Electrostatic and proton-electron interaction in membrane-bound charge transfer proteins under external electric...

Area of Science:

• Biophysics
• Bioenergetics
• Computational Biology

Background:

• Membrane-bound charge transfer proteins are crucial for biological energy conversion and redox processes.
• Their behavior under external electric fields is largely unknown, limiting applications in bio-nanoelectronics.

Purpose of the Study:

• Investigate the response of the NrfH subunit from *Desulfovibrio vulgaris* to static electric fields.
• Assess its potential for integration into bio-nanoelectronic devices.

Main Methods:

• Employed a multiscale computational framework.
• Utilized classical molecular dynamics with constant pH sampling.
• Applied continuum dielectric theory and Laplace/Poisson solvers.

Main Results:

• NrfH maintains structural integrity up to ±100 mV nm⁻¹.
• Voltage drop is localized within the membrane or protein interior.
• External fields induce pKa shifts, but only specific residues change protonation state.
• Electron-proton coupling is weak, with energies generally smaller than kBT.

Conclusions:

• NrfH exhibits significant electrostatic resilience.
• The protein's properties suggest its utility as an electron-conducting element in nanoscale bioelectronic platforms.