将原子与键电负性均衡方法融入分子力学方法,即利用ABEEMσ-π浮动电荷力场与ABEEM-7P水模型相结合的方法及OPLS-AA固定电荷力场方法,对GA88和GB88蛋白进行了水溶液(温度295 K)和真空中的分子动力学模拟.比较两种方法得到的两个蛋白质的结构与实验结构的均方根偏差,分析了两种方法得到的两个蛋白质的回旋半径、氢键分布、径向分布及电荷分布情况.结果表明,ABEEMσ-π-和OPLS-AA力场均能正确模拟蛋白质结构,得到的各项偏差值接近,但从各偏差的波动大小可见,ABEEMσπ力场的模拟更稳定；回旋半径模拟很好地体现了蛋白质的“电致紧缩”现象；氢键分布、径向分布及电荷分布表明,与OPLS-AA固定电荷力场相比,ABEEMσπ浮动电荷力场能更好地体现蛋白质和周围水分子的极化效应.%The dynamic behavior of proteins GA88 and GB88 was investigated at 295 K, using aqueous solution and vacuum molecular dynamics simulations by means of atom-bond electronegativity equalization method fused into molecular mechanics i. e. , ABEEMσπ fluctuating charge force field and the explicit ABEEM-7P water solvent model as well as OPLS-AA fixed-point charge force field. The root-mean-square deviations (RMSDs) of these two proteins' structures obtained from ABEEMσπ and OPLS-AA force fields were compared. The radius of gyration, the distribution of hydrogen bond, the radial distribution function, and the distribution of charge were also analyzed by these two force fields. The results demonstrate that both force fields simulate crystal structures correctly, and the RMSDs simulated are close to each other, but the systems simulated from ABEEMσπ force field are more stable than those from OPLS-AA force field according to the fluctuating ; simulating results of radius of gyration in aqueous solution and in vacuum show the " electrostatic compactness" phenomenon; the distributions of hydrogen bond and radial distribution function, and the distribution of charge indicate that ABEEMσπ fluctuating charge force field account for the polarization effect better than OPLS-AA fixed-point charge force field.
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