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. 2021 Sep 17;22(12):757–773. doi: 10.1038/s41576-021-00408-x

Fig. 3. SARS-CoV-2 spike-targeted antibody classifications.

Fig. 3

Classification of monoclonal antibodies (mAbs) targeting the SARS-CoV-2 spike receptor-binding domain (RBD) epitopes. For the two classes of mAbs binding the receptor-binding motif (RBM), 90o rotated side views and one top view of a surface RBD representation are shown (parts a,b). For the two classes of RBD core-binding mAbs, just the 90o rotated side views are shown (parts c,d). Each image derived from coordinates of the Protein Databank (PDB) structure 6M0J. Bold highlighted mAbs are in phase III clinical trials (as of July 2021). Blue intensity is proportional to the number of mAbs binding to the underlying amino acid residues. RBM refers to the region of the RBD containing the angiotensin-converting enzyme 2 (ACE2)-binding residues. RBM class 1 mAbs (part a) bind the RBD only in its up position, whereas RBM class 2 mAbs (part b) can bind the RBD in its up or down position. A third RBM mAb class binds to a quaternary epitope comprising more than one RBD but is not shown as it would require the trimeric spike. Epitopes for amino-terminal domain-binding mAbs are not shown.