Mechanisms and stereochemistry of the activation of (2S)- and (2R)-serine O-sulfate as suicide inhibitors for Escherichia coli glutamic acid decarboxylase

Abstract

E. coli glutamic acid decarboxylase is inactivated by both enantiomers of the suicide inhibitor serine O-sulfate, inactivation by the (2S)-enantiomer involving C^α–H bond cleavage and inactivation by the (2R)-isomer involving C^α-decarboxylation; both processes occur on the 4′-Re-face of the coenzyme, the opposite face to that utilised in the physiological decarboxylation reaction.