Identification by mass spectrometry of Nε-formyl-lysine residues in a peptide from bee venom

Abstract

A mixture of variant forms of the peptide (1) has been isolated from bee venom. The variants have the same amino-acid sequence and arrangement of disulphide bridges as the parent peptide but differ from it in that the side chains of lysine residues at positions 2, 17, and possibly 21 are chemically modified. The modifying group has been identified, by mass spectrometry, as formyl. Each variant probably contains only one modified lysine residue.