Electrostatics, hydration, and proton transfer dynamics in the membrane domain of respiratory complex I.

ABSTRACT: Complex I serves as the primary electron entry point into the mitochondrial and bacterial respiratory chains. It catalyzes the reduction of quinones by electron transfer from NADH, and couples this exergonic reaction to the translocation of protons against an electrochemical proton gradient. The membrane domain of the enzyme extends ∼180 Å from the site of quinone reduction to the most distant proton pathway. To elucidate possible mechanisms of the long-range proton-coupled electron transfer process, we perform large-scale atomistic molecular dynamics simulations of the membrane domain of complex I from Escherichia coli. We observe spontaneous hydration of a putative proton entry channel at the NuoN/K interface, which is sensitive to the protonation state of buried glutamic acid residues.

SUBMITTER: Kaila VR 

PROVIDER: S-EPMC4024853 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature