Shinagawa K, Ichikawa K, Matsusaka N, Sugii S
Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Japan.
J Vet Med Sci. 1991 Jun;53(3):469-74. doi: 10.1292/jvms.53.469.
A mouse lethal toxin (MLT) produced by Bacillus cereus isolated in vomiting-type food poisoning was purified by chromatography on DEAE-Sephadex A-25 followed by gel filtration on Sephadex G-75. Purified MLT possessed a molecular weight of 33,000-34,000. It showed mouse lethality and hemolytic (HL) activity on sheep and rabbit erythrocytes; the latter erythrocytes were more weakly hemolyzed than the former ones. However, fluid accumulation in mouse ligated intestinal loops was not induced by purified MLT at the highest concentration used. Both MLT and HL activities were stable at pH 6-9, during storage at -20 degrees C for 8 weeks, and resistant to papain, cholesterol, lecithin, and dithiothreitol treatments. Most activity was lost during storage at 4 degrees C or 25 degrees C for 2 weeks or upon treatment with trypsin, trypanblue, or ethanol. The activities were resistant to heating at 37 degrees C for 5 min, less resistant at 98 degrees C for 5 min, and sensitive at 60 degrees C for 5 min. It can be concluded from the results that MLT is different from the diarrheagenic toxin produced by B. cereus isolated in diarrheal-type food poisoning, but is similar to, if not identical, hemolysin II.
通过在DEAE - Sephadex A - 25上进行色谱分离，随后在Sephadex G - 75上进行凝胶过滤，对从呕吐型食物中毒中分离出的蜡样芽孢杆菌产生的小鼠致死毒素（MLT）进行了纯化。纯化后的MLT分子量为33,000 - 34,000。它对绵羊和兔红细胞表现出小鼠致死性和溶血（HL）活性；兔红细胞的溶血程度比绵羊红细胞弱。然而，在所使用的最高浓度下，纯化的MLT并未诱导小鼠结扎肠袢出现液体蓄积。MLT和HL活性在pH 6 - 9时稳定，在-20℃储存8周期间稳定，并且对木瓜蛋白酶、胆固醇、卵磷脂和二硫苏糖醇处理具有抗性。在4℃或25℃储存2周或用胰蛋白酶、台盼蓝或乙醇处理后，大部分活性丧失。这些活性对37℃加热5分钟具有抗性，对98℃加热5分钟抗性较弱，对60℃加热5分钟敏感。从结果可以得出结论，MLT与从腹泻型食物中毒中分离出的蜡样芽孢杆菌产生的致腹泻毒素不同，但与溶血素II相似（即便不完全相同）。
