CYTOCHROMES OF BACILLUS SUBTILIS .2. PURIFICATION AND SPECTRAL PROPERTIES OF CYTOCHROMES C-550 AND C-554

Two c-type cytochromes were isolated from Bacillus subtilis K, a gram-positive bacterium, and purified by column chromatography on DEAE-cellulose and ion exchange resins. Cytochrome c-550 showed spectral properties similar to those of mammalian cytochrome c; it had absorption maxima at 528, 407, and 279 mμ in the oxidized form, and at 550, 520, 414, 316, and 279 mμ in the reduced form.Cytochrome c-554 showed absorption maxima at 523, 409, and 280 mμ in the oxidized form, and at 554, 521, 417, 316, and 280 mμ in the reduced form. The α-peak of this cytochrome associated with a bump at 550mμ, and split into two peaks at 546 mμ and 552mμ at liquid nitrogen temperature. CD*** spectra of the cytochrome showed that the chromophore responsible for the α-peak might be under the influence of anisotropic environments, and showed a large change in the ellipticity occurred in the Soret region with oxidation and reduction of the hemoprotein. Effects of pH, urea, guanidine-HCI, and SDS*** on the absorption spectra of cytochrome c-554 were studied. The absorption spectra of the ferricytochrome with cyanide, azide, and imidazolc were also investigated. © 1969 BY THE JOURNAL OF BIOCHEMISTRY.