1. Bi-paratopic and multivalent VH domains block ACE2 binding and neutralize SARS-CoV-2.
- Author
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Bracken, Colton J, Lim, Shion A, Solomon, Paige, Rettko, Nicholas J, Nguyen, Duy P, Zha, Beth Shoshana, Schaefer, Kaitlin, Byrnes, James R, Zhou, Jie, Lui, Irene, Liu, Jia, Pance, Katarina, QCRG Structural Biology Consortium, Zhou, Xin X, Leung, Kevin K, and Wells, James A
- Subjects
QCRG Structural Biology Consortium ,Vero Cells ,Animals ,Humans ,Peptide Library ,Antibodies ,Viral ,Binding Sites ,Antibody ,Cryoelectron Microscopy ,Protein Binding ,Models ,Molecular ,Protein Interaction Domains and Motifs ,Single-Chain Antibodies ,Antibodies ,Neutralizing ,HEK293 Cells ,Spike Glycoprotein ,Coronavirus ,Protein Conformation ,alpha-Helical ,Protein Conformation ,beta-Strand ,Chlorocebus aethiops ,Angiotensin-Converting Enzyme 2 ,SARS-CoV-2 ,Biochemistry & Molecular Biology ,Medicinal and Biomolecular Chemistry ,Biochemistry and Cell Biology - Abstract
Neutralizing agents against SARS-CoV-2 are urgently needed for the treatment and prophylaxis of COVID-19. Here, we present a strategy to rapidly identify and assemble synthetic human variable heavy (VH) domains toward neutralizing epitopes. We constructed a VH-phage library and targeted the angiotensin-converting enzyme 2 (ACE2) binding interface of the SARS-CoV-2 Spike receptor-binding domain (Spike-RBD). Using a masked selection approach, we identified VH binders to two non-overlapping epitopes and further assembled these into multivalent and bi-paratopic formats. These VH constructs showed increased affinity to Spike (up to 600-fold) and neutralization potency (up to 1,400-fold) on pseudotyped SARS-CoV-2 virus when compared to standalone VH domains. The most potent binder, a trivalent VH, neutralized authentic SARS-CoV-2 with a half-maximal inhibitory concentration (IC50) of 4.0 nM (180 ng ml-1). A cryo-EM structure of the trivalent VH bound to Spike shows each VH domain engaging an RBD at the ACE2 binding site, confirming our original design strategy.
- Published
- 2021