High-level recombinant protein production by overexpression of Mlc in Escherichia coli
High-level recombinant protein production by overexpression of Mlc in Escherichia coli
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DOI：
10.1016/j.jbiotec.2005.03.008
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发表时间：
2005-09-23
影响因子：
4.1
通讯作者：
Ryu, S
中科院分区：
文献类型：
--
作者：
Cho, SH;Shin, D;Ryu, S
在含葡萄糖的LB肉汤中，大肠杆菌在好氧生长过程中会分泌乙酸，在葡萄糖消耗殆尽之前，大肠杆菌的生长就停止了，因为乙酸的积累导致了低pH。众所周知，如果Mlc过度表达，即使大肠杆菌在高浓度葡萄糖的存在下生长，乙酸的积累也会减少。在大肠杆菌中，由于自动调节和低翻译效率，细胞内Mlc浓度很低。我们利用定点诱变技术构建了多种可以表达更高水平Mlc的突变体，其中一个Mlc过量突变体表现出葡萄糖消耗率降低和乙酸产量降低。在葡萄糖存在的情况下，突变体的外源基因表达水平高于亲本菌株。这些结果表明，过量生产Mlc的大肠杆菌菌株具有提高的葡萄糖利用能力，可以作为高水平生产有用重组蛋白的更好宿主。(c) 2005 Elsevier B.V.版权所有
Escherichia coli excretes acetate during aerobic growth on LB broth containing glucose and growth ceases before depletion of glucose because of the low pH caused by the accumulation of acetate. It has been known that the acetate accumulation is reduced even when E. coli is grown in the presence of high concentration of glucose if Mlc is overexpressed. The intracellular concentration of Mlc is very low in E coli because of autoregulation and a low efficiency of mlc translation. We constructed various mutants that can express higher levels of Mlc using site-directed mutagenesis and one of the Mlc-overproducing mutant showed reduced glucose consumption rate and low production of acetate. The mutant showed higher foreign gene expression level than that of its parental strain in the presence of glucose. These results suggest that the Mlc overproducing E coli strain having an improved ability of glucose utilization can be a better host for high-level production of useful recombinant proteins. (c) 2005 Elsevier B.V. All rights reserved.