Characterization of human triosephosphate isomerase S-nitrosylation

ROMERO, J.M., CARRIZO, M.E. AND CURTINO, J.A.

NITRIC OXIDE-BIOLOGY AND CHEMISTRY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2018 vol. 77 p. 26 - 26

1089-8603

riosephosphate isomerase (TPI), the glycolytic enzyme that catalyzes the isomerization of dihydroxyacetonephosphate (DHAP) to glyceraldehyde-3-phosphate (G3P), has been frequently identified as a target of S-nitrosylationby proteomic studies. However, the effect of S-nitrosylation on its activity has only been explored inplants and algae. Here, we describe the in vitro S-nitrosylation of human TPI (hTPI), and the effect of themodification on its enzymatic parameters. NO-incorporation into the enzyme cysteine residues occurred by atime-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 analysesshowed that only Cys217 was S-nitrosylated. hTPI S-nitrosylation produced a 30% inhibition of the Vmax of theDHAP conversion to G3P, without affecting the Km for DHAP. This is the first study describing features of humanTPI S-nitrosylation.