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 Carbohydrate biosynthesis; gluconeogenesis. Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate from glycerone phosphate: step 1/1. Homodimer. Expressed in skeletal muscle (at protein level). Causes an allergic reaction in human. Binds to IgE of patients allergic to crabs (PubMed:30187588, PubMed:31668066). Binds to IgE in 23% of the 30 patients tested (PubMed:30187588). Binds to IgE in all 12 patients tested. Induces activation of human basophils (PubMed:31668066). Belongs to the triosephosphate isomerase family.