Effect of conformation of the substrate on enzymatic decarboxylation of alpha-arylmalonic acid.

The configuration and conformation of a compound are critical factors that determine whether it can be accepted by an enzyme as a substrate or not. We have examined enzyme-catalyzed decarboxylation of some alpha-substituted malonic acids and proposed that the syn-periplanar conformation is required for the substrates to be bound to the active site of the enzyme. Theoretical calculation of potential energy surfaces also supports the conclusion from experimental results.