Phthalimide-PEG3-C2-OTs (Compound 5) is a PROTAC linker, which refers to the PEGs composition. Phthalimide-PEG3-C2-OTs can be used in the synthesis of a series of PROTACs. 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].
[1]. Stegmaier P, et al. Photoactive branched and linear surface architectures for functional and patterned immobilization of proteins and cells onto surfaces: a comparative study. Chemphyschem. 2009 Feb 2;10(2):357-69.
