College: Eberly College of Science
Address: 107 Chemistry Building
Engineering of enzymes important for bacterial and viral pathogenesis
We are interested in changing enzyme catalysts important for viral and bacterial pathogenesis. Shutting down these enzymes (e.g. by a small molecule inhibitor) has been shown to stop diseases, like tuberculosis and poliomyelitis. We view these enzymes as tiny nanoscopic machines, and just like everyday machines, they have moving parts important for their function. We use a variety of biochemical and biophysical techniques, including nuclear magnetic resonance spectroscopy, to gain insight into these machines. By understanding the coordination amongst these various moving parts, we better understand how enzymes work (i.e. we’re “molecular mechanics”) and how to engineer them towards particular tasks (i.e. we’re “enzyme or protein engineers”).
The first major project in the lab involves the study of enzymes important for aromatic amino acid biosynthesis. These metabolic pathways are not found in humans, and so have been targeted in an attempt to find new antibiotics. Our interest mostly lies in understanding how these enzymes are allosterically regulated. We have developed protocols that identify allosteric pathways in these enzymes. These pathways offer means to generate novel ways of regulating enzymes through protein engineering and/or of identifying new surfaces for the targeting of small molecules.
The second major project in the lab involves the study of key enzymes important for RNA virus pathogenesis. While our studies use poliovirus as a model system, these studies are applicable to a wide-range of RNA viruses (e.g. hepatitis C, Zika virus, HIV, etc.). Here we study the RNA-dependent RNA polymerase responsible for RNA replication and the protease responsible for cutting the large polyprotein into its functional parts. Interestingly, the speed and error frequency of the polymerase helps determine viral pathogenesis. As such, it has been suggested that viruses encoding polymerases with altered properties can serve as live attenuated vaccine strains. While this finding isn’t so important for poliovirus, this strategy could be used to generate therapies for other viruses. Based our understanding of the structure and dynamics of the polymerase, we have begun to rationally engineer the polymerase towards this end.
Undergraduate students learn a variety of biochemistry (e.g. enzyme kinetics, protein production and purification), biophysical (e.g. spectroscopy, calorimetry), molecular biology (e.g. gene cloning, PCR, site-directed mutagenesis) and microbiology tools in the lab. We’ve had undergraduate students go successfully onto graduate school, medical school and industry.