(S,R,S)-AHPC-PEG4-Alkyne

Background Introduction

(S,R,S)-AHPC-PEG4-Alkyne is a specialized E3 ligase ligand-linker conjugate engineered for use in the development of PROTACs (Proteolysis Targeting Chimeras) and related targeted protein degradation technologies. The molecule features the high-affinity von Hippel-Lindau (VHL) ligand (AHPC) in its stereochemically defined (S,R,S) configuration, a flexible tetraethylene glycol (PEG4) linker, and an alkyne functional group for versatile conjugation with targeting warheads. Such heterobifunctional molecules are essential to enable next-generation therapeutics and research tools for selective protein knockdown.

Mechanism

(S,R,S)-AHPC-PEG4-Alkyne operates by leveraging the ubiquitin-proteasome system through PROTAC technology. The AHPC moiety specifically recruits the VHL E3 ubiquitin ligase complex, while the PEG4 linker provides spatial flexibility. The terminal alkyne group enables bioorthogonal conjugation, commonly via click chemistry, to a ligand or warhead targeting a protein of interest. When incorporated into a PROTAC molecule, this conjugate brings the E3 ligase into close proximity with the target protein, resulting in its ubiquitination and subsequent degradation by the proteasome. This mechanism allows for the targeted elimination of disease-relevant or previously 'undruggable' proteins.

Applications

(S,R,S)-AHPC-PEG4-Alkyne is widely used in medicinal chemistry and chemical biology for the design and synthesis of PROTACs targeting a variety of proteins, such as kinases, transcription factors, and epigenetic regulators. Its versatile alkyne group supports modular assembly via click chemistry, facilitating the rapid development of custom degraders. Applications include validation of new drug targets, creation of tool compounds for functional genomics, cancer research, neurodegenerative disease studies, and the broader development of targeted protein degradation therapeutics. The compound's structure also enables labeling or imaging studies when conjugated with appropriate probes.

• Alkyne-functionalized PEG4 linker enables efficient and versatile click chemistry conjugation for building diverse PROTACs.
• High specificity and affinity for the VHL E3 ligase, ensuring robust target protein ubiquitination in PROTAC applications.

The (S,R,S)-AHPC-PEG4-Alkyne is a versatile E3 Ligase Ligand-Linker Conjugate used in the design of PROTACs for targeted protein degradation. This compound enhances the precision of protein degradation by connecting a specific E3 ligase to a target protein, which is detailed in the following descriptions of the linker, ligand, and reactive site.

Linker: The compound features a PEG4 linker, known for its optimal length and flexibility, which facilitates efficient spatial orientation between the ligand and the target protein. Its non-cleavable nature ensures stability, making it suitable for sustained interactions in cellular environments.

Ligand: The ligand component, AHPC, is an E3 ligase recruiter with a tricyclic structure that ensures high affinity and specificity towards the Cereblon E3 ligase. This structural characteristic aids in the efficient recruitment of the ligase to the target protein.

Reactive Site: The alkyne functional group serves as the reactive site, enabling coupling with azide-functionalized target protein ligands through click chemistry. This reaction type is favored for its high efficiency and bioorthogonal nature, ensuring minimal interference with biological systems.

Recommended Target Protein Ligand: A suitable warhead for this conjugate is an azide-functionalized ligand, which can form a stable triazole linkage with the alkyne. This compatibility allows for a robust conjugation process, ideal for applications in studying protein-protein interactions and validating target proteins in drug discovery research.