Mitochondrial Peroxiredoxin 3 Is Rapidly Oxidized and Hyperoxidized by Fatty Acid Hydroperoxides

Cardozo, Giuliana - Mastrogiovanni, Mauricio - Zeida, Ari - Viera, Nicolás - Radi, Rafael - Reyes, Aníbal M. - Trujillo, Maida

Resumen:

Human peroxiredoxin 3 (HsPrx3) is a thiol-based peroxidase responsible for the reduction of most hydrogen peroxide and peroxynitrite formed in mitochondria. Mitochondrial disfunction can lead to membrane lipoperoxidation, resulting in the formation of lipid-bound fatty acid hydroperoxides (LFA-OOHs) which can be released to become free fatty acid hydroperoxides (fFA-OOHs). Herein, we report that HsPrx3 is oxidized and hyperoxidized by fFA-OOHs including those derived from arachidonic acid and eicosapentaenoic acid peroxidation at position 15 with remarkably high rate constants of oxidation (>3.5 × 107 M-1s-1) and hyperoxidation (~2 × 107 M-1s-1). The endoperoxide-hydroperoxide PGG2, an intermediate in prostanoid synthesis, oxidized HsPrx3 with a similar rate constant, but was less effective in causing hyperoxidation. Biophysical methodologies suggest that HsPrx3 can bind hydrophobic structures. Indeed, molecular dynamic simulations allowed the identification of a hydrophobic patch near the enzyme active site that can allocate the hydroperoxide group of fFA-OOHs in close proximity to the thiolate in the peroxidatic cysteine. Simulations performed using available and herein reported kinetic data indicate that HsPrx3 should be considered a main target for mitochondrial fFA-OOHs. Finally, kinetic simulation analysis support that mitochondrial fFA-OOHs formation fluxes in the range of nM/s are expected to contribute to HsPrx3 hyperoxidation, a modification that has been detected in vivo under physiological and pathological conditions.

Detalles Bibliográficos
2023
Antioxidant systems
Fatty acid hydroperoxide
Kinetics
Lipid peroxidation
Mitochondria
Peroxiredoxin
PEROXIRREDOXINAS
PERÓXIDO DE HIDRÓGENO
ÁCIDO PEROXINITROSO
MITOCONDRIAS
PERÓXIDOS LIPÍDICOS
CINÉTICA
PEROXIDACIÓN DE LÍPIDO
Inglés
Universidad de la República
COLIBRI
https://hdl.handle.net/20.500.12008/52239
Acceso abierto
Licencia Creative Commons Atribución (CC - By 4.0)