Effect of the addition of glycans at positions 234 N and 295 N on HIV-1 sensitivity to GRFT and mGRFT-tandemers. Pseudoviruses from either (A) HIV-1 CAAN5342.A2 or (B) HIV-1 CAP206.8 bearing either wild-type gp120 (black bars) or re-engineered mutant gp120 restoring the glycosylation sites at position 234 and 295 (white bars) were tested for their sensitivity to native GRFT or mGRFT tandemers. Anti-HIV activity was visualized using the single-cycle Tzm-bl assay system with activity reported as the effective concentration that inhibited infection by 50% (EC50). All experiments were done in triplicate with the average value reported. Numbers in red indicate fold-difference in EC50 values between wild-type and mutant gp120 bearing pseudoviruses.