Figure 1. Representation of the relative binding affinities of antibody PGT121 family members to wild-type and glycan-variant SOSIP trimers.

Schematic representation of the PGT121 family phylogenetic tree with heavy chains paired with the corresponding light chains. Dissociation constants (K_d) were determined by ITC for selected members of this family from inferred germline to intermediates (precursors) and to affinity-matured Abs in complex with SOSIP.664 trimers and N137A or N332A glycan knock-out variants, expressed in either 293S or 293F cells (Figure S1). The fold changes in binding affinity (nM) (Figure S1B) on glycan removal were used to estimate how the N137 glycan contributes to affinity maturation. A relative scale for both positive and negative contributions to the Ab affinity was determined based on the extent of the changes in dissociation constants (K_d’s) (see also Figure S1B for complete thermodynamic data). Top right: surface representation of the location of glycans (colored) that interact with PGT121 family with the variable heavy chain in grey and variable light chain in light brown.