Research On Aluminum Metalloenzymes With Respect To Ab Initio Method And ABEEMσπ Model

A plurality of aluminum metalloenzymes were selected as model molecules in this paper,using the ab initio method (HF/STO-3G method), we rectified and ascertained the ABEEMσπparameters of aluminum metalloenzymes with our own program, then we calculated thecharge distributions (involving atom charges, bond charges and lone pair electron charges) ofthe aluminum metalloenzymes (PDB code:1BS1,1L3R and3UKD) by the ABEEMσπ modelestablished by Yang et al. The results revealed that the linear correlation coefficients of thecharge distributions when regressed to atoms of these molecules got by the ABEEMσπ modeland the charge distributions calculated by the HF/STO-3G method are more than0.96,showing that these charge distributions calculated by the ABEEMσπ model can well simulatethe results of the ab initio method, moreover, we could save time via the ABEEMσπ model,so it implies that the ABEEMσπ model can be employed to rapidly and accurately calculatethe charge distributions of large molecules. Meanwhile, the ABEEMσπ parameters lay afoundation for construction of ABEEMσπ/MM fluctuating charge force field model foraluminum metalloenzymes. Then, with the ABEEMσπ parameters, we calculated the Fukuifunction of the active areas of the aluminum metalloenzymes which was stated above andknew that aluminum ion is the active center in each of them, which accord with theexperimental conclusions, consequently, the ABEEMσπ model can be introduced to correctlyconfirm the active center of the aluminum metalloenzymes. Finally, we calculated andanalyzed the charge distributions of1L3R and the new molecule that the serine was integratedwith1L3R, the results illuminated that the charge of the aluminum ion decreased by0.122ewhen the serine was integrated with1L3R, which was greater than other areas, so it could beseen that the aluminum ion is the active center of1L3R. We calculated the Fukui function ofthe molecule that the serine was integrated with1L3R simultaneously, we found that theFukui function was no longer the greatest one in it, showing that the reactivity of1L3R turnedto be weaker because of the serine. In addition, the calculation of the generalized Fukuifunction of the aluminum ion in the two molecules showed that it could be adopted to explorereactivities among molecules, which shows that the ABEEMσπ model can also be utilized toforecast inhibitors of the aluminum metalloenzymes.