m-PEG24-NH2

m-PEG24-NH2 is a polyethylene glycol (PEG) linker designed to provide a hydrophilic, flexible spacer for PROTAC architectures. Its ether-rich backbone and terminal amine facilitate conjugation to targeting ligands or other PROTAC components while helping to tune solubility and reduce non-specific interactions. The linker’s compatibility with common bioconjugation chemistries makes it useful for constructing degrader molecules, and the details below describe its structural features and practical assembly considerations.

Structure: m-PEG24-NH2 contains a repeating PEG ether chain that imparts strong hydrogen-bonding capacity and conformational flexibility. The molecule terminates in a primary amine, enabling formation of stable amide or carbamate linkages. The predominant C–O ether bonds confer chemical stability under typical coupling conditions.

Reactivity: The terminal amine supports standard PROTAC linker coupling strategies, including amide bond formation with activated carboxylic acids and carbamate formation with activated carbonyl derivatives. Typical approaches employ coupling reagents such as carbodiimides or activated esters, often in polar aprotic solvents with controlled pH to maintain amine nucleophilicity. Reaction progress is commonly monitored by chromatographic methods, and purification is performed to remove coupling byproducts.