Su Xiaoyun, Zhang Shan, Wang Li, Dong Zhiyang
Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
Biochem Biophys Res Commun. 2009 Dec 18;390(3):673-7. doi: 10.1016/j.bbrc.2009.10.026. Epub 2009 Oct 13.
The small heat shock protein IbpB of Escherichia coli can accelerate protein disaggregation from inclusion body by Hsp100-Hsp70 re-activation system in vitro. It was therefore hypothesized that overexpression of IbpB might be able to promote protein disaggregation from inclusion body, by which more soluble recombinant proteins would be obtained. The overexpression of IbpB actually enhanced production of more active soluble XynB of Streptomyces olivaceovirdis in E. coli BL21(DE3). Surprisingly, the disaggregation of XynB from inclusion body was not accelerated. It seemed that the overexpressed IbpB protected improperly or partially folded XynB from aggregation and mediated the subsequent refolding. These results show potential of improving production of active heterologous proteins in E. coli.
大肠杆菌的小热休克蛋白IbpB可在体外通过Hsp100 - Hsp70再激活系统加速蛋白质从包涵体中的解聚。因此推测，IbpB的过表达可能能够促进蛋白质从包涵体中的解聚，借此可获得更多可溶性重组蛋白。IbpB的过表达实际上增强了橄榄绿链霉菌的活性可溶性木聚糖酶XynB在大肠杆菌BL21(DE3)中的产量。令人惊讶的是，XynB从包涵体中的解聚并未加速。似乎过表达的IbpB保护了折叠不当或部分折叠的XynB不发生聚集，并介导了随后的重折叠。这些结果显示了提高大肠杆菌中活性异源蛋白产量的潜力。
