MONTE CARLO SIMULATION ON AQUEOUS SOLUTION OF BIOLOGICAL MOLECULES——ALANINE SOLUTION

The Monte Carlo simulation is performed for a cluster consisting of a neutral alanine molecule surrounded by 56 water molecules. The average water-water and alanine-water interaction energies are found. The space surrounding the alanine molecule is divided into three regions, where the central atoms are C' atom for the earboxyl group region, N atom for the amino group region and C~β atom for the methyl group region. The water-water and water-alanine interaction energies as functions of the distance between the oxygen atom in a water molecule and the central atom in each region are calculated. In each region the orientational correlation function for the dipole moments of water molecules, the radial distribution function for the oxygen and hydrogen atoms of water molecules are evaluated. In addition, the numbers of water molecules in the first solvation shells of each region and of entire alanine molecule are also counted.     

生物分子水溶液的Monte Carlo模拟——丙氨酸溶液

本文对由五十六个水分子包围一个中性的丙氨酸分子所构成的分子集团做了MC模拟计算。求出了水—水和氨基酸—水的平均相互作用能。将丙氨酸分子周围的空间划分为三个区域——羧基区、氨基区和甲基区。分别以羧基碳、氨基氮和甲基碳作为中心原子,统计了各区中水—水和水—氨基酸相互作用能随着水分子中的氧原子和该区中心原子的距离而改变的函数,各区中水分子偶极矩的取向关联函数以及水分子中氧原子和氢原子的径向分布函数。此外,还计算了各区第一个水化层的水分子数和整个丙氨酸分子第一个水化层的水分子数。     

超离域度与多环芳烃的致癌作用

本文用HMO法计算了DNA碱基(A、T、G、C、A—T、G—C)和一系列苯并[α]蒽甲基取代衍生物的超离域度,并用EHMO法计算了苯并[α]芘和苯并[α]蒽的最终代谢致癌活性分子的超离域度.我们看到,以碱基中各个位置的亲电超离域度和苯并[α]芘、苯并[α]蒽的最终代谢致癌活性分子各个位置的近似亲核超离域度作为反应活性指数时,理论计算能较好地与实验结果符合.同时发现,苯并[α]蒽甲基取代衍生物的∑S_r~E—∑_r~E 的数值与其致癌活性间存在着较好的相关性。