应用ab initio方法和ABEEMσπ模型研究含铝金属酶

Study on Aluminum Metalloenzymes by ab initio Method and ABEEMσπ Model

应用原子-键电负性均衡方法中的σπ模型(ABEEMσπ模型),通过大量量子化学计算,拟合确定了含铝金属酶体系的ABEEMσπ参数.将这些参数应用到含铝金属酶大分子体系的电荷分布及Fukui函数的计算,结果显示,ABEEMσπ模型计算得到的电荷分布及Fukui函数与从头算和实验结论均有很好的一致性.还进一步计算分析了1L3R酶与丝氨酸结合前后的分子各区域的电荷分布,结果表明,Al 3+是1L3R酶的活性中心,根据结合后分子的Fukui函数可以得出丝氨酸会使1L3R酶的活性降低.另外,通过比较两者结合前后Al 3+的广义Fukui函数,证明了广义Fukui函数可用于该体系分子间反应活性的比较,同时也说明利用ABEEMσπ模型来预测含铝金属酶的抑制剂是可行的.

By applying the atom-bond electronegativity equalization δπ model （ABEEMδπ model）, a large number of quantum chemistry calculations were performed to determine the ABEEMδπ parameters of aluminum metalloenzymes. Then these parameters were employed to study the charge distributions and Fukui function of aluminum metalloenzymes. Calculated results obtained by ABEEMδπ model are in good agreement with those by the ab initio method and experimental conclusions. Further analysis of the charge distributions between 1L3R and 1L3R-serine indicates that AP＋ is the active center of 1L3R,and serine would reduce the activity of 1L3R according to Fukui function. In addition,comparing the general- ized Fukui function of AP＋ in 1L3R with that in 1L3R-serine,generalized Fukui function is proved to be appropriate in this system, and ABEEMδπ model is feasible to predict the inhibitors of aluminum met- alloenzymes.