Size Effect on the Raman Spectra and Electronic Structure of the Glycine-alanine Oligopeptide Chains  

作　　者：余敏 孟耀勇 

机构地区：[1]MOE Key Laboratory of Laser Life Science & Laboratory of Photonic Chinese Medicine,College of Biophotonics,South China Normal University

出　　处：《Chinese Journal of Structural Chemistry》2016年第8期1289-1296,共8页结构化学（英文）

基　　金：Supported by the National Natural Science Foundation of China(No.60878063);the Program from Traditional Chinese Medicine Bureau of Guangdong Province(No.2008233)

摘　　要：A theoretical study on oligopeptide chains of glycine-alanine by density functional theory（DFT） is given in this paper. Raman spectra of the oligopeptide chains are examined. The geometric structures, frontier orbital, energy gap, atomic charge distribution, density of states and chemical activity of the side chain are studied at the B3LYP/6-31G（d） level. Results show that, with the number of residues increasing, vibrations of typical functional groups present Raman frequency shift, and the energy gap is gradually reduced. The HOMO and LUMO focus on the amino and carboxyl at the ends of oligopeptides. It is helpful for oligopeptides to self-assemble into chains. In addition, different residues（glycine or alanine） at the ends of chains result in the even-odd effect of orbital energy in the growth process. The size effects of physical and chemical properties only exist when the oligopeptides are shorter, and the phenomenon disappeared as the chain continues to grow.A theoretical study on oligopeptide chains of glycine-alanine by density functional theory（DFT） is given in this paper. Raman spectra of the oligopeptide chains are examined. The geometric structures, frontier orbital, energy gap, atomic charge distribution, density of states and chemical activity of the side chain are studied at the B3LYP/6-31G（d） level. Results show that, with the number of residues increasing, vibrations of typical functional groups present Raman frequency shift, and the energy gap is gradually reduced. The HOMO and LUMO focus on the amino and carboxyl at the ends of oligopeptides. It is helpful for oligopeptides to self-assemble into chains. In addition, different residues（glycine or alanine） at the ends of chains result in the even-odd effect of orbital energy in the growth process. The size effects of physical and chemical properties only exist when the oligopeptides are shorter, and the phenomenon disappeared as the chain continues to grow.

关 键 词：density functional theory（DFT） Raman spectra electronic structure size effect glycine-alanine oligopeptide chains 

分 类 号：Q51[生物学—生物化学]