The Amino Acid Sequence of Bovine Heart Cytochrome c

Abstract

The amino acid composition of beef heart cytochrome c was determined. The protein was digested with chymotrypsin and trypsin and the digests were resolved by ion exchange chromatography on Dowex 50 with volatile buffers. From the chymotryptic and tryptic digests, 16 and 17 fractions, respectively, were isolated and characterized. From the overlapping composition and sequences plus the use of the chemical reagents, cyanogen bromide and N-bromosuccinimide, the complete sequence of 104 residues was deduced. Bovine heart cytochrome c has an amino acid sequence identical with that of pig and sheep cytochromes c.