scholarly journals Specific Binding Sites for Triiodothyronine in the Plasma Membrane of Rat Thymocytes

1982 ◽  
Vol 70 (5) ◽  
pp. 919-926 ◽  
Author(s):  
Joseph Segal ◽  
Sidney H. Ingbar
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Specific Binding ◽  
Specific Binding Sites

Characterization of Specific Binding Sites for Corticosterone in Mouse Liver Plasma Membrane

1989 ◽  
Vol 8 (4) ◽  
pp. 229-239 ◽  
Author(s):  
Miguel Trueba ◽  
IÑAki Ibarrola ◽  
Ana Isabel Vallejo ◽  
MarÍA José Sancho ◽  
Aida Marino ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Mouse Liver ◽  
Specific Binding ◽  
Liver Plasma Membrane ◽  
Specific Binding Sites

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 Specific binding sites for albumin restricted to plasmalemmal vesicles of continuous capillary endothelium: receptor-mediated transcytosis.

1986 ◽  
Vol 102 (4) ◽  
pp. 1304-1311 ◽  
Author(s):  
L Ghitescu ◽  
A Fixman ◽  
M Simionescu ◽  
N Simionescu
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Specific Binding ◽  
Short Exposure ◽  
Gold Complex ◽  
Membrane Microdomains ◽  
Capillary Endothelium ◽  
Plasmalemmal Vesicles ◽  
Specific Binding Sites

The interaction of homologous and heterologous albumin-gold complex (Alb-Au) with capillary endothelium was investigated in the mouse lung, heart, and diaphragm. Perfusion of the tracer in situ for from 3 to 35 min was followed by washing with phosphate-buffered saline, fixation by perfusion, and processing for electron microscopy. From the earliest time examined, one and sometimes two rows of densely packed particles bound to some restricted plasma membrane microdomains that appeared as uncoated pits, and to plasmalemmal vesicles open on the luminal front. Morphometric analysis, using various albumin-gold concentrations, showed that the binding is saturable at a very low concentration of the ligand and short exposure. After 5 min, tracer-carrying vesicles appeared on the abluminal front, discharging their content into the subendothelial space. As a function of tracer concentration 1-10% of plasmalemmal vesicles contained Alb-Au particles in fluid phase; from 5 min on, multivesicular bodies were labeled by the tracer. Plasma membrane, coated pits, and coated vesicles were not significantly marked at any time interval. Heparin or high ionic strength did not displace the bound Alb-Au from vesicle membrane. No binding was obtained when Alb-Au was competed in situ with albumin or was injected in vivo. Gold complexes with fibrinogen, fibronectin, glucose oxidase, or polyethyleneglycol did not give a labeling comparable to that of albumin. These results suggest that on the capillary endothelia examined, the Alb-Au is adsorbed on specific binding sites restricted to uncoated pits and plasmalemmal vesicles. The tracer is transported in transcytotic vesicles across endothelium by receptor-mediated transcytosis, and to a lesser extent is taken up by pinocytotic vesicles. The existence of albumin receptors on these continuous capillary endothelia may provide a specific mechanism for the transport of albumin and other molecules carried by this protein.

Specific binding sites for corticosterone in isolated cells and plasma membrane from rat liver

1991 ◽  
Vol 120 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Miguel Trueba ◽  
Iñaki Ibarrola ◽  
Kepa Ogiza ◽  
Aida Marino ◽  
José María Macarulla
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Binding Sites ◽  
Specific Binding ◽  
Isolated Cells ◽  
Specific Binding Sites

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.

Sign in / Sign up

Export Citation Format

Share Document