Further quantitative in silico analysis of SARS-CoV-2 S-RBD Omicron BA.4, BA.5, BA.2.75, BQ.1, and BQ.1.1 transmissibility

The Covid-19 variants' transmissibility was further quantitatively analyzed in silico to study the binding strength with ACE-2 and find the binding inhibitors. The molecular interaction energy values of their optimized complex structures (MIFS) demonstrated that Omicron BA.4 and 5's MIFS value (344.6 kcal mol(−1)) was equivalent to wild-type MIFS (346.1 kcal mol(−1)), that of Omicron BQ.1 and BQ. 1.1's MIFS value (309.9 and 364.6 kcal mol(−1)). Furthermore, the MIFS value of Omicron BA.2.75 (515.1 kcal mol(−1)) was about Delta-plus (511.3 kcal mol(−1)). The binding strength of Omicron BA.4, BA. 5, and BQ.1.1 may be neglectable, but that of Omicron BA.2.75 was urging. Furthermore, the 79 medicine candidates were analyzed as the binding inhibitors from binding strength with ACE-2. Only carboxy compounds were repulsed from the ACE-2 binding site indicating that further modification of medical treatment candidates may produce an effective binding inhibitor.