Effects of Chain Length and N-Methylation on a Cation–π Interaction in a β-Hairpin Peptide

✍ Scribed by Robert M. Hughes; Matthew L. Benshoff; Marcey L. Waters

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 806 KB
• Volume: 13
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200601753

✦ Synopsis

Abstract

The effects of N‐methylation and chain length on a cation–π interaction have been investigated within the context of a β‐hairpin peptide. Significant enhancement of the interaction and structural stabilization of the hairpin have been observed upon Lys methylation. Thermodynamic analysis indicates an increased entropic driving force for folding upon methylation of Lys residues. Comparison of lysine to analogues ornithine (Orn) and diaminobutyric acid (Dab) indicates that lysine provides the strongest cation–π interaction and also provides the most stable β‐hairpin due to a combination of side chain–side chain interactions and β‐sheet propensities. These studies have significance for the recognition of methylated lysine in histone proteins.