Biomaterial Database

Graves' immunoglobulins protect the human TSH receptor: further evidence for TSH receptor antibodies in Graves' disease. 1983

T F Davies, and M Platzer

We have investigated whether membrane-bound TSH and Graves' immunoglobulins (Ig) were able to inhibit the action of the disulphide-reducing agent dithiothreitol (DTT) which reduced the binding of 125I-bTSH to thyroid membranes. Human thyroid (20,000 g fraction) was incubated with increasing concentrations of cold bTSH, washed and resuspended in 10 mmol/lDTT for 60 min at 37 degrees C. After the DTT was removed, 70-80% of the receptor-bound bTSH dissociated with 2 mol/l NaCl. In the absence of cold bTSH, 80% of the binding of receptor-purified 125I-bTSH was inhibited after membrane exposure to DTT but in the presence of bTSH-occupied receptor sites there was a dose related protection of the receptors, with 100% protection following incubation with 30 mU/ml bTSH. Like bTSH, immunoglobulin fractions from Graves' sera caused a time-dependent reduction in 125I-bTSH binding-inhibition after incubation and washing of thyroid membranes prior to ligand binding. Approximately 25-40% of this reduction was reversible by exposure to 2 mol/l NaCl. After pre-binding normal Ig to thyroid membranes, and subsequent incubation with DTT, there was no protection of TSH receptors. However, each of the Graves' Ig examined (n = 4) was able to provide protection of the TSH receptor binding sites in proportion to their derived TSH receptor occupancy. Receptor-bound bTSH was, therefore, able to protect the human TSH binding site from disulphide reduction. In addition, Graves' Ig, but not normal Ig, contained antibodies which were able to protect the TSH receptor binding sites in the same way as bTSH.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007136	Immunoglobulins	Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.	Globulins, Immune,Immune Globulin,Immune Globulins,Immunoglobulin,Globulin, Immune
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D011989	Receptors, Thyrotropin	Cell surface proteins that bind pituitary THYROTROPIN (also named thyroid stimulating hormone or TSH) and trigger intracellular changes of the target cells. TSH receptors are present in the nervous system and on target cells in the thyroid gland. Autoantibodies to TSH receptors are implicated in thyroid diseases such as GRAVES DISEASE and Hashimoto disease (THYROIDITIS, AUTOIMMUNE).	Receptors, Thyroid Stimulating Hormone,TSH Receptors,Thyroid Stimulating Hormone Receptors,Thyrotropin Receptors,LATS Receptors,Receptor, LATS Immunoglobulins,Receptors, LATS,Receptors, Long-Acting Thyroid Stimulator,Receptors, TSH,TSH Receptor,Thyroid Stimulating Hormone Receptor,Thyrotropin Receptor,Receptor, TSH,Receptor, Thyrotropin,Receptors, Long Acting Thyroid Stimulator
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's
D006111	Graves Disease	A common form of hyperthyroidism with a diffuse hyperplastic GOITER. It is an autoimmune disorder that produces antibodies against the THYROID STIMULATING HORMONE RECEPTOR. These autoantibodies activate the TSH receptor, thereby stimulating the THYROID GLAND and hypersecretion of THYROID HORMONES. These autoantibodies can also affect the eyes (GRAVES OPHTHALMOPATHY) and the skin (Graves dermopathy).	Basedow's Disease,Exophthalmic Goiter,Goiter, Exophthalmic,Graves' Disease,Basedow Disease,Hyperthyroidism, Autoimmune,Basedows Disease,Disease, Basedow,Disease, Basedow's,Disease, Graves,Disease, Graves',Exophthalmic Goiters,Goiters, Exophthalmic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001323	Autoantibodies	Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.	Autoantibody
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining