| 对有机磷农药敏感的海鱼脑AChE筛选研究 |
| 摘要点击 1494 全文点击 1318 投稿时间：2005-03-05 修订日期：2005-06-04 |
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| 中文关键词 海洋鱼类 乙酰胆碱酯酶 有机磷农药 敏感性 |
| 英文关键词 marine fishes acetylcholinesterase(AChE) organophosphorus pesticides sensitivity |
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| 中文摘要 |
| 以10种海洋鱼类:鲅鱼、黄花鱼、鲈鱼、黄鱼、美国红鱼、真鲷、黑鲷、面包鱼、黑头鱼和鳗鲡为实验材料,采用半抑制浓度(IC50)和双分子速率常数(Ki)为指标,通过体外抑制作用比较了这10种海鱼脑AChE对马拉硫磷和甲基对硫磷的敏感性,并分析了海鱼脑AChE作为监测海水中有机磷农药指示酶的可行性,由此筛选出适于制备海水有机磷农药酶传感器的指示酶.实验表明:10种海鱼脑AChE的基础活性在4.62～35.65μmol/(min·g)之间,面包鱼的酶活性最高,黄花鱼的酶活性最低.对马拉硫磷,由IC50所得到的AChE敏感性为:鲅鱼、黄鱼、鲈鱼、真鲷>黑鲷>黑头鱼、鳗鲡>美国红鱼、黄花鱼>面包鱼;由Ki所得到的AChE敏感性为:鲅鱼>黄鱼、鲈鱼、真鲷>黑鲷、黑头鱼、鳗鲡>美国红鱼、黄花鱼>面包鱼.对甲基对硫磷,由IC50所得到的AChE敏感性为:鲅鱼>鲈鱼>黄鱼、黄花鱼、真鲷、黑鲷、黑头鱼、鳗鲡>美国红鱼>面包鱼;由Ki所得到的AChE敏感性为:鲅鱼>鲈鱼、黄鱼、黄花鱼、黑鲷、黑头鱼、鳗鲡>真鲷>美国红鱼>面包鱼.鲅鱼脑AChE对2种有机磷农药都较为敏感.影响鱼脑AChE对有机磷农药敏感性的主要因素为生物来源、农药种类和抑制方式,而与酶的基础活性无关.海鱼脑AChE活力抑制作用与水体中的有机磷农药具有良好的剂量-效应关系,在1～50mg/L浓度范围内,两者间呈现较好的线性相关性(r2≥0.93).根据AChE的敏感性及其对有机磷农药的线性响应程度,鲅鱼脑AChE适于作为监测马拉硫磷和甲基对硫磷酶传感器的指示酶. |
| 英文摘要 |
| Adopting the bimolecular rate constant(Ki) and 50% inhibition concentration(IC50) values as indexes,a comparative study on the sensitivity of brain acetylcholinesterase(AChE) to two organophosphorus pesticides(Ops),malathion and parathion-methyl,was conducted in 10 marine fishes such as Lateolabrax japonicus, Hexagrammosolakii,Sciaenops ocellatus,Pagrosomus major,Sparus macrocephalus,Scomberomorus niphonius(Curier),Navodon septenlrionalis(Günther),Anguilla japonica(Temminek et Schlegel),Sebastodes fuscescens(Houttuyn) and Pseudosciaena polyactis(Bleeker),through in vitro inhibition experiment.The feasibility was analyzed that marine fish brain AChE was used as indicator enzyme to monitor the Ops in seawater,and then the indicator enzyme suitable to prepare seawater Ops enzyme biosensor was selected.Brain AChE activities vary among these 10 fishes,ranging from 4.62 μmol·(min·g)-1(N.septenlrionalis) to 35.65 μmol·(min·g)-1(P.polyactis).The sensitivity of fishes brain AChE to malathion is in the order: S.niphonius,H.otakii,L.japonicus,P.major>S.macrocephalus>A.japonica,S.fuscescens>S.ocellalus,P.polyactis>N.septentrionalis, according to IC50;and in the order: S.niphonius>H.otakii, L.japonicus,P.major>S.macrocephalus,A.japonica,S.fuscescens>S.ocellatus,P.polyactis,N.septentrionalis,according to Ki.Whereas,for the sensitivity to parathion-methyl,there is another order: S.niphonius>L.japonicas>H.otakii,P.polyactis,P. major,S.macrocephalus,A.japonica,S.fuscescens>S.ocellatus>N.septenlrionalis according to IC50;and in the order: S.niphonius>L.japonicas,H.otakii,P.polyactis,S.macrocephalus,A.japonica,S.fuscescens>Pagrosomus major>S.ocellalus>N.septentrionalis according to Ki.The brain AChE from S. niphonius is more sensitive to both malathion and parathion-methyl than others.The main factors affecting the sensitivity of fish brain AChE to Ops are enzyme source,the category of Ops and the inhibition mode rather than enzyme activities.Furthermore,there is an obvious dose-effect relationship between the activity inhibition and the concentration of Ops.The correlation coefficients(r2),more than 0.93,could be found while the concentration of pesticides ranges from 1 to 50mg·L-1.Based on the sensitivity of AChE and its linear correlation to Ops, the AChE from S.niphonius is suitable to be used as the indicator enzyme of enzyme biosensor to monitor malathion and parathion-methyl. |
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