Proteinaceous toxin selected from causative dinoflagellates of paralytic shellfish poisoning and its effect on crustacean

塔玛亚历山大藻无细胞培养基对甲壳类动物的毒性通过卤虫盐藻的生物测定得到证实。在链球菌和细枝杆菌中也观察到了类似的作用。另一方面，在适宜的生长条件下，链藻等有毒甲藻的PSP毒性显著降低，表明它们在形成赤潮时产毒能力很低。在间歇培养过程中，无细胞培养基对虾的毒性与PSP的毒性不存在平行关系。这些结果表明，无鳗鱼培养基对虾的毒性可能是由PSP毒素以外的其他化合物引起的。当无细胞培养液用超滤(MW 10kda)分级时，卤水虾在高分子量组分和低分子量组分中都有毒性。在较低分子量组分中，识别出几种不同极性的组分表现出对卤虾的毒性。经GC或HPL C分析，部分化合物为多不饱和脂肪酸和糖脂。这些物质表现出溶血活性，表明甲壳动物是在这些物质的细胞毒性作用下死亡的。通过凝胶过滤和离子交换层析进一步分离高相对分子质量组分，分离出毒性成分。在该组分中发现了三种有毒成分。这些成分在280 nm处有最大吸收峰，经酶处理后失去活性，表明它们是由蛋白质组成的。这些有毒蛋白的相对分子质量分别为10、25和100 kda。在这些毒素中，分子量最高和最低的组分具有溶血活性，并使硅藻细胞崩溃。另一方面，相对分子质量为25KDA的蛋白质对卤水对虾无细胞毒性，但具有急性毒性，提示该组分具有神经毒性。

Toxicity of cell free media of Alexandrium tamarense to crustacean was confirmed by a bioassay using brine shrimp, Artemia salina. Similar effects were also observed in A. catenella and A. minutum. On the other hand, PSP toxicity of toxic dinoflagellate such as A. catenella decreased significantly under an optimum growth conditions, indicating that toxin productivity would be very low when they form red tide. During the course of a batch culture, toxicity to brine shrimp of cell free media did not showed a parallel relationship to the PSP toxicity. These results indicated that toxicity of eel free media to brine shrimp is possibly caused by some other compound than PSP toxins. Brine shrimp toxicity was found in both higher and lower molecular weight fractions when the cell free medium was fractionated with ultra-filtration (MW 10kda). Several components with different polarities were recognized to show the brine shrimp toxicity in the lower molecular weight fraction. Some of them were identified as polvunsaturated fatty acids and glycolipids by GC or HPLC analyses. These substances showed a hemolytic activity, suggesting that crustacean died with a cytotoxicity of these substances. High molecular weight fraction was further fractionated by gel filtration and ion exchange chromatography to isolate toxic principleas. Three toxic components were found in the this fraction. These components showed absorption maxima at 280 nm and lost their activities by protease treatment, indicating that these are composed of protein. Molecular weight of these toxic proteins was estimated to be 10, 25, and 100 Kda, respectively. Among these toxins, components with the highest and lowest molecular weight showed hemolytic activity and collapsed diatom cells. On the other hand, protein with molecular weight of 25 Kda did not show any cytotoxicity but an acute toxicity to brine shrimp, suggesting that this component possess neurotoxicity.