title: [1,6-alpha-aminosuberic acid,3-(p-azidophenylalanine), 8-arginine] vasopressin as a photoaffinity label for renal vasopressin receptors: an evaluation.
abstract: The photoreactive analog of vasopressin [1,6-alpha-aminosuberic acid,3-(p-azidophenylalanine), 8-arginine]vasopressin was labeled with tritium (specific radioactivity: 39 Ci/mmole). In the absence of UV-light, the tritium-labeled ligand retained a high binding affinity to the vasopressin receptor in plasma membranes from bovine kidney inner medulla (apparent dissociation constant KD: 1.4 X 10(-8) M). Renal plasma membranes were irradiated under conditions of a high ratio of specific versus non-specific binding of the reactive ligand. Sodium dodecyl sulfate gel electrophoresis after solubilization and reduction demonstrated the preferential labeling of a polypeptide with an apparent molecular weight of Mr = 32 000. A comparison with stained gels revealed that this protein is a minor constituent of the bovine kidney membrane. Our results suggest the 32 000-dalton polypeptide is either a component of the vasopressin receptor or that it is located in the immediate vicinity of the vasopressin binding protein.
mesh_terms: D000345:Affinity Labels / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives* / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017483:Receptors, Vasopressin; D014316:Tritium; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D000345:Affinity Labels; D011956:Receptors, Cell Surface; D017483:Receptors, Vasopressin; D014316:Tritium; D014667:Vasopressins; D001127:Arginine Vasopressin; C040153:argipressin, Asu(1,6)-Phe(4-N3)(3)-