Fig. 3.
Characteristics of nanobodies and nanobody-like structures. A: Schematic description of camelid heavy-chain only antibody (HCAbs) demonstrating the nanobody (VHH) section and its cartoon. The HCAbs lacks the CH1 domain. B: Schematic description of IgG antibody showing heavy-chain (VH) section and its cartoon. C: Schematic comparison of VHH and VH, showing the complementary determining regions (CDR1–3), framework regions (FR1–4) and the hydrophilic residues (F42, E49, R50, and G52) and its hydrophobic (V42, G49, L50, and W52) counterparts in VHH and VH, respectively. The disulfide bond linkage in VHH is also shown. D: Schematic arrangement of the CDR loops within the nine β-stranded (β1–9) core architecture of VHH. Variable light (VL), constant chains (CH1-CH3), antigen-binding fragment (Fab); and single-chain variable fragment (scFv).