title: [Improvement of baculovirus expression system and purification of IL-6 protein expressed in insect cells].
abstract: Based on site-specific transposition of an expression cassette into a baculovirus shuttle vector (Bacmid) which propagated in Escherichia coli, the Bac-to-Bac System provides a rapid and efficient method to generate recombinant baculoviruses and is widely used for high level expression of heterologous proteins. And the efficiency of recombinant baculovirus infecting cells plays an important role on the protein expression. In this study, we introduced an EGFP expression cassette driven by polyhedrin promoter into the p74 locus of Bacmid by homologous recombination. The target Bacmid-egfp was then transformed into E. coli DH10B containing the transposition helper plasmid to gain a new transposition receipt strain E. coli DH10Bac-egfp. Because of the intact attTn7 sites and lacZ', target gene cloned in a pFastBac vector can be transposed into the Bacmid-egfp shutter vector to construct recombinant baculovirus, which would allow the tracing of the target protein expression and the recombinant Bacmid transfection or recombinant baculoviral infection under fluorescence microscopes. Recombinant virus Bac-egfp-DsRed was constructed by transposing DsRed into the Bacmid-egfp in E. coliDHl0Bac-egfp, and the Sf9 cells infected with the recombinant virus expressed DsRed and EGFP efficiently. Another protein IL-6 fused with 6 x his tag was expressed and purified sucessfully from Sf9 cells infected with recombinant virus Bac-egfp-6 x his-IL6 constructed by the improved Bac-to-Bac system.
authors.affiliation: Southwest Jiaotong University Pharmacy College, 614202, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Yao
authors.forename: Lun-Guang
authors.initials: LG
authors.lastname: Yao
authors.forename: Yun-Chao
authors.initials: YC
authors.lastname: Kan
authors.forename: Wen-Ke
authors.initials: WK
authors.lastname: Zhou
authors.forename: Yi-Peng
authors.initials: YP
authors.lastname: Qi
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis*; D018411:Spodoptera
chemical_list: D015850:Interleukin-6; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins