title: Complex kinetics of binding of human alpha-2 interferon to human, but not bovine cells.
abstract: Human alpha-2 interferon (HuIFN-alpha 2) is an effective antiviral agent for bovine cells, but does not inhibit the proliferation of these heterologous cells. A comparison of the kinetics of binding of 125I-HuIFN-alpha 2 at 4 degrees C to several bovine and human cells, shows that the kinetics of the initial receptor interactions are very different in the two species. Binding of HuIFN-alpha 2 to bovine cells follows the simple kinetics predicted for one species of ligand interacting with one type of high-affinity receptor. The kinetics of binding to human cells showing a range of sensitivities to the antigrowth effect are complex and indicate that receptor occupancy increases the rate of association of ligand. It is suggested that dimers of HuIFN-alpha 2 may be formed on the human, but not the bovine receptor, and where these occur between receptors, their formation may relate to the inhibition of cell growth.
mesh_terms: D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D006801:Humans; D007370:Interferon Type I / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D011487:Protein Conformation; D011971:Receptors, Immunologic / Q000378:metabolism; D017471:Receptors, Interferon; D013045:Species Specificity
chemical_list: D007370:Interferon Type I; D011971:Receptors, Immunologic; D017471:Receptors, Interferon