Epidermal Growth Factor

Abstract

The three disulfide bridges in epidermal growth factor have been identified by the isolation of three unique cystinyl peptides obtained by thermolytic digestion. The cysteic acid-containing peptide pairs derived from each of the cystinyl peptides were isolated. Their amino acid compositions were in agreement with those predicted from the known amino acid sequence of epidermal growth factor. The cysteinyl residues in positions 6 and 20, 14 and 31, and 33 and 42 were linked as disulfides in this 53 amino acid residue polypeptide.