Cytochrome c from Schizosaccharomyces pombe. 1. Purification, spectral properties, and amino-acid composition

Cytochrome c from the fission yeast Schizosaccharomyces pombe has been purified. Its chromatographic and spectral properties are reported and compared to those of iso-1-cytochrome c from baker's yeast; the amino-acid composition is described. Schiz. pombe cytochrome c has a much lower affinity for Amberlite IRP64 than Sacch. cerevisiae iso-1-cytochrome c. Its alpha absorption band splits into three maxima (calpha1, calpha2, and calpha3) at -190 degrees C; this is unusual in yeasts, as shown by the low-temperature whole-cell absorption spectra which were examined in various yeast genera, species, and strains. A minor component can be separated by Amberlite chromatography. It exhibits the same low-temperature splitting of the alpha absorption band as the main fraction and it has a similar amino-acid composition with a notable exception: it is an unmethylated form of the cytochrome.