Dr. Hubbell's research is focused on understanding the inter-relationship of protein structure, dynamics and function. Of particular interest are proteins involved in visual signal transduction (rhodopsin, the G-protein transducin and arrestin) and soluble ligand-binding proteins. To explore functional protein dynamics in such complex systems, his laboratory has pioneered the technique of "Site-Directed Spin Labeling" (SDSL) in which a paramagnetic nitroxide side chain (R1) is introduced into the protein as a molecular sensor. The technique exploits the sensitivity of Electron Paramagnetic Resonance (EPR) to motions of R1 in the biologically important nanosecond and microsecond time domains that correspond to backbone fluctuations and conformational switching, respectively. Research in the group involves a parallel development of new EPR and SDSL technology and applications to the systems mentioned above.
