IN-SILICO VALIDATION OF A MULTI-TARGET INHIBITION STRATEGY FOR OROPOUCHE VIRUS (OROV)

📄 TECHNICAL NOTE: IN-SILICO VALIDATION OF A MULTI-TARGET INHIBITION STRATEGY FOR OROPOUCHE VIRUS (OROV)   

 Author: Shanmithaa . S                                                                                                                                                           

Affiliation: Independent Researcher, Tiruppur, Tamil Nadu, India                                                                                                   

Date: June 2026                                                                                                                                                                       

Document ID: OROV-2026-002-TN                                                                                                                                       

Keywords: Oropouche Virus, Bunyavirales, Molecular Docking, PLIP, RdRp Core, Nucleoprotein, Gc Glycoprotein

1. ABSTRACT The alarming geographic expansion of the Oropouche virus (OROV) outbreak across the Americas highlights the urgent need for therapeutic countermeasures against Peribunyaviridae. Currently, no FDA-approved vaccines or specific antivirals exist. This study utilizes computational molecular docking and Protein-Ligand Interaction Profiling (PLIP) to validate a novel, broad-spectrum antiviral strategy. Unlike traditional monotherapy, this approach targets three distinct critical checkpoints in the viral lifecycle: genome encapsidation, viral entry, and RNA transcription. In-silico results demonstrate exceptionally high binding affinities (ΔG) ranging from -8.4 to -9.7 kcal/mol across the target sites, stabilized by robust non-covalent interaction networks.

2. INTRODUCTION Oropouche virus is an arthropod-borne Orthobunyavirus causing Oropouche fever, a disease characterized by acute febrile illness and potentially severe neurological complications. Current clinical management is primarily supportive. The challenge in drug design is the rapid evolutionary dynamics of RNA viruses, which frequently leads to resistance against single-target therapies. This research proposes a "multi-key" polypharmacology approach, aiming to neutralize viral attachment, genome encapsidation, and transcription simultaneously to minimize the probability of viral escape through mutation.

3. METHODOLOGY The computational pipeline involved three primary stages: Target Selection: Structural data were retrieved from the RCSB Protein Data Bank (PDB). Targets included the Oropouche Virus Nucleoprotein (6SS2), Oropouche Virus Glycoprotein Gc Head Domain (6H3X), and the Viral RNA-dependent RNA polymerase (RdRp) Core (7OA4). Interaction Profiling (PLIP): Protein-Ligand Interaction Profiler was applied to precisely map non-covalent interactions (hydrogen bonds, π-cation interactions, and hydrophobic contacts) stabilizing the ligand-protein complexes. Molecular Docking: Site-specific docking was executed to calculate the Gibbs free energy (ΔG) of binding within the primary active pockets of the selected structural targets.

4. RESULTS AND DATA ANALYSIS 4.1 BINDING AFFINITIES

   Here is the binding affinity data for the Oropouche Virus (OROV) structural targets formatted into a clean table:

   Target Category	Protein Target (PDB ID)	Binding Affinity (ΔG)	Biological Impact
   Replication	Viral RdRp Core (7OA4)	-9.7 kcal/mol	Arrest of viral mRNA transcription
   Encapsidation	Nucleoprotein (6SS2)	-8.9 kcal/mol	Disruption of RNP complex formation
   Fusion/Entry	Gc Glycoprotein (6H3X)	-8.4 kcal/mol	Inhibition of membrane fusion

   4.2 INTERACTION STABILITY (PLIP) The structural scaffolds demonstrate strong topological anchoring: • Nucleoprotein (Np): Multiple π-cation interactions and deep hydrophobic contacts lock the ligand into the RNA-binding cleft. • Glycoprotein (Gc): Binding relies heavily on a network of stable hydrogen bonds at the fusion loop domain. • RdRp Core: High-affinity binding within the catalytic chamber blocks nucleotide entry pathways.

   1. DISCUSSION The -9.7 kcal/mol affinity against the RdRp Core (7OA4) suggests that this strategy may effectively arrest viral replication by blocking polymerase processivity. Furthermore, the -8.4 kcal/mol affinity at the Gc head domain indicates a potential prophylactic barrier against cellular entry. By targeting these specific topological pockets mapped via PLIP, we establish a framework for synergistic multi-stage inhibition. Future Optimization: Future iterations will focus on rigorous ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling to predict human pharmacokinetics and blood-brain barrier (BBB) permeability, which is vital for treating neuroinvasive Orthobunyavirus strains.

   2. CONCLUSION The in-silico data support the targeted structural scaffolds as highly viable for broad-spectrum anti-Orthobunyaviral development. The multi-target strategy provides a robust framework for preventing viral entry, encapsidation, and replication simultaneously. Immediate in-vitro phenotypic assays are recommended to experimentally confirm the predicted multi-stage inhibition kinetics.

   3. REFERENCES Hellert, J., et al. (2018). Oropouche virus glycoprotein Gc head domain. PDB ID: 6H3X. Oropouche Virus Nucleoprotein Structure. PDB ID: 6SS2. Orthobunyavirus Polymerase/RdRp Core. PDB ID: 7OA4. Salentin, S., et al. (2015). PLIP: fully automated protein-ligand interaction profiler. Nucleic Acids Research.