泥蚶(Tegillarca granosa)重组铁蛋白富集重金属离子的特性及化学传感器的研究

RESEARCH OF CHARACTERISTICS OF ENRICHMENT OF HEAVY METALS BY RECOMBINANT FERRITIN FROM TEGILLARCA GRANOSA

利用泥蚶(Tegillarca granosa)铁蛋白原核表达工程菌获得的重组铁蛋白,通过圆二色光谱分析蛋白二级结构,扫描电镜和电感耦合等离子质谱研究重组铁蛋白富集Fe^(2+)、Mn^(2+)、Cd^(2+)、Cr^(3+)、Hg^(2+)、Pb^(2+)和As^(3+)等7种重金属离子的特性,同时探索利用重组铁蛋白修饰丝网印刷电极,设计和制备重组铁蛋白检测Pb^(2+)和Cd^(2+)浓度的电化学生物传感器。结果表明复性成功的铁蛋白多为完整的?-螺旋结构,而复性不成功的蛋白聚集体则多为无规卷曲。重组铁蛋白的直径和形态与富集的离子种类有关。泥蚶铁蛋白对单一金属离子Fe^(2+)和Mn^(2+)的富集凸显优势。对两种混合金属离子的富集大多表现为竞争关系。但重组铁蛋白对Hg^(2+)和As^(3+)混合组的富集量明显高于单一金属离子组的富集量,对Hg^(2+)和As^(3+)混合组的富集表现出协同促进作用。重组铁蛋白传感器对Pb^(2+)和Cd^(2+)溶液的最低检测限为10μg/L。

The recombinant ferritin protein taken from the Tegillarca granosa ferritin protein prokaryotic expression bacteria was used to design and get the electrochemical biosensors for detection of Pb^2＋ and Cd^2＋ of the recombinant ferritin protein through the analysis of the secondary structure of protein by circular dichroism（CD）, the research of the characteristics of the protein to enrich 7 heavy metal ions such as Fe^2＋, Mn^2＋, Cd^2＋, Cr^3＋, Hg^2＋, Pb^2＋ and As^3＋ by scanning electron microscope（SEM） and inductively coupled plasma mass spectrometry（ICP-MS） and the exploration of the recombinant ferritin protein to modify screen-Printed Electrode. The results showed that the ultra-structure of recombinant ferritin protein with successful refolding was mainly complete α-helix, however, the structure of the protein with unsuccessful refolding is mainly an irregular one. The diameter and shape of the recombinant ferritin protein was related to the type of the enriched ions. T. granosa ferritin had advantage to enrich the single metal ions like Fe^2＋ and Mn^2＋ and performs as a competing role when it came to the enrichment of the 2 mixed metal ions. However, the enriched amount of the mixed metal ions of Hg^2＋ and As^3＋ was obviously higher than the enriched amount of the single metal ions and the protein just promoted the enrichment of the that mixed ion. And the lowest detection concentration of biosensors for Pb^2＋and Cd^2＋ liquor was 10μg/L.