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 2530次   下载 2310 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Two-dimensional Infrared Spectroscopy of a Model Peptide Homodimer
Jian-ping Wang*
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
Abstract:
A pair of peptide groups in space, as modeled by formamide dimer, was used to evaluate vibrational coupling between the amide-I modes and the spatial behavior of the coupling using ab initio quantum chemical calculations. It was found that the coupling between two C=O groups, which is electrostatic in nature, is still quite signiˉcant as the intermolecular distance reaches 10 oA. One- and two-dimensional infrared spectra of the dimer at several conˉgurations were calculated using a vibrational exciton model that utilizes the ab initio computation-obtained parameters. The distance dependence of the coupling is dramatically shown in both the 1D and 2D infrared spectral features. The results suggest that the C=O stretching modes in polypeptide can be coupled and their states can be delocalized over quite a long distance in space.
Key words:  Two-dimensional infrared spectroscopy, Peptide homodimer, Vibrational coupling, Transition dipole coupling, Exciton model
FundProject:the "Hundred Talents Project" of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No.20773136)
同型二聚体肽模型的二维红外光谱
王建平*
中国科学院化学研究所,分子反应动力学国家重点实验室,北京100080
摘要:
利用一个同型二聚体模型,甲酰胺二聚体,模拟一对肽基团.用量子化学从头计算考察了二聚体中酰胺-I带振动模式之间的振动耦合及其在空间的行为. 研究发现C=O伸缩振动耦合以静电作用为主,耦合有效距离能超过10 oA. 一维和二维红外光谱的激子模拟计算表明,耦合常数的空间依赖性能够清楚地表现在光谱特征中. 这些结果意味着多肽中C=O伸缩振动模式能够在很远的距离相互耦合并产生振动态的离域化.
关键词:  二维红外光谱,同型二聚肽,振动耦合,跃迁偶极矩,激子模型
DOI:10.1088/1674-0068/20/05/509-517
分类号: