标题：Preferred conformational structures of disaccharides with beta-1,4-linked N-acetylglucosamine and D-mannose in the gas phase: A tree-step computational approach study
作者：Gao, Jianming; Chen, Dong; Song, Ran; Xue, Huanlu; Wang, Tianxiang; Liu, Bo
作者机构：[Gao, Jianming; Chen, Dong; Song, Ran; Xue, Huanlu; Wang, Tianxiang; Liu, Bo] Henan Univ, Phys & Elect Dept, Kaifeng 475004, Peoples R China.; [Liu, 更多
通讯作者：Chen, D;Liu, B
通讯作者地址：[Chen, D; Liu, B]Henan Univ, Phys & Elect Dept, Kaifeng 475004, Peoples R China.
来源：COMPUTATIONAL AND THEORETICAL CHEMISTRY
关键词：Disaccharides; Tree-step computational approach; IR vibration signature
摘要：N-glycans are highly crucial to the potential application prospect of glycoprotein. However, its structural diversity and instability severely limit its further research. Here we apply the tree-step computational approach to investigate preferred structures of disaccharides with beta-1,4-linked N-acetylglucosamine and D-mannose of core pentasaccharide in N-glycans. Due to the structural character of disaccharides, hydrogen bonds (H-bonds) are classified according to the upper and lower parts of GlcNAc beta(1,4)GlcNAc and Man beta(1,4)GlcNAc. Almost all building conformers (95 for GlcNAc beta(1,4)GlcNAc and 50 for Man beta(1,4)GlcNAc) are generated depending on the combination of H-bonds in the upper and lower parts, except for one conformer. After establishing initial configurations, theoretical simulations for optimization, preferred structures and frequency calculations are employed. Both energy and IR vibration signature are in good accord with the experimental and theoretical literature. Additionally, five new low-energy structures are found, which have not been reported by using the traditional conformational search.