Adsorption-driven deformation and landing-footprints of the RBD proteins in SARS-CoV-2 variants onto biological and inanimate surfaces

Abstract

Respiratory viruses, carried through airborne microdroplets, frequently adhere to surfaces, including plastics and metals. However, our understanding of the interactions between viruses and materials remains limited, particularly in scenarios involving polarizable surfaces. Here, we investigate the role of receptor-binding domain (RBD) mutations on the adsorption of SARS-CoV-2 to hydrophobic and hydrophilic surfaces employing molecular simulations. To contextualize our findings, we contrast the interactions on inanimate surfaces with those on native-biological interfaces, specifically the ACE2 receptor. Notably, we identify a twofold increase in structural deformations for the proteins receptor binding motif onto the inanimate surfaces, indicative of enhanced shock-absorbing mechanisms. Furthermore, the distribution of amino acids (landing-footprints) on the inanimate surface reveals a distinct regional asymmetry relative to the biological interface. In spite of the H-bonds formed at the hydrophilic substrate, the simulations consistently show a higher number of contacts and interfacial area with the hydrophobic surface, with the WT RBD adsorbed more strongly than the delta or omicron RBDs. In contrast, the adsorption of delta and omicron to hydrophilic surfaces was characterized by a distinctive hopping-pattern. The novel shock-absorbing mechanisms identified in the virus adsorption on inanimate surfaces could lead current experimental efforts in the design of virucidal surfaces.