Hydrogen bonded chain mechanisms for proton conduction and proton pumping

Nagle, John F.; Tristram-Nagle, Stephanie

doi:10.1007/bf01870590

Cited by 386 publications

(194 citation statements)

References 109 publications

Supporting

Mentioning

186

Contrasting

Unclassified

Order By: Relevance

“…It has been suggested that passive proton transport across lipid bilayers is mediated by hydrogen-bonded chains of water, which could explain the increased total permeability. 47,48 SAXS measurements confirm that Pad-PC-Pad forms interdigitated bilayers below the main transition temperature, a feature that disappears above the main transition temperature leading to a lamellar L α phase and a thicker water layer between the bilayers. This is in good agreement with the observation that the critical temperature T c of a Pad-PC-Pad monolayer is much lower than the T m of the corresponding bilayer system.…”

Section: ■ Conclusionmentioning

confidence: 77%

Bilayer Properties of 1,3-Diamidophospholipids

et al. 2015

View full text Add to dashboard Cite

A series of 1,3-diamido phosphocholines was synthesized, and their potential to form stable bilayers was investigated. Large and giant unilamellar vesicles produced from these new lipids form a wide variety of faceted liposomes. Factors such as cooling rates and the careful choice of the liposome preparation method influence the formation of facets. Interdigitation was hypothesized as a main factor for the stabilization of facets and effectively monitored by small-angle X-ray scattering measurements.

show abstract

Section: ■ Conclusionmentioning

confidence: 77%

Bilayer Properties of 1,3-Diamidophospholipids

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In our previous work [ll], we observed that the extent of lateral proton conduction ( A F ) was strongly decreased when increasing the lipid molecular area. With our assumption that proton transfer is mediated by the hydrogen bond network linking the lipid polar heads [ll], via a 'hop and turn' mechanism [15], then for a loosely packed film, the efficiency of the 'hop' step would be weaker than in a tightly packed one and trapping of protons by the subphase would be apparently more efficient. This would explain the effect of the packing density.…”

Section: Resultsmentioning

confidence: 99%

Lateral proton conduction at a lipid/water interface

Prats

Tocanne

Teissié

1985

European Journal of Biochemistry

View full text Add to dashboard Cite

Fast lateral proton conduction along the lipid/water interface has recently been experimentally demonstrated in our laboratory [Teissie, J., Prats, M., Soucaille, P. & Tocanne, J. F. (1985) Proc. Natl Acad. Sci. USA, in the press].The present study gives a more precise description of the way various physical parameters can affect this process. The dependence of the distance covered by the proton on time is demonstrated to be quadratic. Increasing the speed of stirring in the injection compartment or the amount of injected acid or the contact between the monolayer and the acidic subphase increased the efficiency of the proton transfer. Raising the strength of the buffer in the bulk phase inhibited proton conduction.Results from experiments where the transfer of protons from the bulk phase to the interface was modified, suggested the occurrence of an 'energy barrier' limiting the access of protons from the bulk phase to the lipid polar head region.Protons are now recognized as being the major driving force in the coupling between electron transport and ATP synthesis catalyzed by the membranes of mitochondria, chloroplasts and bacteria. This coupling is described as being delocalized [l], semi-localized [2] or localized [3]. In the delocalized theory, the membrane plays no role in the transmission of energy, which is assumed to occur via the two bulk aqueous phases on each side of the membrane. Although many experimental results support the delocalized theory, recent data from different laboratories appear to be in agreement with theoretical models where proton movements are assumed to be localized within the membrane or at its surface [2, 4, 51. In the latter case, the proton fluxes between the energy source and the ATP synthase system occur laterally along the membrane in parallel with the above reported delocalized fluxes.From a physical point of view, comparative studies of diffusion along a surface or in a volume have been reported from different laboratories [6, 71. It appears that even if the diffusion coefficient is slightly smaller on the surface (twodimensional space) than in a volume (three-dimensional space), the reduction of dimension will imply that the apparent diffusion is faster along the interface. In this respect, it has been speculated that membranes and even tubular assemblies in the cytoplasm might be preferential pathways for the transfer of ions and metabolites in the cell [8 -lo].Using an original monolayer technique where the lateral flux of protons along a lipid/water interface was monitored by means of a fluorescent pH-sensitive chromophore covalently bound to a phospholipid [l 11, we were able to provide direct

show abstract

“…The lightdependent effects involving the aromatic residues are presumably linked to the movement of the transported protons through the protein. It has been suggested that this transport occurs via the reversible deprotonation of a chain of residues arranged across the membrane barrier [19,20]. Tyrosine (and perhaps tryptophan) may be elements of this chain, and indeed it has been shown that chemical modification of tyrosines [21], and particularly tyrx 1221 and tyra [23] has specific effects on the pi8ment.…”

Section: Abbreviationsmentioning

confidence: 99%

Light‐dependent trans to cis isomerization of the retinal in halorhodopsin

Lanyi

1984

FEBS Letters

View full text Add to dashboard Cite

Flash-induced absorption changes in the near UV were determined for bacteriorhodopsin and halorhodop sin on a millisecond time scale. The difference spectrum obtained for bacteriorhodopsin was comparable to model difference spectra of tyrosine (aromatic OH deprotonated vs protonated), as found by others. The flash-induced difference spectrum for halorhodopsin, in contrast, resembled a model spectrum opbtained for trans to 13-cis isomerization of retinal in bacteriorhodopsin. A model for chloride translocation by halorhodopsin is presented, in which the retinal isomer&&on moves positive charges, which in turn modulate the affinity of a site to chloride. Halorhodopsin Retinal isomerization Tyrosine akprotonationChloride transport Flash spectroscopy

show abstract

Hydrogen bonded chain mechanisms for proton conduction and proton pumping

Cited by 386 publications

References 109 publications

Bilayer Properties of 1,3-Diamidophospholipids

Bilayer Properties of 1,3-Diamidophospholipids

Lateral proton conduction at a lipid/water interface

Light‐dependent trans to cis isomerization of the retinal in halorhodopsin

Contact Info

Product

Resources

About