The Eddy lab uses an integrative structural biology approach to investigate how human membrane receptor proteins bind drugs and communicate this information to partner proteins inside the cell. Our goal is to better understand how the cellular environment controls signaling from the atomic to organism-wide levels in both healthy and diseased states. We combine nuclear magnetic resonance (NMR) with additional biophysical and functional techniques to obtain a comprehensive view of signaling.
G Protein-Coupled Receptors
When cells of higher organisms sense molecules in their surrounding environment, such as hormones, drugs, and neurotransmitters, the resulting interaction is transmitted through 7-transmembrane proteins, called G protein-coupled receptors (GPCRs), into a cascade of signals inside the cell ultimately causing physiological responses. GPCRs are involved in nearly all cellular functions and also play critical roles in the development of diseases, including cancers, HIV, hypertension, and neurodegenerative diseases. Thus GPCRs are the largest "druggable" family of proteins, currently targeted by at least 35% of FDA-approved drugs. We combine biophysical and functional experiments to better understand mechanisms of GPCR drug binding and signaling, ultimately with the goal of using such information to improve drug design criteria.
In Situ Receptor Structural Biology
We are developing new methods for the study of human receptor proteins and their complexes with drugs, hormones, and partner proteins in situ, i.e. directly in their cellular environment. To do this, we leverage the power of dynamic nuclear polarization (DNP) NMR, which can increaes the sensitivity of NMR experiments by multiple orders of magnitude. The increased sensitivity is required in order to observe receptor proteins in physiological conditions (i.e., at physiological concentrations and lipid-to-protein ratios). We seek to leverage the full potential of DNP NMR to study receptor proteins in both healthy and diseased states, ultimately even applying such methodologies to studies of receptor proteins from patient-derived tissues.
New Technologies for Drug Discovery
For many GPCRs and other membrane proteins, there are currently no small molecules available either as clinical treatments or investigational tools to study receptor structure and function. We are developing novel methodologies and technologies to discover compounds that target these "orphan" receptors. Our approach is to develop new screening capabilities that leverage the power of NMR and that can be integrated with other high throughput techniques that detect ligand binding and signaling.
Biochemical and NMR Methodologies for Studying Eukaryotic Proteins
NMR spectroscopy offers the unique advantage of observing multiple, simultaneously populated protein conformers that exist in a function-related equilibrium. We are extending these capabilities to study human proteins expressed in various Eukaryotic organisms. Many complex membrane proteins and protein assemblies are recombinantly expressed in Eukaryotic systems (e.g. insect cells, yeast, and mammalian cells); however, stable-isotope labeling in such systems can be very challenging. We apply a combination of new biochemical protein production methods with state-of-the art NMR techniques to study human proteins expressed in such systems.