A new microarray platform for the display of surface cell membrane receptors is will be developed in this project. The array is intended to be used for the high throughput screening of the binding of membrane receptors with potential binding partners. In the array design, the receptors are sequestered in a supported bilayer, which encapsulates a 1 m in diameter barcoded silica or polystyrene bead to form a lipobead. Insertion of the membrane receptor in the bilayer allows the receptor to retain its biological activity. The lipobeads will be arrayed on a surface by inserting them into micron sized wells (slightly larger than the lipobead). The micro-wells are patterned in a square grid on the surface in which wells are separated by a center-to-center spacing of 3m. The encapsulated particles are barcoded using a label made of luminescent quantum dots embedded into the particles, and covalently linked to the silica or polystyrene matrix. The array has approximately 105 registries on a 1mm x 1mm active area, with the lipobead registries capable of each displaying a different receptor. Binding events are detected and the barcode identifying the receptor on the lipobead read using fluorescence microscopy. The array will be tested by screening the interaction of a cell membrane sequestered glycolipid with a bacterial toxin. Preliminary results are presented on the synthesis of the quantum dot encoded beads and the fabrication of the micro-well patterned surface.The success of this program will have a significant impact in the microarraying of proteins in general and membrane receptors in particular: The platform allows for a miniaturization that is orders of magnitude smaller than any current platforms for the display of membrane receptors or proteins in general, and provides for the facile display of difficult to exhibit membrane receptors with their strict requirement of a lipid environment. The enhanced ability to probe the binding interactions of membrane receptors which this array will afford is particularly important to drug discovery since fifty percent of the molecular targets of drugs are membrane bound. It could also prove be an important tool for the mapping and understanding of the binding interactions of the cell proteome in as much as twenty five percent of the sequenced genes of a given organism code for membrane proteins.
From a broader impacts perspective, the proposal broadly addresses the potential economic and societal benefits of the proposed work. The PIs will participate in CCNY's high school outreach program. The project would include the training of a graduate student and undergraduates will work with the PI and be supported through pre-existing programs at CCNY. The PI has demonstrated that she can work well with undergraduate students, which is a valuable aspect of the proposed work. The education aspects of the proposal are thus a strength of the proposal.
