Competition of various LH-RH analogs and fragments with 125I-LH-RH for specific binding sites on isolated pituitary plasma membranes

1980 ◽  
Vol 17 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Herbert Kuhl ◽  
Rudolf Baumann ◽  
Jiirgen Sandow ◽  
Hans-Dieter Taubert
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Specific Binding Sites ◽  
Lh Rh

Evidence for the presence of specific binding sites for corticoids in mouse liver plasma membranes

1989 ◽  
Vol 108 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Miguel Trueba ◽  
Ana I. Vallejo ◽  
Isabel Rodriguez ◽  
Iñaki Ibarrola ◽  
María J. Sancho ◽  
...  
Keyword(s):  
Binding Sites ◽  
Mouse Liver ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Specific Binding Sites ◽  
Liver Plasma Membranes

scholarly journals Specific binding sites for inositol 1,3,4,5-tetrakisphosphate are located predominantly in the plasma membranes of human platelets

1994 ◽  
Vol 298 (3) ◽  
pp. 739-742 ◽  
Author(s):  
P J Cullen ◽  
Y Patel ◽  
V V Kakkar ◽  
R F Irvine ◽  
K S Authi
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Human Platelet ◽  
Specific Binding ◽  
Human Platelets ◽  
Intracellular Membranes ◽  
Specific Binding Sites ◽  
Carrier Free ◽  
Membrane Location

In the present study we describe the characterization and localization of Ins(1,3,4,5)P4-binding sites in human platelet membranes. Specific binding sites for Ins(1,3,4,5)P4 have been identified on mixed, plasma and intracellular membranes from neuraminidase-treated platelets using highly purified carrier-free [32P]Ins(1,3,4,5)P4. The displacement of Ins(1,3,4,5)P4 from these sites by Ins(1,4,5)P3 and InsP6 occurs at greater than two orders of magnitude higher concentrations and with Ins(1,3,4,5,6)P5 at about 40-fold higher concentrations than with Ins(1,3,4,5)P4. The membranes were further separated by free-flow electrophoresis into plasma and intracellular membranes. The Ins(1,3,4,5)P4-binding sites separated with plasma membranes, and showed similar affinities and specificities as mixed membranes, whereas Ins(1,4,5)P3-binding sites were predominantly in the intracellular membranes. These results suggest a predominantly plasma membrane location for putative Ins(1,3,4,5)P4 receptors in human platelets.

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.

INTERACTION OF [125I]LH-RH AND OTHER OLIGOPEPTIDES WITH PLASMA MEMBRANES OF RAT ANTERIOR PITUITARIES

1979 ◽  
Vol 92 (2) ◽  
pp. 228-241 ◽  
Author(s):  
Rudolf Baumann ◽  
Herbert Kuhl
Keyword(s):  
Pituitary Gland ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Binding Capacity ◽  
Specific Binding ◽  
Biological Activities ◽  
Single Type ◽  
Number Of Binding Sites ◽  
Specificity Of Binding ◽  
Lh Rh

ABSTRACT The specific binding of [125I]LH-RH to isolated plasma membranes of rat pituitaries was investigated. The binding process was found to be highly specific, temperature-dependent and saturable. The dissociation constant as calculated by three different methods was approximately 1.3 · 10−8 m, indicating a single type of binding sites. Maximal binding capacity was 1 · 10−12 moles/mg protein (=2 ng LH-RH/pituitary gland), and the number of binding sites was calculated to be 6 · 1011 per mg membrane protein (= 1 · 1010 binding sites/pituitary gland). When diluted with icecold buffer the dissociation of specifically bound LH-RH occurred very rapidly (half-life 3.17 min) with a rate constant of 0.219 min−1. The dissociation process followed first-order kinetics. Specificity of binding was demonstrated by dose-dependent competition of unlabelled LH-RH, the highly potent analogue D-glutamine-(cyclohexyl)6-LH-RH-nonapeptide-ethylamide and the fragment of an analogue (6-D-Ser(TBu))-LH-RH-(3-9)-heptapeptide-ethylamide with the binding [125I]LH-RH, while angiotensin I, II, oxytocin and bacitracin did not compete. The affinities of LH-RH and the analogue to the binding sites of the pituitary plasma membranes were not consistent with the respective biological activities.

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