Heterogeneous conductorlike solvation model

Area of Science:

• Computational chemistry
• Quantum mechanics
• Biophysical chemistry

Background:

• Solvation models are crucial for accurately predicting molecular properties in solution.
• Continuum solvation models simplify complex solvent environments.
• Heterogeneous solvation models are needed to capture localized dielectric effects.

Purpose of the Study:

• To implement a heterogeneous conductorlike solvation model for quantum chemical methods.
• To derive analytic energy gradients for geometry optimization and molecular dynamics.
• To assess the impact of protein burial on the reduction potential of the type-1 Cu center in rusticyanin.

Main Methods:

• Implementation of a heterogeneous conductorlike screening model/conductorlike polarizable continuum model.
• Variational treatment for the heterogeneous solvation operator.
• Fixed Points with Variable Areas surface tessellation scheme for cavity definition.
• Hartree-Fock and Kohn-Sham quantum chemical methods.

Main Results:

• Analytic energy gradients were derived and implemented.
• Continuous and smooth potential energy surfaces were obtained.
• Desolvation effects due to protein burial were estimated to increase reduction potential by ~200 mV.
• Inclusion of heterogeneity in geometry optimization affected results by ~2 kcal/mol or ~70 mV.

Conclusions:

• The heterogeneous solvation model provides accurate analytic gradients for quantum chemical calculations.
• Protein burial significantly influences the reduction potential of metalloproteins.
• The model is applicable to realistic biomolecular systems.