B.Sc., University of Guelph, Canada
Ph.D., Dalhousie University, Canada
Postdoctoral Fellow, University of Wisconsin– Madison
Enzymes are the chemical catalysts of biological systems. They are responsible for catalyzing thousands of complex and thermodynamically difficult reactions that are fundamental to all living organisms. Understanding general strategies employed by enzymes and unraveling the molecular interactions in specific enzyme systems continues to advance the fields of medicine and biotechnology. My laboratory works at the exciting interface of chemistry and biology, using the tools of protein engineering, kinetic analyses and X-ray crystallography to determine the structure and function of various enzyme systems at the molecular level. Structural and kinetic analyses, used in tandem, provide a powerful means to probe underlying mechanisms of disease and unveil new targets for therapeutic applications.
Work in my laboratory focuses on understanding the molecular basis for catalysis and allosteric regulation in an important group of metabolic enzymes: the biotin-dependent carboxylases. Dysfunction in these enzymes can lead to genetically inherited disorders that range from benign to severe. In addition, these enzymes offer important targets for the treatment of obesity and type-2 diabetes. The primary goal of my research program is to characterize the mechanism of allosteric control and the molecular basis for catalysis in biotin-dependent carboxylases using X-ray crystallography and steady-state kinetic analyses. One particularly intriguing aspect of catalysis in the biotin-dependent enzyme, pyruvate carboxylase, is the allostery imposed by the activator, acetyl-CoA. This molecule binds asymmetrically to one face of the tetramer and dramatically shifts the orientation and distance between enzyme active sites. My laboratory seeks to clarify the relationship between allosteric regulation and activity in the biotin-dependent carboxylase enzymes with the ultimate goal of unveiling new drug targets and developing molecules with significant therapeutic potential.
Lin, Y., and St. Maurice, M. 2013. The structure of allophanate hydrolase from Granulibacter bethesdensis provides insights into substrate specificity in the amidase signature family. Biochemistry. 52: 690-700.
Waldrop, G.L., Holden, H.M., and St. Maurice, M. 2012. The enzymes of biotin dependent CO2 metabolism: What structures reveal about their reaction mechanisms. Protein Science 21(11):1597-1619.
Adina-Zada, A., Sereeruk, C., Jitrapakdee, S., Zeczycki, T.N., St. Maurice, M., Cleland, W.W., Wallace, J.C., and Attwood, P.V. 2012. Roles of Arg427 and Arg472 in the binding and allosteric effects of acetyl CoA in pyruvate carboxylase. Biochemistry 51(41): 1597-1619.
Adina-Zada, A., Hazra, R., Sereeruk, C., Jitrapakdee, S., Zeczycki, T.N., St. Maurice, M., Cleland, W.W., Wallace, J.C., and Attwood, P.V. 2011. Probing the allosteric activation of pyruvate carboxylase using 2′,3′-O-(2,4,6-trinitrophenyl) adenosine 5′-triphosphate as a fluorescent mimic of the allosteric activator acetyl CoA. Arch. Biochem. Biophys. 117-126.
Zeczycki, T.N., Menefee, A.L., Jitrapakdee, S., Wallace, J.C., Attwood, P.V., St. Maurice, M. and Cleland, W.W. 2011. Activation and inhibition of pyruvate carboxylase from Rhizobium etli. Biochemistry 9694-9707.
Lietzan, A.D., Menefee, A.L., Zeczycki, T.N., Kumar, S., Attwood, P.V., Wallace, J.C., Cleland, W.W. and St. Maurice, M. 2011. Interaction between the biotin carrier domain and the biotin carboxylase domain in the structure of Rhizobium etli pyruvate carboxylase. Biochemistry 9708-9723.
Zeczycki, T.N., Menefee, A.L., Adina-Zada, A., Surinya, K.H., Wallace, J.C., Attwood, P.V., St. Maurice, M., and Cleland, W.W. 2011. Novel insights into the biotin carboxylase reaction of pyruvate carboxylase from Rhizobium etli. Biochemistry 9724-9737.
Jitrapakdee, S., St. Maurice, M., Rayment, I., Cleland, W.W., Wallace, J., and Attwood, P.V. 2008. Structure, mechanism and regulation of pyruvate carboxylase. Biochem. J. 413, 369-387.
Adam Lietzan (Ph.D. student)
Yi Lin (Ph.D. student)
Dr. St. Maurice is currently accepting new Ph.D. students into his lab