One- and two-dimensional NMR characterization of oxidized and reduced cytochrome c' from Rhodocyclus gelatinosus

1D and 2D NMR spectra of both the reduced and oxidized forms of cytochrome c' from Rhodocyclus gelatinosus have been recorded. The analysis of the pH dependence of the 1H NMR spectrum of the ferric form has been performed, and two main ionizing groups have been identified. By comparison of the pH dependence of the available spectra of cytochromes c', an ambiguity remaining from previous studies on related cytochromes c' has been solved. By means of 2D spectra, an assignment of all the paramagnetically shifted signals is proposed both for the ferrous and for the ferric forms.