Isolation of cytochrome b from the cytochrome bc1 complex of Rhodopseudomonas sphaeroides GA

Cytochrome b has been isolated from the cytochrome bc 1 complex of Rhodopseudomonas sphaeroides GA. It represents the largest of the 3 polypeptides of this complex (40, 34, 25 kDa). Spectral heterogeneity is lost, but redox heterogeneity is retained to some extent, and the pH‐dependence of the midpoint potential is preserved during isolation.