Neutralizaton ability of some antviral nanobodies was computed against the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-COV 2). CoDockPP Server and COVID-19 Docking Server respectvely was applied for a protein-protein molecular docking. The afnity of candidate nonobodies was investgated for blocking of RBD against the human angiotensin covertng enzyme 2 (ACE2). The neutralizaton ability of nonobodies was compared with natural nanobodies of Ty1, H11-H4, EY6A, H11-D4 and synthetc construct of Sb23, ybody MR17, sybody MR17-K99Y, and SR4 that experimentally was involved against the RBD of SARS-COV 2. It was seen, the 15 reported VHH was able for blocking with an estmated binding energy greater than -235.55 (kcal/mol) for Ty1 with the lowest afnity to the RBD. VHH 7A, VHH PVSP29F, Cameld VHH 9, VHH PVSS8A, VHH 12B, VHH 59H10, VHH PVSP6A, VHH 10E, VHH 17B and VHH 59H10 respectvely was proposed for neutralizaton of RBD while the two last VHH are more confdence due to the greater values of afnity against -342.56 (kcal/mol) for SR4. The energy maps of ACE2, VHH 17B and VHH 59H10 was identfed that hydrogen donor, steric, hydrogen acceptor and electrostatc interactons respectvely were signifcant for blocking RBD of SARS-COV 2. This study conform structural insight for neutralizaton of RBD spike glycoprotein of SARSCOV 2 by nanobodies and suggest VHH that may serve as useful therapeutcs during the pandemic.
