This title appears in the Scientific Report :
2017
Please use the identifier:
http://hdl.handle.net/2128/14862 in citations.
Please use the identifier: http://dx.doi.org/10.1038/s41598-017-04675-9 in citations.
Origin of proton affinity to membrane/water interfaces
Origin of proton affinity to membrane/water interfaces
Proton diffusion along biological membranes is vitally important for cellular energetics. Here we extended previous time-resolved fluorescence measurements to study the time and temperature dependence of surface proton transport. We determined the Gibbs activation energy barrier ΔG‡r that opposes pr...
Saved in:
Personal Name(s): | Weichselbaum, Ewald |
---|---|
Österbauer, Maria / Knyazev, Denis G. / Batishchev, Oleg V. / Akimov, Sergey A. / Hai Nguyen, Trung / Zhang, Chao / Knör, Günther / Agmon, Noam / Carloni, Paolo / Pohl, Peter (Corresponding author) | |
Contributing Institute: |
Computational Biomedicine; INM-9 Computational Biomedicine; IAS-5 |
Published in: | Scientific reports, 7 (2017) 1, S. 4553 |
Imprint: |
London
Nature Publishing Group
2017
|
DOI: |
10.1038/s41598-017-04675-9 |
Document Type: |
Journal Article |
Research Program: |
Addenda |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1038/s41598-017-04675-9 in citations.
Proton diffusion along biological membranes is vitally important for cellular energetics. Here we extended previous time-resolved fluorescence measurements to study the time and temperature dependence of surface proton transport. We determined the Gibbs activation energy barrier ΔG‡r that opposes proton surface-to-bulk release from Arrhenius plots of (i) protons’ surface diffusion constant and (ii) the rate coefficient for proton surface-to-bulk release. The large size of ΔG‡r disproves that quasi-equilibrium exists in our experiments between protons in the near-membrane layers and in the aqueous bulk. Instead, non-equilibrium kinetics describes the proton travel between the site of its photo-release and its arrival at a distant membrane patch at different temperatures. ΔG‡r contains only a minor enthalpic contribution that roughly corresponds to the breakage of a single hydrogen bond. Thus, our experiments reveal an entropic trap that ensures channeling of highly mobile protons along the membrane interface in the absence of potent acceptors. |