Description
CIV is measured in intact mitochondria after inhibiton of CIII by antimycin A, and addition of ascorbate and the artificial substrate TMPD. Ascorbate has to be titrated first. It reduces TMPD, which further reduces cytochrome c, which is the substrate for cytochrome c oxidase (CIV). Since CIV is a proton pump of the electron transfer system, the single step of CIV-linked respiration can be measured in different coupling states: CIV(L), CIV(P), and CIV(E). Measurement of CIV activity requires uncoupler titrations to eliminate any potential control by the phosphorylation system, and a cytochrome c test to avoid any limitation by cytochrome c release.
Abbreviation: CIV
Reference: Gnaiger 2002 Biochem Soc Trans
MitoPedia topics: "Respiratory substrate-coupling state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property. Respiratory substrate-coupling state"Respiratory substrate-coupling state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.