The chemical shifts of the 15N's of the cyclic peptide gramicidin S in dilute aqueous solution were measured and assigned with use of polarization transfer via scalar coupling (INEPT). Long-range perturbations were detected in the 15N spectrum from comparison of these results and those in organic solvents. The effects are transmitted from one peptide linkage to another via an intramolecular hydrogen bond across a total of six bonds. The variation with temperature of the 15N shifts in these solvents further corroborates the roles of the intramolecular hydrogen bond in the propagation of shift effects. From the long-range effects it is possible to examine the relationship between solvent-peptide interactions and the properties of internal hydrogen bonds.
ASJC Scopus subject areas
- Colloid and Surface Chemistry