新型人阳离子抗菌蛋白18的构建及其表达

目的：构建新型人阳离子抗菌蛋白18（NHCAP18）的氨基酸序列,合成其编码基因并在原核细胞表达.方法：设计NHCAP18氨基酸序列,经生物信息学分析后,合成其编码基因,将该基因插入表达载体pGEX-4T-1,尔后在大肠杆菌BL21中经IPTG诱导表达.结果：NHCAP18经生物信息学分析符合改造要求,构建的重组表达质粒pGEX-4T-1/ NHCAP18在大肠杆菌BL21中经IPTG诱导4 h表达量约占菌体总蛋白量的39%,NHCAP18经谷胱甘肽-Sepharose 4B亲合层析纯化后对大肠杆菌有杀灭作用.结论：NHCAP18的成功改造,重组蛋白pGEX-4T-1/HCAP18在大肠杆菌BL21中高效表达及纯化,为研究NHCAP18功能打下了良好的基础.

Construction and expression of new-type human cationic antimicrobial protein 18

Objective: To construct amino acid sequence of new-type human cationic antimicrobial protein 18(NHCAP18),whose genes were synthesized and expressed in prokaryocytes.Methods: NHCAP18 and its coding genes were devised and analyzed by bioinformatics.The genes were synthesized and inserted in expression vector pGEX-4T-1,reconstruction expression plasmid pGEX-4T-1/NHCAP18 was expressed in Escherichia coli BL21 with induction by IPTG.Results:Amino acid sequence of NHCAP18 accorded with that of reformation purpose,which was analyzed by bioinformatics,reconstruction expression plasmid pGEX-4T-1/NHCAP18 was expressed in E.coli BL21 with an amount accounting for 39% of the total bacterial protein after induction by IPTG for 4 hours.NHCAP18 could kill E.coli after affinity chromatography and purification by glutathione sepharose 4B.Conclusion: NHCAP18 is successfully reformed,reconstruction protein GEX-4T-1/is efficiently expressed and purified in E.coli BL21 and NHCAP18 is purified,which establishes a satisfactory foundation for investigating NHCAP18 function.