Genetic Incorporation of Non-canonical Amino Acids in Anti-HER2 VHH: Expression and Characterization

Nanobodies– or VHH– are small proteins (~120 residues) issued from antibodies with an intact recognition for the original target of the antibody. In the present study, we show the possibility of incorporating non-canonical amino acids at precise location of the sequence via classical genetic techniques (Genetic Code Expansion). We demonstrate that the amount of recombinant protein obtained is compatible with large production format. We show that this protein can be purified, that its sequence corresponds to the theoretical molecular weight and that the two non-canonical amino acids are incorporated at the desired locations of the sequence. Finally, we show by SPR that the affinity of these VHHs is maintained towards its target, HER2.