Biophysical characterization of the interaction between M2-1 protein of hRSV and quercetin

Author(s)

Panconato Teixeira, Thiago Salem ; Caruso, Icaro Putinhon ; Pereira Lopes, Bruno Rafael ; Regasini, Luis Octavio ; de Toledo, Karina Alves ; Fossey, Marcelo Andres ; de Souza, Fatima Pereira

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 95, p. 63-71, FEB 2017.
• Web of Science Citations: 2

Abstract

hRSV is the major causative agent of acute respiratory infections. Among its eleven proteins, M2-1 is a transcription antiterminator, making it an interesting target for antivirals. Quercetin is a flavonol which inhibits some virus infectivity and replication. In the present work, the M2-1 gene was cloned, expressed and the protein was purified. Thermal stability and secondary structure were analyzed by circular dichroism and the interaction with Quercetin was evaluated by fluorescence spectroscopy. Molecular docking experiments were performed to understand this mechanism of interaction. The purified protein is mainly composed of a-helix, with a melting temperature of 328.6K (approximate to 55 degrees C). M2-1 titration with Quercetin showed it interacts with two sites, one with a strong constant association K1 (site 1 approximate to 1.5 x 10(6)M(-1)) by electrostatic interactions, and another with a weak constant association K2 (site 2 approximate to 1.1 x 10(5) M-1) by a hydrophobic interaction. Ligand's docking shows it interacts with the N-terminus face in a more polar pocket and, between the domains of oligomerization and RNA and P protein interaction, in a more hydrophobic pocket, as predicted by experimental data. Therefore, we postulated this ligand could be interacting with important domains of the protein, avoiding viral replication and budding. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/24355-2 - Cloning, expression and analysis of the interaction of the M2-1 protein of HRSV with Flavonides: investigation for targets in blocking viral replication
• Grantee: Fátima Pereira de Souza
• Support type: Regular Research Grants