Spira W M, Goepfert J M
Can J Microbiol. 1975 Aug;21(8):1236-46. doi: 10.1139/m75-185.
An enterotoxin synthesized during exponential growth by Bacillus cereus produces fluid accumulation in rabbit ileal loops, alters vascular permeability in the skin of rabbits, and kills mice when injected intravenously. All activities are eluted simultaneously from a Sephadex G-75 column and are distinct from the hemolysin and egg yolk turbidity factor of B. cereus. The enterotoxin is a true exotoxin. It interacts with intestinal receptor sites in a highly transient manner in the ileal loop system. Rabbit immune serum produced against the culture fluids from one strain of B. cereus neutralized the three biological activities in all other strains tested except strain B-6-ac for which none of the activities were neutralized. Enterotoxin proved to be unstable under a wide variety of conditions; ionic strength was especially critical. Enterotoxin was most stable in a pH range of 5.0 to 10.0, but lost activity rapidly outside this range. Alkylation provided some protection of enterotoxin activity in crude preparations but failed to protect activity during purification procedures. It did not appear to affect critically the enterotoxin molecule itself, since elution profiles on Sephadex G-75 chromatography were unchanged after alkylation.
蜡样芽孢杆菌在指数生长期合成的一种肠毒素可使兔回肠肠袢积液，改变兔皮肤血管通透性，静脉注射时可致小鼠死亡。所有这些活性物质在Sephadex G - 75柱上同时被洗脱，且与蜡样芽孢杆菌的溶血素和蛋黄浑浊因子不同。该肠毒素是一种真正的外毒素。在回肠肠袢系统中，它以高度短暂的方式与肠道受体位点相互作用。用一株蜡样芽孢杆菌的培养液制备的兔免疫血清可中和所有其他测试菌株的三种生物学活性，但对B - 6 - ac菌株无效，该菌株的任何活性均未被中和。肠毒素在多种条件下均不稳定；离子强度尤其关键。肠毒素在pH值5.0至10.0的范围内最稳定，但在此范围之外活性迅速丧失。烷基化在粗制品中对肠毒素活性有一定保护作用，但在纯化过程中未能保护其活性。烷基化似乎并未严重影响肠毒素分子本身，因为烷基化后Sephadex G - 75色谱的洗脱图谱未发生变化。
