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.

辛辛那提大学的托马斯贝克得到化学系理论、模型和计算方法项目的支持，对阴离子的特定离子或霍夫迈斯特效应进行计算研究。这项工作采用了一种新的理论方法的统计力学的液体，准经典理论（QCT）。 QCT通过采用硬球约束的空间划分将过量化学势划分为三个贡献：1）用于在溶剂中挖洞的空腔自由能，2）用于将溶质放置到空腔中的自由能，以及3）释放硬球约束的自由能，允许溶质和溶剂之间的直接接触。对于离子溶剂化问题，上述步骤2）产生对水合自由能的最大贡献。 据发现，这一项的平均场估计是相当准确的。 这种方法允许在量子力学水平上计算自由能，并在蛋白质中的结合位点。特定离子或霍夫迈斯特效应在广泛的化学，物理和生物系统中非常重要，例如生物膜的溶胀，溶剂化自由能和活性，表面张力增量，气泡相互作用，离子通道运输，胶体相互作用，pH测量，缓冲行为以及蛋白质折叠和稳定性。 贝克教授参与组织了一个关于化学和生物学中离子的研讨会。他还积极参与了本科生和研究生课程的开发。