Dashnau Jennifer L, Sharp Kim A, Vanderkooi Jane M
Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
J Phys Chem B. 2005 Dec 22;109(50):24152-9. doi: 10.1021/jp0543072.
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, 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.
分子动力学（MD）模拟结合水 - 水氢键角分析、溶剂可及表面积计算以及溶剂化近似自由能计算，用于确定羟基取向对一组化学性质相同的溶质——己醛吡喃糖的溶质水合作用和周围水结构的影响。分子内氢键协同性与己醛吡喃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关键作用，因为它能够利用OH - 6基团参与多个氢键网络。在分子内终止的网络（OH - 4 --> OH - 6 --> O - 5）比那些以游离羟基结尾的网络（OH - 6 --> OH - 4 --> OH - 3）具有相对更多的类非极性水合作用。OH - 2基团通过反式共轴OH - 2/4分子内氢键调节OH - 4网络的强度，这使网络稳定并诱导其方向性。其他反式共轴相互作用，如OH - 1和OH - 3之间的相互作用，仅间接影响水结构。围绕氢键网络的水结构根据水 - 水氢键数量进行了讨论。还综述了反式共轴氢键与邻位氢键的影响。结果表明，诸如蛋白质 - 碳水化合物识别和碳水化合物的冷冻保护等生物学事件可能由分子内氢键协同性驱动。
