Li Lin, Kim Young Soo, Hwang Dong Soo, Seo Jeong Hyun, Jung Hee Jung, Du Juan, Cha Hyung Joon
Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea.
Biotechnol Bioeng. 2007 Apr 15;96(6):1183-90. doi: 10.1002/bit.21193.
Previously, we found that baculoviral polyhedrin (Polh) can successfully be used in Escherichia coli as a fusion partner for the expression of special foreign proteins as inclusion bodies, and the resulting, easily isolatable Polh-induced fusion inclusion bodies had almost the same characteristics as the native Polh. Here, we investigated the effects of co-expression of baculoviral FP25 protein on Polh-induced inclusion-body production in an E. coli expression system, as FP25 is known to be involved specifically in polyhedra formation. Using several analytical tools, including SDS-PAGE, pronase proteolysis, solubilization under alkaline conditions, and electron microscopy, we found that co-expressed FP25 was associated with Polh-induced inclusion bodies and that its co-expression led to formation of compact inclusion bodies as well as high production levels. We confirmed that FP25 co-expression induced higher production levels of other heterologous protein, antimicrobial peptide Hal18, fused with aggregation-prone Polh. Therefore, co-expression of baculoviral FP25 can be promisingly used to increase the levels of baculoviral Polh-fused foreign proteins, especially harmful proteins, expressed as inclusion bodies in an E. coli expression system.
此前，我们发现杆状病毒多角体蛋白（Polh）能够成功地在大肠杆菌中用作融合伴侣，用于表达特殊的外源蛋白并形成包涵体，并且由此产生的、易于分离的由Polh诱导形成的融合包涵体具有与天然Polh几乎相同的特性。在此，我们研究了杆状病毒FP25蛋白的共表达对大肠杆菌表达系统中由Polh诱导的包涵体产生的影响，因为已知FP25特别参与多面体的形成。使用多种分析工具，包括SDS-PAGE、链霉蛋白酶蛋白水解、碱性条件下的溶解以及电子显微镜，我们发现共表达的FP25与由Polh诱导的包涵体相关联，并且其共表达导致形成致密的包涵体以及高产量。我们证实，FP25共表达诱导了与易于聚集的Polh融合的其他异源蛋白抗菌肽Hal18的更高产量。因此，杆状病毒FP25的共表达有望用于提高杆状病毒Polh融合的外源蛋白的产量，尤其是在大肠杆菌表达系统中以包涵体形式表达的有害蛋白。
