Computer-assisted analysis demonstrates that polypeptides induced by natural and recombinant human interferon-alpha are the same and that some have related primary structures.

The biological effects on diploid and trisomy 21 human fibroblasts of pure human interferon IFLrA, a single IFN-alpha species produced from cloned DNA, were compared with those of partially purified natural IFN-alpha. Twelve interferon-induced polypeptides were visualized by two-dimensional gel electrophoresis and autoradiography. Seven of these were shown to have related primary structures and are therefore products of related genes or are related through post-translational modification. Qualitative visual comparisons and computer-aided quantitation of autoradiograms revealed no differences in the patterns of polypeptide induction following treatment with the two types of IFN-alpha, and the two interferons also induced (2'-5') oligoisoadenylate synthetase equally. By these criteria, the activities of the two interferons are qualitatively and quantitatively indistinguishable. In addition, the effects of trisomy 21 on IFLrA-induced polypeptide synthesis and on antiviral response were similar to those previously demonstrated with natural IFN-alpha.