Amino-PEG12-Tris(-PEG24-acid)3

Amino-PEG12-Tris(-PEG24-acid)3 is a multifunctional, PEG-based linker engineered for PROTAC assembly, offering high aqueous solubility, conformational flexibility, and efficient spacing between binding elements. Its terminal amino functionality supports robust conjugation strategies, while the multiple PEG arms and carboxylated termini enable stable, well-defined attachment chemistries for targeted protein degradation workflows. The detailed structural and reactivity considerations are provided below.

Structure: The linker is built from repeating ethylene glycol units that form a flexible, hydrophilic PEG scaffold. It contains a primary amino group for coupling and a tris-substituted architecture bearing multiple carboxylic acid–terminated PEG arms. The structure features ether linkages within PEG and amide-forming potential at the amino terminus.

Reactivity: Suitable PROTAC construction typically relies on amine-reactive coupling at the amino terminus, followed by carboxyl-directed conjugation where needed. Common approaches include amide bond formation using activated carboxylic acids (for example, NHS/EDC-type activation) under mildly basic conditions, or orthogonal chemistries that preserve other functional groups. Solvents such as aqueous buffers with compatible organic co-solvents are commonly used to maintain PEG solubility and reaction efficiency.