[Mechanism of nicotinic acid inhibition of the reaction catalyzed by acetyl-CoA carboxylase].
A kinetic analysis of the activity of acetyl-CoA carboxylase from chicken liver upon alimentary activation of lipogenesis and inhibition of this reaction by nicotinic acid was performed. It was found that the affinity of the enzyme isolated from chicken liver with stimulated lipogenesis is decreased by nicotinic acid for HCO3- but remains unchanged for ATP. The value of Vmax for ATP and the amount of the ATP used in this reaction remain unaffected. At the same time the enzyme affinity for acetyl-CoA is increased with a simultaneous decrease of Vmax. It is assumed that nicotinic acid inhibits the first step of the acetyl-CoA carboxylase-catalyzed reaction.
D000103:Acetyl-CoA Carboxylase / Q000037:antagonists & inhibitors*; D000255:Adenosine Triphosphate; D000818:Animals; D001639:Bicarbonates; D002645:Chickens; D007700:Kinetics; D008025:Ligases / Q000037:antagonists & inhibitors*; D008099:Liver / Q000201:enzymology*; D009539:Nicotinic Acids / Q000494:pharmacology*
D001639:Bicarbonates; D009539:Nicotinic Acids; D000255:Adenosine Triphosphate; D008025:Ligases; D000103:Acetyl-CoA Carboxylase
O mekhanizme ingibirovaniia nikotinovoĭ kislotoĭ reaktsii, kataliziruemoĭ atsetil-CoA-karboksilazoĭ.