15N-NMR of repeat peptides of tropoelastin. The tetrapeptide.

The 15N-NMR data obtained in chloroform and methanol are reported for Boc-L-Val1-L-Pro2-Gly3-Gly4-OMe, a repeat tetrapeptide sequence of tropoelastin. Deuterium substitution for labile peptide protons was carried out to delineate solvent-exposed and solvent-shielded peptide nitrogens. Solvent perturbation of the peptide nitrogen resonances together with the hydrogen-deuterium substitution reaffirms the previously derived conformation of the molecule in chloroform which contains a beta-turn (type II) and a 14-membered hydrogen bond to form a cross-beta structure.