Protein Mobility, Filtering, and Separation in Model Cell Membranes

Graduate SeminarProtein Mobility, Filtering, and Separation in Model Cell MembranesDr. Susan Daniel
Department of Chemistry
Texas A&M UniversityAbstract
Investigating how biomolecules behave in cell membranes gives us insight that can be used
to create better assays, sensors, and devices that mimic the cell surface. Applications for
these devices include rapid combinatorial analysis of drug targets, biosensors for toxin
detection, and proteomics research. Solid-supported lipid bilayers (SLBs) are an excellent
platform for mimicking the surface chemistry of cells. However, there are several drawbacks
to these platforms. First, proteins can lose their mobility in these systems, impairing their
function. Second, there is no good way to discriminate between analytes that bind to the
same surface ligand within these platforms. Third, separation, purification, and formation of
arrays of membrane species is difficult, impeding the progress of rapid combinatorial
assaying of membrane proteins.
Results will be presented on studies conducted to understand these issues and strategies to
overcome them. By investigating the behavior of protein-protein interactions on SLBs, we
found that protein-packing influences the point at which diffusion is arrested in these systems.
To improve binding specificity, we devised a system for size-selective discrimination of
protein analytes that bind to the same ligand, by incorporating poly(ethylene glycol) (PEG)
lipopolymers into SLBs. Using our platform, we were able to achieve discrimination of
several orders of magnitude. Finally, we developed a technique to separate membrane
species within an SLB: bilayer chromatography. Results will be presented that show our
separation method is sensitive enough to differentiate isomers of dye-labeled lipids and is
currently being extended to the separation of membrane proteins.
Friday, January 12, 2007
1:00 p.m.
HED 116
The Scientific Community is Cordially Invited to Attend.

Location: Hedco Pertroleum and Chemical Engineering Building (HED) - 116

Audiences: Everyone Is Invited

Contact: Petra Pearce