CAREER: Elucidating Surfactin Modus Operandi with 2D IR Spectroscopy

Colorado State University, Fort Collins CO

Investigators

Abstract

Through this NSF CAREER award, funded by the Chemical Structure, Dynamics, and Mechanisms B Program (CSDM-B), Professor Amber T. Krummel from Colorado State University will identify the means by which a small pore-forming toxin, surfactin, will interact with model lipid membranes using two-dimensional infrared (2D IR) spectroscopy. Surfactin is known to have antibacterial, antiviral, and antitumor activity, but surfactin has also been implicated in cell-signaling activities during biofilm formation. This project will identify the differences in the mode of action by surfactin during these different activities. The structural sensitivity offered by 2D IR spectroscopy will be utilized to quantify the molecular details of the surfactin-lipid interaction during the surfactin insertion and lipid membrane disruption processes. Pore-forming toxins are proteins that are synthesized by many organisms, including the human immune system. These proteins insert into cell membranes in order to allow small molecules to move into cells, cause cell leakage, or to disrupt the integrity of cells such that cell death occurs. In this work, advanced optical spectroscopy techniques will be used to monitor the protein-lipid interaction with structural sensitivity. The results from these investigations will lead to a new understanding of how a small pore-forming toxin, surfactin, self-assembles and interacts with lipids in order to drive cell signaling processes and the disruption of lipid membranes. During the course of this project, undergraduate researchers and graduate student researchers will be trained in advanced optical spectroscopy techniques, chemical modeling, and data analysis. The approaches used to train the student researchers involved with this project will also be incorporated into the undergraduate curriculum for Chemistry Majors at Colorado State University. Thus, this project will generate new insights into an important chemical system and it will generate new approaches to training the next generation of Chemistry majors at Colorado State University.