Modelling of scFvs, hD1D2, and hD1D2-59E. (A) The antigen-binding site of scFv 10B12. (B) The antigen-binding site of scFv 1C3; VH, variable domain of the heavy chain, VL domain, variable domain of the light chain. (C) The apical surface of hD1D2. (D) The apical surface of hD1D2-59E. (E) The antigen binding loops H1-3 and L1-3 (according to Chothia et al⁴⁵ ) of scFv 10B12. Residues pertinent to the discussion are labeled. Numbering of residues in scFv 10B12 are according to Kabat et al.⁴⁶  Images were produced using the GRASP program³⁹  and are colored for surface charge (red = negative, blue = positive) as described in the text.