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If you decide to place an order during this period, we reserve the right to adjust the price based on the evolving situation. We understand that market changes may cause inconvenience. We will negotiate with you if there’s a significant price fluctuation due to tariff policy changes before the order’s actual delivery, and in such cases we may adjust or cancel the order as necessary.

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主页克隆和表达T7启动子系统

T7启动子系统

 T7启动子具有什么样的序列？

T7 启动子是转录起始位点 +1 (5' – TAATACGACTCACTATAG – 3')前端18 bp长度的DNA序列，可被 T7 RNA 聚合酶识别1。T7启动子常用于调节重组蛋白的基因表达，支持各种下游研究应用2。


 T7质粒表达系统特征

基于细菌T7启动子的载体可表达、检测和纯化大肠杆菌中的重组FLAG®和 MAT™（金属亲和标签）融合蛋白。多种含有 T7 启动子的载体可为FLAG®和MAT™标记融合蛋白提供双重标签选项。这类载体可带来氨苄青霉素耐受性，以便于选择阳性转化体。此外，这些载体还含有 T1T2转录终止子、pMB1（pBR322 的衍生物）复制起点、f1 起点和抑制 T7 启动子的 lacI 基因。

pT7-FLAG®和 pT7-MAT™载体提供极为强效的T7/lac启动子。这类表达载体可提供比tac启动子系统更高的重组蛋白产量。然而，T7 启动子公认存在背景（“漏”）表达问题——当重组蛋白对宿主细胞存在毒性时，这一缺点就会放大。因此，我们的载体包含位于启动子下游的 lac 操纵子 (lacO) 序列，旨在减少漏表达。与 tac 启动子系统不同，pT7 载体必须在含 T7 聚合酶来源的宿主中表达，如 (DE3) 溶原菌株。


 MAT™标签技术

MAT™标签或金属亲和标签 (HNHRHKH) 专为使用 HIS-Select 镍和钴亲和凝胶纯化重组 MAT™ 融合蛋白而设计。HIS-Select 产品可高度选择性纯化组氨酸标记的融合蛋白（例如 MAT™ 融合蛋白）。我们的许多最新载体都使用 MAT™ 标签，通常与众所周知的FLAG®标签结合使用。含载体的MAT™标签以N端或C端标签的形式提供。

T7启动子和表达系统指南产品
产品编号产品名称说明价格
409081Poly(acrylamide-co-diallyldimethylammonium chloride) solution10 wt. % in H2O
191973Poly(2-acrylamido-2-methyl-1-propanesulfonic acid) solutionaverage Mw 2,000,000, 15 wt. % in H2O
191981Poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylonitrile)acrylonitrile ~95 wt. %
447013Poly(acrylic acid sodium salt)average Mw ~5,100 by GPC, powder
420344Poly(acrylic acid sodium salt)average Mw ~2,100
416010Poly(acrylic acid, sodium salt) solutionaverage Mw ~1,200, 45 wt. % in H2O
416029Poly(acrylic acid, sodium salt) solutionaverage Mw ~8,000, 45 wt. % in H2O
416037Poly(acrylic acid, sodium salt) solutionaverage Mw ~15,000, 35 wt. % in H2O
479136Poly(allylamine) solution20 wt. % in H2O
479144Poly(allylamine) solutionaverage Mw ~65,000, 10 wt. % in H2O
283215Poly(allylamine hydrochloride)average Mw ~17,500 (GPC vs. PEG std.)
444464Polyanetholesulfonic acid sodium salt
458627Poly[bis(2-chloroethyl) ether-alt-1,3-bis[3-(dimethylamino)propyl]urea] quaternized, solution62 wt. % in H2O
409014Poly(diallyldimethylammonium chloride) solution20 wt. % in H2O
409030Poly(diallyldimethylammonium chloride) solutionaverage Mw 400,000-500,000 (high molecular weight), 20 wt. % in H2O
409022Poly(diallyldimethylammonium chloride) solutionaverage Mw 200,000-350,000 (medium molecular weight), 20 wt. % in H2O
522376Poly(diallyldimethylammonium chloride) solutionaverage Mw <100,000 (very low molecular weight), 35 wt. % in H2O
181978Poly(ethyleneimine) solutionaverage Mn ~60,000 by GPC, average Mw ~750,000 by LS, 50 wt. % in H2O
408700Poly(ethyleneimine) solutionaverage Mw 1800, 50 wt. % in H2O
482595Poly(ethyleneimine) solutionaverage Mn ~1,200, average Mw ~1300 by LS, 50 wt. % in H2O
卡那霉素基因和氨苄青霉素基因可提高大肠杆菌筛选灵活性

图 1.卡那霉素基因和氨苄青霉素基因可提高大肠杆菌筛选灵活性

参考文献

1.
Rong M, He B, McAllister WT, Durbin RK. 1998. Promoter specificity determinants of T7 RNA polymerase. Proceedings of the National Academy of Sciences. 95(2):515-519. https://doi.org/10.1073/pnas.95.2.515
2.
Komura R, Aoki W, Motone K, Satomura A, Ueda M. High-throughput evaluation of T7 promoter variants using biased randomization and DNA barcoding. PLoS ONE. 13(5):e0196905. https://doi.org/10.1371/journal.pone.0196905
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