霞水母刺丝囊毒素溶血活性的稳定性研究

The study on the stability of the hemolytic activity of the nematocyst venom from jellyfish Cyanea sp.

从霞水母Cyanea sp.中分离刺丝囊,提取刺丝囊毒素(NV),并研究了温度、pH和几种化学组分对其溶血活性稳定性的影响。实验结果表明,在4～37℃范围内NV的溶血活性与温度变化密切相关,毒素在4℃以下几乎没有发生溶血反应,在37℃以下反应45 min以后,溶血活性达到最大值;毒素的溶血活性对pH敏感,在pH 7.8时,溶血活性最强,溶血率为93.53%。EDTA、NaCl和还原型谷胱甘肽(GSH)对NV溶血活性都具有稳定作用。通过正交实验发现,GSH对溶血活性的影响最大,当提取液中含有1.0 mmol/L GSH和5.0 mmol/L NaCl时毒素的溶血活性最强。DTT(二硫苏糖醇)明显降低毒素的溶血活性,说明毒素中溶血蛋白的活性很可能与分布在蛋白质表面的二硫键有关。Ca2+虽然能够增强毒素的溶血活性但是对毒素并没有稳定作用,所以Ca2+可能只是毒素溶血活性的活化剂。甘油对毒素的稳定作用不明显。

In the present article, the nematocyst venom was extracted from the jellyfish Cyanea sp. and the effects of several physical and chemical factors on the stability of the NV hemolytic activity were analyzed. The results indicated that the hemolytic activity of NV was dependent on temperature： at 4℃, no hemolysis occurred; after about 45 min at 37℃, the hemolytic ratio reached the highest, pH value had an influence on the hemolytic activity and the strongest hemolytic activity was found at pH 7.8 and the hemolytic ratio was about 93.53%. The presence of EDTA, NaC1 and GSH was benefit for the stability of the hemolytic activity. According to the results of orthogonal test, GSH had the strongest effect on the hemolytic activity. 1.0 mmol/L GSH and 5.0 mmol/L NaC1 stabilized the hemolytic activity optimally. DTT significantly reduced the hemolytic activity, indicating that the hemolysis related with the disulfide bond（s）. Ca^2＋might only be the activator for the hemolysis of NV since though Ca^2＋ could increase the hemolytic power of NV, it could not protect the hemolytic activity in the long-term storage. Glycerin did not exhibit a significant effect on the stability of NV.