(157l) Membrane Protein Antibody Discovery Using Yeast-Surface Display and Whole Cell Selections in Suspension

Membrane proteins (MPs) are important therapeutic targets as they are responsible for facilitating a wide range of biological functions critical to maintaining homeostasis. Over 60% of all clinically approved drugs target MPs, thus demonstrating the central importance of this class of proteins. Antibody discovery against complex MPs such as G-protein coupled receptors (GPCRs) is challenging due to the difficulty in recombinantly expressing glycosylated seven-pass transmembrane proteins in their native states. Here, we present and characterize a cell-cell interaction platform combining the yeast display directed evolution platform that allows for manipulation and detection of whole cells in suspension that express MP targets. We also employ a novel selection strategy that interfaces magnetic-activated cell-sorting (MACS) with our cell-cell interaction platform to enrich for specific binders to MPs within a yeast-displayed library of antibody fragments. Collectively, our new molecular engineering approaches serve as novel discovery engines for MP-targeted therapeutics.