Anticoronavirus activity of C60 fullerene: in silico and in vitro screening

Abstract

Background: The search for potential therapeutic agents against the most common coronaviruses, which can pose a threat to human and animal life, is an urgent issue of modern biomedicine. Objective of the work was to evaluate in silico the ability of C60 fullerene to interact with the membrane protein ACE2, thereby preventing the formation of the "coronavirus-ACE2" complex and its further penetration into the host cell, as well as the effectiveness of the anticoronavirus action of these carbon nanoparticles in in vitro systems. Methods: The Protein Data Bank was used to study the structural organization of the human ACE2 membrane protein. The CHARMM-GUI and SwissParam web resources were used to construct the membrane and C60 fullerene, respectively. Potential binding pockets for C60 fullerene in the ACE2 structure were determined using the Caver software package. The system molecular docking algorithm (sdock+) was used to study the interaction between C60 fullerene and ACE2. Molecular dynamics (MD) calculations were performed using the Gromacs 2020 software package. Cytotoxicological and virological methods were used in in vitro experiments. Statistical processing of experimental results was carried out using the Statistica 13.3 program. Results: It was found three potential binding sites between the groove of the peptidase domain of the ACE2 protein and C60 fullerene. According to the results of molecular docking and MD, it follows that C60 fullerene forms two stable complexes with the ACE2 protein, thus blocking its potential interaction with coronaviruses. According to the results of in vitro studies, it follows that C60 fullerenes at a maximum allowable concentration of 37.5 μg/ml act on the coronaviruses of swine (α-coronavirus) and cattle (β-coronavirus) at the early stage of replication (1 h) in sensitive cellular systems, significantly reducing their infectious activity by 2.00 TCID50/ml and ≥2,28 TCID50/ml, respectively. Conclusions: C60 fullerene has been shown to form two stable complexes with the membrane protein ACE2, thereby inhibiting its functional activity and blocking potential interaction with coronaviruses. It was established that the C60 fullerenes show antiviral activity against coronaviruses of two groups at the initial stage of infection when interacting with sensitive host cells.

Keywords

• c60 fullerene
• animal coronaviruses
• molecular docking
• molecular dynamics
• antiviral activity in vitro