Alkyne-PEG-Val-Cit-PAB-OH

Terminal alkyne-functionalized discrete poly(ethylene glycol)-valyl-citrulline-p-aminobenzyl alcohol (Alkyne-PEG-Val-Cit-PAB-OH) is an ADC linker intermediate containing a defined-length PEG spacer. It contains a terminal alkyne reactive terminus and a valine–citrulline dipeptide. Discrete chain lengths with different degrees of polymerization are available. The terminal alkyne can undergo suitable copper-catalyzed cycloaddition with azides, linking the PEG spacer to target molecular modules. The valine–citrulline dipeptide provides a sequence variable for studies of protease-cleavable linkers. The PAB spacer links peptide cleavage to the subsequent self-immolation process. The PAB hydroxyl group retains a synthetic handle for subsequent activation and payload derivatization.

Customization available.