Triosephosphate isomerase is an extremely efficient metabolic enzyme that catalyzes the interconversion between dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate (G3P) in glycolysis and gluconeogenesis. It is also responsible for the non-negligible production of methylglyoxal a reactive cytotoxic side-product that modifies and can alter proteins, DNA and lipids. D-glyceraldehyde 3-phosphate = dihydroxyacetone phosphate dihydroxyacetone phosphate = methylglyoxal + phosphate The kcat is 900 sec(-1) for the isomerization of dihydroxyacetone phosphate (PubMed:2021650). The kcat is 0.011 sec(-1) for the production of methylglyoxal via the elimination reaction (PubMed:2021650). Produces methylglyoxal with a calculated cellular velocity of 0.4 mM per day (PubMed:2021650). Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate from glycerone phosphate: step 1/1. Carbohydrate biosynthesis; gluconeogenesis. Homodimer. Asn-16 and Asn-72 undergo deamidation which gives rise to four extra negative charges. These are expected to decrease subunit-subunit interactions and so expose the hydrophobic interface to the aqueous environment. Belongs to the triosephosphate isomerase family.