title: Solubilization and characterization of thyrotropin-releasing hormone receptors from rat brain.
abstract: The thyrotropin-releasing hormone receptor from rat brain was solubilized in a stable unbound form. The natural glycoside digitonin was the only detergent of a variety tested capable of solubilizing the active receptor. The digitonin-solubilized receptor exhibited binding kinetics for 3-[3H]methylhistidine thyrotropin-releasing hormone virtually identical to membrane preparations and responded with a similar order of potency to a series of thyrotropin-releasing hormone analogues that inhibit binding of the labeled ligand. Gel filtration analysis and sucrose density gradient centrifugation indicated a Stokes radius of 5.2 nm, a sedimentation coefficient of 11.2 s, and a corresponding calculated molecular weight of 244,000 for the detergent-receptor complex. The soluble receptor shows a gradual loss of binding activity over 48 to 72 hr when kept at 4 degrees C. However, the preparation may be frozen at -20 degrees C with no significant loss of activity.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004072:Digitonin; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000302:isolation & purification* / Q000378:metabolism; D018025:Receptors, Thyrotropin-Releasing Hormone; D012995:Solubility; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D018025:Receptors, Thyrotropin-Releasing Hormone; D013973:Thyrotropin-Releasing Hormone; D004072:Digitonin