Sulfo-NHS-LC-Biotin

Sulfo-NHS-LC-biotin [磺基琥珀酰亚胺-6-（生物素）己酸]是一种胺反应性的生物素化试剂。作为NHS-LC-biotin的水溶性类似物，Sulfo-NHS-LC-biotin包含一个存在于NHS环上的带负电荷的磺酸基，使其分子内产生足够的极性，允许其可以直接加入到反应性水溶液中，而不需要提前溶解在有机溶剂中。Sulfo-NHS-LC-biotin通过其NHS酯与蛋白或其它分子中的胺基共价结合形成酰胺键，并释放N-Hydroxysuccinimide。与NHS-biotin (13.5 A)相比，Sulfo-NHS-LC-biotin的共价修饰分子与双生物素环之间的长度更长(22.4 A)，使探针更容易到达深埋在蛋白质内部的结合位点。

参考文献：
Bioconjugate Techniques , 2nd ed.  By Greg T.Hermanson  (Pierce Biotechnology, Thermo Fisher Scientific, Rockford, IL).  Academic Press  (an imprint of Elsevier):  London, Amsterdam, Burlington, San Diego . 2008. ISBN 978-0-12-370501-3.

• Protein labeling—biotinylate antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes
• Cell surface labeling—do not penetrate the plasma membrane, biotinylates only surface proteins of whole cells
• Amine-reactive—reacts with primary amines (-NH2), such as lysine side-chains, or the N-terminal-amine
• Soluble—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds
• Irreversible—forms permanent amide bonds; spacer arm cannot be cleaved
• Medium length—spacer arm is 22.4 angstroms; provides excellent balance between adequate length (minimal steric hindrance for biotin binding) and modest mass