Cell Mitochondrial Complex III (Coenzyme Q-Cytochrome C Reductase) Activity Assay Kit

Detection principle: Mitochondrial complex III, also known as cytochrome c reductase complex, its main function is to oxidize the reduced coenzyme Q10 formed by mitochondrial complexes I and II to oxidative coenzyme Q10. In this process, the OD value increased at 550 nm. Therefore, the activity of mitochondrial complex III can be quantified by measure the change OD value at 550 nm. Performance characteristics: Synonyms: Coenzyme Q-Cytochrome C Reductase. Sample type: cell. Sensitivity: 0.73 U/L. Detection range: 0.73-29.3 U/L. Detection method: Colorimetric method. Assay type: Enzyme Activity. Assay time: 30 min. Precision: Average inter-assay CV: 4.5-10%, Average intra-assay CV: 3.5-5.0%. Storage: -20?. Valid period: 12 months. Protein function: [Cytochrome b-c1 complex subunit Rieske, mitochondrial]: Component of the ubiquinol-cytochrome c oxidoreductase, a multisubunit transmembrane complex that is part of the mitochondrial electron transport chain which drives oxidative phosphorylation (PubMed:31883641). The respiratory chain contains 3 multisubunit complexes succinate dehydrogenase (complex II, CII), ubiquinol- cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to transfer electrons derived from NADH and succinate to molecular oxygen, creating an electrochemical gradient over the inner membrane that drives transmembrane transport and the ATP synthase. The cytochrome b- c1 complex catalyzes electron transfer from ubiquinol to cytochrome c, linking this redox reaction to translocation of protons across the mitochondrial inner membrane, with protons being carried across the membrane as hydrogens on the quinol. In the process called Q cycle, 2 protons are consumed from the matrix, 4 protons are released into the intermembrane space and 2 electrons are passed to cytochrome c. The Rieske protein is a catalytic core subunit containing a [2Fe-2S] iron- sulfur cluster. It cycles between 2 conformational states during catalysis to transfer electrons from the quinol bound in the Q(0) site in cytochrome b to cytochrome c1. Incorporation of UQCRFS1 is the penultimate step in complex III assembly (PubMed:28673544). [The UniProt Consortium]