Approximately 60% of drug targets are receptor proteins tasked with transmitting information across membranes. Our experiments probe the complex spatiotemporal dynamics of these proteins as well as how they associate to control functionality.

Bacterial chemotaxis. Chemotaxis is the mechanism by which bacteria sense and respond to chemical gradients within the environment, making chemotaxis a key initial step in the development of a bacterial infection. In the initial steps, transmembrane chemoreceptors bind ligands in the periplasmic domain, which drives a conformational change in their cytoplasmic tails to enable kinase activation. We combine biochemical and spectroscopic techniques to monitor chemoreceptor dynamics across time and length scales in near-physiological conditions.

Epidermal growth factor receptor. Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, plays a very significant role in the pathogenesis of cancer. We are studying the changes in the conformation of the extracellular and intracellular domains of the protein in the presence of its most prominent ligand, the epidermal growth factor (EGF) using fluorescence correlation spectroscopy and single-molecule fluorescence resonance energy transfer.

 Fluorescently-labeled  EGFR immobilized on Ni-NTA coverslip

Fluorescently-labeled  EGFR immobilized on Ni-NTA coverslip

S.D. Quinn, S. Srinivasan, J.B. Gordon, W. He, K.L. Carraway III, M.A. Coleman, G.S. Schlau-Cohen. "Single-molecule fluorescence detection of the epidermal growth factor receptor (EGFR) in membrane discs." Biochemistry, accepted (2018)

Group Members: Julianne, Shwetha, Jesse