Screened Fv-Antibodies\nagainst the Angiotensin-Converting\nEnzyme 2 (ACE2) Receptor Neutralizing the Infection of SARS-CoV‑2

For the prevention of SARS-CoV-2 infection, four Fv-antibodies\nwith binding affinity for the ACE2 receptor were screened from an\nFv-antibody library. The screened Fv-antibodies were expressed as\nsoluble proteins and estimated to have a high binding affinity, comparable\nto that between SARS-CoV-2 and the ACE2 receptor. The interaction\nbetween the Fv-antibodies and the ACE2 receptor was analyzed using\ndocking simulation, and the significant binding affinity of the screened\nFv-antibodies was attributed to the homology in amino acid sequence\nwith the ACE2 receptor. The neutralizing activities of the Fv-antibodies\nwere demonstrated using a cell-based infection assay based on four\npseudo-virus types with SARS-CoV-2 variant spike proteins (Wild-type\nD614, Delta B.1.617.2, and Omicron BA.2, and Omicron BA.4/5).