Biomaterial Database

Isoelectric and mass characterization of human platelet thromboxane A2/prostaglandin H2 receptors. 1989

G W Dorn

Department of Medicine, University of Texas Health Science Center, San Antonio 78284.

To further characterize the human thromboxane A2 (TXA2)/prostaglandin H2 (PGH2) receptor, preparative isoelectric focusing (IEF) was performed on solubilized platelet membranes. TXA2/PGH2 receptors, assayed by specific binding of the TXA2/PGH2 antagonist [125I]PTA-OH, were electrofocused at pH 5.6. Scatchard analysis of IEF fraction pH 5.6 revealed a 180-fold concentration of TXA2/PGH2 receptors (Bmax = 3650 +/- 228 pM/mg focused, 19 +/- 4 pM/mg unfocused) with no change in binding affinity (Kd = 47 +/- 7 nM focused, 36 +/- 14 nM unfocused). SDS-polyacrylamide gel electrophoresis of photoaffinity-labelled electrofocused receptors revealed concentration of specifically labelled proteins having molecular masses of 49,000 and 27,000 Daltons. These results suggest that the human platelet TXA2/PGH2 receptor has a pI of 5.6, molecular mass of 49,000 Daltons, and may exist as a dimer. Preparative IEF should prove useful in the eventual purification of this receptor.

UI	MeSH Term	Description	Entries
D007526	Isoelectric Point	The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.	Isoelectric Points,Point, Isoelectric,Points, Isoelectric
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011982	Receptors, Prostaglandin	Cell surface receptors that bind prostaglandins with high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin receptor subtypes have been tentatively named according to their relative affinities for the endogenous prostaglandins. They include those which prefer prostaglandin D2 (DP receptors), prostaglandin E2 (EP1, EP2, and EP3 receptors), prostaglandin F2-alpha (FP receptors), and prostacyclin (IP receptors).	Prostaglandin Receptors,Prostaglandin Receptor,Receptor, Prostaglandin,Receptors, Prostaglandins,Prostaglandins Receptors
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000345	Affinity Labels	Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.	Affinity Labeling Reagents,Labeling Reagents, Affinity,Labels, Affinity,Reagents, Affinity Labeling
D017482	Receptors, Thromboxane	Cell surface proteins that bind THROMBOXANES with high affinity and trigger intracellular changes influencing the behavior of cells. Some thromboxane receptors act via the inositol phosphate and diacylglycerol second messenger systems.	TP Receptors,Thromboxane Receptors,Receptors, Thromboxanes,TP Receptor,Thromboxane Receptor,Receptor, TP,Receptor, Thromboxane,Receptors, TP,Thromboxanes Receptors
D044244	Receptors, Thromboxane A2, Prostaglandin H2	A subclass of eicosanoid receptors that have specificity for THROMBOXANE A2 and PROSTAGLANDIN H2.	Prostaglandin H2 Receptor,Receptors, Prostaglandin H2,Receptors, TXA2-PGH2,Receptors, Thromboxane A2,TXA2-PGH2 Receptors,Thromboxane A2, Prostaglandin H2 Receptors,PGH2 Receptors,Thromboxane A2 Receptor,H2 Receptors, Prostaglandin,Prostaglandin H2 Receptors,Receptor, Prostaglandin H2,Receptors, PGH2,Receptors, TXA2 PGH2,TXA2 PGH2 Receptors