DasGupta B R, Rasmussen S
Toxicon. 1983;21(4):535-45. doi: 10.1016/0041-0101(83)90131-9.
The procedure we have adopted to purify type E botulinum neurotoxin (mol. wt. approximately 147,000) from bacterial cultures consistently yields a pure protein (a single band in polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate). Our procedure is a modification of one of the five published procedures. Other procedures have failed to yield pure neurotoxin. To develop reliable data on the amino acid composition, three batches of the neurotoxin were analyzed, each batch isolated from a separate neurotoxin producing culture. The best estimate of the number of amino acid residues per neurotoxin molecule was: Asp240 Thr75 Ser98 Glu118 Pro45 Gly58 Ala40 Val62 CyS7 Met17 Ile123 Leu107 Tyr70 Phe62 Lys97 His15 Arg34 Trp16.
我们从细菌培养物中纯化E型肉毒杆菌神经毒素（分子量约为147,000）所采用的方法始终能得到纯蛋白（在十二烷基硫酸钠存在下的聚丙烯酰胺凝胶电泳中呈现单一条带）。我们的方法是已发表的五种方法之一的改进。其他方法未能得到纯神经毒素。为了得出关于氨基酸组成的可靠数据，对三批神经毒素进行了分析，每一批均从单独的神经毒素产生培养物中分离得到。每个神经毒素分子中氨基酸残基数量的最佳估计值为：天冬氨酸240、苏氨酸75、丝氨酸98、谷氨酸118、脯氨酸45、甘氨酸58、丙氨酸40、缬氨酸62、半胱氨酸7、甲硫氨酸17、异亮氨酸123、亮氨酸107、酪氨酸70、苯丙氨酸62、赖氨酸97、组氨酸15、精氨酸34、色氨酸16。
