Nuclear overhauser enhancement demonstration of the type II β-turn in repeat peptides of tropoelastin

Abstract

Nuclear Overhauser enhancement (NOE) experiments have been performed with the elastin peptides, namely; HCO-Val 1-Pro 2-Gly 3-Gly 4-OMe, t-Boc-Val 1-Pro 2-Gly 3-Val 4-Gly 5-OMe and t-Boc-Val 6-Ala 1-Pro 2-Gly 3-Val 4-Gly 5-OMe in DMSO-d 6. An NOE of approximately 10% was observed between the αCH of Pro 2 and the NH of Gly 3 involved in the β-turn of all three peptides. This finding shows the close proximity of two aforementioned protons and thus shows the occurrence of Type II β-turn in the repeat elastin peptides. The intermolecular distances are calculated and compared with the distances obtained from other model systems.