Lian Jiazhang, Ding Shinghua, Cai Jin, Zhang Danping, Xu Zhinan, Wang Xiaoning
Institute of Bioengineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027, China.
Appl Microbiol Biotechnol. 2009 Mar;82(3):463-70. doi: 10.1007/s00253-008-1774-x. Epub 2008 Nov 13.
Aquaporin Z (AqpZ), a typical orthodox aquaporin with six transmembrane domains, was expressed as a fusion protein with TrxA in E. coli in our previous work. In the present study, three fusion partners (DsbA, GST and MBP) were employed to improve the expression level of this channel protein in E. coli. The result showed that, compared with the expression level of TrxA-AqpZ, five- to 40-fold increase in the productivity of AqpZ with fusion proteins was achieved by employing these different fusion partners, and MBP was the most efficient fusion partner to increase the expression level. By using E. coli C43 (DE3)/pMAL-AqpZ, the effects of different expression conditions were investigated systematically to improve the expression level of MBP-AqpZ in E. coli. The high productivity of MBP-AqpZ (200 mg/l) was achieved under optimized conditions. The present work provides a novel approach to improve the expression level of membrane proteins in E. coli.
水通道蛋白Z（AqpZ）是一种典型的具有六个跨膜结构域的传统水通道蛋白，在我们之前的工作中，它在大肠杆菌中作为与硫氧还蛋白（TrxA）的融合蛋白表达。在本研究中，使用了三种融合伴侣（二硫键异构酶A（DsbA）、谷胱甘肽S-转移酶（GST）和麦芽糖结合蛋白（MBP））来提高该通道蛋白在大肠杆菌中的表达水平。结果表明，与TrxA-AqpZ的表达水平相比，通过使用这些不同的融合伴侣，AqpZ与融合蛋白的产量提高了5至40倍，并且MBP是提高表达水平最有效的融合伴侣。通过使用大肠杆菌C43（DE3）/pMAL-AqpZ，系统地研究了不同表达条件对提高大肠杆菌中MBP-AqpZ表达水平的影响。在优化条件下实现了MBP-AqpZ的高产量（200 mg/l）。本工作为提高大肠杆菌中膜蛋白的表达水平提供了一种新方法。
