Studies on there‐Citrate Synthase Reaction

re‐Citrate synthase catalyzes the hydrolysis ofR‐citryl‐CoA andR‐malyl‐CoA. TheSdiastereomers are not attacked. The stereospecificity of the hydrolase activity is an agreement with the stereochemical course of citrate synthesis as catalyzed by this enzyme. The cooperative action of 2‐oxoglutarate and metal ions (Co2+) induces maximum acetyl‐CoA enolase activity ofre‐citrate synthase.R‐Malate is not effective in this reaction. SinceS‐malate is the best inducer of the enolase activity ofsi‐citrate synthase this suggests differences in the architecture of the active sites of these enzymes.Whenre‐citrate synthase is incubated with citrate and coenzyme A in tritiated water, tritium is incorporated into citrate. This indicates that there‐citrate synthase reaction is reversible.