Thalidomide-NH-C5-NH2 hydrochloride

Background Introduction

Thalidomide-NH-C5-NH2 hydrochloride is an advanced E3 ligase ligand-linker conjugate used as a key building block in the synthesis of PROTACs (Proteolysis Targeting Chimeras). This compound features a thalidomide-based cereblon (CRBN) E3 ligase ligand, linked via a flexible C5 linker terminating with a primary amine (NH2) group. This design enables efficient coupling with target-binding warheads, making it essential for researchers developing innovative targeted protein degradation therapies.

Mechanism

Thalidomide-NH-C5-NH2 hydrochloride exerts its function as part of a PROTAC molecule. The thalidomide moiety binds selectively to the cereblon (CRBN) E3 ubiquitin ligase, recruiting it to specific target proteins. Through its C5 linker with terminal amine, this ligand can be conjugated to various target ligands or warheads, forming bifunctional molecules. These chimeric compounds induce proximity between the E3 ligase and the protein of interest (POI), resulting in polyubiquitination and subsequent proteasome-mediated degradation of the target protein.

Applications

Thalidomide-NH-C5-NH2 hydrochloride is primarily applied in the synthesis of custom PROTAC molecules for targeted ubiquitination and degradation studies. Its amine-functionalized linker allows for versatile conjugation chemistry (e.g., amide bond formation) with diverse protein-targeting ligands, enabling the creation of PROTAC libraries aimed at a wide variety of disease-associated proteins. This material is widely used in drug discovery research, cellular target validation, and preclinical therapeutic development targeting cancers, neurodegenerative diseases, and other conditions driven by pathogenic proteins.

• Amine-terminated C5 linker ensures flexible and stable attachment for diverse warhead conjugation.
• Specifically designed for efficient synthesis of CRBN-recruiting PROTACs, improving targeted protein degradation.

Thalidomide-NH-C5-NH2 hydrochloride serves as an essential E3 Ligase Ligand-Linker Conjugate in PROTACs, facilitating targeted protein degradation by bridging E3 ligases to target proteins. This molecule offers a detailed description of its linker, ligand, and recommended target protein ligands, enhancing the specificity and efficiency of the degradation process.

Linker: The linker in this molecule is characterized by a five-carbon chain, providing moderate length and flexibility. It is designed to be non-cleavable, ensuring stable conjugation between the ligand and the target protein, which is crucial for effective protein degradation.

Ligand: The ligand component is derived from thalidomide, a well-characterized immunomodulatory drug. Its structural characteristics include a glutarimide ring, which is critical for binding to the cereblon E3 ligase, facilitating the recruitment of the degradation machinery.

Reactive Site: The reactive site in this molecule is the terminal amine group, which couples efficiently with target protein ligands through amide bond formation. Recommended reaction types include amidation and carbodiimide-mediated coupling, which are widely used in conjugation chemistry.

Recommended Target Protein Ligand: The compatible warhead for this molecule is typically an electrophilic moiety, such as a chloroacetamide, which can form covalent bonds with cysteine residues on the target protein. This approach offers the advantage of irreversible binding, leading to sustained protein knockdown and enabling studies on protein function and degradation pathways.