m-PEG8-ethoxycarbonyl-propanoic acid

This m-PEG8-ethoxycarbonyl-propanoic acid linker is designed for constructing PROTACs that require a hydrophilic, flexible spacer between recognition and recruiting modules. Its PEG-based architecture supports improved solubility and conformational adaptability, which can help modulate effective ternary complex formation. The molecule is well suited for research workflows where robust amide coupling and subsequent conjugation steps are needed; the

Structure: The linker contains an m-PEG ether chain providing a flexible, hydrophilic scaffold, and a terminal ethoxycarbonyl-propanoic acid motif. It features ether linkages within the PEG segment and a carboxylic acid functional group suitable for derivatization. Overall, it behaves as a polar, water-compatible spacer.

Reactivity: The carboxylic acid enables standard peptide-coupling chemistries to form amide bonds with amine-bearing PROTAC partners. Typical approaches use carbodiimide-based coupling systems with an activating additive and an appropriate base in polar aprotic solvents, followed by purification. Mechanistically, activation of the acid forms an intermediate that is attacked by the nucleophilic amine to yield the stable linker–conjugate linkage.