Figure 60.

(a) Cysteine residue in pentapeptide Cys-X-Pro-X-Arg oxidized to formylglycine by FGE generating bioothogonal handle. (b) Microbial transglutaminase (MTGase) strategy on glutamine at position 295 and improved approach by incorporation of additional mutation N297Q. (c) Sortase-mediated conjugation exploiting glycine-functionalised payloads. (d) Tyrosine oxidation by mushroom tyrosinase generating biorthogonal handle for strain-promoted cycloaddition. For clarity, the reaction (a) and (c) is only depicted in one heavy chain.