[Preparation of a mutant human tumor necrosis factor with increased resistance to proteases]

The potential proteolysis sites of human TNF are considered. By site-directed mutagenesis the Arg-31 residue of mature TNF was substituted by Gln. The analysis of cytotoxicity of initial and mutant (R31Q) proteins on mouse L929 fibroblasts did not reveal any differences in biological activity. For the mutant protein a change in proteolysis dynamics was shown in contrast to the natural variant: mutant TNF displayed increased stability when treated with trypsin.