A1 Journal article (refereed)
Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes (2019)

Amdursky, N., Lin, Y., Aho, N., & Groenhof, G. (2019). Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes. Proceedings of the National Academy of Sciences, 116(7), 2443-2451. https://doi.org/10.1073/pnas.1812351116

JYU authors or editors

Publication details

All authors or editors: Amdursky, Nadav; Lin, Yiyang; Aho, Noora; Groenhof, Gerrit

Journal or series: Proceedings of the National Academy of Sciences

ISSN: 0027-8424

eISSN: 1091-6490

Publication year: 2019

Volume: 116

Issue number: 7

Pages range: 2443-2451

Publisher: National Academy of Sciences

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1073/pnas.1812351116

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/64179

Abstract

Proton diffusion (PD) across biological membranes is a fundamental process in many biological systems, and much experimental and theoretical effort has been employed for deciphering it. Here, we report on a spectroscopic probe, which can be tightly tethered to the membrane, for following fast (nanosecond) proton transfer events on the surface of membranes. Our probe is composed of a photoacid that serves as our light-induced proton source for the initiation of the PD process. We use our probe to follow PD, and its pH dependence, on the surface of lipid vesicles composed of a zwitterionic headgroup, a negative headgroup, a headgroup that is composed only from the negative phosphate group, or a positive headgroup without the phosphate group. We reveal that the PD kinetic parameters are highly sensitive to the nature of the lipid headgroup, ranging from a fast lateral diffusion at some membranes to the escape of protons from surface to bulk (and vice versa) at others. By referring to existing theoretical models for membrane PD, we found that while some of our results confirm the quasi-equilibrium model, other results are in line with the nonequilibrium model.

Keywords: molecular dynamics; lipids; diffusion (physical phenomena); protons

Free keywords: proton diffusion; excited-state proton transfer; lipid vesicles; photoacid

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Ministry reporting: Yes

VIRTA submission year: 2019

JUFO rating: 3