In-Depth Molecular Dynamics Simulations Reveal Ligand-Induced Modulations of the HSPA8-SARS-CoV-2 Spike Protein Interaction

Coronavirus disease 2019 continues to pose global health challenges, with the pandemic significantly burdening several economies, healthcare systems, and the social lives of individuals. Furthermore, new cases continue to be reported, underscoring the need for therapeutic strategies targeting conserved regions and host–virus interactions. Building on earlier virtual screening for small molecules, all-atom molecular dynamics simulations and binding-free-energy calculations were performed to elucidate how the two previously identified small molecules (NSC36398 and NSC281245) may affect the dynamic behaviour of the interaction between heat shock 70 kDa protein 8 (HSPA8) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein. Post-MD analyses refined prior docking predictions, where NSC281245 was found to bind tightly to the complex with limited perturbations at the HSPA8-spike protein interaction surface, whereas NSC36398 appeared to induce allosteric-like domain-level destabilisation effects while maintaining stable polar contacts with the protein. Our findings demonstrate the potential of NSC36398 as a promising modulator for disrupting the HSPA8-spike protein complex, which may serve as a structural lead for designing next-generation inhibitors of host–virus interactions.