In our recent work [Phys. Chem. Chem. Phys. 11, 9149 （2009）], a molecular-mechanics force field-based amidc-Ⅰ vibration frequency map （MM-map） for peptides and proteins was constructed. In this work, the temperat...In our recent work [Phys. Chem. Chem. Phys. 11, 9149 （2009）], a molecular-mechanics force field-based amidc-Ⅰ vibration frequency map （MM-map） for peptides and proteins was constructed. In this work, the temperature dependence of the MM-map is examined based on high-temperature molecular dynamics simulations and infrared （IR） experiments. It is shown that the 298-K map works for up to 500-K molecular dynamics trajectories, which reasonably reproduces the 88 ℃ experimental IR results. Linear IR spectra are also simulated for two tripeptides containing natural and unnatural amino acid residues, and the results are in reasonable agreement with experiment. The results suggest the MM-map can be used to obtain the temperature-dependent amide-Ⅰ local mode frequencies and their distributions for peptide oligomers, which is useful in particular for understanding the IR signatures of the thermally unfolded species.展开更多
利用量子化学方法,在B3LYP/6-31+G(d)水平上系统考察气相中赖氨酸二肽(lysine dipeptide,LYSD)分子骨架上对二级结构敏感的振动探针——酰胺-I带的振动光谱。通过势能分布(potential energy distribution,PED)分析方法对酰胺-I带振动模...利用量子化学方法,在B3LYP/6-31+G(d)水平上系统考察气相中赖氨酸二肽(lysine dipeptide,LYSD)分子骨架上对二级结构敏感的振动探针——酰胺-I带的振动光谱。通过势能分布(potential energy distribution,PED)分析方法对酰胺-I带振动模式进行指认,探究酰胺-Ⅰ带振动频率与二肽二级结构之间的相关性,为二肽构象态预测提供了有效途径。展开更多
基金This work was supported by the National Natural Science Foundation of China （No.30870591）, the National Basic Research Program of China （No.2007CB815205） and the Chinese Academy of Sciences （Hundred Talent Fund）. Chen Han thanks Dr. Kai-cong Cai for helpful discussions.
文摘In our recent work [Phys. Chem. Chem. Phys. 11, 9149 （2009）], a molecular-mechanics force field-based amidc-Ⅰ vibration frequency map （MM-map） for peptides and proteins was constructed. In this work, the temperature dependence of the MM-map is examined based on high-temperature molecular dynamics simulations and infrared （IR） experiments. It is shown that the 298-K map works for up to 500-K molecular dynamics trajectories, which reasonably reproduces the 88 ℃ experimental IR results. Linear IR spectra are also simulated for two tripeptides containing natural and unnatural amino acid residues, and the results are in reasonable agreement with experiment. The results suggest the MM-map can be used to obtain the temperature-dependent amide-Ⅰ local mode frequencies and their distributions for peptide oligomers, which is useful in particular for understanding the IR signatures of the thermally unfolded species.
文摘利用量子化学方法,在B3LYP/6-31+G(d)水平上系统考察气相中赖氨酸二肽(lysine dipeptide,LYSD)分子骨架上对二级结构敏感的振动探针——酰胺-I带的振动光谱。通过势能分布(potential energy distribution,PED)分析方法对酰胺-I带振动模式进行指认,探究酰胺-Ⅰ带振动频率与二肽二级结构之间的相关性,为二肽构象态预测提供了有效途径。
