Production of Envelope Protein-Based Virus-like Particles of DENV‑2 in and Investigation of Their Binding Interactions with Gallic Acid Derivatives of Glucose as Potential Drug Candidates.

Perennial endemics of mosquito-borne dengue infection affect millions of lives across tropical and subtropical regions every year. Factors like the Earth's rising temperature, climate change, and lack of dengue-specific drugs and vaccines have led to a significant surge in these infections, warranting urgent efforts to develop new antidengue agents. The dengue virus (DENV) envelope exposes approximately 90 E (envelope) protein dimers on its surface, making it a potent target for drug discovery and vaccine development. E protein-based virus-like particles (VLPs) may serve as an ideal system to test the binding activity of compounds in vitro. Such VLPs have not been defined for DENV serotype 2 (DENV-2). The current study demonstrates the expression of the E protein-ectodomain in and VLP generation. Previously, chebulinic acid (CA), a tannin, was demonstrated as a strong DENV-2 inhibitor in Vero cells. However, the structural complexity of CA made its synthesis a challenging task, whereas toxicity at higher doses limited its therapeutic use. To investigate binding to E protein in silico, simple analogues of CA (mono, di, tri, tetra, and pentagalloylglucose (PGG)) were selected and evaluated using molecular docking, molecular dynamics (MD) simulations, and electrostatic complementarity analysis. Herein, PGG-E-protein complex demonstrated higher docking scores, stable MD simulation patterns and electrostatics, equivalent to that of positive controls, CA, and epigallocatechin-3-gallate. Furthermore, the PGG interaction with VLP molecules was analyzed in vitro using biolayer interferometry, where nM-scale equilibrium constants were recorded. Therefore, a strong in silico and in vitro E protein-binding profile of PGG supports its potential as a DENV-2 inhibitor, which may be developed as an anti-DENV-2 therapeutic.