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Title: A new force field including charge directionality for TMAO in aqueous solution

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4960207· OSTI ID:22678976
; ; ;  [1];  [2]
  1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)
  2. Johannes Gutenberg University Mainz, Staudingerweg 7, 55099 Mainz (Germany)

We propose a new force field for trimethylamine N-oxide (TMAO), which is designed to reproduce the long-lived and highly directional hydrogen bond between the TMAO oxygen (O{sub TMAO}) atom and surrounding water molecules. Based on the data obtained by ab initio molecular dynamics simulations, we introduce three dummy sites around O{sub TMAO} to mimic the O{sub TMAO} lone pairs and we migrate the negative charge on the O{sub TMAO} to the dummy sites. The force field model developed here improves both structural and dynamical properties of aqueous TMAO solutions. Moreover, it reproduces the experimentally observed dependence of viscosity upon increasing TMAO concentration quantitatively. The simple procedure of the force field construction makes it easy to implement in molecular dynamics simulation packages and makes it compatible with the existing biomolecular force fields. This paves the path for further investigation of protein-TMAO interaction in aqueous solutions.

OSTI ID:
22678976
Journal Information:
Journal of Chemical Physics, Vol. 145, Issue 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English