Identification and evaluation of repurposing Food and Drug Administration-approved drugs targeting the pE165R protein of African swine fever virus.

Abstract

Objective African swine fever is a devastating swine disease lacking effective vaccines or antiviral drugs. The African swine fever virus (ASFV) pE165R deoxyuridine triphosphatase (dUTPase), critical for viral replication, is a promising antiviral target. Therefore, identifying inhibitors that target the pE165R protein represents a potential antiviral strategy. Methods The study computationally screened FDA-approved drugs against pE165R's crystal structure. Molecular dynamics simulations elucidated inhibitor-pE165R interactions, and in vitro enzymatic assays quantitatively assessed inhibitory effects. Results 4 candidates predominantly targeted pE165R's active pocket (Serine-72, Arginine-71, and Serine-73), suggesting competitive inhibition, with strong binding free energies (up to -40.5 kcal/mol) observed by molecular mechanics/Poisson-Boltzmann surface area. Conclusions In vitro assays confirmed dideoxyinosine triphosphate (77.9%) potently inhibited pE165R activity at 0.1mM. Clinical Relevance Effective drugs against ASFV remain lacking. Based on a drug-repurposing strategy, this study screened the FDA-approved drug library for compounds targeting pE165R, a key protein involved in ASFV replication. Subsequent pharmacodynamic evaluation is expected to facilitate the identification of affordable and effective anti-ASFV therapeutics for clinical application, thereby providing a theoretical foundation for the effective prevention and control of African swine fever.