[Effect of visible light on the ATP synthetase function of mitochondria].

Dependence of oxidative phosphorylation in rat liver mitochondria on redox state of endogenous flavoenzymes was studied. Regulation of the redox state of endogenous flavins in mitochondria was performed by visible light illumination of lambda = 380 nm in oxygen free as well as in oxygenated media. A decrease of oxidative phosphorylation was obtained at full reduction of flavins (respiratory control and ATP synthesis were measured); this effect was partially recovered when flavin was reoxidized by oxygen. Results of ESR measurements of the signal gl = 2.00 associated with semireduced flavins were in accordance with the appearance of diamagnetically completely reduced form of flavin. These facts may be considered as evidence of the regulative role of flavins in oxidative phosphorylation.