The Intra-Mitochondrial Localization of Flavoproteins Previously Assigned to the Respiratory Chain

摘要: 1 Flavoproteins of intact and fractionated mitochondria have been studied by means spectrophotometric fluorimetric techniques. 2 The high low redox potential fluorescent flavoproteins rat liver previously assigned to the respiratory chain are located in soluble fraction obtained on ultrasonic disintegration. 3 In mitochondria, species has a −279 mV at pH 7.2 25° measured fluorescence or absorbance, undergoes 2 equivalent reduction. After disruption its is -294 m V 25°. 4 In submitochondrial particles, flavoprotein reducible NADH presence rotenone not fluorescent, appears more positive than −209 attributed mainly cytochrome b5 reductase b5. Mersalyl can be used selectively inhibit reductase, it possible estimate concentration free from interference. 5 The flurescent recovered after reduced succinate antimycin A inhibited particulate fraction. This also found kidney but blowfly mitochondria. 6 In non-fluorescent which may non-heme iron. + 30 1 reduction. 7 Flavoprotein measurements subject significant errors caused absorption exciting light, conseuently do always measure interference other carriers, e. q. cytochromes iron proteins.