Spectroscopic studies of Rhodobacter capsulatus cytochrome c' in the isolated state and in intact cells.

@article{Monkara1992SpectroscopicSO,
  title={Spectroscopic studies of Rhodobacter capsulatus cytochrome c' in the isolated state and in intact cells.},
  author={F A Monkara and Stephen J. Bingham and F H Kadir and Alastair G. McEwan and Andrew James Thomson and A G Thurgood and Geoffrey R. Moore},
  journal={Biochimica et biophysica acta},
  year={1992},
  volume={1100 2},
  pages={184-8}
}
Ferricytochrome c' from Rhodobacter capsulatus was investigated by 1H-NMR, EPR and optical spectroscopies. A haem-linked ionisation, occurring with a pKa of 8.4 at 25 degrees C, was observed and assigned to the ionisation of the axial histidine ligand by comparison with data for related proteins. At pH values below this pKa the spin-state of the haem Fe3+ is shown to be a quantum mechanically admixed S = 3/2, 5/2 state. Above the pKa the Fe3+ is high-spin. EPR studies of intact cells grown… CONTINUE READING