POSTTRANSLATIONAL MODIFICATIONS OF THE SULFHYDRYL GROUP OF THE CYSTEINE RESIDUE OF GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE

Abstract

This review considers the main types of oxidative posttranslational modi cations of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) targeting the sulfhydryl group of the catalytic cysteine residue Cys152. The highly reactive sulfhydryl group of Cys152 in the active centre of GAPDH undergoes oxidation and S-nitrosylation, leading to enzyme inactivation and destabilization. Upon reversible oxidation of the sulfhydryl group to form cysteine-sulfenic acid, the enzyme loses dehydrogenase activity, but gains the ability to catalyze the acyl-phosphatase reaction. Hydrolysis of the product of the dehydrogenase reaction, 1,3-diphosphoglycerate, under the action of the oxidized GAPDH leads to uncoupling of oxidation and phosphorylation at this stage of glycolysis. The action of nitric oxide results in S-nitrosylation of Cys152 GAPDH and the subsequent formation of cysteine-sulfenic acid due to hydrolysis of the S-NO-group. Data are presented on the relationship between S-nitrosylation of the catalytic Cys152 of GAPDH and its oxidation followed by S-glutathionylation of the enzyme at Cys152. The role of posttranslational modi cations of the sulfhydryl group of the catalytic cysteine residue in the regulation of enzyme activity, as well as the mechanisms ensuring the reversibility of such modi cations are discussed.