Malsam Jason, Aksan Alptekin
Biostabilization Laboratory, Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
J Phys Chem B. 2009 May 14;113(19):6792-9. doi: 10.1021/jp8099434.
Carbohydrates play important roles in the survival of freeze-tolerant organisms. In order to understand the role of carbohydrates on hydrogen bonding (HB) and thermodynamic/kinetic transitions, aqueous trehalose solutions at cryogenic temperatures were analyzed using FTIR spectroscopy. Distinct changes in water-water and water-carbohydrate HB organization were identified during supercooling, freezing, and vitrification. FTIR spectroscopy revealed the kosmotropic effect of trehalose and the presence of two distinct water families in supercooled carbohydrate solutions, (1) water molecules directly associated with the carbohydrate, forming its hydration layer(s) and (2) water molecules that are involved in water-water HB in small clusters. The latter showed characteristics of water in hydrophilic confinement.
碳水化合物在耐冻生物的生存中起着重要作用。为了了解碳水化合物对氢键（HB）以及热力学/动力学转变的作用，利用傅里叶变换红外光谱（FTIR）对低温下的海藻糖水溶液进行了分析。在过冷、冷冻和玻璃化过程中，发现了水 - 水和水 - 碳水化合物HB结构的明显变化。FTIR光谱揭示了海藻糖的促溶效应以及过冷碳水化合物溶液中存在两种不同的水簇，（1）与碳水化合物直接相关的水分子，形成其水化层，（2）参与小簇中水 - 水HB的水分子。后者表现出亲水受限环境中水的特征。
