Cytochrome C

Characterization of cytochrome c

Abstract

Characterization of cytochrome c, a key protein in the electron transfer chain, provides insight into its importance in cellular processes. The redox potential of cytochrome c, the regulation of cytochrome c activity by allosteric regulator ATP and cytochrome c’s ability to protect DNA from oxidative damage illustrate the importance of this protein in the cell. This study determined the concentration of cytochrome c using UV/vis spectroscopy and Bradford analysis information to be 30.96 μg/μL and 53.42 +/- 2.94 μg/μL respectively. The structure of the protein was analyzed using a spectral scan--indicating the presence of a heme group and the presence of aromatic residues. The molecular weight was is 12,363 kDa. The redox potential, which indicates the ability of cytochrome c to carry electrons, was found to be 260 mV, which is within the range reported in the literature. In addition, it was determined that cytochrome c has at least two binding sites for ATP using size exclusion chromatography and Scatchard analysis. Finally, it was determined that cytochrome c is capable of protecting DNA from oxidative species. Oxidative damage to DNA causes mutations and other abnormalities that are the basis of many pathological diseases, like Alzheimer’s or Parkinson’s. Therefore, the idea that cytochrome c may play a role in the reduction of reactive oxygen species indicates that maybe cytochrome c could be malfunctioning in the diseased patients.

An Introduction to cytochrome c

The purpose of this semester long study is to characterize the protein cytochrome c. cytochrome c is a highly conserved 12,363 kDa (Margoliash 1962) small protein with a conjugated heme prosthetic group that consists of 108 amino acids in a single chain (PDB 2HV4). It is found within the inner membrane of the mitochondria (Nelson 693). It has a globular tertiary structure with one heme group (Figure 1),

and therefore one iron center, within the...