Poor Person's pH Simulation of Membrane Proteins.

Area of Science:

• Computational Biology
• Biophysics
• Structural Biology

Background:

• pH is critical for biomolecule function, but its molecular-level effects are complex.
• Simulating pH effects in large membrane systems using classical molecular dynamics (MD) is challenging.
• Existing methods struggle to capture transient protonation states and their impact on protein conformation.

Purpose of the Study:

• To present an integrative computational pipeline for studying pH effects on transmembrane proteins.
• To combine Multi-Conformation Continuum Electrostatics (MCCE) with MD simulations.
• To analyze coupled conformational changes driven by transient protonation states.

Main Methods:

• Developed an integrative pipeline merging MCCE computations with MD simulations.
• Explained core methodologies and outlined required software with key parameters.
• Applied the pipeline to bioenergetic complexes: NADH dehydrogenase (Complex I) and V-type ATPase V_o domain.

Main Results:

• Successfully captured the effect of transient protonation states on protein conformational changes.
• Identified novel hydrogen bond networks within transmembrane proteins.
• Discovered ligand binding pathways and characterized disease-associated mutations.

Conclusions:

• The hybrid MCCE-MD pipeline provides a robust method for studying pH-dependent biomolecular processes.
• This approach enables deeper insights into the structure-function relationships of membrane proteins.
• The methodology facilitates the discovery of functionally important molecular details and disease mechanisms.