穴居狼蛛毒中抗菌活性物质的耐热及缔合性质

穴居狼蛛(Lycosa singoriensis)毒中的抗菌活性物质具有耐热性(在沸水浴中处理半小时活性不变)、耐酸性和耐碱性。但用透析袋(Visking 18/32)对毒腺提取物透析时,在中性及碱性条件下可全部被透析掉。当用Sephadex G-25柱对较少量样品进行层析时,在酸性条件下至少可被分出8个蛋白峰,其中峰4和峰8具抗菌活性,但随上柱样品量的增加,在层析图上峰4的面积增大,峰8的面积变小,甚至活性消失;反之,在中性或弱碱性条件下所得到的层析图上,则是峰8的面积大,抗菌活性明显,而峰4的面积小,甚至检不出抗菌活性。此峰8样品经热处理后,在酸性条件下经分子筛过滤,又可得到两个分子量不同的抗菌活性峰。这些结果提示,上述耐热和耐酸碱性强的抗菌物质在酸性环境中可能是以目身高聚体或与其它大分子蛋白非共价结合,随pH值的升高而解离成单体或低聚体。

HEAT RESISTANT AND POLYMERIC PROPERTIES OF THE: ANTIBAC-TERIAL SUBSTANCE IN VENOM OF THE SPIDER (LYCOSA SINGORIENS1S)

The lyophilized venom glands of the spider Lycosa singorlensis were homogenized and extracted. The supernatant was lyophilized and used as the venom gland extract. The experimental results were summarized as follows:1. The antibacterial activity of the venom gland extract was not affected by treatmen in boiling water for 30 min and in aqueous sclutions of pH 2 to 11.2. The venom fland extract lost its antibacterial activity completely after dialysis against neutral or basic solutions for 30 hrs, hut the antibacterial activity remained nearly unchanged after dialysis against acid solution,3. The venom gland extract was separated into at least 8 fractions by gel filtration on Senhadex G-25 using acetic acid solution as the eluant. It was identified that peak 4 and 8 conteincd the antibacterial activity. When the amount of loaded sample increased, the peak 4 area was relatively enlarged and peak 8 was reduced or disappeared on the chromato-gram. The peak 8 area was relatively enlarged and peak 4 was greatly reduced, even losing its antibacterial activity, when distilled water (pH value was neutral) was employed as the eluant. When the heat treated peak 8 was loaded on a Sephadex G-25 column and eluted with acetic acid solution (pH 4.5) once again, two antibacterial peaks with different molecular weights reappeared on the elution pattern.The above results suggest that antibacterial substance in the venom of spider Lycosa sing-oriensis has heat and pH resistant and polymeric properties.