1. Mitochondrial peroxynitrite generation is mainly driven by superoxide steady-state concentration rather than by nitric oxide steady-state concentration
- Author
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Laura B. Valdez, Darío E. Iglesias, Silvina Sonia Bombicino, Alberto Boveris, and Ivana Rukavina Mikusic A
- Subjects
0301 basic medicine ,PEROXINITRITE ,Bioenergetics ,Radical ,Mitochondrion ,010402 general chemistry ,01 natural sciences ,Nitric oxide ,Ciencias Biológicas ,SUPEROXIDE ,purl.org/becyt/ford/1 [https] ,03 medical and health sciences ,chemistry.chemical_compound ,MITOCHONDRIA ,purl.org/becyt/ford/1.6 [https] ,Autoxidation ,Superoxide ,STEADY-STATES ,Bioquímica y Biología Molecular ,Biofísica ,0104 chemical sciences ,030104 developmental biology ,chemistry ,Biophysics ,Steady state (chemistry) ,Peroxynitrite ,CIENCIAS NATURALES Y EXACTAS ,NITRIC OXIDE - Abstract
In biological systems, ONOO- production depends on production rates of NO and O2-, and on the reactions of these two free radicals with other biological components, which limit the local concentrations of NO and O2-. In mitochondria, O2- is generated through the autoxidation of semiquinones at Complexes I and III, and it may suffer the SOD-catalysed dismutation reaction to produce H2O2 or react with NO in a classical termination reaction between free radicals. These diffusion-controlled reactions kinetically compete for O2- degradation. Results from our laboratory have shown that even in physiopathological situations in which NO production is reduced, such as the mitochondrial dysfunction associated to stunned heart, mitochondrial ONOO- production rate may be slightly increased if the steady-state concentration of O2- is augmented. The enhancement in O2- concentration leads to an increase in its degradation by reaction with NO, decreasing NO bioavailability and increasing ONOO- production rate. Therefore, mitochondrial ONOO- generation is mainly driven by O2- rather than by NO steady-state concentrations. In this scenario, the switch from signalling pathways of NO to oxidative damage takes place and oxidation reactions of biomolecules or modification of proteins by nitration may occur. Fil: Valdez, Laura Batriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Bombicino, Silvina Sonia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Iglesias, Dario Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Rukavina Mikusic, Ivana Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Boveris, Alberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina
- Published
- 2018