Site specificity of the (alpha)C--H bond dissociation energy for a naturally occurring beta-hairpin peptide-An ab initio study.
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.
Cheng
Wan-Chun
WC
Department of Chemistry, National Chung Hsing University, Taichung, Taiwan 402, Republic of China.
Jang
Soonmin
S
Wu
Chen-Chang
CC
Lin
Ren-Jie
RJ
Lu
Hsiu-Feng
HF
Li
Feng-Yin
FY
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
D010455:Peptides; D011506:Proteins