Raran-Kurussi Sreejith, Waugh David S
Protein Engineering Section, Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland.
Biotechnol Bioeng. 2014 Dec;111(12):2407-11. doi: 10.1002/bit.25317. Epub 2014 Aug 25.
The tendency of recombinant proteins to accumulate in the form of insoluble aggregates in Escherichia coli is a major hindrance to their overproduction. One of the more effective approaches to circumvent this problem is to use translation fusion partners {solubility-enhancers (SEs)}. E. coli maltose-binding protein (MBP) and N-utilization substance A (NusA) are arguably the most effective solubilizing agents that have been discovered so far. Here, we show that although these two proteins are structurally, functionally, and physicochemically distinct, they influence the solubility and folding of their fusion partners in a very similar manner. These SEs act as "holdases" that prevent the aggregation of their fusion partners. Subsequent folding of the passenger proteins, when it occurs, is either spontaneous or chaperone-mediated.
重组蛋白在大肠杆菌中以不溶性聚集体的形式积累的倾向是其过量生产的主要障碍。规避这一问题的一种更有效的方法是使用翻译融合伙伴{溶解度增强剂(SEs)}。大肠杆菌麦芽糖结合蛋白(MBP)和氮利用物质A(NusA)可以说是迄今为止发现的最有效的增溶剂。在这里,我们表明,尽管这两种蛋白质在结构、功能和物理化学性质上不同,但它们以非常相似的方式影响其融合伙伴的溶解度和折叠。这些SEs充当“保持酶”,防止其融合伙伴聚集。随后,客体蛋白的折叠,一旦发生,要么是自发的,要么是伴侣介导的。