title: Coexpression of interleukin-6 and -2 from giant panda in Escherichia coli and the biological activity of the fusion protein.
abstract: To construct a fusion cytokine protein with more and stronger bioactivities to enhance the immunity of the cytokine alone, we expressed interleukin (IL)-6/(IL)-2 from giant panda (Ailuropoda melanoleuca) in Escherichia coli as a 59.4-kDa fusion protein. Subsequently, the inclusion bodies were solubilized with 8 M urea and applied onto a Ni-nitrilotriacetic acid column. The final production of IL-6/IL-2 reached 6 mg/L in soluble form, and the purified final product was >96% pure. In Western blot assays, the recombinant IL-6/IL-2 was recognized by polyclonal antibodies against IL-6 and IL-2 of giant panda. The results demonstrated that the protein mixture contained correctly folded IL-2 and IL-6 proteins. A 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide assay demonstrated that IL-6/IL-2 can promote lymphocyte proliferation and differentiation. These data suggest that the fusion protein could be used to develop a novel immunoadjuvant to enhance the immunity of animals against infectious diseases.
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Yuchen, Ya'an, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yi
authors.forename: Y-Y
authors.initials: YY
authors.lastname: Nian
authors.forename: H-W
authors.initials: HW
authors.lastname: Ji
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: Z-W
authors.initials: ZW
authors.lastname: Xu
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D001503:Ursidae / Q000235:genetics* / Q000378:metabolism
chemical_list: D007376:Interleukin-2; D015850:Interleukin-6; D011993:Recombinant Fusion Proteins