Universal short-range ab initio atom-atom potentials for interaction energy contributions with an optimal repulsion...

Area of Science:

• Computational chemistry
• Molecular modeling
• Biophysics

Background:

• Conventional force fields contain significant errors in the repulsion term.
• The analytical form of repulsion functions may be overly simplistic, leading to inaccuracies.

Purpose of the Study:

• To develop a more accurate analytical function for the repulsion term in force fields.
• To derive new potentials for exchange, delocalization, and electrostatic penetration.
• To improve the accuracy of molecular docking simulations.

Main Methods:

• Analyzed various analytical functions for the repulsion term using ab initio exchange component values.
• Derived universal exchange, delocalization, and electrostatic penetration potentials based on hybrid variation-perturbation theory (HVPT).
• Utilized a training set of 660 biomolecular complexes and nonempirical D a s functions for correlation estimation.

Main Results:

• Identified (α + β R (-1))exp(-γ R) as the optimal analytical form for the repulsion term.
• Developed non-empirical atom-atom potentials (NEAAP) that approximate key interaction energy components.
• Achieved improved docking results for urokinase-inhibitor complexes using the NEAAP.

Conclusions:

• The proposed analytical form and derived potentials significantly enhance the accuracy of the repulsion term in force fields.
• NEAAP provides a more reliable representation of intermolecular interactions, leading to better molecular docking predictions.
• This work offers a pathway to more precise molecular simulations in computational chemistry and drug discovery.