Abstract:
Influenza A presents a significant concern for public health as it is the cause of
seasonal outbreaks and global pandemics. The influenza A proteins, matrix protein 1 (M1)
and matrix protein 2 (M2), have been shown to be essential for the propagation of new
viruses, especially through their roles in viral assembly and budding. The M2 cytoplasmic
tail interacts with the M1 protein, recruiting it to the viral budding site and enabling proper
packaging of the viral genome. The Howard lab has previously characterized residues 50-
70 in the M2 cytoplasmic tail and the M2 protein’s conformational equilibria by sitedirected
spin label electron paramagnetic resonance (SDSL-EPR). This work lays
groundwork for the establishment of a system in which to see changes in the M2 protein
upon M1 binding. Methods for the overexpression and purification of the M1 protein are
presented. Selected M2 sites (43, 57, 68) were studied by SDSL-EPR in the presence of Nterminal
M1 (residues 1-165), with M2 sites 43 and 57 acting as indicators of the M2
protein’s conformational dynamics. Binding between M1 and M2 could not be rigorously
established, but preliminary results suggest little change in the M2 protein in the presence
of the M1 protein.