An n.m.r. spectroscopy study of pure alamethicin shows it to be a linear polypeptide of 19 residues. The N-terminus is blocked by an acetyl group, and the eighteenth residue, glutamic acid, is linked by an amide bond on its side chain to phenylalaninol (Fig. 6). The new formula is confirmed by a comparison between pure chemical compounds and the products of partial hydrolysis.
