Role of Glycans and Related Ligands in Disruption of Entry Mechanism of SARS-CoV-2 into host cell 

 Presenting Author – Aaftaab Sethi

The Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) spread like wildfire throughout  the globe and continues to do so. Stringent measures like complete lockdown and extensive testing  have been employed by many countries to slow it down in its tracks as no viable treatment is available  till date. Therefore, in the current scenario, prompt solutions need to be uncovered to tackle the virus.  In the present study, different isoforms of galectins along with 330 galectin inhibitors were tested  against the SARS-CoV-2 Spike (S) protein. The spike being the sole protein responsible for entry of  virus into host cell. The studies were performed with the aid of protein-protein docking, ligand-protein  docking, induced fit docking and molecular dynamics. Finally, the binding free energy and contributing  energies were calculated for the top scoring ligands by using MM-GBSA method. Many of them were  found to bind to the site of contact of S protein to ACE2. Thus, they show promise of disrupting the  ACE2-S protein binding and prevent the virus from invading the host cell. Among the ligands screened,  TD-139, a molecule currently in Phase IIb clinical trials to treat idiopathic pulmonary fibrosis, was  found to be one of the potential hits. The present study paves the way for in vitro and in vivo testing  of galectin proteins and galectin inhibitors to halt SARS-CoV-2 in its tracks.