title: A V1-vascular vasopressin antagonist suitable for radioiodination and photoaffinity labeling.
abstract: We have previously characterized the V1-vascular arginine vasopressin (AVP) receptors of human platelets (Thibonnier M, J Biol Chem 1987;262: 10960-10964). We now report on a radiomonoiodinated and photoreactive V1-vascular AVP antagonist (V1-ag) to be used for the purification of human V1-vascular AVP receptors. The V1-ag, d(CH2)5Tyr(Me)Tyr(NH2)AVP was modified by radiomonoiodination of d(CH2)5-Tyr(Me)Tyr(NH2)AVP with the Iodogen technique, and derivatization of d(CH2)5Tyr(Me)Tyr[125I](NH2)-AVP with the photoreactive crosslinker, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) (each step included HPLC purification). In competition experiments, the affinity of these V1-ag for the human platelet AVP receptors remained excellent: [table: see text] Irreversible photoaffinity labeling of the platelet V1-vascular AVP receptor was successfully achieved by UV lamp exposure (365 nm, 20 min). Thus, AzBz-d(CH2)5Tyr(Me)Tyr[125I](NH2)AVP is a promising tool to use for the purification of human V1-vascular AVP receptors.
authors.affiliation: Department of Medicine, University Hospital of Cleveland, Case Western Reserve University School of Medicine, Ohio 44106.
authors.forename: M
authors.initials: M
authors.lastname: Thibonnier
authors.forename: N
authors.initials: N
authors.lastname: Chehade
authors.forename: A
authors.initials: A
authors.lastname: Hinko
mesh_terms: D000345:Affinity Labels; D001127:Arginine Vasopressin / Q000031:analogs & derivatives / Q000378:metabolism; D001386:Azides; D001792:Blood Platelets / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D014667:Vasopressins / Q000037:antagonists & inhibitors*
chemical_list: D000345:Affinity Labels; D001386:Azides; D007457:Iodine Radioisotopes; D014667:Vasopressins; D001127:Arginine Vasopressin; C055245:argipressin, beta mercapto-beta,beta-cyclopentamethylenepropionic acid(1)-O-methyl-Tyr(2)-TyrNH2(9)-; C029534:hydroxysuccinimidyl-4-azidobenzoate