Metabolite repair in glycolysis : dephosphorylation of three ‘abnormal’ metabolites made by side-activities of glycolytic enzymes

Enzymes of intermediary metabolism are considered as very specific. However, most of them show weak side activities toward compounds that are structurally related to their physiological substrates, thereby producing side products that may be toxic. Increasing evidence suggests that cells possess metabolite repair systems that eliminate side products or reconvert them into useful metabolites. This work shows the existence of a new example of a conserved metabolite repair enzyme, known as phosphoglycolate phosphatase in mammals. This enzyme dephosphorylates three non-classical phosphate esters, 4-P-erythronate, L-2-P-lactate and P-glycolate, made by central glycolytic enzymes. The repair activity of phosphoglycolate phosphatase prevents inhibitory interferences between metabolic pathways.