WSSV-VP37小肽在大肠杆菌中的偏爱型表达

Preferential expression of WSSV-VP37 peptide in E.coli

选用对虾白斑综合征病毒(White Spot Syndrome Virus,WSSV)囊膜蛋白VP37的功能区段,利用大肠杆菌密码子偏爱性,在氨基酸不变的情况下将VP37中的密码子通过人工合成改为大肠杆菌偏爱型密码子,并克隆至表达载体pBAD/gIIIA中,构成重组载体pBAD/gIIIA-VP37p′。将重组载体转化入大肠杆菌Top10中,在相同条件下用L-阿拉伯糖与未优化的重组菌株Top10-pBAD/gIIIA-VP37p一同诱导。结果显示,与野生型基因VP37p相比,经密码子优化的VP37p′基因表达目的蛋白量占总蛋白的40.5%,明显高于野生型6.5%的目的蛋白表达量。

The expression levels of proteins in Escherichia coli appear to be preferential for some special codons.In order to enhance the expression level,we designed a partial sequence of the WSSV-VP37 gene based on the codons of E.coli so that its expression level would be optimized.The optimized VP37 fragment was ligated to the expression vector pBAD/gIIIA.Then the resulted recombinant pBAD/gIIIA-VP37p＇ was transformed into E.coli Top10 and the cells were induced by L-arabinose.SDS-PAGE analysis showed that the content of VP37p＇ constituted 40.5% of the total proteins.Compared with the wild type recombinant pBAD/gIIIA-VP37p,the expression level of the optimized recombinant VP37p＇（40.5% of the total proteins）was significantly higher than that of the wild type VP37p（6.5% of the total proteins）.