Associate Professor of Chemistry Myriam Cotten and her research team received instrument time at the National Institute of Standards and Technology (NIST). Samples were prepared at Hamilton by Kim Bogardus ’14, Jeremy Brendle ’14 and Cotten and sent to collaborator Prof. Ella Mihailescu for analysis on MAGIK, a world-class instrument dedicated to membrane biology measurements by neutron diffraction and reflectometry.
Instrument time is awarded based on a competitive peer-reviewed proposal process. Neutron diffraction experiments take advantage of the different scattering lengths of hydrogen and deuterium. Using antimicrobial peptide piscidin that was specifically labeled with deuterium to obtain contrast, the location of the peptide in bilayers that mimic bacterial cells has been directly determined at high resolution (~0.2 Å). The experiments have also been used to characterize the degree of bilayer distortion (e.g. membrane-thinning) induced by the peptide.
Information from these investigations is crucial to decipher the mechanism by which the peptide disrupts bilayers and induces cell death. Studies of piscidin performed in Cotten’s group seek to determine molecular characteristics that allow piscidin and similar antimicrobial peptides to kill bacteria in a few minutes. This research could inform the design of antibacterial compounds that are active against drug-resistant bacteria. Cotten’s research is supported by a CAREER grant from the National Science Foundation.