title: Production in Escherichia coli of human thymosin beta 4 as chimeric protein with human tumor necrosis factor.
abstract: We have produced thymosin beta 4 protein in Escherichia coli as a chimeric protein with tumor necrosis factor (TNF). The protein was abundantly expressed, was immunoreactive against both anti-thymosin beta 4 and anti-TNF antibodies, and retained cytotoxicity in a TNF assay using mouse L929 fibroblasts. This latter characteristic enabled the easy and simple purification of thymosin beta 4 merely by following the TNF activity. The chimeric protein was designed to have an Asp-Pro bridge between thymosin beta 4 and TNF which could be specifically cleaved under suitable acidic conditions to release the thymosin beta 4 from the chimeric protein. These results indicate that the expression system in E.coli of a chimeric protein composed of thymosin beta 4 and TNF is appropriate for obtaining an abundant amount of the beta 4 peptide, especially since its purification from tissues is usually difficult because of limited yield and obscurity of its biological activity.
authors.affiliation: Biotechnology Research Center, Teikyo University, Kanagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuji
authors.forename: N
authors.initials: N
authors.lastname: Kitahara-Tanabe
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.forename: T
authors.initials: T
authors.lastname: Gatanaga
authors.forename: D
authors.initials: D
authors.lastname: Mizuno
authors.forename: G
authors.initials: G
authors.lastname: Soma
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000096:biosynthesis*; D013947:Thymosin / Q000096:biosynthesis* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D013947:Thymosin