The riboflavin/FAD cycle in rat liver mitochondria

摘要: Here we provide evidence that mitochondria isolated from rat liver can synthesize FAD riboflavin has been taken up and endogenous ATP. Riboflavin uptake takes place via a carrier-mediated process, as shown by the inverse relationship between fold accumulation concentration, saturation kinetics [riboflavin Km Vmax values were 4.4 ± 1.3 µm 35 ± 5 pmol·min−1·(mg protein)−1, respectively] inhibition thiol reagent mersalyl, which cannot enter mitochondria. synthesis is due to existence of synthetase (EC 2.7.7.2), localized in matrix, substrate pair mitochondrial ATP FMN synthesized putative kinase. In light certain features, including protein thermal stability molecular mass, differs cytosolic isoenzyme. Apparent apparent for 5.4 ± 0.9 µm 22.9 ± 1.4 pmol·min−1·(mg matrix respectively. Newly inside be exported manner sensitive atractyloside but insensitive mersalyl. The occurrence riboflavin/FAD cycle proposed account biogenesis recovery flavoprotein degradation; both are prerequisites flavin cofactors.