MOLECULAR MODELING AND DOCKING ANALYSIS OF SWINEFLU (H1N1) NEURAMINIDASE PROTEIN AGAINST THE PHYTOCHEMICALS OF ANDROGRAPHIS PANICULATA

Abstract

Background: Swine flu has become a life-threatening disease involving two main proteins neuraminidase (NA) and hemagglutinin (HA). Inhibition of NA, the protein responsible for initiation of viral infection is the important treatment step in the eradication of swine flu. In silico analysis of natural compounds for swine flu treatment serves as a lead for drug development. Objective: The aim of this study is to obtain the 3 dimensional structure of Swine flu (HIN1) virus NA protein and to perform docking analysis to identify major residues involved in the binding of agonist and antagonist. Methods: H1N1 NA protein structure was predicted using the principles of homology modeling using Swiss model. The predicted protein structure was then subjected to docking studies with phytocompounds from Andrographis paniculata using Autodock 4.2 tools. A total of 16 compounds were tested for Lipinski’s rule and molecules which satisfied Lipinski’s rule were subjected to docking analysis against NA protein of H1N1. Results: Homology modeling is widely used structure prediction method for the proteins with no known experimental structures. In this study, the structure of NA protein was predicted using Swiss model. The protein was energy minimized using Swiss PDB Viewer and the final energy of the protein obtained was -87624.516 KJ/Mol. The predicted model was then subjected to docking studies. The compounds showed a binding energy in the range of -2.31 kcal/mol to -8.61 kcal/mol. The control drug Ostelmivir showed a binding energy of -3.35 kcal/mol. Conclusion: The structure of H1N1 NA was predicted using the principles of homology modeling. The docking results showed that andrograpanin and neoandrographolide were found to have binding energies of -8.61 kcal/mol and -7.39 kcal/mol respectively. These compounds showed good inhibitory effect by binding to the active site of the protein. The identified plant-based compounds can be an alternative to chemically synthesized drug in treating swine flu. Hence, these compounds can be further considered for in vitro and in vivo evaluation against swine flu virus.