NH-bis-PEG2

This NH-bis-PEG2 linker is designed to support PROTAC assembly by providing a flexible, hydrophilic polyethylene glycol-based spacer that can improve solubility and help tune the spatial relationship between the recruited target-binding and E3 ligase-binding modules. Its ether-rich backbone and terminal functional handle facilitate reliable conjugation strategies commonly used in targeted protein degradation workflows. Detailed structural and reactivity considerations are provided below.

Structure: NH-bis-PEG2 is a bis-PEG linker featuring polyethylene glycol segments and an amide-linked “NH” functionality. The molecule contains ether linkages along the PEG chain, providing conformational flexibility, hydrogen-bonding capacity, and enhanced aqueous compatibility. Such linkers typically present multiple heteroatoms that influence polarity and solvation.

Reactivity: The NH functional group enables coupling reactions used to connect PROTAC warheads or ligands to PEG-based spacers, often via amide-forming or related nucleophilic substitution pathways depending on the complementary partner functionality. Suitable conditions generally involve activating carboxylic acids or acyl equivalents with standard peptide-coupling chemistries, using polar aprotic solvents and controlled temperature to minimize side reactions. Reaction progress is commonly monitored by chromatographic methods to confirm complete linker incorporation.