Post-translational Modifications of Glycolytic Enzymes

The impairment of glucose utilization could result from the modification of the glycolytic enzymes under oxidative stress effects. Oxidative stress is an important factor leading to the pathophysiologcal alterations in conformational diseases. Oxidative stress is manifested in protein oxidation, lipid peroxidation, DNA oxidation, and advanced glycation end-products, as well as reactive oxygen species (ROS), and reactive nitrogen species (RNS) formation. Either the oxidants or the products of oxidative stress could modify the proteins or activate other pathways that may lead to additional impairment of cellular functions and to neuronal loss [57, 58]. 

PGM catalyzes the interconversion of 3-phosphoglycerate and 2-phosphoglycerate. A significant increase in oxidation of PGM and a decrease in protein expression were observed in AD hippocampus [66] that is consistent with the reported decreased expression and activity of PGM in AD brain, as compared with the age-matched controls [70, 71]. 

another glycolytic enzyme that catalyzes the interconversion of dihydroxy-acetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate in glycolysis, was also oxidatively modified [32, 63, 66]. However, no change of TPI activity was observed [66], probably because the carbonyl groups added were localized away from the catalytic site of this enzyme. TPI was strongly inhibited by endogenous 

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