NADPH oxidase was measured based on its capacity to reduce ferricytochrome c in
ferrocytochrome at pH of 7.8 (22).
Stern, "Among a range of transition metals and ligands, vanadium desferroxamine excels in accelerating reactivity of
ferrocytochrome C toward molecular oxygen," Biochemistry and Cell Biology, vol.
Ferrocytochrome c (15 [micro]M) was added, and reaction rates were measured using a Cary 1E spectrophotometer.
The formation of [H.sub.2][O.sub.2] in the mixture was measured at 550 nm by estimating the oxidation product of
ferrocytochrome.
This colorimetric assay is based on an observation of the decrease in absorbance at 550 nm of
ferrocytochrome c caused by its oxidation to ferricytochrome c by cytochrome c oxidase.
There are three kinds of reductases that reduce trivalent iron of methemoglobin, NADH is the coenzyme of the first one, NADPH--the second one, and the third one acts with participation of
ferrocytochrome [b.sub.5] [22].
Xanthine oxidase (XOD) converts xanthine to uric acid, yielding superoxide anions as a byproduct and subsequently converting ferricytochrome C directly to
ferrocytochrome C, which exhibits absorbance at 550 nm.
Yu et al., 1997, used 660 nm laser at a power density of 10 mW cm-1 and showed increased oxygen consumption following (0.6 J cm-2 and 1.2 J cm-2) radiance exposure, increased phosphate potential, and energy charge (at 1.8 J cm-2 and 2.4 J cm-2) and enhanced activities of NADH: ubiquinone oxidoreductase, ubiquinol: ferri cytochrome c oxidoreductase and
ferrocytochrome c : oxygen oxidoreductase (between 0.6 J cm-2, and 4.8 J cm-2) (45).
Hoppel, "Decreased activities of ubiquinol: ferricytochrome c oxidoreductase (complex III) and
ferrocytochrome c:oxygen oxidoreductase (complex IV) in liver mitochondria from rats with hydroxycobalamin[c-lactam]-induced methylmalonic aciduria," Journal of Biological Chemistry, vol.
Decreased activities of ubiquinol:ferricytochrome C oxidoreductase (complex III) and
ferrocytochrome C:oxygen oxidoreductase (complex IV) in liver mitochondria from rats with hydroxycobalamin[C-lactam]-induced methylmalonic aciduria.
Ferrocytochrome c reduction assay: formation or removal of oxygen radicals.
Complex II = succinate dehydrogenase complex; succinate; ubiquinone oxidoreductase; coenzyme Q reductase Complex III = cytochrome [bc.sub.l] complex;ferrocytochrome c oxidoreductase; coenzyme Q; cytochrome c reductase Complex IV = cytochrome oxidase; terminal oxidase;
ferrocytochrome c; oxygen oxidoreductase; cytochrome c oxidase.