FIG. 6.

Dependence of BMS-488043 activity on the order in which ligands are added to virions. (A) Inhibition of HIV LAI virion binding to sCD4-IgG by BMS-488043. The inhibitor was added to the assay mixture at the time indicated, and the level of virion (p24) bound to sCD4-IgG was measured. Bound-virion levels were normalized to virion levels detected in the absence of the inhibitor. Initiation of virion sCD4-IgG binding is marked as time zero. (B) Inhibition of sCD4-induced virion-C34 binding. Virion was coincubated with sCD4 and C34 peptide (from time zero to 60 min) while the BMS-488043 addition time was varied. C34 peptide-bound virions were captured with MAb NC-1, and the p24 level was determined.