mPEG7-amine

mPEG7-amine is a polyethylene glycol (PEG)-based amine linker designed to support PROTAC assembly by providing a hydrophilic, sterically flexible spacer between targeting and recruiting modules. Its ether-rich backbone can improve solubility and reduce nonspecific interactions, while the terminal primary amine enables robust conjugation chemistries. The resulting constructs can be tuned to optimize effective proximity and degradation potency; the linker’s structure and reactivity are described in detail below.

Structure: The linker consists of a linear mPEG chain terminated by a primary amine, featuring multiple ether linkages along the PEG backbone. It presents a polar, flexible, hydrogen-bonding functional group at the terminus, supporting water compatibility and stable covalent attachment to electrophilic partners.

Reactivity: The terminal primary amine readily participates in standard bioconjugation reactions used in PROTAC synthesis, including amide bond formation with activated carboxylic acids or acyl derivatives, and nucleophilic substitution toward activated esters. Typical conditions use mild organic solvents with buffering bases to maintain amine nucleophilicity while minimizing PEG chain degradation; coupling reagents commonly employed for amide formation can be used to drive efficient conjugation.