金属离子对菜青虫酚氧化酶活力的影响  

Effects of Some Metal Ions on the Activity of Phenoloxidase from Pieris rapae L.

作　　者：薛超彬[1] 王勤[2] 贺量[2] 柯莉娜[2] 罗万春[1] 陈清西[2] 

机构地区：[1]山东农业大学植保学院,山东泰安271018 [2]厦门大学生命科学学院细胞生物学与肿瘤细胞工程教育部重点实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2005年第B06期120-122,共3页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(30270887);福建省科技攻关课题(2004N002)资助

摘　　要：以菜青虫五龄幼虫为材料,冰浴匀浆,在4℃下8000r/min离心,取上清液,经35%饱和(NH4)2SO4沉淀,经SephadexG100凝胶柱层析等步骤分离,获得部分纯化的菜青虫酚氧化酶制剂.研究多种金属离子对该酶活性的影响,结果表明:碱金属离子K+、Li+和Na+对酶活力没有影响.碱土金属离子Mg2+、Ba2+和Ca2+对酶有激活作用,激活作用的大小顺序为Mg2+>Ca2+>Ba2+.过渡金属离子Mn2+、Co2+、Cu2+和Zn2+对酶活力的影响呈现不同的效应,Mn2+、Co2+和Zn2+对该酶活性有不同程度的激活作用,Cu2+浓度在0.10mmol/L内对该酶有一定的激活作用,浓度大于0.13mmol/L为抑制作用,其IC50为0.65mmol/L.重金属离子Hg2+、Cd2+和Pb2+对酶活力有不同程度的激活作用,以Hg2+的激活作用最为显著.Phenoloxidase is responsible for enzymatic browning during the growth of the insects.It is also involved in the defense reaction and has some certain relation with the immune condition of the insects.Phenoloxidase is a metalloenzyme oxidase which catalyzes two distinct reactions of melanin synthesis:the hydroxylation of monophenol and the oxidation of ο-diphenol to the corresponding ο-quinone.As a series of researches,in the present paper,effects of some metal ions on the activity of phenoloxidase from the 5~th instar of Pieris rapae L.were studied.The results showed that K+,Li+ and Na+ had no any effects on the activity of the tested enzyme.Mg^2+ ,Ba^2+ and Ca^2+ activated the enzyme and the activated order following:Mg^2+ >Ca^2+ >Ba^2+ .The transitional metal ions had different effects on the activity of the enzyme.Mn^2+ 、Co^2+ and Zn^2+ activated the enzyme.Cu^2+ had different behaviors.At low concentration (lower than 0.10 mmol/L) Cu^2+ could enhance the enzyme activity,but,at high concentration (higher than 0.13 mmol/L) Cu^2+ could inhibit the enzyme and its IC_50 was estimated to be 0.65 mmol/L.The results also indicated that Hg^2+ ,Cd^2+ and Pb^2+ enhanced the enzyme activity and Hg^2+ was a more efficacious activator in the heavy metal ions what we had determined.

关 键 词：酚氧化酶活力 菜青虫 离子对 (NH4)2SO4 SEPHADEX 激活作用 Mn^2+ CO^2+ Zn^2+ Cu^2+ Hg^2+ 碱土金属离子 过渡金属离子 凝胶柱层析 碱金属离子 Mg^2+ Ca^2+ Ba^2+ 重金属离子 Pb^2+ Cd^2+ 部分纯化 Na^+ Li^+ 抑制作用 

分 类 号：X703[环境科学与工程—环境工程] S968.226[农业科学—水产养殖]