Abstract
The cytochrome c(3) of Desulfovibrio desulfuricans and that of D. vulgaris were purified to homogeneity as judged by disc gel electrophoresis and by ultracentrifugation. Both cytochromes had an oxidation-reduction potential of -205 +/- 5 mv at pH 7.0 and showed characteristic absorption bands at 525 and 553 nm in the reduced state. The molecular weights of the two cytochromes (calculated from sedimentation and diffusion data) were similar, with values of 13,500 to 14,300 for D. desulfuricans and 13,800 to 14,700 for D. vulgaris. The two cytochromes differed in their electrophoretic properties on Geon and polyacrylamide gel electrophoresis and did not share a common precipitating antigenic determinant as judged by immunodiffusion data.