Chromatography of oxidized and reduced cytochrome c on carboxymethylcellulose.

1. Cytochrome c was isolated from horse heart by a chromatographic method. 2. Oxidized and reduced cytochrome c were chromatographed on CM-cellulose that was in equilibrium with several buffer systems of constant composition at pH values of 8.4, 6.75 and 4.9. 3. Separation was better at the higher pH values; the oxidized form was retarded more than twice as much as the reduced form, though they differed by only a single charge. 4. Self-competition between cytochrome molecules is suggested to account for the peak distortion observed at high loads (above 20mum protein concentration).