Protonation-State-Dependent Communication in Cytochrome c Oxidase.

ABSTRACT: Proton transfer in cytochrome c oxidase from the cellular inside to the binuclear redox center (BNC) can occur through two distinct pathways, the D- and K-channels. For the protein to function as both a redox enzyme and a proton pump, proton transfer into the protein toward the BNC or toward a proton loading site (and ultimately through the membrane) must be highly regulated. The P_R → F transition is the first step in a catalytic cycle that requires proton transfer from the bulk at the N-side to the BNC. Molecular dynamics simulations of the P_R → F intermediate of this transition, with 16 different combinations of protonation states of key residues in the D- and K-channel, show the impact of the K-channel on the D-channel to be protonation-state dependent. Strength as

SUBMITTER: Bagherpoor Helabad M 

PROVIDER: S-EPMC5567593 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature