cytochrome b | cytochrome ''b'' | Cytochrome c oxidase | cytochrome c oxidase | cytochrome ''c'' oxidase | Cytochrome P450, family 1, member A1 | Cytochrome P450 | cytochrome P450 | Cytochrome c oxidase subunit I |
Cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced cytochrome c to oxygen.
Emanuel Margoliash's first publication of sequence data for cytochrome c allowed comparison of the rates of molecular evolution for different proteins (cytochrome c seemed to evolve faster than hemoglobin), which Zuckerkandl discussed at a 1964 conference in Bruges.
When the inhibition of these is lifted, they result in the translocation of Bax and activation of mitochondrial dysfunction resulting in release of mitochondrial apoptogenic proteins cytochrome c, SMAC, and apoptosis-inducing factor (AIF) leading to caspase activation and cell death.
However, if Bax and Bak become activated, and Bcl-xL is sequestered away by gatekeeper BH3-only factors (e.g. Bim), causing a pore to form, cytochrome c is released leading to initiation of caspase cascade leading to apoptotic events.
Heme A was first isolated by the great German biochemist Otto Warburg in 1951 and shown by him to be the active component of the integral membrane metalloprotein cytochrome c oxidase.