- high-resolution terminology - matching measurements at high-resolution
Complex IV single step
Description
CIV: Electron flow through Complex IV (cytochrome c oxidase) is measured in intact mitochondria after inhibiton of CIII by antimycin A, and addition of ascorbate (As) and the artificial substrate TMPD (Tm). Ascorbate has to be titrated first. It reduces TMPD, which further reduces cytochrome c, which is the substrate of 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: L, P, and 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. Total oxygen uptake in the ascorbate&TMPD(&c) stimulated state (Tm) has to be corrected for chemical background oxygen consumption.
Abbreviation: CIV
Reference: Gnaiger 2002 Biochem Soc Trans
MitoPedia concepts:
Respiratory state,
SUIT state
