Purification of human interleukin 2 to apparent homogeneity and its molecular heterogeneity.
Interleukin 2 (IL-2), produced with and without co-stimulation by the Burkitt's lymphoma line Daudi, was purified 37,000-fold to apparent homogeneity from lymphocyte conditioned medium by (NH4)2SO4 precipitation, DEAE-cellulose ion-exchange chromatography, gel filtration, and chromatography on blue agarose and on Procion-red agarose. The purified IL-2 showed a 10(6) U/mg protein sp act. IL-2 produced in the absence of Daudi cells had a mol wt of 26,000 as measured by gel filtration and an isoelectric point of 6.7. This IL-2 showed a 16,000 and 17,000 mol wt in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IL-2, produced in the presence of Daudi cells (10(6)/ml), showed a mol wt of approximately 14,000, as measured by both gel filtration and SDS-PAGE, and an isoelectric point of 8.1. The purified IL-2 lacked detectable interferon (alpha and gamma), granulocyte-macrophage colony-stimulating factor, B cell growth factor, T cell-replacing factor, and thymocyte-differentiating activity and was free of any contaminating proteins as judged by silver staining in SDS-PAGE. All three molecular forms of IL-2 were biologically active at concentrations of 10(-11) - 10(-10) M, supporting the growth of human and murine cytotoxic T cell lines.
D000818:Animals; D001681:Biological Assay; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007376:Interleukin-2 / Q000302:isolation & purification* / Q000494:pharmacology; D007525:Isoelectric Focusing; D008222:Lymphokines / Q000302:isolation & purification*; D051379:Mice; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
D007376:Interleukin-2; D008222:Lymphokines