title: Irreversible inactivation of yeast glucose-6-P dehydrogenase by penicillin G.
abstract: Yeast glucose-6-P dehydrogenase is irreversibly inactivated by penicillin G. Kinetic data show that 1 molecule of penicillin G reacts with each active unit when the enzyme is inactivated. The rate of inactivation increases greatly with increasing pH. This irreversible inactivation by penicillin G is largely prevented by pyridoxal-P, a reversible inactivator or this enzyme. Prior treatment of penicillin G with penicillinase totally abolishes its ability to inactivate the enzyme.
mesh_terms: D004305:Dose-Response Relationship, Drug; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors*; D049673:History, 20th Century; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010400:Penicillin G / Q000494:pharmacology*; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
chemical_list: D011732:Pyridoxal Phosphate; D005954:Glucosephosphate Dehydrogenase; D010400:Penicillin G