A 400 MHz 1H NMR study of fortuitin, a natural linear lipopeptide

Fortuitin is a linear acyl nonapeptide methyl ester in which all the peptide residues are hydrophobic. Its 400 MHz 1H NMR spectrum in pyridine-d5 has been assigned. In this solvent, its conformation is not random and seems to form a hairpin. Conformational equilibria exist in pyridine as well as in less polar solvents such as CDCl3 and CD2Cl2. As for other lipopeptides, conformation and self-association properties strongly depend on the polarity of the environment. These properties should be related to the interactions of lipopeptides with membranes and to their capacity to induce pore formation.