ABEEMσπ FLUCTUATING CHARGE FORCE FIELD APPLIED TO ALANINE DIPEPTIDE AND ALANINE DIPEPTIDE-WATER SYSTEMS

作者：Liu, Cui^*; Zhao, Dong-Xia; Yang, Zhong-Zhi

来源：Journal of Theoretical and Computational Chemistry, 2010, 9(supp01): 77-97.

DOI：10.1142/S0219633610005530

• ABEEM sigma pi/MM
• fluctuating charge force field
• geometry
• hydration

Atom-bond electronegativity equalization method at sigma pi level fused into molecular mechanics (ABEEM sigma pi/MM) divides the bond regions into sigma and pi bond regions on the basis of previous ABEEM/MM. It may suitably reflect intramolecular and intermolecular interaction and polarization. The fitting function k(H-bond) in the hydrogen bond (HB) interaction region increases the capability of ABEEM sigma pi/MM to simulate the hydration. Hydration of alanine dipeptide (AD) in aqueous solution is determined by the intramolecular and intermolecular HBs and the competition among the molecular packing effects. The acceptor molecule in HB complex contains at least one pair of lone pair electrons, sometimes contains pi bonds, whose orientations directly effect the orientation of HBs. Therefore, ABEEM sigma pi/MM has obviously predominance to discuss the AD and AD-water systems, which contain many lone pair electrons, pi bonds, and abundant HB nets. Properties of six AD conformers, clusters AD+(H2O)(1-4) obtained from ABEEM sigma pi/MM agree well with the results of experiments, ab initio and other force fields. Structural and dynamical properties of the hydration water molecules have just embodied that the ABEEM sigma pi/MM gives correct hydration description relative to other force fields.

• 出版日期2010
• 单位辽宁师范大学