Mentors: W.E. Moerner and Ed Solomon
Project Title: Oxidative Enzyme Mechanisms
Dr. Gabriela Schlau-Cohen is a Postdoctoral Fellow working with Prof. W.E. Moerner and Prof. Ed Solomon. She completed her PhD in 2011 under the direction of Prof. Graham Fleming at the University of California, Berkeley and her B.S. in 2003 at Brown University. In addition to the work on multi-copper oxidases, her research interests have included investigating the early events in photosynthesis. Her work has involved using single-molecule and ultrafast techniques to explore the structure-function relationships that underlie the efficiency of photosynthetic light-harvesting.
Multicopper oxidases (MCOs) comprise a broad class of enzymes responsible for oxidation of organic substrates and metal ions coupled to the reduction of dioxygen to water. They function at a low overpotential, which makes them promising enzymes for incorporation into fuel cells. Detailed investigation of the catalytic cycle under turnover conditions — including the reaction timescales and intermediates – requires both single-molecule and bulk techniques. In a joint project of the Moerner and Solomon labs, we will employ a dual-pronged approach using time-dependent, single-molecule spectroscopy and steady-state ensemble measurements to study the kinetics of electron transfer in Fet3p, the MCO responsible for iron uptake in yeast. Using ensemble fluorescence and EPR spectroscopies, the fluorescence intensity can be correlated to the redox state of the enzyme. Using a single-molecule technique developed in the Moerner lab, known as the ABEL (Anti-Brownian ELectrokinetic) trap, the redox state of the enzyme can be monitored for the entire catalytic cycle under turnover conditions. With this approach, the intermediate states and multi-step kinetics of the catalytic cycle of Fet3p will be explored.