Direct association of interleukin-6 with a 130-kDa component of the interleukin-6 receptor system.
Affinity cross-linking of membrane bound 125I-interleukin-6 (IL-6) on several cell lines revealed a three-band pattern of IL-6-containing cross-linked complexes with molecular masses of 100, 120, and 150 kDa. To identify the membrane components that were associated with IL-6 in the three complexes, we employed the Denny-Jaffe reagent, a heterobifunctional, cleavable cross-linker that allows the transfer of 125I from the ligand to its receptor. Samples cross-linked with Denny-Jaffe reagent were analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis in which the cross-linker was cleaved prior to the second dimension. This analysis revealed that IL-6 directly associates with a 130-kDa membrane protein thus allowing the formation of the 150-kDa complex. In addition, both the 100- and 120-kDa cross-linked complexes were shown to include an 80-kDa membrane glycoprotein associated with one and two IL-6 molecules, respectively.
D'Alessandro
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Clinical Pharmacology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Colamonici
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Nordan
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D000818:Animals; D003432:Cross-Linking Reagents; D015180:Electrophoresis, Gel, Two-Dimensional; D015850:Interleukin-6 / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D009101:Multiple Myeloma; D010777:Photochemistry; D011971:Receptors, Immunologic / Q000378:metabolism*; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins / Q000378:metabolism; D013388:Succinimides; D014407:Tumor Cells, Cultured
D003432:Cross-Linking Reagents; D015850:Interleukin-6; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins; D013388:Succinimides; C019358:disuccinimidyl suberate