香港海鸥菌OsmC蛋白的原核表达、纯化及活性研究

Prokaryotic expression,purification and antioxidant activity detection of L.hongkongensis OsmC

[目的]原核表达纯化香港海鸥菌OsmC蛋白,并检测其抗氧化功能。[方法]通过PCR法扩增香港海鸥菌OsmC基因,将目的片段进行双酶切后连接到pET28a,构建重组质粒pET28a-OsmC并转化大肠杆菌,诱导OsmC蛋白表达,亲和层析纯化目的蛋白并利用氧化铁二甲酚橙实验检测其过氧化物酶活性。[结果]克隆得到全长基因,大小为441bp,编码147个氨基酸。得到重组表达质粒pET28a-OsmC,表达并纯化获得重组OsmC蛋白,OsmC蛋白能够降解H2O2。[结论]Osm C蛋白具有过氧化物酶活性,为研究香港海鸥菌的抗氧化机制奠定了基础。

[ Objective] This study aim to purify Laribacter hongkongensis OsmC protein from E. coli,and identify its antioxi- dant activity. [ Methods] The OsmC was amplified by PCR from the L. hongkongensis. The gene encoding sequence of OsmC was inserted into the pET28a vector to generate recombinant plasmid pET28a - OsmC. The plasmid pET28a - OsmC was trans- formed into E. coli BL21 （DE3） to create transformed strain of BL/pET28a -OsmC. The OsmC protein was induced by IPTG and was purified by Ni2＋ - affinity chromatography. The peroxidase activity of OsmC was detected by ferrous oxidation xylenol orange （FOX） assay. [ Results] The OsmC gene was inserted into pET28a to created the recombinant plasmid pET28a -OsmC which had 441bp and encoding 147 amino acids. OsmC protein was expressed and was purified successfully. H2O2 was decom- posed by OsmC protein. [ Conclusion] The present work shows purified OsmC protein possess peroxidase activity in vitro ,which provides a foundation for understanding the mechanisms of oxidative stress tolerance in L. hongkongensis.