Authors: Kenneth A. Mwawasi, David C. Bulir, Seiji N. Sugiman-Manrangos, Murray S. Junop, Christopher Stone, James B. Mahony.
Influenza virus is a major respiratory virus infection responsible for seasonal outbreaks, global pandemics, and an estimated 500,000 deaths annually. The RNA polymerase of influenza virus is a heterotrimeric enzyme complex made up of three subunits that interact to form an active holoenzyme. In this study, in silico molecular modeling was used to predict the hypothetical free energy of binding between the PB1 and PA subunits for various single amino acid substitutions within the PB1 subunit. Two significant substitutions for threonine at position six were identified: glutamic acid (T6E) and arginine (T6R). We engineered native and modified PB1 peptide mimetics with a carrier protein and a cell penetrating peptide (HIV Tat NLS) to deliver the peptides to cells. These peptide mimetics inhibited Influenza a virus transcription and translation in MDCK cells in a dose-dependent manner with 98% inhibition at 50 μM. The inhibitory activity of peptide mimetics containing T6E and T6R substitutions, were three- to four-fold higher than the wild type peptide consistent with the in silico molecular modeling prediction. These results demonstrate that molecular modeling of protein-protein interactions can be used to design peptide mimetics as protein therapeutics which have increased anti-viral activity.
View/Download pdf