CHARACTERIZATION OF HUMAN TRIOSEPHOSPHATE ISOMERASE S-NITROSYLATION

ROMERO JM; CARRIZO ME; CURTINO JA

NITRIC OXIDE-BIOLOGY AND CHEMISTRY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2018 p. 26 - 34

1089-8603

Triosephosphate isomerase (TPI), theglycolytic enzyme that catalyzes the isomerization of dihydroxyacetonephosphate (DHAP) to glyceraldehyde-3-phosphate (G3P), has been frequentlyidentified as a target of S-nitrosylation by proteomic studies. However, theeffect of S-nitrosylation on itsactivity 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 onlyCys217 was S-nitrosylated. hTPI S-nitrosylation produced a 30% inhibition ofthe Vmax of the DHAP conversion to G3P, without affecting the Km for DHAP. Thisis the first study describing features of human TPI S-nitrosylation