Carbon dioxide/bicarbonate is required for sensitive inactivation of mammalian glyceraldehyde-3-phosphate dehydrogenase by hydrogen peroxide.

ABSTRACT: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) contains an active site Cys and is one of the most sensitive cellular enzymes to oxidative inactivation and redox regulation. Here, we show that inactivation by hydrogen peroxide is strongly enhanced in the presence of carbon dioxide/bicarbonate. Inactivation of isolated mammalian GAPDH by H₂O₂ increased with increasing bicarbonate concentration and was sevenfold faster in 25 mM (physiological) bicarbonate compared with bicarbonate-free buffer of the same pH. H₂O₂ reacts reversibly with CO₂ to form a more reactive oxidant, peroxymonocarbonate (HCO₄^-), which is most likely responsible for the enhanced inactivation. However, to account for the extent of enhancement, w

SUBMITTER: Winterbourn CC 

PROVIDER: S-EPMC10161126 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature