New Candidates for Furin Inhibition as Probable Treat for COVID-19: Docking Output

Furin is a serine protease that takes part in the processing and activation of the host cell pre-proteins. The enzyme also plays an important role in the activation of several viruses, such as the SARS-CoV-2 virus, the causative agent of COVID-19 disease which inflicted a high rate of mortality. Unlike other viral enzymes, furin has a constant sequence and active site characteristics and seems to be a better target for drug design for COVID-19 treatment. Considering furin active site as receptor and some approved drugs as ligands, we have carried out docking experiments in HEX software to pick up those which are capable of binding furin active site with high affinity. The tested drugs were chosen from different classes, including antivirals, antibiotics, and anti-protozoa/anti-parasites with suspected beneficial effects on COVID-19. Our docking experiments show that saquinavir, nelfinavir, and atazanavir with respective cumulative inhibitory effects of 2.52, 2.16, and 2.13, respectively are the best candidates for furin inhibition. Clarithromycin, niclosamide, and erythromycin show cumulative inhibitory indices of 1.97, 1.90, and 1.84, respectively. Considering the lower side effects of clarithromycin, niclosamide, and erythromycin in contrast to the antivirals such as saquinavir, nelfinavir, and atazanavir, we suggest the formers as prophylaxes and even at severe states of COVID-19 as adjuvant therapy.