Structural highlights
Disease[TPIS_HUMAN] Defects in TPI1 are the cause of triosephosphate isomerase deficiency (TPI deficiency) [MIM:190450]. TPI deficiency is an autosomal recessive disorder. It is the most severe clinical disorder of glycolysis. It is associated with neonatal jaundice, chronic hemolytic anemia, progressive neuromuscular dysfunction, cardiomyopathy and increased susceptibility to infection. Publication Abstract from PubMedTriosephosphate isomerase (TPI), the glycolytic enzyme that catalyzes the isomerization of dihydroxyacetone phosphate (DHAP) to glyceraldehyde-3-phosphate (G3P), has been frequently identified as a target of S-nitrosylation by proteomic studies. However, the effect of S-nitrosylation on its activity has only been explored in plants and algae. Here, we describe the in vitro S-nitrosylation of human TPI (hTPI), and the effect of the modification on its enzymatic parameters. NO-incorporation into the enzyme cysteine residues occurred by a time-dependent S-transnitrosylation from both, S-nitrosocysteine (CySNO) and S-nitrosoglutathione (GSNO), with CySNO being the more efficient NO-donor. Both X-ray crystal structure and mass spectrometry analyses showed that only Cys217 was S-nitrosylated. hTPI S-nitrosylation produced a 30% inhibition of the Vmax of the DHAP conversion to G3P, without affecting the Km for DHAP. This is the first study describing features of human TPI S-nitrosylation. Characterization of human triosephosphate isomerase S-nitrosylation.,Romero JM, Carrizo ME, Curtino JA Nitric Oxide. 2018 Apr 17;77:26-34. doi: 10.1016/j.niox.2018.04.004. PMID:29678765[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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