In-silico and biophysical investigation of biomolecular interaction between naringin and nsP2 of the chikungunya virus.

Chikungunya virus; the pathogen for chikungunya febrile and arthritic disease, having 11.8 kb positive-sense RNA genome encodes polyproteins for structural and non-structural regions. The polyprotein (P1234) corresponding to the non-structural part from 5' end gets auto-cleaved by the action of nsP2 protease, which leads to the generation of individual functional enzymatic proteins like nsP4, nsP1, nsP2 and nsP3. Thus, nsP2 protein initiates viral replication. Targeting nsP2 to block virus replication has always been the foremost strategy to develop antivirals. Plant-based molecules are one of the top choices to develop as inhibitor due to their less toxicity and wide availability. Using a combination of receptor-based docking and MD simulations, we identified a flavanone glycoside- naringin, which binds to nsP2 protease at nM affinity. The biomolecular interaction between naringin and nsP2 was established through SPR. As discerned through FTIR and intrinsic fluorescence studies, upon binding with naringin, a global structural change in nsP2 occurs. This structural modulation in nsP2 due to binding of naringin is likely to interfere with the normal functioning of this enzyme during the viral life cycle. In conclusion, this report highlights the potential of naringin as an anti-viral agent against Chikungunya.