptides; D011480:Protease Inhibitors; C002101:chymostatin; D002918:Chymotrypsin