title: Expression, in Escherichia coli, of a soluble human tumor necrosis factor receptor.
abstract: We have expressed in Escherichia coli a soluble, truncated form of the human 55 kDa Tumor Necrosis Factor (TNF) receptor. For this purpose a plasmid was constructed which contains the extracellular domain of the 55 kDa TNF receptor fused to the coding sequence of the IgG binding domains of protein A from Staphylococcus aureus. The fusion product (TNFR-PA) obtained in E. coli is a soluble protein which bound human TNF alpha (huTNF alpha) with high affinity. In ligand-blotting experiments huTNF alpha bound to a single 52 kDa protein, a molecular mass corresponding to that expected for the monomeric fusion product. In gel filtration experiments binding activity was recovered from fractions that eluted at a volume corresponding to 140-150 kDa. TNFR-PA neutralized huTNF alpha in an in vitro cytotoxicity assay.
authors.affiliation: Department of Biotechnology, Farmitalia Carlo Erba, Nerviano, Italy.
authors.forename: M B
authors.initials: MB
authors.lastname: Saccardo
authors.forename: L
authors.initials: L
authors.lastname: Grazioli
authors.forename: E
authors.initials: E
authors.lastname: Cozzi
authors.forename: P
authors.initials: P
authors.lastname: Sarmientos
authors.forename: F
authors.initials: F
authors.lastname: Marcucci
mesh_terms: D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D012995:Solubility; D013205:Staphylococcal Protein A / Q000096:biosynthesis
chemical_list: D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; D013205:Staphylococcal Protein A