Azide-PEG3-Tos is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs[1]. Azide-PEG3-Tos is also a non-cleavable 3 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[2].
PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein. PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins[1].ADCs are comprised of an antibody to which is attached an ADC cytotoxin through an ADC linker[2].
[1]. Borchmann DE, et al. GRGDS-Functionalized Poly(lactide)-graft-poly(ethylene glycol) Copolymers: Combining Thiol-Ene Chemistry with Staudinger Ligation. Macromolecules. 2013 Jun 11;46(11):4426-4431.
[2]. Park, Tae Kyo, et al. Compound bearing beta-galactoside-introduced self-immolative linker. WO2018124758A2.