Andrew L Lee
Area of interest
Protein-ligand interactions drive the molecular events underlying cellular proliferation. We have a fundamental interest in understanding the energetic, structural, and dynamic properties of proteins that have evolved to interact with one another. Our central approach takes advantage of the site-specific information (atomic resolution) offered by nuclear magnetic resonance (NMR) spectroscopy. As a major component of our biophysical approach, we are using state-of-the-art 1H, 13C, 15N, and 2H multinuclear, multidimensional NMR methods to detail the structural, dynamic, and mechanistic properties of proteins and protein interfaces. With this approach, specific biomolecular interactions may be understood on a per-residue basis. It is this type of detailed knowledge that will be necessary for a full understanding of the effects of regulatory events on normal protein function.
Several research projects in the lab have direct or indirect relevance to cancer. Dihydrofolate reductase (DHFR) is a longstanding target for cancer treatment. It also happens to be an enzyme studied because of its interesting conformational changes and dynamic properties. To gain a deeper understanding into the fundamental nature of protein-drug interactions, we are investigating how a number of small molecules – including cancer drug methotrexate – affect the internal dynamics of bacterial DHFR. NMR characterization indicates that different small molecules modulate DHFR dynamics differently, and in some cases novel, dynamic binding modes are apparent. These findings have implications for discovery of novel enzyme inhibitors.
DNA lesions, resulting from external agents or intracellular events, that are not repaired accurately and expeditiously can leave mutations or deletions that become permanently integrated into the genome. In unfavorable cases this can lead to an inheritable predisposition to cancer. Polymerase u (Pol u) is a DNA polymerase that adds nucleotides in double-stranded break repair of DNA. In addition to the polymerase core, Pol u contains a BRCT domain (BRCAI C-terminal domain), a motif commonly found in proteins involved in DNA repair, recombination, checkpoint control, transcription, and chromatin remodeling. BRCT domains have been implicated in protein-protein and protein-nucleic acid interactions of broad specificity, and hence this domain represents an intriguing point from which to dissect the determinants of macromolecular interactions controlling genome maintenance.
Another protein motif found throughout eukaryotic evolution is the PDZ motif. These approximately 100 amino acid domains are essentially protein recognition modules, mediating specific protein-protein interactions for the assembly of molecular complexes in signal transduction and subcellular transport. Outstanding issues regarding PDZ domains involve questions of how specific binding is achieved and how amino acid residues throughout the protein structure can contribute to target recognition at a localized binding interface. We are investigating PDZ structure, dynamics, and allostery for isolated PDZ domains and PDZ domains in the context of their parental proteins. NMR spectroscopy is ideal for characterizing the dynamic features of these PDZ-containing proteins.
Awards and Honors
- 2001-2002 American Association of Colleges of Pharmacy (AACP) New Investigators Program (NIP) Award for Pharmacy Faculty: University of North Carolina at Chapel Hill.
- 2006 Junior Faculty IBM Fund Award