Universal short-range ab initio atom–atom potentials for interaction energy contributions with an optimal repulsion functional form
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The repulsion term in conventional force fields constitutes a major source of error. Assuming that this could originate from a too simple analytical functional form, we analyzed various analytical functions using ab initio exchange component values as a reference and obtained (α + β R −1)exp(−γ R) as the optimal form to represent the repulsion term. Universal exchange, delocalization, and electrostatic penetration potentials approximating the corresponding interaction energy components defined within hybrid variation-perturbation theory (HVPT) were derived using as a reference a training set of 660 biomolecular complexes. The electrostatic multipole term was calculated using cumulative atomic multipole moments, whereas correlation contribution including dispersion term and first-order correlation correction was estimated from nonempirical D a s functions derived by Pernal et al. The resulting non-empirical atom–atom potentials (NEAAP) were tested for several urokinase–inhibitor complexes yielding improved docking results.
KeywordsIntermolecular interactions Nonempirical potentials Exchange repulsion Optimal analytical function
This work was supported by Wroclaw Research Centre EIT+ within the project ”Biotechnologies and advanced medical technologies” - BioMed (POIG.01.01.02-02-003/08) co-financed by the European Regional Development Fund (Operational Programme Innovative Economy, 1.1.2). Partial financing by a statutory activity subsidy from Polish Ministry of Science and Higher Education for Faculty of Chemistry of Wroclaw University of Technology is also acknowledged. Calculations were performed in supercomputer centers in Wroclaw (WCSS), Poznan (PCSS), and Warsaw(ICM). The authors are indebted to Dr. Karol M. Langner from the University of Virginia at Charlottesville, VA, USA, for stimulating discussion and valuable comments.
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