N-(m-PEG4)-N'-(Acid-PEG3)-benzothiazole Cy5

This PEG-based bifunctional linker is designed to support targeted protein degradation workflows by providing orthogonal attachment points for assembling PROTAC constructs. Its flexible, hydrophilic polymer segments can enhance solubility and reduce nonspecific interactions while maintaining effective spatial reach between the ligand-binding moieties. The benzothiazole-containing handle supports robust conjugation strategies commonly used in PROTAC linker design. The following points describe the structure and practical reactivity considerations in detail below.

Structure: The material is a heteroaromatic benzothiazole–containing PEG linker bearing two distinct PEG segments with terminal functional groups suitable for conjugation. It contains ether linkages characteristic of PEG, amide-type connectivity at the linker junctions, and a conjugated aromatic core that can participate in stable coupling chemistries.

Reactivity: Suitable PROTAC assembly typically relies on standard bioconjugation reactions that connect ligand warheads to the linker termini while preserving the integrity of the PEG chains. Employ coupling chemistries compatible with PEG-bound amine or acid functionalities, using commonly adopted peptide-coupling approaches for amide formation where appropriate. Select solvents that solubilize both polymer and ligands, and use mild base or activating agents consistent with amide-bond construction; purification is generally required to remove excess reagents and byproducts.