We use a combination of single-molecule and ultrafast spectroscopies to explore the energetic and structural dynamics of biological systems.
Our work is multidisciplinary; we combine tools from chemistry, optics, biology, and microscopy to develop new approaches to probe dynamics. There are two major research thrusts. The first is developing a single-molecule ultrafast experiment, which will be a tool to connect sub-nanosecond and second dynamics. The second is merging optical spectroscopy with model membrane systems to provide a novel probe of how biological processes extend beyond the nanometer scale of individual proteins.
Inspired by the growing need for solar energy, one application of these approaches will be exploring the underlying mechanisms of photosynthetic light harvesting. Photosynthetic organisms convert absorbed sunlight to chemical energy with remarkable near unity quantum efficiency by transporting energy through a network of proteins. To understand the mechanisms behind this fundamental process, experiments will probe both the heterogeneity of the individual proteins and how they are wired together to produce efficient and adaptive systems.
I. Single-molecule ultrafast spectroscopy
Biological systems exhibit energetic and structural dynamics that span decades of time scales. How slow conformational dynamics impact ultrafast energy and electron transfer dynamics, however, remains unexplored.
We will look at both energy transfer and conformational dynamics to determine how photosynthetic proteins are robust to fluctuations and electron transfer rates in nanomaterials to characterize heterogeneity.
II. Emergent functionality from protein-protein interactions
Much of the function of membrane proteins arises from interactions with other proteins. However, research often focuses either on isolated proteins or on intact systems, which average over huge numbers of heterogeneous interactions. In particular, protein-protein interaction in the membrane has not been elucidated.
By constructing model membrane systems, we will achieve a controllable, physiological environment to explore protein-protein interaction using both ensemble and single-molecule ultrafast spectroscopy. In particular, we are interested in investigating how protein-protein interactions drive photosynthetic light harvesting and signal transduction.