progress report; drug synthesis; native chemical ligation;
The influenza A virus integral membrane protein, M2, is a proton-conducting channel. The ability of influenza A virus to unpack its genome, replicate, and infect its host is contingent upon the M2-mediated acidification of the viral interior. The antiviral drugs amantadine and rimantadine were previously effective in blocking proton influx through M2; however, mutations in the proton channel have rendered these drugs ineffective. Multiple models for the inhibiting mechanism of the adamantane drugs have been hypothesized. In an attempt to better understand the mechanism of M2 inhibition, and ultimately to assist in the development of a replacement M2-targeting antiviral drug, we have set out to determine the site of interaction between rimantadine and M2 using native chemical ligation, a reaction that will result in the formation of a peptide bond between the cysteine residue of mutated M2 and a rimantadine thiol group. We report that we have made significant progress towards growth, harvest, and purification of the M2 (22-62) mutants S31C and G34C (mutation names being based on the full-length protein residue numbers). Additionally, we have successfully synthesized the second to last intermediate, an azido alcohol, of our rimantadine thiol synthesis scheme with 82% yield. This report indicates our progress towards the completion of our project, a project which we believe will assist with further understanding the interaction between M2 and antiviral drugs.