[Characterization of an inhibitor of glucose-6-phosphate dehydrogenase].
A strong inhibitor of G6PDH has been detected in rat liver homogenates. The inhibitor, isolated by ultrafiltration methods, proved to be very stable under incubation with trypsin and high temperatures. Gel-filtration through Sephadex G-75 showed it to have a molecular weight of 3,500 daltons, though perchloric acid treatment produced a light form of 900 daltons. Both forms of inhibitor act as competitive inhibitor with respect to G6P and exhibit non-competitive inhibition pattern with respect to NADP+. Physical and kinetic properties, and the increase of G6PDH activity at low NADP+ concentrations, in the presence of NADPH and inhibitor or palmitoyl-CoA, in relation to the G6PDH activity in presence of NADPH, lead to the identification of the low-molecular weight inhibitor as palmitoyl-CoA.
D000214:Acyl Coenzyme A / Q000032:analysis*; D000818:Animals; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors*; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D009249:NADP / Q000494:pharmacology; D010171:Palmitoyl Coenzyme A / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains
D000214:Acyl Coenzyme A; D010171:Palmitoyl Coenzyme A; D009249:NADP; D005954:Glucosephosphate Dehydrogenase
Caracterización de un inhibidor de la G6PDH.