Structural characterization of the NS2 protein of Respiratory Syncytial Virus and study of the interaction with flavonoids:search for candidate molecules for antiviral design.

Abstract

Human Respiratory Syncytial Virus (hRSV) is the major causative agent of acute respiratory infections (ARI - Acute Respiratory Infections) such as pneumonia and bronchiolitis. This is a virus of the Paramyxoviridae family, with helical symmetry and lipid envelope. It has a single strand RNA genome, not segmented, with 10 coding genes. One of the factors that contribute to success in viral replication is the immune system evasion by the virus, this process is directed by the NS1 and NS2 proteins. These proteins may act as by inhibiting or neutralizing various steps of the pathway of interferons as to assist in silencing ribonucleoprotein complex (RNP) of RSV. To date NS2 protein by hRSV has not resolved its three-dimensional structure and is also a protein that doesn´t have known homology. Thus know the protein structure and seek promising ligands that can interact with it and block its action is a route search for potential antiviral and a candidate to prevent NS2 interactions with others proteins thereby preventing the success of viral replication . This project aims is to resolve the three-dimensional structure of these protein by nuclear magnetic resonance, investigate the interaction of NS2 with Quercetin and Morin, by fluorescence spectroscopy and verify the physical-chemical characteristics of protein interaction with these ligands.To achieve these goals will be carried out cloning, expressing and purifying the NS2 protein of hRSV and then determine these three-dimensional structure and verify the interaction process. The NS2 gene will be cloned into pJEXpress401-T5 vector and expressed in Escherichia coli Gold DE3 strain. The expressed protein will be purified by affinity chromatography. The results of this study will provide know the protein structure, identify the site of interaction with quercetin and morin besides protein stability, making it possible to have interaction model and propose therapeutic models. (AU)