AcS-PEG3-OH

AcS-PEG3-OH is a PEG-based linker designed to support PROTAC assembly by providing a hydrophilic, flexible spacer that can improve effective spatial presentation between the target-binding ligand and the E3 ligase recruiter. Its ether-rich backbone and terminal functional group enable reliable conjugation strategies commonly used in targeted protein degradation workflows. The following sections describe the linker’s structural features and practical reactivity considerations in detail.

Structure: AcS-PEG3-OH contains a polyethylene glycol segment with repeating ether units, providing conformational flexibility and enhanced water compatibility. The molecule features an ether-linked PEG chain terminating in a hydroxyl group, along with an acylsulfide (AcS) functionality that supports controlled derivatization and subsequent PROTAC-linking chemistries.

Reactivity: The terminal hydroxyl group is suitable for standard functionalization routes used to generate PROTAC-compatible intermediates, such as activation to form reactive esters or ethers for coupling to ligand-bearing nucleophiles. The acylsulfide moiety can participate in thiol-related transformations under conditions that preserve the integrity of sensitive ligands. Typical PROTAC synthesis employs inert atmosphere when needed, polar aprotic solvents, and carefully controlled temperatures to balance reactivity and stability.