MTS-17-PEG5-MTS

MTS-17-PEG5-MTS is a PEG-based, bifunctional linker engineered for modular PROTAC assembly, enabling efficient connection between an E3 ligase-binding ligand and a target-binding moiety. Its ether-rich polyethylene glycol segment provides conformational flexibility and improved solubility, which can support productive ternary complex formation. The thiol-reactive termini facilitate chemoselective conjugation under standard linker-attachment workflows. Detailed structural and reactivity considerations are provided below.

Structure: The linker comprises a polyethylene glycol chain flanked by two methylene-thiol reactive groups, connected through stable ether linkages. It contains flexible C–O–C segments that promote solvent compatibility and dynamic conformations. The presence of sulfur-containing functional handles supports formation of covalent adducts with compatible nucleophiles.

Reactivity: Suitable PROTAC construction typically uses thiol-reactive coupling strategies where the linker is first activated or directly reacted with a complementary nucleophilic partner on one ligand, followed by coupling to the second component. Reactions are commonly performed in polar organic or mixed solvent systems under inert or controlled atmospheres to minimize thiol oxidation and side reactions. Base selection and temperature are chosen to preserve ligand integrity and maximize chemoselectivity, often without requiring metal catalysts.