Bind3P: Optimization of a Water Model Based on Host-Guest Binding Data.

Area of Science:

• Computational chemistry
• Molecular modeling
• Physical chemistry

Background:

• Accurate molecular models are crucial for simulating chemical and biological systems.
• Existing water models like TIP3P have limitations in predicting host-guest binding affinities.
• Force field parametrization often requires extensive experimental data.

Purpose of the Study:

• To develop an improved water model, Bind3P, by optimizing Lennard-Jones parameters.
• To evaluate Bind3P's performance against experimental binding free energies and enthalpies.
• To assess the model's accuracy for hydration free energies and bulk water properties.

Main Methods:

• Sensitivity analysis was employed to readjust Lennard-Jones parameters.
• The TIP3P water model was used as a base for parametrization.
• Experimental binding free energies for six host-guest systems and pure liquid properties were used for training.
• Bind3P was tested against over 100 distinct experimental binding free energies and enthalpies.

Main Results:

• Bind3P demonstrated a consistent reduction in mean signed error for binding free energies compared to TIP3P.
• The model showed improvements in hydration free energies for small organic molecules.
• Accuracy of bulk water properties, including density and heat of vaporization, was preserved.
• The parametrization approach proved effective for host-guest binding data integration.

Conclusions:

• Bind3P represents a significant improvement over TIP3P for host-guest binding simulations.
• Integrating host-guest binding data into force field parametrization is a viable strategy for enhancing model accuracy.
• The developed method can be extended to refine other sophisticated water models.