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A molecular mechanics force field for biologically important sterols
Author(s) -
Cournia Zoe,
Smith Jeremy C.,
Ullmann G. Matthias
Publication year - 2005
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20277
Subject(s) - lanosterol , force field (fiction) , molecular mechanics , chemistry , molecular dynamics , sterol , computational chemistry , atomic charge , potential energy , campesterol , molecule , chemical physics , molecular physics , classical mechanics , physics , quantum mechanics , cholesterol , organic chemistry , biochemistry
A parameterization has been performed of the biologically important sterols cholesterol, ergosterol, and lanosterol for the CHARMM27 all‐atom molecular mechanics force field. An automated parameterization method was used that involves fitting the potential to vibrational frequencies and eigenvectors derived from quantum‐chemical calculations. The partial charges were derived by fitting point charges to quantum‐chemically calculated electrostatic potentials. To model the dynamics of the hydroxyl groups of the sterols correctly, the parameter set was refined to reproduce the energy barrier for the rotation of the hydroxyl group around the carbon connected to the hydroxyl of each sterol. The frequency‐matching plots show good agreement between the CHARMM and quantum chemical normal modes. The parameters are tested in a molecular dynamics simulation of the cholesterol crystal structure. The experimental geometry and cell dimensions are well reproduced. The force field derived here is also useful for simulating other sterols such as the phytosterols sigmasterol, and campesterol, and a variety of steroids. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1383–1399, 2005