Department of Chemistry, ‡University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
J Am Chem Soc. 2012 Mar 7;134(9):4057-9. doi: 10.1021/ja211931f. Epub 2012 Feb 21.
Dithiothreitol (DTT) is the standard reagent for reducing disulfide bonds between and within biological molecules. At neutral pH, however, >99% of DTT thiol groups are protonated and thus unreactive. Herein, we report on (2S)-2-amino-1,4-dimercaptobutane (dithiobutylamine or DTBA), a dithiol that can be synthesized from l-aspartic acid in a few high-yielding steps that are amenable to a large-scale process. DTBA has thiol pK(a) values that are ~1 unit lower than those of DTT and forms a disulfide with a similar E°' value. DTBA reduces disulfide bonds in both small molecules and proteins faster than does DTT. The amino group of DTBA enables its isolation by cation-exchange and facilitates its conjugation. These attributes indicate that DTBA is a superior reagent for reducing disulfide bonds in aqueous solution.
二硫苏糖醇（DTT）是还原生物分子间和分子内二硫键的标准试剂。然而，在中性 pH 下，>99%的 DTT 巯基质子化，因此无反应性。本文报道了（2S）-2-氨基-1,4-二甲巯基丁烷（二硫丁基胺或 DTBA），一种可以从 L-天冬氨酸中合成的二硫醇，经过几步高产率的反应，适用于大规模生产。DTBA 的巯基 pKa 值比 DTT 低约 1 个单位，与具有相似 E°'值的二硫键形成。DTBA 还原小分子和蛋白质中二硫键的速度比 DTT 快。DTBA 的氨基基团可通过阳离子交换进行分离，并促进其缀合。这些特性表明 DTBA 是一种在水溶液中还原二硫键的优越试剂。
