N-Succinimidyl 6-maleimidohexanoate丨CAS 55750-63-5

N-Succinimidyl 6-maleimidohexanoate (SMCC) is widely used as a heterobifunctional crosslinking reagent in bioconjugation and chemical biology. It is employed to link proteins, peptides, antibodies, and other biomolecules through its amine-reactive N-hydroxysuccinimide (NHS) ester and thiol-reactive maleimide group. SMCC enables the preparation of antibody–drug conjugates (ADCs), enzyme–polymer conjugates, fluorescent probes, and targeted therapeutics, providing a controlled and stable covalent linkage. In research and development, it is utilized for immobilizing biomolecules on surfaces, creating functionalized biomaterials, and studying protein interactions. Its precise and selective reactivity makes it an essential tool in medicinal chemistry, diagnostics, and advanced bioengineering applications.

The compound offers several benefits due to its heterobifunctional nature and high selectivity. The NHS ester reacts efficiently with primary amines under mild conditions, while the maleimide group selectively reacts with thiols, enabling site-specific conjugation and reducing non-specific modifications. This dual functionality allows for predictable and reproducible linkage formation, critical in the synthesis of therapeutics such as ADCs and protein–polymer conjugates. SMCC is chemically stable, soluble in common organic solvents, and compatible with aqueous and mixed media, making it versatile for laboratory and industrial use. Additionally, it preserves the biological activity of sensitive biomolecules, ensuring that the conjugated products maintain functionality, binding affinity, or enzymatic activity.