拟南芥Alpha-dioxygenase1的原核表达、纯化及活性的检测

Expression,Purification and Activity Analysis of Arabidopsis-dioxygenase 1

从经水杨酸处理的拟南芥开花期植株中获得cDNA,扩增得到Alpha-dioxygenase 1(DOX1)基因,进行原核表达、纯化和生物活性检测。利用原核表达载体pMAL-c4x在T7 Express CompetentE.coli和BL21(DE3)-RIPL codon+菌株中表达DOX1,经Amylose Resin亲和层析柱纯化。SDS-PAGE结果表明,重组融合蛋白在BL21(DE3)-RIPL codon+中的表达通过灰度值比较分析以可溶性为主,表达率约3.7%,纯化的DOX1纯度可达45%。愈创木酚法表明,可溶性重组蛋白不具有过氧化物酶活性;2,4-DNP法测试表明可溶性重组蛋白具有脂肪酸双加氧酶活性。

Recombinant DOX1 was cloned into pMAL-c4x expression vector and expressed in E. coli T7 Express Competent E. coli and BL21 （DE3）RIPL codon＋ . Purified using amylose resin column, a fusion protein about 114 kD was detected by SDS-PAGE in the IPTG induced recombinant BL21 （DE3）RIPL codon＋ strain, and it＇s yield accounts for 3.7 % of the total bacterial proteins, the purity of recombinant protein was about 45 %. The soluble fusion protein had undetectable peroxidase activity by the guaiacol method ; The alpha dioxygenase activity of the purified protein was tested using 2,4-DNP,resuh showed that the soluble fusion protein had detectable alpha-dioxygenase activity.