吡喃葡萄糖旋转异构体的纳米机械控制

Nanomechanical control of glucopyranose rotamers.

作者信息

Lee Gwangrog, Nowak Wiesław, Jaroniec Justyna, Zhang Qingmin, Marszalek Piotr E

机构信息

Department of Mechanical Engineering and Materials Science and Center for Biologically Inspired Materials and Materials Systems, Duke University, Durham, North Carolina 27708, USA.

出版信息

J Am Chem Soc. 2004 May 26;126(20):6218-9. doi: 10.1021/ja0491984.

DOI:10.1021/ja0491984

PMID:15149204

Abstract

Single molecules of beta-1 --> 6-linked d-glucose polysaccharides, when stretched in an atomic force microscope, display a hookean-like elasticity unusual for polymers. High-level ab initio calculations and microsecond-scale molecular dynamics simulations reveal that this elasticity is governed by force-induced rotations of the exocyclic group on the glucopyranose rings from their short and less energetic gt and gg conformations to the extended and high-energy tg state. These observations indicate that a simple stretching of 1 --> 6-linked glucose polysaccharides provide a unique means to control glucopyranose rotamer populations.

摘要

当在原子力显微镜中拉伸时，β-1→6连接的d-葡萄糖多糖单分子显示出聚合物中不常见的类胡克弹性。高水平的从头算计算和微秒级分子动力学模拟表明，这种弹性是由吡喃葡萄糖环上的环外基团从其短且能量较低的gt和gg构象力诱导旋转到伸展且高能的tg状态所控制的。这些观察结果表明，对1→6连接的葡萄糖多糖进行简单拉伸提供了一种控制吡喃葡萄糖旋转异构体群体的独特方法。