studies of hybrid cytochromes , prepared by a reconstitution procedure involving the cleavage and re-formation of peptide bond 65-66 , show that these differences result from single amino acid replacements , beef cytochrome c differs in binding capacity from horse cytochrome c as a result of the substitution of a glycine for a lysine residue in sequence position 60 , and the difference between rabbit cytochrome c and beef cytochrome c reflects the substitution of a valine for a proline residue in position 44 .
C0002520
amino acid
C0017890
glycine