title: In vitro interaction of penicillins and cephalosporins with human placenta GSH S-transferase.
abstract: Human purified placenta GSH S-transferase was generally inhibited by penicillins and cephalosporins to a different extent. Among the seven penicillins tested the dihalogenate dicloxacillin and flucloxacillin were the strongest inhibitors. All cephalosporins showed competitive inhibition for the electrophilic substrate, while penicillins acted as non-competitive inhibitors. Exposure of the enzyme to cephalosporins led to the loss of the catalytic activity. Addition of reduced glutathione in the incubation system would induce the formation of a conformational state of the enzyme which prevents cephalosporins binding.
mesh_terms: D002511:Cephalosporins / Q000494:pharmacology*; D005260:Female; D005982:Glutathione Transferase / Q000037:antagonists & inhibitors*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D010406:Penicillins / Q000494:pharmacology*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy
chemical_list: D002511:Cephalosporins; D010406:Penicillins; D005982:Glutathione Transferase