Date of Award

Spring 2024

Document Type

Restricted Thesis

Terms of Use

© 2024 Caleb Porter. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts

Department

Chemistry & Biochemistry Department

First Advisor

Kathleen P. Howard

Abstract

The Influenza A virus, responsible for yearly epidemics and periodic pandemics, is a pressing public health concern. The tetrameric membrane protein M2 is a potential target of interest for antivirals to replace those against which most influenza strains have already developed immunity. The monomeric amphipathic helix of M2 is well characterized, but previous structural studies have been unable to develop distance constraints between monomers in the M2 tetrameric bundle. The goal of this thesis is to optimize nanodiscs for the collection of inter-monomer distances using pulsed electron paramagnetic resonance spectroscopy (EPR) to better resolve the quaternary structure of M2.

Nanodisc preparations were optimized to eliminate clusters of M2 and empty nanodiscs, and were characterized using size exclusion chromatography and dynamic light scattering. Upon collection of EPR data, samples were determined to have improved EPR spectra qualities in deuterated buffer. Collected EPR data showed four expected inter-monomer distances and higher quality data in the presence of the drug rimantadine. Lastly, simulations were performed to compare EPR data with predicted data based on two models of M2 and to determine optimal sites for future studies. It was determined that both collected and existing distance data agreed more with a published Howard Lab structure than with a model of tetrameric M2 that was determined using solid state NMR.

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