Molecular Mechanism of Cell Membrane Protection by Sugars: A Study of Interfacial H-Bond Networks
Molecular Mechanism of Cell Membrane Protection by Sugars: A Study of Interfacial H-Bond Networks
复制标题
糖保护细胞膜的分子机制：界面氢键网络的研究
DOI：
10.1021/acs.jpclett.1c02451
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Baiz, Carlos R.
中科院分区：
文献类型：
--
作者：
You, Xiao;Lee, Euihyun;Xu, Cong;Baiz, Carlos R.
糖通过在脱水、热应力和冻融循环期间稳定生物分子而起到生物保护剂的作用。许多有机体在暴露于极端条件下时会发生糖的积累。了解糖对膜的生物保护作用是通过表征脂-水界面处的氢键网络来实现的。在这里，我们报告的头基H-键的人口，结构和动力学的1，2-dimyristoyl-sn-glycero-3-phosphocholine囊泡在浓缩的葡萄糖溶液中使用超快二维红外光谱结合分子动力学模拟。在酯羰基位置的氢键群体和动力学在很大程度上不受影响，即使在非常高的，600毫克/毫升，糖浓度。此外，动力学表现出轻微的非单调依赖糖浓度。模拟，这是在近定量的协议与测得的动力学，表明氢键结构基本上保持完整的糖的存在。本研究表明，糖的生物保护作用是通过模拟纯水中氢键网络的膜界面上稳定的脂-糖-水氢键网络实现的。
Sugars function as bioprotectants by stabilizing biomolecules during dehydration, thermal stress, and freeze–thaw cycles. A buildup of sugars occurs in many organisms upon their exposure to extreme conditions. Understanding sugar’s bioprotective effects on membranes is achieved by characterizing the H-bond networks at the lipid–water interface. Here, we report the headgroup H-bond populations, structures, and dynamics of 1,2-dimyristoyl-sn-glycero-3-phosphocholine vesicles in concentrated glucose solutions using ultrafast two-dimensional infrared spectroscopy in conjunction with molecular dynamics simulations. H-Bond populations and dynamics at the ester carbonyl positions are largely unaffected even at very high, 600 mg/mL, sugar concentrations. In addition, dynamics exhibit a slight nonmonotonic dependence on sugar concentration. Simulations, which are in near-quantitative agreement with measured dynamics, show that the H-bond structure remains largely intact by the existence of sugar. This study shows that the bioprotection of sugar is realized through stable lipid–saccharide–water H-bond networks at the membrane interface that mimic the H-bond networks in pure water.