MS-PEG1-THP

MS-PEG1-THP is a polyethylene glycol-based PROTAC linker designed to connect a ligand-recruiting warhead to an E3 ligase-binding moiety while providing conformational flexibility and improved aqueous compatibility. Its ether-rich PEG character can help modulate effective intramolecular distances and reduce steric constraints during ternary complex formation. The linker is intended for use in targeted protein degradation workflows, and the following sections describe its structure and practical coupling considerations in detail below.

Structure: The linker incorporates a short ether-containing segment bearing a mesylate (methanesulfonate) leaving group at one end and a THP-protected alcohol at the other. It presents a polar, flexible backbone with ether oxygen atoms that support solvation, while the mesylate serves as an SN2 leaving group and the THP ether masks an alcohol.

Reactivity: MS-PEG1-THP is typically employed in PROTAC synthesis through SN2 substitution at the mesylate with a suitable nucleophile and acid-mediated deprotection of the THP ether when a free alcohol is required. Substitution is commonly performed using an appropriate nucleophile and base under conditions compatible with the ether chain, followed by THP deprotection or further functionalization as needed. Reaction design should prioritize chemoselectivity, aqueous tolerance, and maintenance of linker integrity to preserve degradation activity.