High affinity specific antiestrogen binding sites are concentrated in rough microsomal membranes of rat liver

1984 ◽  
Vol 120 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Colin K.W. Watts ◽  
Robert L. Sutherland
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
High Affinity ◽  
Microsomal Membranes

scholarly journals The association in vitro of polyribosomes with ribonuclease-treated derivatives of hepatic rough endoplasmic reticulum. Characteristics of the membrane binding sites and factors influencing association

1971 ◽  
Vol 125 (1) ◽  
pp. 67-79 ◽  
Author(s):  
T. K. Shires ◽  
L. Narurkar ◽  
H. C. Pitot
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
Binding Capacity ◽  
Trypsin Treatment ◽  
Partial Removal ◽  
Adult Rat ◽  
Microsomal Membranes ◽  
Derivatives Of ◽  
Membrane Binding Sites

1. Pancreatic ribonuclease in dilute EDTA has been shown to condition rough-microsomal membranes from adult rat liver to accept exogenously added rat liver polyribosomes in vitro at 0–4°C. Treated smooth membranes would not significantly interact with polyribosomes. 2. The conditioning process decreased the membrane RNA content and removed polyribosomes from vesicle surfaces as viewed electron-microscopically. 3. Binding to these conditioned membranes was shown to be uninfluenced by changes of temperature (0–37°C) and pH (6.9–7.8) or the presence of cell sap, but was inhibited by increasing the concentration of potassium chloride. 4. Possession of a polyribosome-binding capacity by conditioned rough membranes was not dependent on adventitious materials that could be dislodged by high ionic strengths. 5. Trypsin treatment under mild conditions destroyed the binding capacity of ribonuclease-conditioned rough membranes. 6. A 2–10S residual RNA was recovered from ribonuclease-conditioned membranes, but its partial removal had no effect on the capacity of membranes to accept polyribosomes. However, some role for this residual RNA in attaching polyribosomes could not be discounted. 7. Evidence is considered that polyribosome-binding sites are intrinsic features of conditioned membranes isolated from rough-microsomal fractions, and that long-range ionic bonding is a primary factor in polyribosome interaction with these binding sites.

scholarly journals Isolation and characterization of membrane proteins responsible for attachment of polyribosomes to rough microsomal fraction of rat liver

1977 ◽  
Vol 164 (1) ◽  
pp. 53-66 ◽  
Author(s):  
S Fujita ◽  
F Ogata ◽  
J Nakamura ◽  
S Omata ◽  
H Sugano
Keyword(s):  
Rat Liver ◽  
Protein Fraction ◽  
Microsomal Fraction ◽  
Binding Capacity ◽  
Gel Filtration ◽  
High Affinity ◽  
Isolation And Characterization ◽  
Microsomal Membranes ◽  
Equilibrium Centrifugation

A protein fraction which has a high affinity for polyribosomes was isolated from rough microsomal membranes of rat liver. The mode of polyribosome binding to this fraction (R-fraction) was studied by using CsCl equilibrium centrifugation and compared with that for stripped rough microsomal membranes. The following were found. (1) The polyribosome-binding cpacity of the R-fraction was heat-labile and sensitive to trypsin, and was suppressed by increasing KCl concentration and addition of 0.1 mM-aurintricarboxylic acid. (2) Of the four subfractions obtained by gel filtration of the R-fraction on a Sephadex G-200, only the R1-fraction, eluted at the void volume, showed a high affinity for polyribosomes. The polyribosome-binding capacity of the R1-fraction decreased with time on storage at 4 degrees C. (3) The R1-fraction contained three major proteins with mol. wts. 108,000, 99,000 and 65,000.

scholarly journals Spatial orientation of glycoproteins in membranes of rat liver rough microsomes. I. Localization of lectin-binding sites in microsomal membranes.

1978 ◽  
Vol 78 (3) ◽  
pp. 874-893 ◽  
Author(s):  
E Rodriguez Boulan ◽  
G Kreibich ◽  
D D Sabatini
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Binding Sites ◽  
Microsomal Fraction ◽  
Lectin Binding ◽  
Membrane Glycoproteins ◽  
Con A ◽  
Microsomal Membranes ◽  
Carbohydrate Chains ◽  
Lectin Binding Sites

Carbohydrate-containing structures in rat liver rough microsomes (RM) were localized and characterized using iodinated lectins of defined specificity. Binding of [125I]Con A increased six- to sevenfold in the presence of low DOC (0.04--0.05%) which opens the vesicles and allows the penetration of the lectins. On the other hand, binding of [125I]WGA and [125I]RCA increased only slightly when the microsomal vesicles were opened by DOC. Sites available in the intact microsomal fraction had an affinity for [125I]Con A 14 times higher than sites for lectin binding which were exposed by the detergent treatment. Lectin-binding sites in RM were also localized electron microscopically with lectins covalently bound to biotin, which, in turn, were visualized after their reaction with ferritin-avidin (F-Av) markers. Using this method, it was demonstrated that in untreated RM samples, binding sites for lectins are not present on the cytoplasmic face of the microsomal vesicles, even after removal of ribosomes by treatment with high salt buffer and puromycin, but are located on smooth membranes which contaminate the rough microsomal fraction. Combining this technique with procedures which render the interior of the microsomal vesicles accessible to lectins and remove luminal proteins, it was found that RM membranes contain binding sites for Con A and for Lens culinaris agglutinin (LCA) located exclusively on the cisternal face of the membrane. No sites for WGA, RCA, soybean (SBA) and Lotus tetragonobulus (LTA) agglutinins were detected on either the cytoplasmic or the luminal faces of the rough microsomes. These observations demonstrate that: (a) sugar moieties of microsomal glycoproteins are exposed only on the luminal surface of the membranes and (b) microsomal membrane glycoproteins have incomplete carbohydrate chains without the characteristic terminal trisaccharides N-acetylglucosamine comes from galactose comes from sialic acid or fucose present in most glycoproteins secreted by the liver. The orientation and composition of the carbohydrate chains in microsomal glycoproteins indicate that the passage of these glycoproteins through the Golgi apparatus, followed by their return to the endoplasmic reticulum, is not required for their biogenesis and insertion into the endoplasmic reticulum (ER) membrane.

scholarly journals The rat liver vasoactive intestinal peptide binding site. Molecular characterization by covalent cross-linking and evidence for differences from the intestinal receptor

1985 ◽  
Vol 225 (2) ◽  
pp. 473-479 ◽  
Author(s):  
A Couvineau ◽  
M Laburthe
Keyword(s):  
Binding Site ◽  
Vasoactive Intestinal Peptide ◽  
Rat Liver ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
High Affinity ◽  
Cross Linker ◽  
A Minor

To identify the molecular components of the vasoactive intestinal peptide (VIP) binding sites in the liver, 125I-labelled VIP was covalently linked to liver membranes by using the cleavable cross-linker dithiobis(succinimidylpropionate). Purified rat liver plasma membranes were incubated with 125I-VIP, washed and treated with 1 mM-cross-linker. Polyacrylamide-gel electrophoresis of membrane proteins followed by autoradiography revealed a major 125I-VIP-protein complex of Mr 51 000. A minor Mr 89 000 complex was also observed. An identical pattern of protein labelling was obtained using crude membranes from rat liver. Labelling of the Mr 51 000 and 89 000 species was specific in that it could be abolished by native VIP, but was unaffected by 1 microM-glucagon and cholecystokinin octapeptide. Densitometric scanning of autoradiographs indicated that the labelling of the two species was abolished by similar low VIP concentrations (0.1-100 nM). It was also reduced by two VIP agonists, peptide histidine isoleucine amide and secretin, with a potency that is 1/7 and 1/200 that of native VIP, respectively. The guanine nucleotide GTP in the concentration range between 10(-7) and 10(-3) M reduces the labelling of the major Mr 51 000 protein and that of the minor Mr 89 000 protein, but with a slightly higher potency. Assuming one molecule of 125I-VIP was bound per molecule of protein, a major Mr 48 000 protein and a minor Mr 86 000 protein were identified as components of the high-affinity VIP binding sites in liver. This contrasts markedly with the pattern of labelling of rat intestinal epithelial membranes, where a Mr 73 000 protein was identified as a high-affinity VIP receptor and a Mr 33 000 protein as a low-affinity VIP binding site [Laburthe, Bréant & Rouyer-Fessard (1984) Eur. J. Biochem. 139, 181-187], suggesting structural differences between VIP binding sites in rat liver and intestinal epithelium.

scholarly journals Specific, High Affinity Binding Sites for an Antifungal Plant Defensin onNeurospora crassaHyphae and Microsomal Membranes

1997 ◽  
Vol 272 (51) ◽  
pp. 32176-32181 ◽  
Author(s):  
Karin Thevissen ◽  
Rupert W. Osborn ◽  
David P. Acland ◽  
Willem F. Broekaert
Keyword(s):  
Binding Sites ◽  
Affinity Binding ◽  
Plant Defensin ◽  
High Affinity Binding ◽  
High Affinity ◽  
Microsomal Membranes

Characterization of high-affinity melatonin binding sites in purified cell nuclei of rat liver

1994 ◽  
Vol 16 (2) ◽  
pp. 100-112 ◽  
Author(s):  
Dario Acuña-Castroviejo ◽  
Russel J. Reiter ◽  
Armando Menendez-Pelaez ◽  
Maria I. Pablos ◽  
Alejandro Burgos
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
Cell Nuclei ◽  
High Affinity

High-affinity receptor for insulin-like growth factor II in rat liver: properties and regulation in vivo

1987 ◽  
Vol 113 (1) ◽  
pp. 27-35 ◽  
Author(s):  
J. M. Bryson ◽  
R. C. Baxter
Keyword(s):  
Growth Factor ◽  
Rat Liver ◽  
Cross Reactivity ◽  
Female Rats ◽  
Insulin Like Growth Factor ◽  
High Affinity ◽  
Factor Ii ◽  
High Affinity Receptor ◽  
Microsomal Membranes ◽  
Affinity Receptor

ABSTRACT Receptors for insulin-like growth factor II (IGF-II) have been identified in many tissue types and have been shown to differ widely in their specificities and affinities. We have characterized the IGF-II receptor in rat liver microsomal membranes, both in the intact membrane and in a solubilized extract. Binding was time- and temperature-dependent and was unaffected by changes in pH in the range 6–9. Half-maximal displacement was obtained with 0·33 ng IGF-II/ml standard, and Scatchard analysis showed a class of receptors with an affinity for IGF-II of 1·33 ± 0·36 × 1010 litres/mol which increased threefold in the presence of Ca (1 mmol/l) to 3·74 ± 0·89 × 1010 litres/mol. There was also a threefold decrease in the rate of dissociation in the presence of Ca. Cross-reactivity with IGF-I was < 1% and there was no cross-reactivity with insulin. Infusion of rat GH or prolactin for 1 week, at the rate of 175–200 μg/day, into female rats had no effect on IGF-II binding in control animals, but rat GH infusion caused a 60% increase (P< 0·001) in binding in hypophysectomized rats by increasing the number of receptors. These studies demonstrate that rat liver microsomal membranes contain a highly specific, high-affinity receptor for IGF-II which may be under partial GH control J. Endocr. (1987) 113, 27–35

scholarly journals Lactogenic and somatogenic binding sites in intact and detergent-solubilized membrane preparations of female rat liver

1988 ◽  
Vol 252 (2) ◽  
pp. 509-514 ◽  
Author(s):  
L A Haldosén ◽  
J A Gustafsson
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Growth ◽  
Microsomal Membrane ◽  
Gel Chromatography ◽  
Female Rat ◽  
Microsomal Membranes ◽  
Triton X

The presence of lactogenic and somatogenic binding sites in intact microsomal membranes and in detergent-solubilized microsomal membrane preparations of female rat liver has been studied by affinity cross-linking-SDS/polyacrylamide-gel electrophoresis. In microsomal membrane preparations an Mr 40,000 lactogenic binder is present which is not disulphide-linked to another protein. Triton X-100 solubilization of membranes results in the appearance of three lactogenic 125I-human growth hormone (125I-hGH) binders with Mr values of 87,000, 40,000 and 35,000, and one somatogenic 125I-hGH binder with Mr 32,000. Treatment of rats with oestrogen increased the amount of lactogenic and somatogenic binding species in liver. The lactogenic binding sites are present as one entity in Triton X-100-solubilized preparations, clearly separated from the somatogenic binder as analysed by gel chromatography. Furthermore, 125I-hGH interacts with an Mr 95,000 somatogenic binder in membrane preparations to which the hormone can be cross-linked only following Triton X-100 solubilization.

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