Structural Enzymology. Enzymes play a key role in all metabolic and cell-signaling processes. Characterization of an enzyme’s biological function must include the description of its mechanisms at an atomic level. Our laboratory is deciphering the catalytic mechanism of several enzyme families, using a combination of molecular biology, biochemistry and structural Biology. Systems under study fall into two classes: enzymes that recognize or process phosphates and redox enzymes. These systems include: pyrophosphate hydrolases, farnesyl pyrophosphate synthases, PI3K, flavoenzymes and copper hydroxylases. All experiments necessary to address mechanistic questions are carried out in the laboratory. Cloning and expression, ultrapurification, kinetic characterization, mutational analysis, mass spectrometry, crystallization, and structure determination by x-ray diffraction are some of the techniques we bring to bear to characterize the mechanisms of these enzymes. In addition to being intrinsically interesting some of these systems are being developed as targets for drug design.
Transporters and channels. Ion movements across biological membranes are highly specific processes at the core of numerous physiological conditions and disease states. We are studying the mechanism of the Na+ / I– symporter, NIS, and the cardiac voltage- activated Na+ channel, Nav 1.5.
For the determination of the structure and the mechanisms of I– transport by the Na+ / I– symporter using experimental and computational methods to identify the different molecular species that participate in the transport cycle. We are also studying the regulation of the cardiac voltage regulated Na+ channel Nav 1.5 by calmodulin and Ca2+ using structural and thermodynamic techniques.