FIG. 5.

Independent and combined effects of the 197 N/S change, V1/V2 loop deletion, and temperature on 48d recognition of gp120. Approximately 100 μl of supernatants containing radiolabeled wild-type and mutant gp120 glycoproteins were preincubated with or without sCD4 (30 μg/ml) at 37°C for 1 h. The supernatants were incubated with 48d (5 μg/ml) and protein A-Sepharose at 4 or 37°C for 2 h. Precipitated proteins were analyzed using SDS-PAGE and a phosphorimager. The results were normalized for the relative abundance of gp120 in the supernatants, which was determined by a parallel precipitation with a mixture of sera from HIV-1-infected individuals. The mean values and ranges for duplicate experiments are shown.