✦ LIBER ✦

A molecular mechanics force field for biologically important sterols

✍ Scribed by Zoe Cournia; Jeremy C. Smith; G. Matthias Ullmann

Publisher: John Wiley and Sons
Year: 2005
Tongue: English
Weight: 478 KB
Volume: 26
Category: Article
ISSN: 0192-8651
DOI: 10.1002/jcc.20277

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

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

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