dc.contributor.author
Wolf, Alexander
dc.contributor.author
Dragelj, Jovan
dc.contributor.author
Wonneberg, Juliane
dc.contributor.author
Stellmacher, Johannes
dc.contributor.author
Balke, Jens
dc.contributor.author
Woelke, Anna Lena
dc.contributor.author
Hodoscek, Milan
dc.contributor.author
Knapp, Ernst Walter
dc.contributor.author
Alexiev, Ulrike
dc.date.accessioned
2020-06-02T11:19:40Z
dc.date.available
2020-06-02T11:19:40Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/27582
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-27336
dc.description.abstract
Cytochrome c oxidase (CcO), a redox-coupled proton pump, catalyzes the reduction of molecular oxygen to water, thereby establishing the transmembrane proton gradient that fuels ATP synthesis. CcO employs two channels for proton uptake, the D- and the K-channel. In contrast to the D-channel, the K-channel does not constitute a continuous pathway of H-bonds for proton conduction and is only active in the reductive phase rendering its proton transport mechanism enigmatic. Theoretical studies have suggested selective hydration changes within the K-channel to become activated and being essential for vectorial proton transport. Here, we unravel a previously unidentified mechanism for transient proton channel activation by combining computational studies with site-directed nano-environmental probing of protonation, structural changes, and water dynamics. We show that electrostatic changes at the binuclear center lead to long-range conformational changes propagating to the K-channel entrance as evidenced by time-resolved fluorescence depolarization experiments and molecular dynamics (MD) simulations. These redox-induced long-range structural rearrangements affect the H-bond network at the K-channel's protein surface as shown by pKa-shift analysis of a local probe in experiment and simulation. Concomitantly, selective channel hydration at the K-channel entrance was revealed by dipolar relaxation studies to be associated with channel opening. We propose that instead of a singular change, it is the intricate interplay of these individual redox-triggered changes in the cause–effect relationship that defines the mechanism for transient proton conduction of the K-channel.
en
dc.format.extent
9 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by-nc/4.0/
dc.subject
cytochrome c oxidase
en
dc.subject
redox-coupled proton-channel opening
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
dc.title
The redox-coupled proton-channel opening in cytochrome c oxidase
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1039/C9SC06463J
dcterms.bibliographicCitation.journaltitle
Chemical science
dcterms.bibliographicCitation.number
15
dcterms.bibliographicCitation.pagestart
3804
dcterms.bibliographicCitation.pageend
3811
dcterms.bibliographicCitation.volume
11
dcterms.bibliographicCitation.url
https://doi.org/10.1039/C9SC06463J
refubium.affiliation
Physik
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
2041-6539
refubium.resourceType.provider
WoS-Alert