Browsing by Author "Mitchell, Cristopher"

Coxsackievirus A9 (CVA9) is a member of the Picornaviridae family of viruses and Enterovirus genus. CVA9 is mostly associated with milder Enterovirus symptoms such as rashes, but there are also individual cases of more serious diseases caused by CVA9 infection, including hepatitis. The picornavirus capsid structure is largely conserved and composed of 3-4 viral proteins (VP). At the base of VP1 there is a hydrophobic pocket occupied by a lipid factor. The expulsion of that lipid factor leads to expansion of the capsid, viral uncoating and genome release into the cell. To prevent that expansion, an ongoing study has been screening and synthesizing hundreds of potential molecules to target the VP1 pocket and replace the pocket factor. One such molecule is CL300, an N-phenyl benzamide, which has an antiviral effect on CVA9. The purpose of this study was to validate the proposed mechanism of action of CL300 on CVA9 by confirming its binding location with cryogenic electron microscopy and single-particle processing methods. Through processing, 31,050 particles were narrowed down to 21,230 particles that were reconstructed into a 2.26 Å resolution density map of CVA9 with a heterogeneous density in the VP1 pocket. Due to features present in that density and the presence of multiple rotamer densities in a nearby residue, Y210, it was concluded that either CL300 or lipid factors were present in different VP1 pockets, resulting in an averaged density in the map. The final result of this study was a model of CVA9 with CL300 in the hydrophobic pocket. These results, in conjunction with the ongoing study into the antiviral effect of CL300, have implications for the potential future production of antivirals and vaccines to combat CVA9 and other Enterovirus infections where there is conservation of the binding pocket.