Date of Award
© 2017 Grace Kim. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.
Bachelor of Arts
Chemistry & Biochemistry
Kathleen P. Howard
The M2 protein is a 97-residue multifunctional transmembrane homotetrameric protein. It is found in the viral coat of the Influenza A virus, which is responsible for approximately 250,000 to 500,000 deaths annually worldwide.¹ Extensive research has elucidated M2's role as an ion channel, which plays a critical role in the uncoating of the viron once it has entered the host cell. The C-terminal tail of M2 has also been shown to play a crucial role in generating curvature in the cell membrane to mediate viral budding.²³ Deletions in the C-terminal tail of the M2 protein lead to impaired viral infectivity.⁴ While the early portion of the C-terminal tail (residues 46-60) has been previously shown to be an amphipathic helix and has been extensively studied. High-resolution structural detail is limited in the region (residues 61-70), though it has been shown that these regions also play a role in viral budding. This study uses site-directed spin-label electron paramagnetic resonance (SDSL-EPR) to look at the region (residues 61-70) in the absence and presence of cholesterol. Continuous wave EPR line shapes demonstrate that this region is more mobile than amphipathic helix (46-60) suggesting that its movement is not restricted by the lipid bilayer. This assertion is also confirmed by power saturation EPR which demonstrate low ΔP_(1/2) values, suggesting that this region is not as oxygen accessible. Interestingly, a novel finding from this study is that this region has a regular conformation, which contrasts previous predictions that suggest that this region may be disordered. While further investigation is necessary, the experiments presented in this study provide a preliminary characterization to the later C-terminal domain (residues 61- 70) of the Influenza M2 protein.
Kim, Grace , '17, "SDSL-EPR of Residues 60-70 of Influenza M2 Protein Reveals Structural Properties of a Region Involved in Viral Budding" (2017). Senior Theses, Projects, and Awards. 228.