Fabre et al. (2012) report surface plasmon resonance enhanced ellipsometry (SPREE) analysis of BK ion channel incorporation into lipid membranes supported on zirconium phosphonate modified surfaces prepared using (a) 20%, (b) 10%, and (c) 0% octadecanol. The kinetics study shows the formation of supported lipid bilayers followed by the insertion of the transmembrane protein. After formation of the POPC/POPS lipid bilayers, free vesicles were then removed with buffer rinsing. The membrane was then incubated with the ion channel and then again rinsed with buffer. The buffer used was trizmahydrochloride and sodium chloride at pH 7.4.
Fabre RM, Okeyo GO, Talham DR (2012,) Supported Lipid Bilayers at Skeletonized Surfaces for the Study of Transmembrane Proteins. Langmuir 28, 2835−2841.
Ross et al (2012) report the use of a novel type of substrate, poly-p-xylylenes coating prepared by chemical vapor deposition (CVD) polymerization, for SPREE studies. Subsequent SPREE imaging and fluorescence microscopy indicated that the synthetic substrates supported detectable binding of a cascade of biomolecules. Moreover, analysis revealed a useful thickness range for CVD films in the assessment of protein and/or antigen-antibody binding via SPREE imaging. With a variety of functionalized end groups available for biomolecule immobilization and ease of patterning, CVD thin films are useful substrates for spatially-resolved, quantitative binding arrays.
Ross A., Zhang D, Deng X, Chang SL, Lahann J. (2011) CVD-based Polymer Substrates for Spatially-resolved Analysis of Protein Binding by Imaging Ellipsometry. Anal Chem. 83, 874–880.
Schuy et al. (2009) present a universal mimetic approach of the prehairpin intermediate of gp41, which represents the
active drug target for fusion inhibitors of HIV (human immunodeficiency virus) and SIV (simian immunodeficiency virus) based on membrane anchored lipopeptides. For this purpose, we have in situ coupled terminal cysteine-modified peptides originating from the NHR of SIV and HIV to a maleimide-functionalized DOPC bilayer and monitored the interactions with potential antagonists of the trimer-of-hairpin conformation C34 and T20 peptides by means of atomic force microscopy and ellipsometry.
Schuy S, Schäfer E, Yoder NC, Kumar K, Vogel R, Janshoff A (2009) Lipopeptides derived from HIV and SIV mimicking the prehairpin intermediate of gp41 on solid supported lipid bilayers. Journal of Structural Biology 168, 125–136
Bo Liedberg and colleagues demonstrate a chip platform for the adresseable immobilization of protein-loaded vesicles on a microarray for parallelized high-trough put analysis of lipid-protein systems. Imaging surface Plasmon resonance in ellipsometric mode, performed with an EP³ SE was used to monitor vesicle immobilization, protein tethering, protein-protein interaction and chip regeneration.
The imaging ellipsometer was equipped with an SPR-cell in Kretschmann configuration. Images of the surface were taken at indicated times and difference images were produced. The change of mass was recorded in correlation to the ellipsometric parameter Delta – in parallel at different regions of interest on the array.
Klenkar G, Brian B, Ederth Th, Stengel G, Höök F, Piehler J, Liedberg B (2008) Addressable adsorption of lipid vesicles and subsequent protein inter¬action studies. Biointerphases 3: 29-37.
Ellipsometric Platform EP³ SPR
Multi-Channel and Imaging Surface Plasmon Resonance Analyser