title: A numerically stable restrained electrostatic potential charge fitting method.
abstract: Inspired by the idea of charge decomposition in calculation of the dipole preserving and polarization consistent charges (Zhang et al., J. Comput. Chem. 2011, 32, 2127), we have proposed a numerically stable restrained electrostatic potential (ESP)-based charge fitting method for protein. The atomic charge is composed of two parts. The dominant part is fixed to a predefined value (e.g., AMBER charge), and the residual part is to be determined by restrained fitting to residual ESP on grid points around the molecule. Nonuniform weighting factors as a function of the dominant charge are assigned to the atoms. Because the residual part is several folds to several orders smaller than the dominant part, the impact of ill-conditioning is alleviated. This charge fitting method can be used in quantum mechanical/molecular mechanical (QM/MM) simulations and similar studies, where QM calculated electronic properties are frequently mapped to partial atomic charges.
authors.affiliation: Center for Laser and Computational Biophysics, State Key Laboratory of Precision Spectroscopy, Department of Physics and Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zeng
authors.forename: LiLi
authors.initials: L
authors.lastname: Duan
authors.forename: John Z H
authors.initials: JZ
authors.lastname: Zhang
authors.forename: Ye
authors.initials: Y
authors.lastname: Mei
mesh_terms: D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D011789:Quantum Theory; D055672:Static Electricity
chemical_list: D010455:Peptides