| Biochem/physiol Actions | Cytochrome c is primarily known as an electron-carrying mitochondrial protein. The transition of cytochrome c between the ferrous and ferric states within the cell makes it an efficient biological electron-transporter and it plays a vital role in cellular oxidations in both plants and animals. It is generally regarded as a universal catalyst of respiration, forming an essential electron-bridge between the respirable substrates and oxygen |
| | Cytochrome c has been identified as an important mediator in apoptotic pathways. The release of mitochondrial cytochrome c into the cytoplasm stimulates apoptosis and is commonly used as an indicator of the apoptotic process in the cell. |
| Other Notes | View more information on cytochrome c and electron transport at www.sigma-aldrich.com/enzymeexplorer. |
| Preparation Note | Prepared using TCA. |
| | A further purification of C2506 |
| General description | This cytochrome c product is prepared from equine heart using trichloroacetic acid. Alternatively, acetic acid may be used to prepare cytochrome c. The trichloroacetic acid method may reduce the amount of superoxide dismutase (SOD) present, but tends to cause dimerization or acid-modified structures of cytochrome c. In contrast, acetic acid preparations may have slightly higher amounts of SOD, but a lower proportion of dimeric cytochrome c.
The product is supplied as a lyophilized powder. The final step before lyophilization is extensive dialysis against 6 mM ammonium hydroxide, which is volatile under lyophilization conditions, so the final product should not contain any buffer salts. The product is mainly the oxidized form of the protein. The reduced form of cytochrome c can be prepared with either sodium dithionite or sodium ascorbate, followed by gel filtration. |
