小球藻锌结合类金属硫蛋白的提取和分离  

Extraction and Separation of Zn-MT-like Induced from C. vulgaris Under the Stress of ZnCl_2

作　　者：李连平[1] 梁英[2] 黄志勇[1] 徐同玲[2] 

机构地区：[1]集美大学生物工程学院 [2]集美大学水产学院,福建厦门361021

出　　处：《食品与发酵工业》2009年第6期188-192,共5页Food and Fermentation Industries

基　　金：国家自然科学基金项目(40771185);福建省科技计划重点项目(2007Y0028);集美大学创新团队基金资助项目(2006A003)

摘　　要：小球藻经60μmol/L的锌胁迫培养5天后,离心收集藻泥,经超声波细胞破碎后,离心得到上清液即蛋白质粗提液。粗提液经葡聚糖凝胶层析柱G-75及脱盐柱G-25分离、纯化后,收集的蛋白组分经真空冷冻干燥后获得小球藻锌结合蛋白。实验测定了在不同pH值下小球藻锌结合蛋白的紫外光谱特征,发现该蛋白质的紫外光谱特征与兔肝金属硫蛋白(Zn-MTs)十分相似。经阴离子交换层析柱(DEAE Sephadex A-25)及反相液相色谱分离表明,小球藻锌结合蛋白的色谱行为与兔肝Zn-MTs有一定的相似性。此外,经Tricine-SDS-PAGE法测定该蛋白质的分子量约为8.2kDa;蛋白质分子中半胱氨酸含量达15%以上。由此可见,小球藻在锌胁迫下可诱导生成与兔肝Zn-MTs相似的锌结合蛋白质,即类金属硫蛋白(Zn-MT-like)。每克鲜藻可诱导Zn-MT-like蛋白达0.2g以上。C. vulgaris was cultivated for five days under the stress of 60 μmol/L of Zn^2 ＋ （ ZnCl2 ）. After harvest by centrifugation, the algal ceils were washed with EDTA and water, and were homogenized by a supersonic cell disintegrator. After centrifugation, the supernatant, a crude protein-containing extract, was separated and purified with a gel filtration column （Sephadex G-75, 3.5 i.d. × 80 cm） and a desahing gel filtration column （Sephadex G-25, 1.5 i.d. × 30 cm）, respectively. The purified Zn-binding protein was characterized by the methods of UV spectrum and the different chromatograms. In addition, the molecular weight of the purified Zn-binding protein measured with Tricine-SDS-PAGE was about 8.2 ku. The content of cysteine in the protein was more than 15%. Results indicated that the Zn-binding proteins from C. vulgaris were the analogues of Zn-binding metallothioneins, and were referred as Zn-MT-like. In addition, 0.2% （w/w） of purified Zn-MT-like could be obtained from fresh alga.

关 键 词：小球藻 锌结合类金属硫蛋白 诱导 分离 

分 类 号：Q946[生物学—植物学]