Homology between the C2 domain of FVIII and VH region of mAb14C12. (A) The sequence homology between the variable parts of mAb14C12 and the C2 domain of FVIII, including one PL binding site (Leu2251-Leu2252), is primarily carried by the VH region. (A) Views of a model structure of the FVIII C2 domain on which amino acids Leu2251 and Leu2252, highlighted in black, can be aligned with identical residues Leu102 and Leu103 of the VH mAb14C12. (B) Sequence alignment resulting from combination of data obtained by secondary structure alignment, global sequences alignment, and 3-D structural comparison are shown. Homologue residues between C2 domain and mAb14C12 are highlighted in black; similar residues are highlighted in gray. For mAb14C12, CDR position is indicated above the sequence.