Post-Translational Modifications of the Sulfhydryl Group of the Cysteine Residue of Glyceraldehyde-3-phosphate Dehydrogenase

The main types of oxidative post-translational modifications of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPD & Ncy;) targeting the sulfhydryl group of the catalytic cysteine residue Cys152 are reviewed. The highly reactive sulfhydryl group of Cys152 in the active center of GAPDH undergoes oxidation and S-nitrosylation, leading to inactivation and destabilization of the enzyme. 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 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 in GAPDH with the subsequent formation of cysteine-sulfenic acid due to hydrolysis of the S-NO-group. Data are presented on the relationship between S-nitrosylation, oxidation and S-glutathionylation of Cys152 in GAPDH. The role of post-translational modifications 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 modifications are discussed.