Carbohydrate intramolecular hydrogen bonding cooperativity and its effect on water structure
Carbohydrate intramolecular hydrogen bonding cooperativity and its effect on water structure
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DOI：
10.1021/jp0543072
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发表时间：
2005-12-22
影响因子：
3.3
通讯作者：
Vanderkooi, JM
中科院分区：
文献类型：
--
作者：
Dashnau, JL;Sharp, KA;Vanderkooi, JM
采用分子动力学（MD）模拟，结合水-水氢键角分析、溶剂可达表面积和溶剂化近似自由能计算，确定了羟基取向对一组化学性质相同的溶质-醛己糖的溶质水化和周围水结构的影响。分子内氢键的协同性与醛己糖立体异构体周围水结构的变化密切相关。OH-4基团在水合作用中起着关键作用，因为它能够利用OH-6基团参与许多氢键网络。终止于分子内的网络（OH-4 -> OH-6 -> O-5）比终止于游离羟基的网络（OH-6 -> OH-4 -> OH-3）具有相对更多的非极性水合作用。OH-2基团通过双轴OH-2/4分子内氢键C调节OH-4网络的强度，从而稳定和诱导网络的方向性。其他双轴相互作用，如OH-1和OH-3之间的相互作用，仅间接影响水的结构。从水-水氢键族的角度讨论了围绕氢键网络的水结构。此外，还综述了双轴氢键对相邻氢键的影响。结果表明，蛋白质-碳水化合物识别和碳水化合物的低温保护等生物事件可能是由分子内氢键协同作用驱动的。
Molecular dynamics (MD) simulations combined with water-water H-bond angle analysis and calculation of solvent accessible surface area and approximate free energy of solvation were used to determine the influence of hydroxyl orientation on solute hydration and surrounding water structure for a group of chemically identical solutes-the aldohexopyranose sugars. Intramolecular hydrogen bond cooperativity was closely associated with changes in water structure surrounding the aldohexopyranose stereoisomers. The OH-4 group played a pivotal role in hydration as it was able to participate in a number of hydrogen bond networks utilizing the OH-6 group. Networks that terminated within the molecule (OH-4 -> OH-6 -> O-5) had relatively more nonpolar-like hydration than those that ended in a free hydroxyl group (OH-6 -> OH-4 -> OH-3). The OH-2 group modulated the strength of OH-4 networks through syndiaxial OH-2/4 intramolecular hydrogen bonding, C, which stabilized and induced directionality in the network. Other syndiaxial interactions, such as the one between OH-1 and OH-3, only indirectly affected water structure. Water structure surrounding hydrogen bond networks is discussed in terms of water-water hydrogen bond populations. The impact of syndiaxial versus vicinal hydrogen bonds is also reviewed. The results suggest that biological events such as protein-carbohydrate recognition and cryoprotection by carbohydrates may be driven by intramolecular hydrogen bond cooperativity.