Probing the kinetics of lipid membrane formation and the interaction of a nontoxic and a toxic amyloid with plasmon waveguide resonance

Abstract

The kinetics of formation of solid-supported lipid model membranes were investigated using a home-made plasmon waveguide resonance (PWR) sensor possessing enhanced properties relative to classic surface plasmon resonance sensors. Additionally, the kinetics of interaction of two amyloid peptides with zwitterionic and anionic membranes and their effect on lipid organization were followed.

Real time monitoring of membrane GPCR reconstitution by plasmon waveguide resonance: on the role of lipids

“…PWR spectra were obtained with a home-made instrument equipped with a He-Ne laser at 632 nm whose light is linearly polarized at 45°, allowing acquisition of both p - (TM component of light; light that is parallel to the incident light) and s -polarization (TE component of light; light that is perpendicular to the incident light) data within a single angular scan5. Experiments are performed in a controlled temperature environment of 23 °C.…”

“…Excess of lipid solution is then removed by washing the bilayer with buffer. To ensure that a proper solid-supported lipid bilayer is formed, the changes in the resonance minimum position (resulting from changes in mass density, anisotropy and thickness following film deposition) for both polarizations are measured and compared to values previously established to correspond to a lipid bilayer5.…”

“…Regardless of the method used, the process itself remains most often intractable (with the exception of an indirect Isothermal Titration Calorimetry approach reported by S. Keller and coworkers based on phase transition monitoring4). Herein we demonstrate that Plasmon Waveguide Resonance (PWR) spectroscopy can be used to directly follow the reconstitution of a detergent-solubilized GPCR into a planar solid-supported lipid membrane5. The method can be extended to any detergent-purified membrane protein, considering that the detergent used does not induce large perturbations or partial destruction of the lipid membrane where the protein is to be reconstituted.…”

Putative interaction site for membrane phospholipids controls activation of TRPA1 channel at physiological membrane potentials

“…The principles behind the technique and information obtained have been reported elsewhere (see, e.g., [20,47,48]). Resonances can be obtained with light whose electric vector is either parallel (s-polarization) or perpendicular (p-polarization) to the plane of the resonator surface.…”

“…Resonances can be obtained with light whose electric vector is either parallel (s-polarization) or perpendicular (p-polarization) to the plane of the resonator surface. The principles behind the technique and information obtained have been reported elsewhere (see, e.g., [20,47,48]). The sample to be analyzed (a lipid bilayer membrane) was immobilized on the resonator surface and placed in contact with an aqueous medium (TBS buffer, pH 7.6), into which the peptides were then introduced.…”