Dr. Martin St. Maurice

Enzyme Structure and Function; The Molecular Basis for Catalysis and Regulation in Biotin-dependent Enzymes. 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.

Hakala, J., Laseke, A., Koza, A., St. Maurice, M. (2022) Conformational selection governs carrier domain positioning in Staphylococcus aureus pyruvate carboxylase. Biochemistry, 61:1824–1835.