引用本文:
【打印本页】   【HTML】   【下载PDF全文】   View/Add Comment  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1466次   下载 1186 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Gas Phase Conformations of Tetrapeptide Glycine-Phenylalanine-Glycine-Glycine
Hui-bin Chen,Yao Wang,Xin Chen,Zi-jing Lin*
Author NameAffiliationE-mail
Hui-bin Chen Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, China  
Yao Wang Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, China  
Xin Chen Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, China  
Zi-jing Lin* Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, China zjlin@ustc.edu.cn 
Abstract:
Systematic search of the potential energy surface of tetrapeptide glycine-phenylalanine-glycine-glycine (GFGG) in gas phase is conducted by a combination of PM3, HF and BHandHLYP methods. The conformational search method is described in detail. The rela-tive electronic energies, zero point vibrational energies, dipole moments, rotational constants, vertical ionization energies and the temperature dependent conformational distributions for a number of important conformers are obtained. The structural characteristics of these conformers are analyzed and it is found that the entropic effect is a dominating factor in determining the relative stabilities of the conformers. The measurements of dipole moments and some characteristic IR mode are shown to be effective approaches to verify the theoreti-cal prediction. The structures of the low energy GFGG conformers are also analyzed in their connection with the secondary structures of proteins. Similarity between the local structures of low energy GFGG conformers and the α-helix is discussed and many β- and γ-turn local structures in GFGG conformers are found.
Key words:  Potential energy surface, Conformational stability, Hydrogen bond, Entropy effect, Secondary structure
FundProject:
甘氨酸-苯丙氨酸-甘氨酸-甘氨酸四肽气相稳定构型的系统寻找
陈惠宾,王耀,陈欣,林子敬*
摘要:
利用PM3、HF和BHandHLYP方法的结合,系统寻找了甘氨酸-苯丙氨酸-甘氨酸-甘氨酸(GFGG)四肽在气相中的稳定构型.对该构型寻找方法进行了详细的描述,并给出了一些重要构型的基本参数,如电子能、零点振动能、偶极矩、转动常数、垂直电离能和不同温度的构型分布等.通过对重要构型结构特征的分析,发现熵的效应是决定构型稳定性的重要因素,并讨论指出了对构型偶极矩和特征振动模的测量是验证理论预言的有效途径.对GFGG构型与蛋白质二级结构的联系的分析表明,GFGG低能构型出现了类似于α-螺旋的局域结构,以及数量可观的蛋白质β转角和γ转角的局域结构.
关键词:  势能面,构型稳定性,氢键,熵效应,二级结构
DOI:10.1088/1674-0068/25/01/77-85
分类号: