Characterization and solubilization of the human platelet vasopressin receptor
The authors recently showed that human platelets bear specific vasopressin (AVP) V1-vascular receptors. They now present the identification of AVP intra-platelet messenger and solubilization of AVP receptors. AVP binding to its platelet receptors is modulated by divalent cations but not TP or Gpp(NH)p, (10 /sup 3/M). AVP-induced reduction of adenylate cyclase activity is blocked by a phospholipase C inhibitor. In the presence of calcium (1 mM), AVP stimulates the phosphorylation of two endogenous proteins (M.W. = 40,000 and 20,000 daltons) which are substrates for protein kinase C and calcium calmodulin-dependent kinase, respectively. Phosphorylation is also stimulated by a V1-vascular agonist but not V2-renal agonists and is more potently blocked by a V1-vascular antagonist than by a V2-renal antagonist. AVP platelet membrane receptor is solubilized with 3-((3-cholamidopropyl)-dimethylammonio)-1-propane sulfonate. Separation of free (/sub 3/H)AVP from solubilized receptor-hormone complexes is done by filtration through polyethylenimine-treated filters. The solubilized receptor retains its binding characteristics (Kd = 11.03 +/- 1.86 nM, Bmax 288 +/- 66 fmol/mg protein, n = 6). In human platelets, AVP intra-cellular messengers are diacylglycerol and calcium, not adenylate cyclase. Solubilization of AVP human receptor opens the way to its purification.
- Research Organization:
- Medical College of Ohio, Toledo
- OSTI ID:
- 5498282
- Report Number(s):
- CONF-8604222-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:3; ISSN FEPRA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD PLATELETS
BODY FLUIDS
CALCIUM
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CYCLASES
ELEMENTS
ENZYME INHIBITORS
ENZYMES
HORMONES
IONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LYASES
MATERIALS
MEMBRANE PROTEINS
METALS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORYLATION
PITUITARY HORMONES
PROTEINS
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VALENCE
VASOPRESSIN