title: Site specificity of the (alpha)C--H bond dissociation energy for a naturally occurring beta-hairpin peptide-An ab initio study.
abstract: A naturally occurring beta-hairpin peptide (PDB ID 1UAO) was used as a model to study the backbone oxidation of a protein with ab initio calculation at the B3LYB/6-31G(d) without any constraints. The (alpha)C--H bond dissociation energy of three different glycyl radicals located at different sites on the beta-hairpin peptide was calculated to evaluate the site specificity of backbone oxidation. The molecular and electronic structures of these glycyl radicals were analyzed to rationalize this site specificity. The overall molecular structure of the alpha-H abstracted beta-hairpin peptide remained almost unchanged with the exception of the local conformation of the attacked residue. However, the (alpha)C--H bond strength varied dramatically among these different sites.
authors.affiliation: Department of Chemistry, National Chung Hsing University, Taichung, Taiwan 402, Republic of China.
authors.forename: Wan-Chun
authors.initials: WC
authors.lastname: Cheng
authors.forename: Soonmin
authors.initials: S
authors.lastname: Jang
authors.forename: Chen-Chang
authors.initials: CC
authors.lastname: Wu
authors.forename: Ren-Jie
authors.initials: RJ
authors.lastname: Lin
authors.forename: Hsiu-Feng
authors.initials: HF
authors.lastname: Lu
authors.forename: Feng-Yin
authors.initials: FY
authors.lastname: Li
mesh_terms: D003198:Computer Simulation; D006860:Hydrogen Bonding; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry; D011789:Quantum Theory; D014732:Vibration
chemical_list: D010455:Peptides; D011506:Proteins