title: Hysteretic behaviour of citrate synthase. Isotopically chiral citryl-CoA reveals increased number of reversals of the synthase condensation step under steady-state conditions.
abstract: Citrate specimens derived from chiral acetates were converted to the CoA derivatives. These were reconverted with citrate synthase to citrates under conditions of either predominating hydrolytic burst or predominating steady-state period. The stereochemical purity of substrates and products was determined. Reversal of the synthase condensation step occurs under both conditions but is markedly increased during the steady-state period. The results indicate that citryl-CoA-derived acetyl-CoA and oxaloacetate create the steady-state conditions. The hydrolase state and the ligase/lyase state of the synthase predominate under burst and steady-state conditions, respectively. This result indicates a conversion of the hydrolase state into the ligase/lyase state during the transition.
mesh_terms: D000085:Acetates / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism*; D002950:Citrate (si)-Synthase / Q000378:metabolism*; D002951:Citrates / Q000096:biosynthesis; D019343:Citric Acid; D006867:Hydrolases / Q000378:metabolism; D007700:Kinetics; D008025:Ligases / Q000378:metabolism; D008190:Lyases / Q000378:metabolism; D007652:Oxo-Acid-Lyases / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D000085:Acetates; D000214:Acyl Coenzyme A; D002951:Citrates; D019343:Citric Acid; C029890:citryl-coenzyme A; D002950:Citrate (si)-Synthase; D006867:Hydrolases; D008190:Lyases; D007652:Oxo-Acid-Lyases; D008025:Ligases