Albuminamide: a novel peptide amide isolated from bovine serum

During a systemic search for peptides that possess the C-terminal amide structure, a novel heptapeptide with isoleucine amide was isolated from bovine serum by sequential steps of reversed phase HPLC. Microsequence and amino acid analyses revealed the structure: Asp-Thr-His-Lys-Ser-Glu-Ile-NH2. Since this peptide has the identical sequence to N-terminal (1-7) fragment of bovine serum albumin (BSA), we have designated it albuminamide. The final HPLC step yielded 10 micrograms of homogeneous peptide preparation from 1 liter of bovine serum.