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Reovirus type 3 and [125I]-iodocyanopindolol bind to distinct domains on the beta-adrenergic like receptor.

Authors :
Liu J
Co MS
Greene MI
Source :
Immunologic research [Immunol Res] 1988; Vol. 7 (3), pp. 232-8.
Publication Year :
1988

Abstract

Antireceptor antibodies have been developed as a probe to study the cellular receptor for reovirus type 3. Using this probe, a glycoprotein with a molecular weight of 65-67 kilodaltons and a pI of 5.8-6.0 was isolated and identified as the reovirus receptor. This protein was also structurally similar to the affinity-purified beta-adrenergic receptor from calf lung. In this report, we employ [125I]-iodocyanopindolol, a high affinity beta-adrenergic antagonist, to further characterize this protein. We show that R1.1, a murine thymoma cell line, possesses about 2,000 receptors per cell with high affinity for ICYP (kD = 3.3 X 10(-11) M). Competitive inhibition studies suggest that the receptor is of the beta-2 subtype. Solubilized receptor proteins from R1.1 cells bound to the antireceptor antibody were further purified by SDS-PAGE and electroelution from the gel. Five percent of the proteins thus obtained could bind ICYP with high affinity (kD = 1.6 X 10(-10) M). This suggests that the purification procedure produced a collection of forms of this 65- to 67-kilodalton protein, some of which retained the conformation for binding the beta ligands. We also demonstrate that the isolated receptor protein was able to bind ICYP even when the virus binding site was occupied by the anti-idiotype, suggesting that reovirus type 3 and the beta ligands bind to distinct domains on the receptor protein.

Details

Language :
English
ISSN :
0257-277X
Volume :
7
Issue :
3
Database :
MEDLINE
Journal :
Immunologic research
Publication Type :
Academic Journal
Accession number :
2903881
Full Text :
https://doi.org/10.1007/BF02918138