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Updated: Jun 1, 2026
12:15
Single Liposome Measurements for the Study of Proton-Pumping Membrane Enzymes Using Electrochemistry and Fluorescent Microscopy
Published on: February 21, 2019
Electrostatic models of electron-driven proton transfer across a lipid membrane
Anatoly Yu Smirnov1, Lev G Mourokh, Franco Nori
1Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198, Japan.
Summary
Electron energy drives uphill proton transport across membranes through electrostatic interactions in two models. These models achieve high quantum yields and power-conversion efficiency, offering insights into biological energy conversion.
Area of Science:
- Biophysics
- Computational Biology
- Electrochemistry
Background:
- Biological membranes facilitate crucial energy conversion processes.
- Electron and proton transport are fundamental to cellular energy.
- Understanding mechanisms of uphill proton transport is key to bioenergetics.
Purpose of the Study:
- To model electron-driven uphill proton transport across lipid membranes.
- To investigate energy conversion via electrostatic interactions.
- To analyze mechanisms in cytochrome c oxidase and bacterial nitrate respiration.
Main Methods:
- Developed two theoretical models for proton transport.
- Utilized a cluster-based approach simplifying complex systems.
- Solved equations of motion for electron and proton operators, including Coulomb interactions and environmental effects.
- Incorporated Langevin-type equations for shuttle dynamics in the second model.
Main Results:
- Unified approach derived for both cytochrome c oxidase and bacterial nitrate respiration models.
- Expressions for electron and proton currents derived, dependent on various system parameters.
- Demonstrated potential for up to 100% quantum yield.
- Achieved a power-conversion efficiency of up to 35%.
Conclusions:
- Electron energy can be effectively converted to proton gradients via electrostatic interactions.
- The models provide a framework for understanding biological energy transduction.
- High efficiencies suggest potential for artificial energy conversion systems.
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