mPEG7-thiol

mPEG7-thiol is a polyethylene glycol-based thioether/thiol-functional linker designed to support PROTAC assembly and related conjugation strategies by providing a hydrophilic, flexible spacer and a reactive sulfur handle. Its PEG segment can improve solubility and reduce non-specific interactions, while the thiol functionality enables site-selective coupling to electrophilic partners. The product is therefore useful for constructing PROTACs and for preparing linker intermediates that require controlled attachment chemistry; the detailed structural and reactivity features are described below.

Structure: mPEG7-thiol comprises a methoxy-terminated polyethylene glycol chain bearing a terminal thiol group. The structure features an ether-rich PEG backbone with flexible C–O and C–C connectivity, plus a sulfur–hydrogen functional group enabling thiol-mediated conjugation. The PEG segment imparts high polarity and water compatibility.

Reactivity: The terminal thiol can participate in nucleophilic substitution and thiol–electrophile coupling reactions to form stable thioether linkages, commonly via maleimide, haloacetamide, or other activated electrophiles used in bioconjugation workflows. For reliable performance, thiols are typically handled under inert or low-oxidation conditions and in solvents compatible with both thiol stability and the electrophile reactivity. Mild bases or pH-controlled buffers are often used to modulate thiolate formation while minimizing thiol oxidation; reaction progress is generally monitored by chromatographic or spectroscopic methods.