On the limited peptic digestion of horse heart cytochrome C. isolation of C-terminal peptide sequences.

Proteolysis of horse heart cytochrome C with pepsin for 3 min produces a large heme peptide, which was shown to be a mixture of the sequences 1–64 and 1–66. By ion exchange chromatography, gel filtration and preparative paper chromatography the heme-free fraction was resolved into seven peptide fragments, corresponding to sequences 65–94, 65–96, 67–94, 67–96, 67–80, 95–104 and 97–104.