title: Effects of chain length and N-methylation on a cation-pi interaction in a beta-hairpin peptide.
abstract: The effects of N-methylation and chain length on a cation-pi interaction have been investigated within the context of a beta-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-pi interaction and also provides the most stable beta-hairpin due to a combination of side chain-side chain interactions and beta-sheet propensities. These studies have significance for the recognition of methylated lysine in histone proteins.
authors: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
authors: Robert M
authors: RM
authors: Hughes
authors: Matthew L
authors: ML
authors: Benshoff
authors: Marcey L
authors: ML
authors: Waters
mesh_terms: D020816:Amino Acid Motifs; D000613:Aminobutyrates / Q000737:chemistry; D002412:Cations; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008958:Models, Molecular; D015394:Molecular Structure; D009952:Ornithine / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000613:Aminobutyrates; D002412:Cations; D010455:Peptides; D009952:Ornithine; D008239:Lysine