An approach for analysis of protein toxins based on thin films of lipid mixtures in an optical biosensor.

Biological membrane-like lipid films were deposited on the sensing surface in an optical biosensor instrument. The membranes were mixtures of biologically occurring lipids. Eight surfaces were prepared, some of which contained various glycolipids as minor components.

From liposomes to supported, planar bilayer structures on hydrophilic and hydrophobic surfaces: an atomic force microscopy study.

The sequence of events involved in the transition from attached liposomes to bilayer patches on hydrophilic and hydrophobic solid supports were visualized in situ by Tapping Mode atomic force microscopy in liquid. In a smooth manner, the attached liposomes spread and flattened from the outer edges toward the center until the two membrane bilayers were stacked on top of each other. The top bilayer then either rolls or slides over the bottom bilayer, and the adjacent edges join to form a larger membrane patch.

Distribution and stability of membrane proteins in lipid membranes on solid supports.

Bacteriorhodopsin and the nicotinic acetylcholine receptor were biotinylated and reconstituted in lipidic membranes on silicon supports by fusion with proteoliposomes. The presence and distribution of the proteins were studied by binding with streptavidin. Radio-labelled streptavidin was employed for quantifying the amounts of protein remaining in the supported membranes after storage in buffer.

Helicobacter pylori interactions with human gastric mucin studied with a resonant mirror biosensor.

Helicobacter pylori, a human pathogen colonizing the gastrointestinal tract, is first interacting with mucus glycoproteins to penetrate the gastric mucus layer and then attach to specific epithelial cell targets. An optical biosensor technique based on the resonant mirror was used to study H. pylori interactions with human gastric mucin.