Sun M, Zan Y, Ma Y, Zhang G, Du Q, Dai C
Department of Molecular Biology, Institute of Medical Biology, CAMS & PUMC, Kunming 650118.
Chin Med Sci J. 2001 Sep;16(3):129-34.
Using a recombinant human adenovirus to express modified VP4 gene of rotavirus SA11 strain.
A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consists of human cytomegalovirus promoter, and then the gene was cloned to the transfer vector of human adenovirus type 5. Homologous recombination was performed by co-transfection to 293 cell lines with recombinant plasmid and viral genome using CaPO4 precipitation.
No mutation was found in the whole VP4 gene sequence of 2362 base pair. The expressed product in recombinant adenovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both the Western blot and immunoprecipitation assay showed that the molecular mass of the expressed protein was higher than the wild type VP4 protein, and that the modified product was corresponding to a glycosylation of VP4 protein.
To modify the target gene might be an effective method to enhance the stability, antigenicity and immunogenicity of expressed protein.
利用重组人腺病毒表达轮状病毒SA11株修饰的VP4基因。
通过PCR获得完整的VP4基因,并在基因N端诱导信号肽。将嵌合基因克隆到由人巨细胞病毒启动子组成的pCMV质粒中,然后将该基因克隆到5型人腺病毒的转移载体中。使用磷酸钙沉淀法将重组质粒和病毒基因组共转染至293细胞系进行同源重组。
在2362个碱基对的完整VP4基因序列中未发现突变。通过间接免疫荧光试验证实重组腺病毒中的表达产物具有特异性且抗原性更强。蛋白质印迹法和免疫沉淀试验均表明,表达蛋白的分子量高于野生型VP4蛋白,且修饰产物对应于VP4蛋白的糖基化。
修饰靶基因可能是提高表达蛋白稳定性、抗原性和免疫原性的有效方法。