title: Inhibition of aminoacylase from hog kidney by 2-ethoxy-1-(ethoxycarbonyl)-1,2-dihydroquinoline.
abstract: Aminoacylase is inactivated by 2-ethoxy-1-(ethoxycarbonyl)-1,2-dihydroquinoline (EEDQ), a specific carboxyl reagent; inactivation is pH-dependent. The inhibition kinetics were of the first-order type. pH titration shows that half-maximal inactivation is obtained at pH 6.0 +/- 0.2, suggesting that the EEDQ reactive carboxyl group has a rather high pK value. Protection against EEDQ inactivation of the enzyme is afforded by competitive inhibitors, most effectively by tosyl-L-phenylalanine. These results suggest that a carboxyl group is located at or near the active site of the enzyme. A possible function of the carboxyl group in the catalytic process is proposed.
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors*; D000818:Animals; D001667:Binding, Competitive; D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D011804:Quinolines / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet; D013552:Swine
chemical_list: D011804:Quinolines; C000470:EEDQ; D000581:Amidohydrolases; C019672:aminoacylase I