Fig. 1. (A) N-Acetyl-l-cysteine and glutathione (GSH) conjugation to 5HP2O 2, 3, 7, 15 and 16. Conversion of 2 to 28 was observed by RP-HPLC and the product was analysed by LC-MS ([M − H]− = 365.1). (B) Conjugation of different 5HP2Os (using 10 equiv.) is achieved on alphabody (34–37, 39 and 40) at a pH of 8. (C) Conjugate 34 was incubated with 100 equiv. of GSH and the reaction was monitored by RP-HPLC. No thiol-exchanged product 29 was found. (D) Protein conjugates were efficiently prepared for BSA (41 and 42) and for the antibody trastuzumab (43–47) using 100 equiv. of 5HP2O at a pH of 8.
