SMCC and its water-soluble analog Sulfo-SMCC are heterobifunctionalcrosslinkers that contain N-hydroxysuccinimide (NHS) ester and maleimide groups that allow covalent conjugation of amine- and sulfhydryl-containing molecules. NHS esters react with primary amines at pH 7~9 to form amide bonds, while maleimides react with sulfhydryl groups at pH 6.5~7.5 to form stable thioether bonds. In aqueous solutions, NHS ester hydrolytic degradation is a competing reaction whose rate increases with pH. The maleimide group is more stable than the NHS-ester group but will slowly hydrolyze and loses its reaction specificity for sulfhydryls at pH values > 7.5. For these reasons, conjugations with these crosslinkers are usually performed at pH 7.2~7.5, with the NHS-ester (amine-targeted) reacted before or simultaneous with the maleimide (sulfhydryltargeted) reaction.
Sulfo-SMCC is soluble in water and many other aqueous buffers to approximately 10 mM, although solubility decreases
|>98% on TLC
|Net Mass Added