Solution structure of mitochondrial cytochrome c. II. 1H nuclear magnetic resonance of ferrocytochrome c.

The 1H nuclear magnetic resonance spectrum of tuna ferrocytochrome c has been studied and the resonances of all 49 amino acid methyl groups have been assigned to specific absorption lines. In comparison with resonance assignments in the ferricytochrome c spectrum, the secondary shifts of resonances of ferrocytochrome c are smaller and the identification of characteristic spin-systems from comparison of spectra from homologous proteins more difficult. For this reason, two-dimensional nuclear magnetic resonance exchange correlated spectroscopy has been used to correlate the assigned resonances of tuna ferricytochrome c with previously unassigned resonances of tuna ferrocytochrome c.