(A and B) Schematic diagrams show the structures of BiIA-DG and BiIA-SG bearing the scFv binding domain(s) to gp120 (orange VH/VL of PGT128) and to human CD4 (green VH/VL of Hu5A8). (C) The released BiIA-DG, BiIA-SG, and parental IAs were determined in culture supernatants by Western blot analysis under nonreducing conditions (NR, whole left panel) or reducing conditions (R). (D) ELISA binding profiles of BiIA-DG and BiIA-SG to human sCD4 and HIV-1JR-FL gp120, respectively, compared with IA-PGT128, IA-Hu5A8, and VRC01-IgG. Data represent mean ± SD with duplicates. All experiments were repeated at least twice.