FIG 2.

ELISAs demonstrate that V2i MAb Fabs preferentially recognize the sCD4-induced open conformation of B41 Env. (A) Schematic view of an ELISA in which D7324-tagged B41 SOSIP trimer was captured by the anti-D7324 antibody JR-52 (6), and V2i Fabs were added in the absence (sCD4⁻, left) or presence (sCD4⁺, right) of sCD4. (B) Positive control demonstrating preferential binding of the CD4i 17b Fab in the presence of sCD4. (C) Binding of the indicated V2i Fabs to B41 Env in the presence and absence of sCD4.