Nicolas A, Ferron F, Toker L, Sussman J L, Silman I
Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
Acta Crystallogr D Biol Crystallogr. 2001 Sep;57(Pt 9):1348-50. doi: 10.1107/s0907444901010411. Epub 2001 Aug 23.
Histochemical methods are employed to detect and localize a wide range of enzymes. Even though protein crystallographers do not commonly use this technique, the extensively used colorimetric reaction of Karnovsky was successfully adapted for easy and quick identification of acetylcholinesterase crystals. The method relies on the reduction of ferricyanide to ferrocyanide by thiocholine, released from acetylthiocholine by enzymatic hydrolysis, followed by formation of a cupric ferrocyanide precipitate, and allows rapid differentiation between salt and enzyme crystals and between native and inhibited crystals of the enzyme.
组织化学方法用于检测和定位多种酶。尽管蛋白质晶体学家通常不使用这种技术，但广泛使用的卡诺夫斯基比色反应已成功应用于乙酰胆碱酯酶晶体的简易快速鉴定。该方法依赖于硫代胆碱将铁氰化物还原为亚铁氰化物，硫代胆碱由乙酰硫代胆碱经酶水解释放，随后形成亚铁氰化铜沉淀，并且能够快速区分盐晶体和酶晶体，以及该酶的天然晶体和抑制晶体。
