FIG. 1.

DexS inhibition of MAb binding to the conserved coreceptor binding site. Monomeric recombinant sgp120 derived from the MN or JRFL strain of HIV-1 was captured on the solid phase by an antibody to the conserved COOH terminus, then preincubated without (−) or with (+) 12.3 μM DexS prior to addition of sequential dilutions of gp120 antibodies specific for the CD4bs (IgG1b12) (A), the V3 loop (447-52D) (B), and the CD4i epitopes 17b (C) and 48d (D). Detection of bound MAb was carried out by ELISA, and the results are presented as optical densities at 450 nm. Each datum point is the mean of values obtained from triplicate samples, and each experiment was repeated on at least three separate occasions.