EXPERIMENTALLY DERIVED POINT CHARGES FOR PROTEINS

我们建议，以确定原子的部分电荷，常见的氨基 酸，蛋白质的组成部分，从实验数据。 这些 电荷是分子中所用力场的必要参数， 蛋白质的建模研究。 此前，此类收费已衍生出 使用量子力学和其他理论技术。 以来 蛋白质的能量和构象被认为是非常重要的。 受这些分子内电荷-电荷相互作用的影响， 重要的是，在分子力学中使用的电荷参数， 动力学计算应尽可能准确。 使用最近衍生的 方法，我们现在能够从高精度导出必要的电荷 X射线晶体学数据。 如此厘定的控罪， 目的包括：1）它们将用于改进的力场 用于蛋白质的未来分子建模研究; 2）它们将服务于 作为一组对照数据，与理论结果进行比较， 收费计算 通过比较电荷集合，我们可以改进 理论技术（确定最佳基组，会计 对于氢键的作用等），最终使这些方法 在那些情况下， 实验测定是不可行的。

We propose to determine atomic partial charges for commonly occurring amino acids, the building blocks of proteins, from experimental data. These charges are necessary parameters for the force fields used in molecular modeling studies of proteins. Previously, such charges have been derived using quantum mechanical and other theoretical techniques. Since the energies, and thus conformations, of proteins are believed to be heavily influenced by charge-charge interactions within these molecules, it is very important that the charge parameters used in molecular mechanics and dynamics calculations be as accurate as possible. Using recently derived methods, we are now able to derive the necessary charges from high accuracy x-ray crystallographic data. The charges so determined will serve a number of purposes, including: 1) They will be used in an improved force field for future molecular modeling studies of proteins; and 2) They will serve as a control set of data with which to compare the results of theoretical charge calculations. By comparing charge sets, we can improve the theoretical techniques (determination of an optimal basis set, accounting for the effects of hydrogen bonding, etc.), ultimately making these methods more reliable for charge determinations in those cases for which an experimental determination is infeasible.