鲅鱼乙酰胆碱酯酶对海水甲基对硫磷的响应条件研究

Study on the response conditions of acetylcholinesterase from Scomberomorus niphonius to methyl parathion in seawater

动物体内乙酰胆碱酯酶(AChE)的活性变化常被用于表征环境中有机磷农药(OPs)的污染状况。以鲅鱼脑组织AChE粗酶液为试验材料,以甲基对硫磷为OPs代表,从不同条件海水中鲅鱼AChE的活性变化入手,优化甲基对硫磷对鲅鱼AChE活性的抑制条件,获得了甲基对硫磷浓度与AChE活性抑制程度之间的关系曲线。结果表明,抑制时间为30min,温度为35℃,海水pH为7.5时,鲅鱼AChE的活性较高,甲基对硫磷对其抑制程度最强;在最佳的抑制条件下,甲基对硫磷在10～500μg/L时,其质量浓度与AChE活性抑制率之间具有良好的线性关系(R=0.9944),检测下限低于1.0μg/L。

Acetylcholinesterase （ACHE） in animals has been usually used to indicate the organophosphorus pesticides（OPs）pollution levels in the environment. AChE extracted from the brain tissue of Scornberomorus niphonius was selected as an experimental material, and methyl parathion as a representative of OPs. On the basis of determining AChE activity changes in seawater at different conditions, the relative factors at which methyl parathion inhibited AChE activity in seawater were optimized, and the relationship between methyl parathion concentration and decreasing rate of AChE activity was obtained. Experimental results showed that, AChE not only had a higher activity but also was mostly sensitive to methyl parathion when the reaction time lasted for 30 min, the temperature was 35℃, and the pH was 7.5. At these optimal conditions, when methyl parathion concentration changed from 10μ/L to 500 9g/L, their was a good linear relation（R= 0. 994 4）between the methyl parathion concentration and the inhibition rate of AChE activity, with a detection limit of less than 1.0μg/L.