Nov 6
Chemistry Department Seminar: Tenure Track Candidate
"Exploring Biology at the Cell Membrane Using Model Lipid Bilayers"
The cell bilayer is not just a passive material that holds cells together; it contains a diverse array of lipids and proteins that participate in key cellular functions. To study such a complex and heterogeneous environment, researchers have turned to model lipid bilayers, such as nanodiscs, to investigate biological processes at the cell membrane in a simplified and controlled membrane environment. In this talk, I will discuss my work using nanodiscs to investigate the inter-protein energy transfer of photosynthetic purple bacteria. Photosynthetic purple bacteria contain light-harvesting proteins that absorb, transfer, and capture sunlight with almost 100% quantum efficiency. The light-harvesting proteins are located in a lipid bilayer environment with the proteins arranged in a heterogeneous network. The factors that govern such high efficiency within this complex environment, such as inter-protein distance, are poorly understood. To investigate how inter-protein distance affects light harvesting, we developed nanodiscs of various diameters to reproduce protein pairs spanning a range of such distances found in vivo. Using ultrafast spectroscopy, we, for the first time, directly measured the inter-protein energy transfer rate between these protein-pairs as a function of distance. Overall, our results provide insight into how membrane organization influences the efficiency of photosynthetic light harvesting and demonstrate that nanodiscs are a powerful platform to study complicated protein networks within the cell membrane.
*This seminar counts towards the chemistry major seminar attendance requirement.