Adrenal medullary chromaffin granule peptides: two major ovine peptides and their precursor.

An octapeptide and decapeptide which are not derived from proenkephalin were isolated from ovine adrenal chromaffin granules. Their sequences are Asn-Leu-Asp -Pro-Lys-Leu-Asp-Leu and Val-Ala-Glu-Leu-Asp-Gln-Leu-Leu-His-Tyr. These two peptides were found to be derived from a single precursor peptide which has also been isolated and sequenced. The proteolytic cleavage occurs at a Lys-Arg site typical of prohormone to hormone cleavages.