Stereochemistry of the re ‐Citrate‐Synthase Reaction
1971; Wiley; Volume: 24; Issue: 2 Linguagem: Inglês
10.1111/j.1432-1033.1971.tb19673.x
ISSN1432-1033
AutoresP. Wunderwald, Wolfgang Buckel, Helmut Lenz, Verena Buschmeier, Hermann Eggerer, Gerhard Gottschalk, J. W. Cornforth, John W. Redmond, R. Mallaby,
Tópico(s)Chemical Reactions and Isotopes
ResumoR ‐Acetate and S ‐acetate, as the coenzyme‐A esters, were converted into citrates on re citrate synthase. The citrate were assayed for chirality at the 2‐position (a) by incubation with aconitate hydratase (aconitase) and (b) by cleavage to malate by citrate lyase combined with malate dehydrogenase, followed by incubation of the isolated malate with fumarate hydratase (fumarase). In each case, the citrate (or malate) derived from R ‐acetate retained most of its tritium, and the citrate (or malate) derived from S ‐acetate lost most of its tritium, on incubation with the hydratase. It was concluded that if a normal intramolecular deuterium‐isotope effect is operative, the condensation of oxaloacetate with acetyl‐coenzyme A on re ‐citrate synthase proceeds with inversion of configuration at the methyl group.
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