Department of Biotechnology, BMS Block-1, South Campus, Panjab University, Chandigarh, 160014, India.
Int J Biol Macromol. 2018 Jan;106:803-822. doi: 10.1016/j.ijbiomac.2017.08.080. Epub 2017 Aug 19.
E. coli is most preferred system used for the production of recombinant proteins in bacteria and the availability of improved genetic tools/methods are making it more valuable than ever. Major challenges faced by this expression system are the expression of unusually difficult/complex proteins with rare codons or membrane and toxic proteins. The proteins expressed either in large amount or hydrophobic in nature tend to form insoluble mass. Despite the appropriate expression system, some proteins express at very low level or not at all. Choosing the correct expression system/protocols are obligatory for the substantial expression of protein in the native form. A number of vectors, their compatible hosts and culture conditions can be used to express recombinant proteins in large amounts and in native form. Also, vectors with the fusion tags/chaperons facilitate protein expression in soluble fraction and assist in proper protein folding besides restoring the native structure of protein. The recovery of native proteins from insoluble inclusion bodies can be achieved by optimization of refolding conditions. In the present review, we discussed recent updates on prokaryotic expression system for successful heterologous gene expression in E. coli and focused on strategies to maximize the yields of native recombinant proteins.
大肠杆菌是细菌中用于生产重组蛋白的最首选系统，并且改进的遗传工具/方法的可用性使其比以往任何时候都更有价值。该表达系统面临的主要挑战是表达具有稀有密码子或膜和毒性蛋白的异常困难/复杂的蛋白质。大量表达或本质上疏水性的蛋白质往往会形成不溶性物质。尽管有适当的表达系统，但有些蛋白质的表达水平非常低或根本不表达。选择正确的表达系统/方案对于以天然形式大量表达蛋白质是强制性的。许多载体、它们兼容的宿主和培养条件可用于大量表达和以天然形式表达重组蛋白。此外，带有融合标签/伴侣的载体有助于可溶性部分中的蛋白质表达，并有助于正确折叠蛋白质，同时恢复蛋白质的天然结构。通过优化复性条件可以从不溶性包涵体中回收天然蛋白质。在本综述中，我们讨论了原核表达系统在大肠杆菌中成功异源基因表达的最新进展，并重点介绍了最大限度提高天然重组蛋白产量的策略。
