ε-N-马来酰亚胺基己酸-（2-硝基-4-磺酸）-苯酯钠盐

ε-N-马来酰亚胺基己酸-（2-硝基-4-磺酸）-苯基酯钠盐（mal-sac-HNSA）是常用的自由水溶性异双功能交联剂，用于偶联含巯基（半胱氨酸）的肽携带蛋白质。mal-sac-HNSA与氨基的反应可通过分光光度法进行监控，因为会伴随释放出1-羟基-2-硝基-4-苯磺酸的二价阴离子。

epsilon-N-Maleimidocaproic acid-(2-nitro-4-sulfo)-phenyl ester sodium salt (mal-sac-HNSA) is an often used freely water-soluble, heterobifunctional crosslinking reagent for conjugation of sulfhydryl (cysteine)-containing peptides to carrier proteins. The reaction of mal-sac-HNSA with amino groups can be monitored spectrophotometrically due to the concomitant release of the dianion of 1-hydroxy-2-nitro-4-benzenesulfonic acid.