Evidence for the Existence of Imidazoline-Specific Binding Sites in Synaptosomal Plasma Membranes of the Bovine Brainstem

2002 ◽  
Vol 71 (5) ◽  
pp. 2193-2202 ◽  
Author(s):  
F. M. J. Heemskerk ◽  
M. Dontenwill ◽  
H. Greney ◽  
C. Vonthron ◽  
P. Bousquet
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Specific Binding Sites ◽  
Synaptosomal Plasma Membranes

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.

scholarly journals Specific Binding of Rubidium in Chlorella

1962 ◽  
Vol 45 (5) ◽  
pp. 959-977 ◽  
Author(s):  
Dan Cohen
Keyword(s):  
Active Transport ◽  
Binding Sites ◽  
Specific Binding ◽  
High Concentration ◽  
External Concentration ◽  
Specific Binding Sites ◽  
Dense Suspension ◽  
Concentration Of Ions ◽  
The Individual ◽  
A Site

Specific binding sites for potassium, which may be components of the carriers for active transport for K in Chlorella, were characterized by their capacity to bind rubidium. A dense suspension was allowed to take up Rb86 from a low concentration of Rb86 and a high concentration of ions which saturate non-specific sites. The amount bound was derived from the increase in the external concentration of Rb86 following addition of excess potassium. The sites were heterogeneous. The average affinity of Rb and various other ions for the sites was determined by plotting the degree of displacement of Rb86 against log molar concentration of the individual ions. Interpolation gave the concentration for 50 per cent displacement of Rb, which is inversely related to affinity. The order of affinity was not changed when the cells were frozen, or boiled either in water or in 70 per cent ethanol. The affinity is maximal for ions with a crystalline radius of 1.3 to 1.5 A and a high polarizability, and is not related to the hydrated radius or valency. It is suggested that binding groups in a site are rigidly arranged, the irregular space between them being 2.6 to 3.0 A across, so that affinity is high for ions of this diameter and high polarizability.

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