Figure 4. (A) Sensorgram showing direct binding of HIV-1_YU2 gp120 to immobilized [₂₀AGSF₂₃]-ST. Concentrations are 6.25, 12.5, 25, 50, 60, 75, 100, 125, 150, 200, and 300 nm. (B) Competition of sCD4 for gp120 binding by [₂₀EGLV₂₃]-ST mimetic peptide. With sCD4 immobilized on the sensor chip surface, solutions of gp120 (100 nm) with or without mimetic peptide (39.5–200 μm) are passed over the sensor chip and binding is recorded. (C) Effect of [₂₀AGSF₂₃]-ST on gp120 binding to mAb 17b. Solutions of gp120 (100 nm) with or without [₂₀AGSF₂₃]-ST were passed over the chip. As the amount of [₂₀AGSF₂₃]-ST increases (0.025–1.27 μm), binding between gp120 and 17b also increases.