Presenter: Kehinde Idowu
Department: Pharmaceutical and Environmental Health Sciences
Abstract:
After the emergence of severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2), various variants have emerged due to mutations to the viral proteins. Out of these variants, Delta (B.1.617.2) and Omicron (B.1.1.529) variants have proven to be of significant concern, considering their influence on the virus's transmissibility and pathogenicity. Employing computational techniques, this study evaluates the impact of mutations on these two variants on the molecular interactions between the viral spike protein and the human angiotensin converting enzyme 2 (hACE2), recognized as the receptor for the entry of SARS-COV-2 into cells. Based on the docking results and the calculated free binding affinity, Omicron variant exhibited higher docking score and binding energy of -134.4 kcal/mol and -43.591 kcal/mol, respectively. These values are higher than the calculated docking score and binding energy for Delta variant (-59.2 kcal/mol and -19.743 kcal/mol) and the wild type (-119.8 kcal/mol and -29.700 kcal), respectively. These findings corroborate high infectivity/transmissibility associated with Omicron variant. Furthermore, the structural analyses of the impact of mutations on the receptor binding domain (RBD) and hACE2 (RBD) complexes revealed that the presence of mutations destabilizes the complexes as the structural analysis plots showed higher values than the wild type. However, the structural analyses, further showed that instability impact on Delta variant is more than the Omicron variant as evidenced by higher average values of structural analysis plots than the Omicron. This reported high structural instability might suggests the reason behind the severity in Delta variant infection/disease than the Omicron infection.