In-vitro binding of gonadotrophin to fish ovary

1986 ◽  
Vol 111 (3) ◽  
pp. 407-413 ◽  
Author(s):  
Md. Jamal Uddin ◽  
S. Bhattacharya
Keyword(s):  
Plasma Membranes ◽  
Binding Capacity ◽  
Specific Binding ◽  
Ovarian Tissue ◽  
Silver Carp ◽  
Binding Studies ◽  
Binding Characteristics ◽  
Physiological Importance ◽  
Plot Analysis

ABSTRACT Binding of piscine and mammalian gonadotrophin to plasma membranes from the ovaries of a fish, the murrel (Channa punctatus), clearly suggests that the fish ovary possesses distinct and specific binding sites for both piscine and mammalian gonadotrophins. Maximum specific binding of 125I-labelled human chorionic gonadotrophin (125I-hCG) and 125I-labelled silver carp gonadotrophin (125I-scG) was obtained at 30 °C and pH 7·5 during 2 h of incubation. In competitive binding studies, binding of radiolabelled scG was effectively inhibited by piscine gonadotrophins while LH and hCG had less effect and FSH showed no inhibition. By using plasma membrane preparations from kidney, skeletal muscle, brain and ovary it could be shown that specific binding of radiolabelled gonadotrophins was restricted to ovarian tissue. Binding characteristics of both 125I-scG and 125I-hCG to a preparation of murrel ovarian plasma membranes showed saturability with high affinity and low capacity. Scatchard plot analysis gave a higher dissociation constant for hCG (Kd = 235 pmol/l) than for scG (Kd= 127 pmol/l). Maximum binding capacity of scG was about twofold higher (6·27 fmol/mg protein) than that of hCG (3·76 fmol/mg protein). An increase in gonadotrophin binding resulted in a greater formation of pregnenolone from cholesterol, indicating functional relevance. At a concentration of 8 mmol/l, Ca2+ markedly inhibited the binding of gonadotrophin. The physiological importance of this inhibition is discussed. J. Endocr. (1986) 111, 407–413

scholarly journals Contribution of gangliosides to thyroxin binding with plasma membranes

1995 ◽  
Vol 41 (2) ◽  
pp. 28-30
Author(s):  
T. S. Saatov ◽  
F. Ya. Gulyamova ◽  
G. U. Usmanova
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Binding Capacity ◽  
Specific Binding ◽  
Brain Cell ◽  
Cell Recognition ◽  
High Affinity ◽  
Specific Binding Sites

Besides intracellular receptors of thyroid hormones, specific binding sites for T3 and T4 were detected on plasma membranes (PM) of some cells and a relationship between membrane reception .and lipid composition of membranes shown. The parameters of 125I-T4 binding to highly purified PM of hepatic and cerebral cells of rats were studied. The hepatic and cerebral cellular membranes were found to contain two sites of hormone binding each, one of these sites being characterized by a high affinity and low capacity, and the other by low affinity and a higher binding capacity. The association constant of highly affine site of hepatocyte membranes was found to be higher than that of brain cell membranes. T4 membranous receptors may be significant in the process of cell “recognition" by the hormone. In vivo and in vitro experiments with 125I-T4 and 14C-labeled thyroxin in ganglioside fractions showed appreciable binding of the hormone to Gm3 fraction, this evidently pointing to participation of this, ganglioside in T4 interaction with membrane receptor. It is possible that gangliosides situated on membranous surface are components of or function as receptors.

The Identification and Significance of a Thr→Pro Polymorphism in Kringle IV Type 8 of Apolipoprotein(a)

1997 ◽  
Vol 77 (05) ◽  
pp. 0949-0954 ◽  
Author(s):  
J Prins ◽  
F R Lues ◽  
Y Y van der Hoek ◽  
J J.P Kastelein ◽  
B N Bouma ◽  
...  
Keyword(s):  
Case Control Study ◽  
Amino Acid Position ◽  
Case Control ◽  
Binding Studies ◽  
Binding Characteristics ◽  
Apolipoprotein A ◽  
Significant Independent Risk Factor ◽  
And Gender ◽  
Control Study

SummaryElevated plasma levels of lipoprotein(a) [Lp(a)] represent a significant independent risk factor for the development of atherosclerosis. Interindividual levels of apo(a) vary over 1000-fold and are mainly due to inheritance that is linked to the locus of the apolipoprotein(a) [apo(a)] gene. The apo(a) gene encodes multiple repeats of a sequence exhibiting up to 85% DNA sequence homology with plasminogen kringle IV (K.IV), a lysine binding domain. In our search for sequence polymorphisms in the K.IV coding domain, we identified a polymorphism predicting a Thr→Pro substitution located at amino acid position 12 of kringle IV type 8 of apo(a). The functional and clinical significance of this polymorphism was analysed in a case-control study and by comparing the in vitro lysine binding characteristics of the two Lp(a) subtypes.The case-control study (involving 153 subjects having symptomatic atherosclerosis and 153 age and gender matched normolipidemic controls) revealed an overall allele frequency for the Thr12-→Pro substitution in kringle IV type 8 of 14% and a negative association between presence of the Pro12-subtype and symptomatic atherosclerosis (p <0.03). The in vitro lysine binding studies, using Lp(a) isolated from subjects homozygous for either Thr12 or Pro12 in K.IV type 8, revealed comparable lysine-Sepharose binding fractions for the two subtypes. The binding affinity (Kd) for immobilised plasmin degraded des- AA-fibrin (DesafibTM-X) was also comparable for the two subtypes, however a decreased maximal attainable binding (Bmax) for immobilised desafibTM-X was observed for the Pro12-subtype Lp(a).

scholarly journals Rationale design and synthesis of some novel imidazole linked thiazolidinone hybrid molecules as DNA minor groove binders

2020 ◽  
Vol 11 (2) ◽  
pp. 120-132
Author(s):  
Javeed Ahmad War ◽  
Santosh Kumar Srivastava
Keyword(s):  
Molecular Docking ◽  
Binding Affinity ◽  
Specific Binding ◽  
Minor Groove ◽  
Stable Complex ◽  
Binding Studies ◽  
In Vitro Susceptibility ◽  
Reference Drug ◽  
Hybrid Molecules

A new series of imidazole linked thiazolidinone hybrid molecules was designed and subsequently synthesized through a feasible, three step reaction protocol. The structures of these molecules were established using FT-IR, 1H NMR, 13C NMR and HRMS techniques. In vitro susceptibility tests against some Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) exhibited broad spectrum potency of the molecules. The most potent molecule (S2A7) amongst the screened molecules, showed minimum inhibitory concentration (MIC) value not less than 2.0 µg/mL which was at par with the reference drug Streptomycin. Structure activity relationships revealed nitro and chloro groups being crucial for bioactivity when present at meta position of arylidene ring in 3-(3-(imidazol-1-yl)propyl)-5-(benzylidene)-2-(phenylimino)thiazolidin-4-one. Deoxyribonucleic acid (DNA)and bovine serum albumin (BSA) binding studies for S2A7 under simulated physiological pH were probed using UV-Visible, fluorescence quenching, gel electrophoresis and molecular docking techniques. These studies established that S2A7 has strong binding affinity towards DNA and binds at the minor groove of DNA with binding constant (Kb) of 0.1287×102 L/mol. Molecular docking simulations of S2A7 with DNA and BSA predicted binding affinity of -9.2 and -7.2 kcal/mol, respectively. Van der Waals forces and hydrogen bonding interactions were predicted as the main forces of interaction. With DNA, S2A7 exhibited specific binding affinity towards adenine-thiamine base pairs. The compound S2A7 forms a stable complex with BSA by binding at subdomain IIIA implying high bio-distribution of the compound.

Development of a Selective Adsorbing Material for Binding of Pyrrolizidine Alkaloids in Herbal Extracts, Based on Molecular Group Imprinting

Planta Medica ◽  
2019 ◽  
Vol 85 (13) ◽  
pp. 1107-1113 ◽  
Author(s):  
Thomas Kopp ◽  
Mona Abdel-Tawab ◽  
Martin Khoeiklang ◽  
Boris Mizaikoff
Keyword(s):  
Pyrrolizidine Alkaloids ◽  
Binding Capacity ◽  
Specific Binding ◽  
Pyrrolizidine Alkaloid ◽  
Daily Intake ◽  
Chelidonium Majus ◽  
Molecular Imprinted Polymers ◽  
Binding Characteristics ◽  
Molecular Group ◽  
Plant Constituents

AbstractPyrrolizidine alkaloids are secondary plant constituents that became a subject of public concern because of their hepatotoxic, pneumotoxic, genotoxic, and cytotoxic effects. Due to disregardful harvesting and/or contamination with pyrrolizidine alkaloid-containing plants, there is a high risk of ingesting these substances with plant extracts or natural products. The limit for the daily intake was set to 0.007 µg/kg body weight. If contained in an extract, cleanup methods may help to minimize the pyrrolizidine alkaloid concentration. For this purpose, a material for depleting pyrrolizidine alkaloids in herbal preparations was developed based on the approach of molecular imprinting using monocrotaline. Molecular imprinted polymers are substances with specific binding characteristics, depending on the template used for imprinting. By means of group imprinting, only one molecule is used for creating selective cavities for many molecular pyrrolizidine alkaloid variations. Design of Experiment was used for the development using a 25 screening plan resulting in 64 polymers (32 MIPs/32 NIPs). Rebinding trials revealed that the developed material can compete with common cation exchangers and is more suitable for depleting pyrrolizidine alkaloids than C18- material. Matrix trials using an extract from Chelidonium majus show that there is sufficient binding capacity for pyrrolizidine alkaloids (80%), but the material is lacking in selectivity towards pyrrolizidine alkaloids in the presence of other alkaloids with similar functional groups such as berberine, chelidonine, and coptisine. Beyond this interaction, the selectivity could be proven for other structurally different compounds on the example of chelidonic acid.

scholarly journals Different Forms of TFF2, A Lectin of the Human Gastric Mucus Barrier: In Vitro Binding Studies

2019 ◽  
Vol 20 (23) ◽  
pp. 5871 ◽  
Author(s):  
Franziska Heuer ◽  
René Stürmer ◽  
Jörn Heuer ◽  
Thomas Kalinski ◽  
Antje Lemke ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Gastric Mucus ◽  
Binding Studies ◽  
Binding Characteristics ◽  
Duodenal Glands ◽  
Vitro Binding ◽  
Trefoil Factor Family ◽  
Mucus Barrier ◽  
Mass Form

Trefoil factor family 2 (TFF2) and the mucin MUC6 are co-secreted from human gastric and duodenal glands. TFF2 binds MUC6 as a lectin and is a constituent of the gastric mucus. Herein, we investigated human gastric extracts by FPLC and identified mainly high- but also low-molecular-mass forms of TFF2. From the high-molecular-mass forms, TFF2 can be completely released by boiling in SDS or by harsh denaturing extraction. The low-molecular-mass form representing monomeric TFF2 can be washed out in part from gastric mucosa specimens with buffer. Overlay assays with radioactively labeled TFF2 revealed binding to the mucin MUC6 and not MUC5AC. This binding is modulated by Ca2+ and can be blocked by the lectin GSA-II and the monoclonal antibody HIK1083. TFF2 binding was also inhibited by Me-β-Gal, but not the α anomer. Thus, both the α1,4GlcNAc as well as the juxtaperipheral β-galactoside residues of the characteristic GlcNAcα1→4Galβ1→R moiety of human MUC6 are essential for TFF2 binding. Furthermore, there are major differences in the TFF2 binding characteristics when human is compared with the porcine system. Taken together, TFF2 appears to fulfill an important role in stabilizing the inner insoluble gastric mucus barrier layer, particularly by its binding to the mucin MUC6.

Evidence for a direct action of GH on haemopoietic cells of a marine fish, the gilthead sea bream (Sparus aurata)

1995 ◽  
Vol 146 (3) ◽  
pp. 459-467 ◽  
Author(s):  
J A Calduch-Giner ◽  
A Sitjà-Bobadilla ◽  
P Álvarez-Pellitero ◽  
J Pérez-Sánchez
Keyword(s):  
Binding Sites ◽  
Sparus Aurata ◽  
Binding Capacity ◽  
Specific Binding ◽  
Head Kidney ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Single Class ◽  
Lower Vertebrate

Abstract Receptors for GH were characterized in the head kidney of gilthead sea bream (Sparus aurata), using radioiodinated and biotinylated ligands. The specific binding of radiolabelled recombinant gilthead sea bream GH (rsbGH) to head kidney membrane preparations was dependent on membrane concentration. Salmon prolactin, salmon gonadotrophin and carp gonadotrophin did not compete for 125I-labelled rsbGH-binding sites. Unlabelled rsbGH competitively displaced 125I-labelled rsbGH bound to head kidney membranes. Scatchard plots were always linear, denoting the presence of a single class of binding sites. The binding affinity (Ka=2·7 × 109 m−1) was equivalent to that found in liver membrane preparations, but the binding capacity (2·5 ±0·30 fmol/mg protein) was 50- to 75-fold lower. To identify the cells which express the GH receptor, head kidney smears were incubated with biotinylated rsbGH, followed by incubation with an avidin–biotin complex conjugated to alkaline phosphatase. The reaction with the new-fuchsin substrate gave a red precipitate, showing a specific and intense labelling in erythroblasts, polychromatophilic erythroblasts and myeloblasts. Noticeable binding was observed in myelocytes and immature granulocytes, tending to disappear at the latter stages of granulocyte maturation. Light but appreciable binding was also observed in monocytes, lymphocytes and acidophilic erythroblasts, whereas it was completely absent in proerythrocytes and erythrocytes. The proliferative action of rsbGH and recombinant human IGF-I on in vitro cultures of head kidney cells was demonstrated by a 5-bromo-2′-deoxy-uridine immunoassay. To our knowledge, this is the first report that provides suitable evidence for a role of GH as a haemopoietic growth and differentiation factor in lower vertebrate species. Journal of Endocrinology (1995) 146, 459–467

Receptors for insulin-like growth factor-I in plasma membranes isolated from bovine mesenteric arteries

1988 ◽  
Vol 117 (4) ◽  
pp. 428-434 ◽  
Author(s):  
Karin E. Bornfeldt ◽  
Hans J. Arnqvist ◽  
Hans H. Dahlkvist ◽  
Anna Skottner ◽  
Jarl E. S. Wikberg
Keyword(s):  
Plasma Membranes ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mesenteric Arteries ◽  
Binding Characteristics ◽  
Factor I ◽  
Reducing Conditions ◽  
Ic50 Value ◽  
Igf I ◽  
High Concentrations

Abstract. Binding of IGF-I to plasma membranes from bovine mesenteric arteries was studied. The maximal specific binding of IGF-I was found to be 7.4 ± 1.7% of total 125I-IGF-I added to the incubation medium. Unlabelled IGF-I displaced 125I-IGF-I with an IC50 value of 0.5 nmol/l and a maximal displacement of 64.2 ± 2.8% of total binding. The potency of insulin to displace 125I-IGF-I was 100–1000-fold lower. Crosslinking of 125I-IGF-I to the receptor with disuccinimidyl suberate, followed by SDS-polyacrylamide gel electrophoresis under reducing conditions showed an IGF-I binding protein with a molecular weight of 146000 Dalton. In summary, we have shown the presence of receptors for IGF-I in plasma membranes isolated from macrovessels. The binding characteristics and the size of the binding unit were found to be similar to those of the IGF-1 receptor found in cultured vascular smooth muscle cells. Furthermore, insulin at high concentrations was found to interact with the IGF-I receptor.

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.

Autoradiographic detection of kinin receptors in the human medulla of control, hypertensive, and diabetic donors

2002 ◽  
Vol 80 (4) ◽  
pp. 249-257 ◽  
Author(s):  
Hudson de Sousa Buck ◽  
Brice Ongali ◽  
Gaétan Thibault ◽  
Charles J Lindsey ◽  
Réjean Couture
Keyword(s):  
Receptor Binding ◽  
Binding Sites ◽  
Specific Binding ◽  
Inferior Olivary Nucleus ◽  
Binding Studies ◽  
Specific Binding Sites ◽  
Kinin Receptors ◽  
Medullary Nuclei ◽  
Inferior Olivary

Kinins have been elected to the status of central neuromediators. Their effects are mediated through the activation of two G-protein-coupled receptors, denoted B1 and B2. Functional and binding studies suggested that B1 and B2 receptors are upregulated in the medulla and spinal cord of hypertensive and diabetic rats. The aim of this study was to localize and quantify kinin receptors in post-mortem human medulla obtained from normotensive, hypertensive, and diabetic subjects, using in vitro receptor autoradiography with the radioligands [125I]HPP-HOE140 (B2 receptor) and [125I]HPP[des-Arg10]-HOE140 (B1 receptor). Data showed specific binding sites for B2 receptor (0.4–1.5 fmol/mg tissue) in 11 medullary nuclei from 4 control specimens (paratrigeminal > ambiguus > cuneate, gelatinous layer of the caudal spinal trigeminal nucleus > caudal and interpolar spinal trigeminal, external cuneate, solitary tract > hypoglossal > gracile > inferior olivary nuclei). Increased density of B2 receptor binding sites was observed in seven medullary nuclei of four hypertensive specimens (paratrigeminal > external cuneate > interpolar and caudal spinal trigeminal, gracile, inferior olivary > hypoglossal nuclei). B2 receptor binding sites were seemingly increased in the same medullary nuclei of two diabetic specimens. Specific binding sites for B1 receptor (1.05 and 1.36 fmol/mg tissue) were seen only in the inferior olivary nucleus in two out of the ten studied specimens. The present results support a putative role for kinins in the regulation of autonomic, nociceptive, and motor functions at the level of the human medulla. Evidence is also provided that B2 receptors are upregulated in medullary cardiovascular centers of subjects afflicted of cardiovascular diseases.Key words: bradykinin, hypertension, diabetes, human brain.

Triiodothyronine binding to lymphocyte nuclei and plasma cyclic AMP response to intravenous glucagon in patients with peripheral resistance to thyroid hormones

1981 ◽  
Vol 97 (1) ◽  
pp. 54-59 ◽  
Author(s):  
A. Elewaut ◽  
M. De Baets ◽  
A. Vermeulen
Keyword(s):  
Thyroid Hormone ◽  
Cyclic Amp ◽  
Binding Capacity ◽  
Peripheral Resistance ◽  
Resistance To Thyroid Hormone ◽  
Binding Characteristics ◽  
Nuclear Binding ◽  
Resistance To Thyroid Hormones ◽  
The Family

Abstract. In vitro studies of nuclear binding of triiodothyronine (T3) in lymphocytes were performed in three members of a family with hereditary peripheral resistance to thyroid hormone action. Ficoll-Hypaque® purified lymphocytes were used; the binding characteristics were analyzed by Scatchard's methods. In 5 euthyroid subjects the apparent mean equilibrium association constant (Ka) was 6.1 × 109 1/mol and the mean maximal binding capacity (Cap) 14.4 × 10−15 mol/ 100 μg DNA. In the 3 members of the family one single set of saturable T3 nuclear binding sites with affinity constants similar to those in the controls (mean Ka = 3.2 × 109 1/mol; mean Cap = 17.4 × 10−15 mol/100 μg DNA) were found. The glucagon stimulated increase in plasma cyclic AMP was studied in 6 healthy subjects and the four members of the family. The plasma cyclic AMP levels of the patients with hormone resistance were generally within the normal range. These observations demonstrate that in these patients with peripheral resistance to thyroid hormone binding of T3 to the receptor in the nucleus of lymphocytes is normal; in relation to the high circulating thyroid hormone levels, the thyroid hormone mediated cyclic AMP response is disturbed, suggesting that the defect is at the post-receptor effector level.

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