We have constructed several hybrid human interleukin-6 (IL-6) variants in which the carboxyl-terminus, which includes a receptor binding site of IL-6 has been replaced with the C-terminus of various proteins homologous to human IL-6, IL-6 hybrids with the C-terminus of human growth hormone and human granulocyte-colony stimulating factor maintain part of the biological activity of human IL-6. Replacing the C-terminus of human IL-6 with the C-terminus of mouse and rat IL-6 resulted in a normal or increased activity on a mouse cell line; however, this gave a low (to 200-fold less) activity on a human cell line compared to wild-type human IL-6. We therefore conclude that the C-terminus of IL-6 plays in important role in the species specificity of IL-6.

growth factor, hybrid protein, interleukin-6, interleukin-6 receptor, species specificity
dx.doi.org/10.1016/0014-5793(92)81013-C, hdl.handle.net/1765/61343
F E B S Letters
Department of Hematology

Leebeek, F.W.G, & Fowlkes, D.M. (1992). Construction and functional analysis of hybrid interleukin-6 variants. Characterization of the role of the C-terminus for species specificity. F E B S Letters, 306(2-3), 262–264. doi:10.1016/0014-5793(92)81013-C