title: Significance of the 56th tyrosine on cytotoxic activity of tumor necrosis factor.
abstract: After using site-specific mutagenesis a conserved amino acid residue, the 56th tyrosine in human tumor necrosis was substituted by glutamine. The expression level of the mutant protein in E. coli did not changed significantly, however, its specific activity of the cytotoxicity on L929 cultural cells was decreased to 1/583 of that of the unmutant tumor necrosis factor. The results show that the 56th tyrosine residue or the region where tyrosine 56th located is important for the cytotoxic activity of tumor necrosis factor.
authors.affiliation: Fourth Military Medical University, Xian, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Zhi
authors.forename: C
authors.initials: C
authors.lastname: Su
mesh_terms: D001483:Base Sequence; D003602:Cytotoxicity, Immunologic / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009841:Oligonucleotides / Q000138:chemical synthesis; D013329:Structure-Activity Relationship; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000276:immunology; D014443:Tyrosine / Q000235:genetics*
chemical_list: D009841:Oligonucleotides; D014409:Tumor Necrosis Factor-alpha; D014443:Tyrosine