mPEG8-thiol

mPEG8-thiol is a polyethylene glycol-based thiol-functional linker designed to support PROTAC assembly and related targeted-degradation workflows. Its PEG segment improves solubility and biocompatible handling, while the terminal thiol provides a versatile reactive handle for conjugation strategies that connect ligands or scaffold components. These features make it useful for constructing PROTAC derivatives and for tailoring physicochemical properties during linker optimization, as detailed in the following sections.

Structure: mPEG8-thiol consists of a methoxy-terminated poly(ethylene glycol) chain bearing a terminal thiol group. The molecule is characterized by ether linkages along the PEG backbone and a reactive sulfur–hydrogen functionality at the terminus. Its amphiphilic, flexible polymeric architecture supports aqueous compatibility and stable conjugation chemistry.

Reactivity: The terminal thiol can participate in thiol–maleimide coupling, disulfide exchange, or other thiol-directed conjugation approaches commonly used to connect PROTAC components. Practical use typically involves maintaining thiol integrity by minimizing oxidation, selecting appropriate pH and reducing conditions when disulfide formation or exchange is desired, and using compatible solvents such as aqueous buffers or polar organic media. Reaction design should account for thiol reactivity control and purification of conjugates to remove unreacted linker.