Control of superoxide production in mitochondria from maize mesocotyls.
To understand the biochemical events that control the generation of superoxide, the effect of inhibiting the respiratory complexes III and IV (C-III and C-IV) and alternative oxidase (AOX) on the rate of superoxide production was analyzed in mitochondria from maize seedlings. To increase superoxide production, it was required to inhibit C-III or C-IV by at least 30% or 50%, respectively. Below this inhibition threshold, AOX exerted the highest degree of control on superoxide production, whereas above it, the highest degree of control was exerted by C-IV. The contribution of C-III to control superoxide production became significant when AOX activity was modulated.
Camacho
Adriana
A
Departamento de Bioquímica, Facultad de Química, UNAM, 04510 Mexico D.F. camacho@servidor.unam.mx
Moreno-Sanchez
Rafael
R
Bernal-Lugo
Irma
I
D004305:Dose-Response Relationship, Drug; D004579:Electron Transport; D014450:Electron Transport Complex III; D003576:Electron Transport Complex IV / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010940:Plant Proteins; D018514:Plant Structures / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D013696:Temperature; D003313:Zea mays / Q000378:metabolism*; D000099188:Alternative Oxidase
D014450:Electron Transport Complex III; D003576:Electron Transport Complex IV; D004791:Enzyme Inhibitors; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010100:Oxygen; D010940:Plant Proteins; D013481:Superoxides; D000099188:Alternative Oxidase