HS-PEG7-CH2CH2NH2

This HS-PEG7-CH2CH2NH2 linker is designed for modular PROTAC assembly, providing a flexible polyethylene glycol (PEG) spacer that can improve solubility and enable controlled positioning between the ligand and the recruiting moiety. The terminal thiol-reactive handle and primary amine functionality support robust, stepwise conjugation strategies commonly used in targeted protein degradation workflows. Detailed structural and synthetic considerations are provided below.

Structure: The linker contains a PEG-based ether backbone offering conformational flexibility, terminated by a thio-functional group and a primary amine at the distal end. It features ether linkages, carbon–nitrogen bonds, and a sulfur-containing functional group that can participate in thiol-based coupling chemistries. Overall, it is expected to be hydrophilic and PROTAC-compatible.

Reactivity: The thiol-reactive site enables conjugation via thiol-selective chemistries (for example, maleimide or activated disulfide formats) under aqueous, near-neutral conditions to preserve sensitive ligands. The terminal primary amine can be used for amide bond formation with carboxy-activated partners or for reductive amination with aldehydes/ketones. Typical approaches employ standard coupling reagents, mild bases, and polar solvents; reaction progress is monitored by chromatographic methods to ensure selective linker attachment.