Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes
| Autor: | Noora Aho, Gerrit Groenhof, Yiyang Lin, Nadav Amdursky |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
protonit
kalvot (orgaaniset objektit) Proton Diffusion Non-equilibrium thermodynamics 02 engineering and technology lipidit 010402 general chemistry Kinetic energy 01 natural sciences diffuusio Molecular dynamics diffuusio (fysikaaliset ilmiöt) proton diffusion molekyylidynamiikka ta116 Multidisciplinary Chemistry Biological membrane Nanosecond photoacid 021001 nanoscience & nanotechnology molecular dynamics 0104 chemical sciences lipid vesicles Membrane excited-state proton transfer PNAS Plus Chemical physics lipids (amino acids peptides and proteins) 0210 nano-technology |
| Zdroj: | Proceedings of the National Academy of Sciences. 116(7):2443-2451 |
| ISSN: | 0027-8424 |
| Popis: | 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. peerReviewed |
| Databáze: | OpenAIRE |
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