Theory and Modeling of Specific Ion Effects in Chemistry and Biology

化学和生物学中特定离子效应的理论和建模

• 批准号: 1011746
• 负责人: Thomas Beck
• 金额: $ 42万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1011746&HistoricalAwards=false
• 关键词: Theory; Modeling; Specific; Ion; Effects

Thomas Beck of the University of Cincinnati is supported by the Theory, Models and Computational Methods program in the Chemistry Division to carry out computational studies of specific ion or Hofmeister effects for anions. This work employs a novel theoretical approach for the statistical mechanics of liquids, the quasi-classical theory (QCT). The QCT partitions the excess chemical potential into three contributions by enacting a spatial partitioning with a hard-sphere constraint: 1) the cavity free energy for digging a hole in the solvent 2) the free energy for placing the solute into the cavity, and 3) the free energy to release the hard-sphere constraint, allowing direct contact between the solute and solvent. For ion solvation problems, step 2) above yields the largest contribution to the hydration free energy. It was found that a mean-field estimate of this term is quite accurate. This method permits computations of free energies at the quantum mechanical level, and in binding sites in proteins.Specific ion or Hofmeister effects are very important in a wide array of chemical, physical, and biological systems, for example the swelling of biological membranes, solvation free energies and activities, surface tension increments, bubble interactions, ion channel transport, colloid interactions, pH measurements, buffer behavior and protein folding and stability. Professor Beck is involved in organizing a workshop on ions in chemistry and biology to be held in Telluride CO. He is also heavily involved in undergraduate and graduate curriculum development.

辛辛那提大学的 Thomas Beck 在化学系理论、模型和计算方法项目的支持下，对特定离子或阴离子的霍夫迈斯特效应进行计算研究。这项工作采用了一种新颖的液体统计力学理论方法，即准经典理论（QCT）。 QCT 通过使用硬球约束进行空间划分，将多余的化学势分为三个部分：1) 在溶剂中挖洞的空腔自由能 2) 将溶质放入空腔的自由能，以及 3 ）自由能释放硬球约束，允许溶质和溶剂之间直接接触。对于离子溶剂化问题，上述步骤 2) 对水合自由能的贡献最大。 人们发现该项的平均场估计是相当准确的。 该方法允许计算量子力学水平以及蛋白质结合位点的自由能。特定离子或霍夫迈斯特效应在各种化学、物理和生物系统中非常重要，例如生物膜的膨胀、溶剂化自由能和活性、表面张力增量、气泡相互作用、离子通道传输、胶体相互作用、pH 测量、缓冲行为以及蛋白质折叠和稳定性。 Beck 教授参与组织了在特柳赖德 CO 举办的化学和生物学离子研讨会。他还积极参与本科生和研究生课程的开发。