醫(yī)學(xué)免費論文:pET15bYARAEGFP原核表達質(zhì)粒的構(gòu)建及融合蛋白YARAEGFP的表達與純化
【摘要】 目的:構(gòu)建原核表達載體pET15bYARAEGFP,并進行YARAEGFP融合蛋白的表達和純化。方法:用分子克隆技術(shù)構(gòu)建出表達型載體pET15bYARAEGFP,在E.coli BL21(DE3)中表達融合蛋白YARAEGFP,并進行Ni2+NTA樹脂柱親和層析以純化蛋白。結(jié)果:經(jīng)測序證實成功構(gòu)建了表達型載體pET15bYARAEGFP,YARAEGFP融合蛋白在E.coli BL21(DE3)中得到表達,純化后的蛋白濃度為1.098 mg/mL。SDSPAGE和Western blot分析表明純化蛋白為目的蛋白YARAEGFP。結(jié)論:已成功制備出YARAEGFP融合蛋白。
【關(guān)鍵詞】 細胞穿透肽 增強型綠色熒光蛋白 原核表達 融合蛋白
Construction of Prokaryotic Expression Plasmid pET15bYARAEGFP and Expression and Purification of YARAEGFP Fusion Protein CHEN Sisi1,2,WANG Jianing2^,HUANG Yongzhang2,GUO Lingyun2,ZHENG Fei2 (1Cardiovascular Research Institute,Renmin Hospital,Wuhan University,Wuhan,Hubei 430060;2Institute of Clinical Medicine,Renmin Hospital,Yunyang Medical College,Shiyan,Hubei 442000,China)
Abstract:Objective To construct the expression vector pET15bYARAEGFP and express and purify the fusion protein YARAEGFP.Methods Two oligonucleotides encoding YARA were synthesized and annealed to generate YARAencoding DNA. The recombinant plasmid pET15bYARAEGFP was constructed by inserting YARAencoding DNA into pET15bEGFP. The fusion protein YARAEGFP induced with IPTG in E.coli BL21(DE3)was purified with Ni2+resin affinity chromatography and confirmed with SDSPAGE and western blot.Results Sequence analysis confirmed successful construction of the expression vector pET15bYARAEGFP,the fusion protein YARAEGFP was expressed and purified and its concentration was 1.098 mg/mL.SDSPAGE and Western blot demonstrated the fusion protein was YARAEGFP.Conclusion YARAEGFP fusion protein is successfully prepared醫(yī).學(xué).全.在.線m.zxtf.net.cn.
Key words:Cell penetrating peptides;Enhanced green fluorescent protein;Prokaryotic expression;Fusion protein
自人類基因組計劃的完成和蛋白組計劃的實施以來,人們發(fā)現(xiàn)了許多生物大分子具有潛在的治療價值。但細胞膜是脂質(zhì)雙分子層,具有選擇通透性,這種天然屏障作用在保護細胞的同時也限制了生物大分子自由進入細胞內(nèi)發(fā)揮作用。傳統(tǒng)的將大分子物質(zhì)轉(zhuǎn)導(dǎo)入細胞內(nèi)的常用方法有電穿孔、脂質(zhì)體轉(zhuǎn)染等,這些方法不但轉(zhuǎn)導(dǎo)效率低,而且對轉(zhuǎn)導(dǎo)的細胞均有毒副作用,且僅適用于體外實驗。最近研究發(fā)現(xiàn),某些蛋白質(zhì)的結(jié)構(gòu)區(qū)域具有將外源性蛋白轉(zhuǎn)導(dǎo)入細胞內(nèi)的特性,這些區(qū)域被稱為蛋白轉(zhuǎn)導(dǎo)結(jié)構(gòu)域或細胞穿透肽[1],它能攜帶有治療作用的蛋白質(zhì)轉(zhuǎn)導(dǎo)入細胞內(nèi)并發(fā)揮相應(yīng)的生物學(xué)效應(yīng),這使它有可能成為一種理想的蛋白轉(zhuǎn)導(dǎo)載體。目前研究最為深入的是來源于人類免疫缺陷病毒反式激活因子的TAT蛋白轉(zhuǎn)導(dǎo)結(jié)構(gòu)域,其氨基酸序列為YGRKKRRQRRR。Choi領(lǐng)導(dǎo)的研究小組[2-8]已經(jīng)證實了TATGFP、TATGDH、TATSOD和TATCAT等融合蛋白能轉(zhuǎn)導(dǎo)入哺乳動物細胞內(nèi)和皮膚組織。為了進一步提高細胞穿透肽的轉(zhuǎn)導(dǎo)效率,Ho等[9]將TAT的氨基酸序列進行優(yōu)化,合成了一種新的蛋白轉(zhuǎn)導(dǎo)結(jié)構(gòu)域即YARA,其氨基酸序列為YARAAARQARA,發(fā)現(xiàn)其轉(zhuǎn)導(dǎo)效率為TAT的33倍。為了探討YARA介導(dǎo)的融合蛋白的離體和在體轉(zhuǎn)導(dǎo)能力,本研究設(shè)計合成了編碼YARA的DNA序列,通過基因重組技術(shù)構(gòu)建了原核表達質(zhì)粒pET15bYARAEGFP,表達并純化出YARAEGFP融合蛋白,為YARA介導(dǎo)的生物大分子EGFP穿透細胞能力的研究奠定了基礎(chǔ)。