Figure 2

Sequences of isolated toxin binding sdAb. Fifteen potential binders for each tested target were sequenced. The resulting unique sequences were decoded into amino acid sequences, which were aligned using ClustalW and compared. Two BoNT/A complex toxoid binders had common R32, T33 in CDR1 (residue 28–35); E47, R48, I49, S50, I51 in HV2 (residue 44–53); K61 in HV4 (residues 61–65); and R92 in CDR3 (residues 86–101) (A). Two SEB binders shared identical CDR1, similar HVs except residues 4 and 61, and two conserved residues, R92 and R93 in CDR3 (residues 86–98) (B). The ricin binder had C33 in CDR1 and 16 residues in CDR3 (C). The homologous residues between binders were labeled with "*" and similar substitution with ":"and '.'. The CDRs and hyper variable regions are indicated within the box area. The invariant W31 within CDR1 in type 3 NAR V is in bold and underlined.