Figure 4

Capacity of WT and mutant gp41 virus strains to bind to sCD4. On average 48 ng p24 of the (mutant) HIV-1_NL4.3 strains was lysed using triton-X100 and brought into contact with ELISA strips coated with sCD4. The binding efficiency was calculated after normalization to WT virus lacking envelope glycoprotein expression (to correct for aspecific interactions) and as relative to the binding of WT virus (set at 100%). Data are the means ± SEM of at least 2 to 4 independent experiments. The difference between WT and mutant was considered to be significant when the p value calculated using the student’s t-test was <0.05 (* = p < 0.05, ** = p < 0.005).