In the present study, homology modeling and MD simulations
were applied on the commercially available drugs bound to the
NA and M2-channel of the new influenza A (H1N1) virus. Based
on the MD/LIE method, the predicted binding affinity of oseltamivir
towards the new A (H1N1) influenza isolate was considerably
higher than the avian H5N1 strain. Except for the absence of a
weak H-bond with residue 347, all interactions of OTV-N1/
09H1N1 complex were considerably conserved. Interestingly, oseltamivir
was well oriented in the binding pocket and its –COO
group interacted strongly with the arginine triad, similar to that
found in the crystal structure of N9. For M2/09H1N1 channels with
two adamantanes bound, water transport explicitly passed
throughout the channel of the 3H state, representing the activated
channel at a low pH. Either amantadine or rimantadine have totally
lost the H-bond interactions with the M2 residues in this state,
which results from the M2 transmembrane domain containing
the S31N mutation as well as other two residues, I28 at the extracellular
site and T43 close to the W41 gating residue, which differs
from the avian H5N1. Overall, the simulated results have clearly
explained at a molecular level how anti-influenza drugs can either
potently inhibit (oseltamivir) or not (amantadine and rimantadine)
the new A (H1N1) influenza virus.