title: Characterization by EPR spectroscopy of cytochrome b-562 isolated from the cytochrome b-c1 complex of Rhodopseudomonas sphaeroides R-26.
abstract: The EPR spectra of cytochrome b-562 isolated from the cytochrome b-c1 complex of Rhodopseudomonas sphaeroides were measured at liquid helium temperature. The purified cytochrome b-562 gives a high spin signal at g = 6.0. Anaerobic titration of this signal confirmed the presence of two redox components with Em = 40 and -110 mV at pH 7.5. These values are consistent with the published ones, Em = 55 and -100 mV at pH 7.0, that were optically estimated for the same type of preparation (Iba et al. (1985) FEBS Lett. 183, 151-154). The power saturation behavior of the g = 6.0 signal at different redox potentials indicated a direct spin-spin interaction between these two redox centers.
mesh_terms: D003573:Cytochrome b Group / Q000302:isolation & purification*; D004578:Electron Spin Resonance Spectroscopy; D014450:Electron Transport Complex III / Q000302:isolation & purification*; D029968:Escherichia coli Proteins; D012242:Rhodobacter sphaeroides / Q000201:enzymology*
chemical_list: D003573:Cytochrome b Group; D029968:Escherichia coli Proteins; C017850:cytochrome b562, E coli; D014450:Electron Transport Complex III