Iodo-PEG12-acid

Iodo-PEG12-acid is a PEG-based PROTAC linker designed to connect targeting ligands through a reactive iodo handle while providing a hydrophilic, flexible spacer to promote productive ternary complex formation. Its carboxylic acid functionality enables reliable conjugation strategies, and the ether-rich PEG segment supports solubility and conformational adaptability in aqueous conditions. The details below describe the linker’s structural features and practical reactivity for constructing targeted protein degradation molecules.

Structure: The linker comprises an ether-rich polyethylene glycol chain terminated by a carboxylic acid and bearing an iodinated functional group for electrophilic reactivity. It contains multiple ether C–O bonds that confer flexibility, polarity, and water compatibility, alongside a carbonyl-containing acid for stable amide or ester formation.

Reactivity: The iodinated site is suitable for nucleophilic substitution or coupling approaches commonly used to install PROTAC “warheads” or ligand handles, typically under conditions that preserve the PEG chain and avoid hydrolysis. The carboxylic acid can be activated for amide bond formation using standard coupling chemistries (e.g., carbodiimide-based activation) in polar aprotic or buffered aqueous-organic solvents, enabling stepwise, modular linker–ligand assembly.