大肠杆菌表达的重组猪β_2微球蛋白二级结构的圆二色谱分析  

Analyzing secondary structure of β_2 microglobulin in Escherichia coli with circular dichroism spectrum

作　　者：高凤山[1] 夏春[2] 张强[3] 李云岗[4] 李新生[2] 许崇波[1] 白婧[1] 

机构地区：[1]大连大学生物工程学院,大连116622 [2]中国农业大学动物医学院,农业部预防兽医学重点实验室,北京100094 [3]中国农业科学院兰州兽医研究所,兰州730046 [4]山东省动物疫病预防与控制中心,济南250022

出　　处：《微生物学报》2009年第12期1596-1600,共5页Acta Microbiologica Sinica

基　　金：国家自然科学基金(30972169);大连大学博士启动项目(0302173)~~

摘　　要：【目的】研究巴马小型猪β2微球蛋白(β2m)的结构和功能。【方法】亚克隆巴马小型猪β2m的成熟肽部分,并构建与pMAL-p2X的重组质粒,转化大肠杆菌TB1并诱导后,融合表达蛋白分别经过Western blot、纯化及Factor Xa切割,分离纯化单体蛋白。圆二色谱(circular dichroism spectrum,CD)测定蛋白的二级结构。【结果】重组表达的融合蛋白MBP-β2m大小为53.1kDa。切割后去除MBP的单体蛋白大小为10.6kDa。圆二色谱分析单体蛋白β2m二级结构元件α-螺旋、β-折叠、转角和随机卷曲所含有的氨基酸残基数目分别为0、45、8和45。【结论】分析揭示表达的β2m具有正确的二级结构,可以用于体外多肽结合等研究。[ Objective] In order to study the structure and function of β2 microglobulin （β2m）. [ Methods] We sub-cloned the mature peptide of β2m into the p2X plasmid and transformed them to Escherichia coli TB1. The recombinant bacterium was induced to be expressed and the expressed fusion protein was detected by SDS-PAGE and western blot. After purifying and cleaving with Factor Xa, we separated the monomer protein β2m from MBP. Finally, we determined the secondary structure of the β2m protein by circular dichroism （CD） spectrum. [Results] MBP-β2m was 52.1 kDa, and the monomer protein β2m was 10.6 kDa. The α-helix, β-sheet, turn, and random coil of the fusion protein showed 0, 45, 8 and 45 amino acids, respectively, detected by CD estimation. [ Conclusion] The β2m protein had correct secondary structure and could be used for further research of peptide binding in vitro.

关 键 词：二级结构 圆二色谱 Β2微球蛋白 

分 类 号：Q78[生物学—分子生物学] S435.72[农业科学—农业昆虫与害虫防治]