• Nanion技术: 离子通道研究的智能工具

    Nanion技术: 离子通道研究的智能工具

  • SyncroPatch 384i: HTS Automated Patch Clamp

    SyncroPatch 384i: HTS Automated Patch Clamp

  • SURFE²R 96SE: 非标记高通量转运体筛选

    SURFE²R 96SE: 非标记高通量转运体筛选

  • Dynamic Clamp: Patchliner

    Dynamic Clamp: Patchliner

  • 脂双层记录: Orbit产品系列

    脂双层记录: Orbit产品系列

  • CardioExcyte 96 SOL:用光遗传的手段起搏心肌细胞

    CardioExcyte 96 SOL:用光遗传的手段起搏心肌细胞

我们的产品目录

SyncroPatch 384

SyncroPatch 384

Patchliner

Patchliner

Port-a-Patch

Port-a-Patch

Port-a-Patch mini

Port-a-Patch mini

CardioExcyte 96

CardioExcyte 96

FLEXcyte 96

FLEXcyte 96

SURFE²R 96SE

SURFE²R 96SE

SURFE²R N1

SURFE²R N1

Orbit 16 TC

Orbit 16 TC

Orbit Mini

Orbit Mini

Vesicle Prep Pro

Vesicle Prep Pro

2002 - Photocurrents Generated by Bacteriorhodopsin Adsorbed on Thiol/Lipid Bilayers Supported by Mercury

Icon N1   SURFE²R-technology (custom-built system) publication in Langmuir (2002)

Authors:
Dolfi A., Tadini-Buoninsegni F., Moncelli M.R., Guidelli R.

Journal:
Langmuir (2002) 18(16): 6345-6355


Abstract:

The kinetics of light-driven proton transport by bacteriorhodopsin (bR) were investigated over a broad pH range upon adsorbing purple membrane (PM) fragments on a mercury-supported mixed alkanethiol/phospholipid bilayer. The light-on and light-off capacitive photocurrents were measured under short-circuit conditions in the absence of photoartifacts. Using dioleoylphosphatidylcholine as the lipid monolayer, a bell-shaped curve of the peak current versus pH, with a maximum in the proximity of 6, was obtained. The analysis of the biphasic decay kinetics of the light-on and light-off currents allows an estimate of the pKa values for the steps releasing protons to, and taking up protons from, the bathing solution. In particular, the pKa values obtained from the light-off current (pK1 = 3.5, pK2 = 5.3, pK3 = 7.5, and pK4 = 9.0) suggest a mechanism similar to that proposed by Balashov et al. for dark adaptation, albeit in the opposite direction (Balashov, S. P.; Imasheva, E. S.; Govindjee, R.; Sheves, M.; Ebrey, T. G. Biophys. J. 1996, 70, 473). The time dependence of the light-on and light-off currents in the proximity of pH 6 is interpreted on the basis of both a simple equivalent circuit and a kinetic model making use of spectroscopic data available in the literature. When using dioleoylphosphatidylserine (DOPS) as the lipid monolayer, an inversion in the sign of both light-on and light-off currents, as well as a change in their shape and magnitude, was observed by increasing the pH above 9 and then, at all pH values from 9 to 1, by subsequently decreasing the pH on the same mercury-supported mixed alkanethiol/DOPS bilayer. The normal situation was restored only by adding sodium azide. This inversion in current and the notable hysteresis observed under these conditions are critically discussed.


Download here

返回总览

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.