scholarly journals The relation between lipid mobility and the specific hormone binding of thyroid membranes

1975 ◽  
Vol 146 (2) ◽  
pp. 473-479 ◽  
Author(s):  
C L Bashford ◽  
S J Harrison ◽  
G K Radda ◽  
Q Mehdi
Keyword(s):  
Plasma Membranes ◽  
Membrane Lipids ◽  
Specific Binding ◽  
Thyroid Stimulating Hormone ◽  
Human Thyroid ◽  
Hormone Binding ◽  
Cortical Cells ◽  
Lipid Mobility ◽  
Number Of Binding Sites ◽  
Adrenal Cortical Cells

1. The specific binding of thyroid-stimulating hormone to isolated human thyroid membranes was examined under a variety of conditions. 2. In phosphate-saline buffer (in the presence of 0.14 M-NaCl) on increasing the temperature the binding of the hormone is increased, the plots of bound/free hormone against temperature showing a distinct break around 30 degrees C. 3. Detailed analysis showed that the increased binding is associated with an increase in the number of binding sites. 4. The motional characteristics of three membrane-bound fluorescent probes, 2-(9-anthroyl)palmitic acid, 12-(9-anthryl)stearic acid and N-1-naphthyl-N-phenylamine, were also examined as a function of temperature by measuring both fluorescence polarizations and lifetimes. 5. The results indicated that the ‘fluidity’ of membrane lipids also increased with temperature. The temperature-dependence of this property also shows a change at about 30 degrees C. 6. Bivalent cations decreased both membrane fluidity and hormone binding. 7. Similar correlations were found between the binding of adrenocorticotrophic hormone and the fluidity of the plasma membranes obtained from adrenal-cortical cells, with the discontinuity occurring in this case at 23 degrees C. 8. The possibility of lipid mobility being important in controlling hormone-receptor function is discussed.

SPECIFIC BINDING OF THYROID-STIMULATING HORMONE BY HUMAN SERUM GLOBULINS

1981 ◽  
Vol 88 (3) ◽  
pp. 339-349 ◽  
Author(s):  
J. BÍRÓ
Keyword(s):  
Binding Sites ◽  
Binding Capacity ◽  
Specific Binding ◽  
Negative Control Group ◽  
Paper Electrophoresis ◽  
Negative Control ◽  
Thyroid Stimulating Hormone ◽  
Human Thyroid ◽  
Control Group ◽  
Binding Characteristics

Globulin preparations (41) from patients with Graves's disease (positive to thyroid stimulating immunoglobulins; TSI) and 12 from healthy persons (TSI-negative) were tested for their specific thyrotrophin (TSH)-binding properties. Globulins from both groups possessed binding sites for 131I-labelled TSH. The mean dissociation constant (Kd) was 6·8 pmol/l per mg globulin and the maximum specific binding (Bmax) was 3·0 pmol/mg globulin per 1 for the TSI-negative control group. Twenty-four (58·5%) globulin preparations from the TSI-positive group had similar TSH-binding characteristics with mean Kd of 7·2 pmol/l per mg globulin and Bmax of 3·6 pmol/mg globulin per 1 (A-type binding) but the remaining 17 (41·5%) bound TSH in a different fashion with Kd of 71·5 pmol/l per mg globulin and Bmax of 13·6 pmol/mg globulin per 1 (B-type binding). Both types of specific TSH binding reached the maximal level within 1 h of incubation and had an optimum pH of 7–8. There was a linear correlation between the amount of bound TSH and the globulin content of the samples. Both types of binding were reversible by the addition of an excess of TSH and gonadotrophins, ACTH, prolactin and insulin competed with TSH for the binding sites only when in relatively high concentrations. The binding sites were associated with macromolecules; they emerged with the void volume after chromatography on Sephadex G-200 and migrated with immunoglobulin G (IgG) on paper electrophoresis. The binding capacity of the globulin preparations could be decreased by preincubation with antiserum to human IgG or with human thyroid membranes.

SPECIFIC RECEPTORS FOR PROLACTIN IN THE OVARY

1975 ◽  
Vol 80 (1) ◽  
pp. 126-137 ◽  
Author(s):  
Tokuko Saito ◽  
Brij B. Saxena
Keyword(s):  
Protein Concentration ◽  
Plasma Membranes ◽  
Ovarian Function ◽  
Specific Binding ◽  
Receptor Protein ◽  
Tissue Homogenate ◽  
Mammary Tissue ◽  
Number Of Binding Sites ◽  
Specific Receptors

ABSTRACT A role of prolactin (PRL) in ovarian function has been suggested in several species, but not unequivocally established except in the rat. We, therefore, examined the presence of specific receptor for PRL in ovaries of rat, cow, and human. Human PRL (hPRL) labelled with 125I by the lactoperoxidase method was shown to be capable of specific binding to rat mammary tissue homogenate. Human, cow, and rat ovarian homogenates and/or partially purified plasma membranes were also shown to specifically bind 125I-hPRL. Binding was a saturable phenomenon and was dependent on receptor protein concentration. Optimal binding was observed at pH 7.0 and at 37°C. Binding was reversibly inhibited by exposure of membranes to pH 10.0 and irreversibly destroyed by exposure to pH 3.0. Bound 125I-hPRL was displaceable by unlabelled human, ovine, and bovine PRL but not by FSH or LH. However, human chorionic somatomammotrophin (hCS) and hGH showed some competition with 125I-hPRL. Number of binding sites/mg protein was lowest (0.8 × 10−12 m) during metoestrus and increased during dioestrus (11 × 10−12 m) reaching the maximum number at pro-oestrus (24.6 × 10−12 m). These results demonstrate that presence of specific PRL receptor in the ovaries and are consistent with a role of PRL at the ovarian level.

scholarly journals Extended Hormone Binding Site of the Human Thyroid Stimulating Hormone Receptor

2008 ◽  
Vol 283 (26) ◽  
pp. 18048-18055 ◽  
Author(s):  
Sandra Mueller ◽  
Gunnar Kleinau ◽  
Holger Jaeschke ◽  
Ralf Paschke ◽  
Gerd Krause
Keyword(s):  
Binding Site ◽  
Hormone Receptor ◽  
Thyroid Stimulating Hormone ◽  
Human Thyroid ◽  
Hormone Binding ◽  
Stimulating Hormone

Effects of hypophysectomy and GH administration on bovine and human GH binding to rat liver membranes

1985 ◽  
Vol 249 (1) ◽  
pp. E56-E62
Author(s):  
J. L. Messina ◽  
S. Eden ◽  
J. L. Kostyo
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Human Growth ◽  
Male Rats ◽  
Normal Male ◽  
Number Of Binding Sites ◽  
Liver Membranes ◽  
Isolated Liver

Experiments were conducted to investigate the specific binding of highly purified bovine and human growth hormones (bGH and hGH) to purified liver plasma membranes of male rats at various times after hypophysectomy and after the acute intravenous administration of bGH. Liver membranes prepared from hypophysectomized male rats showed a two- to threefold increase in the specific binding of either [125I]iodo-bGH or [125I]iodo-hGH, when compared with membranes prepared from the livers of age-matched normal male rats. The increase in GH binding was apparent within 3 days after hypophysectomy and persisted for a number of weeks after the operation. The increase in GH binding produced by hypophysectomy appeared to be due to an increase in the number of binding sites present on the membranes. The intravenous injection of 200 micrograms of bGH into hypophysectomized male rats 5-60 min before they were killed markedly reduced the ability of liver membranes prepared from these animals to bind [125I]iodo-bGH specifically. This decrease in GH binding seen after the injection of bGH may have been due to the development of a slowly dissociating hormone-binding site complex, which thereby reduced the number of available binding sites. This conclusion is supported by the finding that bGH, which is bound in vitro to isolated liver membranes, dissociates slowly and incompletely in the presence of an excess of unlabeled hormone. Moreover, the degree to which the bound hormone can dissociate appears to depend on the length of time that association is allowed to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin binding to liver plasma membranes in salmonids with modified plasma insulin levels

1991 ◽  
Vol 69 (11) ◽  
pp. 2745-2750 ◽  
Author(s):  
Joaquim Gutiérrez ◽  
Erika M. Plisetskaya
Keyword(s):  
Binding Affinity ◽  
Plasma Insulin ◽  
Plasma Membranes ◽  
Coho Salmon ◽  
Binding Capacity ◽  
Specific Binding ◽  
Insulin Binding ◽  
Term Treatment ◽  
Liver Plasma Membranes ◽  
Number Of Binding Sites

Insulin binding to the liver plasma membranes was assessed in coho salmon (Oncorhynchus kisutch) injected intraperitoneally with 6.6 μmol arginine/g body weight, and in rainbow trout (Oncorhynchus mykiss) fasted for 40 days and then refed for 15 days. Corresponding control groups of fish were injected with saline (coho salmon) or fed regularly (trout). Arginine injection was followed by a substantial elevation of plasma insulin titres from 12.5 to 76.8 ng/mL, an increase in the binding capacity and, consequently, an increase in specific binding of insulin to the liver plasma membranes from 3.4 to 5.5%. The binding affinity remained unchanged. Food deprivation lowered plasma insulin titres from 13.2 to 3.0 ng/mL, increased the binding capacity, but decreased the binding affinity, so the specific binding remained essentially unchanged (5.6% in fed versus 5.1% in fasted fish). Refeeding of fasted fish resulted in restoration of insulin levels and an increase in binding affinity relative to both control and fasted groups of fish. This led to a substantial elevation of the specific binding of insulin up to 7.1%. The binding of insulin to liver plasma membranes in salmonids depends both on the number of binding sites (binding capactity) and on the binding affinity. Long-term treatment, such as food deprivation, resulted in altered affinity and capacity of binding, whereas short-term treatment, such as arginine injection, affected mostly the binding capacity. Modulation of the number of binding sites in liver plasma membrane according to the insulin level was observed only in experiments on trout conducted at a higher (15 °C) water temperature.

scholarly journals Immunohistochemical localization of a thyroid hormone-binding protein (p55) in human tissues.

1987 ◽  
Vol 35 (10) ◽  
pp. 1043-1046 ◽  
Author(s):  
M C Willingham ◽  
A V Rutherford ◽  
S Y Cheng
Keyword(s):  
Endoplasmic Reticulum ◽  
Thyroid Hormone ◽  
Cultured Cells ◽  
Binding Protein ◽  
Immunohistochemical Localization ◽  
Hormone Binding ◽  
Cortical Cells ◽  
Multiple Organs ◽  
Hormone Binding Protein ◽  
Adrenal Cortical Cells

We have localized p55, a thyroid hormone-binding protein found in the endoplasmic reticulum in cultured cells, in samples of normal human and monkey tissues, using a monoclonal antibody with cryostat sections and immunoperoxidase histochemistry. Large amounts of p55 were found in many tissues, generally corresponding to the amount of endoplasmic reticulum contained in each cell type. Intense localization of p55 was found in cells of the anterior and intermediate pituitary lobes, in epithelial cells of thyroid follicles, in the glandular epithelium of mammary gland, in hepatocytes, in Paneth cells and Brunner's glands in duodenum, in acinar cells of pancreas, in adrenal cortical cells, and in scattered interstitial fibroblastic cells in many tissues. These results suggest a potential role for thyroid hormone and p55 in regulating protein synthesis or secretion in multiple organs.

Studies of thyroid-stimulating hormone binding to bovine thyroid plasma membranes

Metabolism ◽  
1975 ◽  
Vol 24 (8) ◽  
pp. 959-971 ◽  
Author(s):  
Masanobu Kotani ◽  
Toshitsugu Kariya ◽  
James B. Field
Keyword(s):  
Plasma Membranes ◽  
Thyroid Stimulating Hormone ◽  
Hormone Binding ◽  
Bovine Thyroid ◽  
Stimulating Hormone
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