Bis-Biotin-PEG23

Bis-Biotin-PEG23 is a biotin-functionalized, polyethylene glycol-based PROTAC linker designed to connect targeting ligands to enable efficient recruitment of biotin-binding components in targeted protein degradation workflows. Its flexible PEG scaffold supports favorable solvation and conformational adaptability, while the bis-biotin architecture can enhance multivalent engagement. This product is well suited for constructing modular, tunable PROTACs; the following points describe its structure and practical reactivity considerations in detail below.

Structure: The linker comprises a long, hydrophilic PEG chain bearing two biotin moieties, providing flexible ether-rich connectivity and multiple hydrogen-bonding sites. It contains amide and ureido-like functionalities characteristic of biotin, along with ether linkages that confer water solubility and reduced nonspecific interactions.

Reactivity: PROTAC assembly using PEG-biotin linkers typically relies on orthogonal, bioconjugation-compatible coupling strategies such as activated ester or amide-forming chemistries, or thiol–maleimide style conjugations when complementary handles are present on the partner ligands. Reactions are commonly performed under mild, aqueous or mixed-solvent conditions with buffering to maintain ligand integrity, followed by purification to remove unreacted components and verify conjugation by analytical methods.