Triosephosphate isomerase (TIM)

Triosephosphate isomerase is a highly conserved, homodimeric enzyme that catalyzes the rapid and efficient interconversion of dihydroxyacetone phosphate and D-glyceraldehyde-3-phosphate, a central reaction in the glycolytic and gluconeogenesis pathways[1][2][5][8][9]. Each subunit is composed of approximately 250 amino acids organized into a TIM-barrel structure, with the active site located at the center of the barrel and stabilized by key residues including glutamic acid, histidine, lysine, and asparagine[1][5][7]. Functional TIM requires dimerization for full enzymatic activity. The enzyme’s regulated loop motions shield the reaction intermediate, maintaining strict substrate specificity and suppression of methylglyoxal formation, a cytotoxic by-product[1][5]. Mutations in TIM cause triosephosphate isomerase deficiency, resulting in severe metabolic disorder. TIM is a validated drug target for parasitic diseases due to its essential role in pathogen glycolysis, but is unsuitable for broad therapeutic intervention in humans due to high toxicity risk upon inhibition[9].

Other names

Triosephosphate isomeraseTIMTriose-phosphate isomeraseEC 5.3.1.1Methylglyoxal synthasePhosphotriose isomeraseTriosephosphate mutase[4][8]

Most drug design efforts focus on inhibiting enzymatic activity in pathogenic parasites to disrupt glycolytic pathway and energy metabolism[9]. Enzyme inhibitors would act as competitive or allosteric blockers of substrate interconversion (DHAP ←→ G3P).