Fluorescence studies of cytochrome c1 and a cytochrome c1-cytochrome c complex

Abstract

Summary Cytochrome c 1 and cytochrome c form a complex in aqueous solution. The complex is stable to chromatography on Sephadex but is dissociated in media of high ionic strength. Results from the fluorescence probe technique using 8-anilino-1-naphthaline sulphonic acid strongly suggest that (i) the heme group of cytochrome c 1 is completely buried in the protein moiety, in contrast to cytochrome c ; (ii) ferricytochrome c 1 undergoes a conformation change on reduction which produces a more tightly closed structure; and (iii) in the cytochrome c -cytochrome c 1 complex the edge of the cytochrome c heme group evidently continues to be exposed.