Jonasson Per, Liljeqvist Sissela, Nygren Per-Ake, Ståhl Stefan
Department of Biotechnology, Kungliga Tekniska Högskolan, Stockholm, Sweden.
Biotechnol Appl Biochem. 2002 Apr;35(2):91-105. doi: 10.1042/ba20010099.
Genetic strategies have been used for more than two decades to improve bacterial bioprocesses and to simplify recovery procedures. Such strategies include the design of efficient expression vectors and the improvement of bacterial production strains in different ways, e.g. by deletion of protease genes or engineering for overexpression of rare-codon tRNAs, foldases or chaperones. Gene multimerization is another such principle that has proved beneficial to improve production yields. Genetic strategies have furthermore been exploited to facilitate recovery processes by adapting the product for a particular purification principle. In this area, affinity fusions have been commonly used, but other principles, such as modified isoelectric point (pI) or hydrophobic properties have also been successfully investigated. A recent drastic step forward in the use of gene technology to improve recovery processes for recombinant proteins is the introduction of combinatorial protein engineering to generate tailor-made product-specific affinity ligands. This strategy, which allows efficient recovery of a recombinant protein in its native form, is likely to be increasingly used also in industrial-scale bioprocesses, since novel protein ligands have been described that can be sanitized using common industrial cleaning-in-place procedures. The examples presented in this review make it evident that genetic strategies will be of utmost importance in the future for facilitating production and recovery of recombinant proteins.
二十多年来，遗传策略一直被用于改善细菌生物工艺并简化回收程序。这些策略包括设计高效表达载体，以及通过不同方式改进细菌生产菌株，例如删除蛋白酶基因或对稀有密码子tRNA、折叠酶或伴侣蛋白进行过表达工程改造。基因多聚化是另一个已被证明有助于提高产量的原理。此外，遗传策略已被用于通过使产物适应特定的纯化原理来促进回收过程。在这一领域，亲和融合已被广泛使用，但其他原理，如修饰的等电点（pI）或疏水性质也已得到成功研究。利用基因技术改进重组蛋白回收过程的一个近期重大进展是引入组合蛋白工程以生成定制的产物特异性亲和配体。这种策略能够以天然形式高效回收重组蛋白，由于已经描述了可以使用常见的工业在位清洗程序进行消毒的新型蛋白质配体，因此它在工业规模的生物工艺中也可能会越来越多地被使用。本综述中给出的例子表明，遗传策略在未来促进重组蛋白的生产和回收方面将至关重要。
