2008/06/19 by Anatoly Yu. Smirnov, Sergey Savel’ev, Smirnov, Anatoly Yu. +4 · 1 citation
Biochemistry, Genetics and Molecular Biology · Neuroscience · Physics and Astronomy · #Biological Physics (physics.bio-ph) #FOS: Biological sciences #FOS: Physical sciences #Mitochondrial Function and Pathology #Other Condensed Matter (cond-mat.other) #Photoreceptor and optogenetics research #Photosynthetic Processes and Mechanisms #Subcellular Processes (q-bio.SC) #cond-mat.other #physics.bio-ph #q-bio.SC
paper · pdf · doi:10.48550/arxiv.0806.3233
22 pages, 6 figures
arxiv created 2008/06/19 · openalex publication_date 2008/06/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Shuttle-assisted charge transfer is pivotal for the efficient energy transduction from the food-stuff electrons to protons in the respiratory chain of animal cells and bacteria. The respiratory chain consists of four metalloprotein Complexes (I-IV) embedded in the inner membrane of a mitochondrion. Three of these complexes pump protons across the membrane, fuelled by the energy of food-stuff electrons. Despite extensive biochemical and biophysical studies, the physical mechanism of this proton pumping is still not well understood. Here we present a nanoelectromechanical model of the electron-driven proton pump related to the second loop of the respiratory chain, where a lipid-soluble ubiquinone molecule shuttles between the Complex I and Complex III, carrying two electrons and two protons. We show that the energy of electrons can be converted to the transmembrane proton potential gradient via the electrostatic interaction between electrons and protons on the shuttle. We find that the system can operate either as a proton pump, or, in the reverse regime, as an electron pump. For membranes with various viscosities, we demonstrate that the uphill proton current peaks near the body temperature T ≈ 37 ∘C.