Characterization of human interferon-gamma receptor purified from placenta.
Membranes prepared from human placenta were used for characterization of the receptor for human interferon-gamma (HuIFN-gamma) after large-scale purification. HuIFN-gamma linked covalently to Affigel-10 was used for the purification of the receptor from octylglucoside-solubilized placental membranes. Radiolabeled IFN-gamma [32P]HuIFN-gamma, was used in binding and cross-linking studies to detect the receptor at different stages of the purification. From binding assays it was calculated that an average placenta contained 90-120 micrograms of receptor with a Kd value of 1.3 x 10(-9) M. Thus, human placenta is a rich and convenient source of receptor for IFN- gamma. When purified receptor was cross-linked to [32P]HuIFN-gamma, a variety of cross-linked bands were detected dependent on the preparation conditions. The use of protease inhibitors in the course of processing prevented degradation of the 90-kD intact receptor, showing that the lower-molecular-weight products detected in previous studies are degradation products of the receptor. Furthermore, a 20-kD fragment of the receptor was found to be active in binding HuIFN-gamma.
Stefanos
S
S
University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Department of Molecular Genetics and Microbiology, Piscataway 08854-5635.
Ahn
Y H
YH
Pestka
S
S
D003432:Cross-Linking Reagents; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D010920:Placenta / Q000276:immunology* / Q000378:metabolism; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000302:isolation & purification / Q000378:metabolism*; D017471:Receptors, Interferon
D003432:Cross-Linking Reagents; D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D007371:Interferon-gamma