Analysis of murine interferon-gamma binding to its receptor on intact cells and solubilized membranes. Identification of an 80 kDa receptor.
The receptor for murine-interferon-gamma (Mu-IFN-gamma) has been characterized for its molecular size and equilibrium binding constant on a thymoma cell line, EL-4. Binding of 125I-IFN-gamma to intact cells and their solubilized membranes has shown a single class of receptor with Kd values of 1.9 x 10(-9) M and 1.3 x 10(-8) M, respectively. It was shown that solubilization of the Mu-IFN-gamma receptor with a Zwitterionic detergent (Chaps) preserves its binding activity. A direct comparison of the molecular mass of the Mu-IFN-gamma receptor on intact cells versus detergent-solubilized membranes was performed using a radiolabeled photoactivated crosslinking reagent and direct hybridization with 125I-labeled IFN-gamma on Western blots of solubilized receptor. The results indicate that both types of receptors have an identical molecular mass of approximately 80 kDa.
Cofano
F
F
National Cancer Institute, Bethesda, Maryland 20892.
Landolfo
S
S
Appella
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E
Ullrich
S J
SJ
D000345:Affinity Labels; D000818:Animals; D015153:Blotting, Western; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism; D003432:Cross-Linking Reagents; D007371:Interferon-gamma / Q000378:metabolism*; D051379:Mice; D008970:Molecular Weight; D011971:Receptors, Immunologic / Q000378:metabolism*; D017471:Receptors, Interferon; D014407:Tumor Cells, Cultured
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D007371:Interferon-gamma