Mal-(CH2)5-COOH contains a maleimide group and a terminal carboxylic acid. The terminal carboxylic acid readily reacts with primary and secondary amine under EDC, DCC, HATU or other amide coupling conditions to form a stable amide bond. The maleimide group reacts specifically with a thiol group to form a covalent C-S bond, enabling the bioconjugation with a thiol bearing molecules.
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