Mechanism of Proton Pumping in Complex I of the Mitochondrial Respiratory Chain

Quantum Reports

Michele Vittadello¹  Lev Mourokh²  Jonathan Friedman² 

[1] Department of Chemistry and Environmental Science, Medgar Evers College of the City University of New York, Brooklyn, NY 11225, USA;Department of Physics, Queens College of the City University of New York, Flushing, NY 11367, USA;

关键词: mitochondrial respiratory chain;    proton-pumping Complex I;    conformation-assisted transport;    proton-coupled electron transfer;    quantum yield;   

DOI  :  10.3390/quantum3030027

来源: DOAJ

【 摘 要 】

We propose a physical mechanism of conformation-induced proton pumping in mitochondrial Complex I. The structural conformations of this protein are modeled as the motion of a piston having positive charges on both sides. A negatively charged electron attracts the piston, moving the other end away from the proton site, thereby reducing its energy and allowing a proton to populate the site. When the electron escapes, elastic forces assist the return of the piston, increasing proton site energy and facilitating proton transfer. We derive the Heisenberg equations of motion for electron and proton operators and rewrite them in the form of rate equations coupled to the phenomenological Langevin equation describing piston dynamics. This set of coupled equations is solved numerically. We show that proton pumping can be achieved within this model for a reasonable set of parameters. The dependencies of proton current on geometry, temperature, and other parameters are examined.

【 授权许可】

Unknown