Figure 1

(A) Binding of purified rabbit IgGs immunized with different Fab preparations and control (pre-immun IgG fraction) to Ab2/3H6Fab and recombinant HIV-1 gp140 (UG37); (B) Binding of the Ab3 (2F5-like) Ab fraction purified from pooled rabbit IgG fractions to recombinant HIV-1 gp140 (UG37) and (C) synthetic 2F5 epitope (ELDKWA); (D) Competition ELISA. Biotinylated 2F5 (2F5-B) was allowed to complex with serial dilutions of Ab2/3H6 mutants and afterwards uncoupled 2F5-B was determined on an epitope pre-coated ELISA plate. The optical density resulting from binding of 2F5-B to the synthetic epitope GGGELDKWASL is plotted versus the logarithm of the concentration of Ab2/3H6 mutants.