Our design approach involved covalently linking a RIPK2 PROTAC to each Ab scaffold via a disulfide rebridging reagent (dibromopyridazinedione, diBrPD). This approach enabled attachment of the PROTAC linkage to a precise site on the Ab scaffold i.e., at the interchain cysteines. The diBrPD warhead was coupled to the PROTAC via a protease cleavable valine-citrulline-para-aminobenzylalcohol (VC-PAB) linker. A second antibody, anti-IL4 pascolizumab, was also selected as a negative control. A terminal alkyne was incorporated onto the second nitrogen of the diBrPD to act as a flexible handle for potential downstream functionalisation.