Empirical modeling of the peptide amide I band IR intensity in water solution
Empirical modeling of the peptide amide I band IR intensity in water solution
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DOI：
10.1063/1.1622384
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发表时间：
2003-12-01
影响因子：
4.4
通讯作者：
Keiderling, TA
中科院分区：
文献类型：
--
作者：
Bour, P;Keiderling, TA
为了考虑水环境对C双键伸缩振动(酰胺I)的影响，提出了对酰胺基真空力场的经验修正。用密度泛函理论方法在BPW91/6-31G(**)水平上研究了N-甲基乙酰胺与不同氢键的水分子簇相互作用的振动吸收光谱强度与几何构型的关系。然后推广这些团簇结果，形成对酰胺I(C=O伸展)模力场和偶极强度的经验修正。作为其推广的一个例子，将该方法应用于一个较大的(β转角模型)多肽分子，并对其红外光谱进行了模拟。如果光谱是从从头算力场产生的，而从头算力场通过扰动从使用分子动力学模拟获得的溶剂几何构型得到修正，则该方法为酰胺I带提供了真实的带宽。(C)2003年美国物理学会。图
An empirical correction to amide group vacuum force fields is proposed in order to account for the influence of the aqueous environment on the Cdouble bondO stretching vibration (amide I). The dependence of the vibrational absorption spectral intensities on the geometry is studied with density functional theory methods at the BPW91/6-31G(**) level for N-methyl acetamide interacting with a variety of of water molecule clusters hydrogen bonded to it. These cluster results are then generalized to form an empirical correction for the force field and dipole intensity of the amide I (C=O stretch) mode. As an example of its extension, the method is applied to a larger (beta-turn model) peptide molecule and its IR spectrum is simulated. The method provides realistic bandwidths for the amide I bands if the spectra are generated from the ab initio force field corrected by perturbation from an ensemble of solvent geometries obtained using molecular dynamic simulations. (C) 2003 American Institute of Physics.figref