SMCC, also known as succinimidyl-4-[N-maleimidomethyl]cyclohexane-1-carboxylate, is a heterobifunctional protein crosslinker. SMCC is an amine-to-sulfhydryl crosslinker that contains NHS-ester and maleimide reactive groups at opposite ends of a medium-length cyclohexane-stabilized spacer arm (8.3 angstroms). SMCC conjugation occurs via a maleimide group that is sulfhydryl (thiol; -SH) reactive and a NHS ester group that is amine reactive and forms stable, covalent protein crosslinks.

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