Binding of the recombinant VHDJH13/VκJκ13 (A), VH13G12-DJH13/Vκ13K20-Jκ13 (B), Lys52/VκJκ13 (C), and Arg58/VκJκ13 (D) IgG1 Abs to human recombinant insulin (●), ssDNA (△), tetanus toxoid (■), human recombinant IL-1β (▲), E. coli β-galactosidase (◇), and BSA (□). The Ag-binding activity of each Ab to solid-phase Ag is expressed as optical absorbance at 492 nm.