ABSTRACT
<p><b>OBJECTIVE</b>To study the relationship between the structure and functional activity of hTNF alpha.</p><p><b>METHODS</b>Four hTNF alpha mutants were constructed, different binding structures and gene responses related with these mutants were studied by the methods of immunoprecipitation and mRNA differential display.</p><p><b>RESULTS</b>The specific activities and LD50 of the different hTNF alpha mutants indicated their different bioactivities. It was shown that the hTNF alpha mutants had the relative binding affinities to the wild types. The mRNA differential display assay proved that the hTNF alpha mutants stimulated different gene responses.</p><p><b>CONCLUSION</b>These results suggest that the specific anti-tumor activities of hTNF alpha mutants are accomplished by inducing different or same gene response at different quantities after its binding to specific receptor.</p>