Fig. 1: Characteristics of the 5 VL6-57 light-chain utilizing antibodies.

a The genetic and functional properties of the five isolated VL6-57 light-chain utilizing antibodies, as previously reported¹⁶. Neutralization titers (IC₅₀) of antibodies were determined against a pseudovirus displaying WT SARS-CoV-2 S-protein. Binding affinities (K_D) of antibodies to SARS-CoV-2 WT RBD were determined by biolayer interferometry (BLI) assays. Germline usage and somatic hypermutation (SHM) analysis of antibodies were performed using IMGT/V-QUEST. b Pairwise binding competition to SARS-CoV-2 RBD was assessed by BLI. A biosensor immobilized with WT SARS-CoV-2 RBD was first saturated with one of the VL6-57 utilizing mAbs until the dashed line before submerging into a solution of another mAb or ACE2 to assess competition. An ACE2 competing antibody B38 (purple) and two non-ACE2 competing antibodies recognizing different RBD epitopes, CR3022 (black)³⁹ and R1-32 (green)¹⁶ were used as controls. c, d BLI binding curves of R1-26 to 2-fold serially diluted RBD (c) or S-protein (d) solutions of WT SARS-CoV-2 and VOCs. The black lines represent the experimentally recorded sensorgram traces, the colored lines represent corresponding fits. Detailed binding kinetics parameters are summarized in Supplementary Table 1. e Neutralization activities of R1-26 towards SARS-CoV-2 WT and VOC authentic viruses in cell culture (data are presented as mean values ± SD, n = 3). Source data for e are provided as a Source Data file.