title: Evidence of isosteric and allosteric nucleotide inhibition of citrate synthease from multiple-inhibition studies.
abstract: Citrate synthases from diverse organisms are inhibited by ATP and NADH. Evidence is presented, from multiple-inhibition studies on various citrate synthases, that ATP acts in all cases as an isosteric inhibitor at the acetyl-CoA site. On the other hand, NADH also acts isosterically with eukaryotic and Gram-positive bacterial citrate synthases, but behaves as an allosteric inhibitor specifically in the case of the Gram-negative bacterial enzyme. After desensitization to this allosteric inhibition, only the isosteric nucleotide inhibition, as found in other citrate syntheases, is observed.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000494:Allosteric Regulation; D000818:Animals; D001410:Bacillus megaterium / Q000201:enzymology; D001665:Binding Sites; D001667:Binding, Competitive; D002950:Citrate (si)-Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology; D009243:NAD / Q000378:metabolism / Q000494:pharmacology*; D007652:Oxo-Acid-Lyases / Q000037:antagonists & inhibitors*; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D013552:Swine
chemical_list: D009243:NAD; D000255:Adenosine Triphosphate; D002950:Citrate (si)-Synthase; D007652:Oxo-Acid-Lyases