Anion binding inhibition of the formation of a helical organogel

2006 ◽  
pp. 3199 ◽  
Author(s):  
Claire E. Stanley ◽  
Nigel Clarke ◽  
Kirsty M. Anderson ◽  
Judith A. Elder ◽  
Joseph T. Lenthall ◽  
...  
Keyword(s):  
Anion Binding ◽  
Binding Inhibition

scholarly journals Kinetics of bicarbonate and chloride transport in human red cell membranes.

1991 ◽  
Vol 97 (2) ◽  
pp. 321-349 ◽  
Author(s):  
P K Gasbjerg ◽  
J Brahm
Keyword(s):  
Chloride Transport ◽  
Anion Binding ◽  
Maximum Flux ◽  
Half Saturation Constant ◽  
Binding Inhibition ◽  
Filtering Technique ◽  
Red Cell Membranes ◽  
Kinetics Of ◽  
Bicarbonate And Chloride Transport ◽  
Human Red Cells

Unidirectional [14C]HCO3- and 36Cl- efflux from human red cells and ghosts was studied under self-exchange conditions at pH 7.8 and 0 degrees C by means of the Millipore-Swinnex filtering technique. Control bicarbonate experiments showed that 14CO2 loss from the cells to the efflux medium was insignificant. The anion flux was determined under (a) symmetric variations of the anion concentration (C(i) = C(o) = 5-700 mM), and (b) asymmetric conditions with CAn constant on one side and varied on the other side of the membrane. Simple Michaelis-Menten-like kinetics (MM fit: J(eff) = J(eff)max.C/(K1/2 + C)) was used to describe anion flux dependence on C for (a) C(i) = C(o) = 5-100 mM, (b) C(i) = 6-100 mM, C(o) = constant, and (c) C(i) = constant, C(o) = 1-25 mM. At higher cellular concentrations noncompetitive self-inhibition by anion binding (inhibition constant Ki mM) to an intracellular site was included in the model (MS fit): J(eff) = J(eff)max.C(i)/[(K1/2 + C(i)).(1 + C(i)/Ki)]. The MM fits show that the external half-saturation constant, Ko1/2 ( = C(o)An for J(eff,o) = 1/2.j(eff,o)max) at C(o) = 1-25 mM is 1.5-2.4 mM (HCO3-) and 1.8-2.6 mM (Cl-). At C(o) = 1-260 mM Ko1/2 is 1.2-1.5 mM (HCO3-) and 1.4-1.8 mM (Cl-). The respective maximum flux, J(eff,o)max (nmol/[cm2.s]), for C(o) = 1-25 mM is 0.41-0.51 (HCO3-) and 0.28-0.38 (Cl-), and for C(o) = 1-260 mM 0.39-0.44 (HCO3-) and 0.27-0.31 (Cl-). The internal half-saturation constant, Ki1/2 mM is: MM fit (C(i) = 6-100 mM, C(o) = 50 mM), 18.0 mM (HCO3-) and 23.8 mM (Cl-); MS fit (C(i) = 6-920 mM, C(o) = 50 mM), 32.0 mM (HCO3-) and 45.1 mM (Cl-). The maximum flux, J(eff,i)max (nmol/[cm2.s]) is: MM fit; 0.50 (HCO3-) and 0.34 (Cl-); MS fit, 0.70 (HCO-3) and 0.50 (Cl-). The half-inhibition constants of the MS fit, Ki, are 393 mM (HCO3-) and 544 mM (Cl-). The MM fit shows that the symmetric half-saturation constant, Ks1/2, is 20.2 (HCO-3) and 23.9 (Cl-) mM, and J(eff,s)max is 0.51 (HCO3-) and 0.32 (Cl-) nmol/(cm2.s). The MS fit shows that for C = 5-700 mM Ks1/2 is 30.4 nM (HCO3-) and 50.1 mM (Cl-), and Ki is 541 mM (HCO3-) and 392 mM (Cl-).(ABSTRACT TRUNCATED AT 400 WORDS)

The Ability of Thrombin Inhibitors to Reduce the Thrombin Activity Generated in Plasma on Extrinsic and Intrinsic Activation

1997 ◽  
Vol 77 (03) ◽  
pp. 498-503 ◽  
Author(s):  
D Prasa ◽  
L Svendsen ◽  
J Stürzebecher
Keyword(s):  
Active Site ◽  
Thrombin Generation ◽  
Anion Binding ◽  
Thrombin Inhibitors ◽  
Coagulation System ◽  
Thrombin Activity ◽  
Continuous Registration ◽  
High Concentrations ◽  
20 Nm ◽  
Generation Test

SummaryIn a thrombin generation test with continuous registration of thrombin activity in plasma we studied the ability of a variety of thrombin inhibitors of different type and mechanism of action to influence the activity of thrombin after activation of the coagulation system. Depending on the inhibitor, the peak of thrombin activity is delayed and/or reduced.By blocking the active site of generated thrombin inhibitors cause a concentration dependent reduction of the thrombin peak and inhibit feed-back reactions of thrombin resulting in a delay of thrombin generation. Highly potent synthetic active-site directed inhibitors (Ki ≤ 20 nM) reduce the thrombin activity formed in plasma after extrinsic or intrinsic activation with the same efficiency (IC50 0.1 - 0.6 μM) as hirudin. The delay and reduction of thrombin generation by inhibitors of the anion-binding exosite 1 of thrombin is only attributed to an inhibition of feed-back reactions of thrombin. For a 50% reduction of thrombin activity in plasma by this type of inhibitors relatively high concentrations were determined.

Cambiarenes: Single-Step Synthesis and Anion Binding of a Clip- Shaped Macrocycle with a Redox-Active Core

2019 ◽  
Author(s):  
Riley J. Petersen ◽  
Brett J. Rozeboom ◽  
Shalisa Oburn ◽  
Nolan Blythe ◽  
Tanner Rathje ◽  
...  
Keyword(s):  
Electron Density ◽  
Single Step ◽  
Anion Binding ◽  
Host Molecule ◽  
Selective Binding ◽  
The Core ◽  
Redox Active ◽  
Active Core ◽  
Guest Binding

<div>We report the synthesis of a novel macrocyclic host molecule that forms in a single step from commercially available starting materials. The core of the macrocycle backbone possesses two quinone rings and, thus, is redox-active. Host-guest binding involving the clip-shaped cavity indicates selective binding of pyridine <i>N</i>-oxides based of the electron density of and steric bulk of the anionic oxygen.</div>

scholarly journals Effects of anion binding on the deprotonation reactions of halorhodopsin.

1986 ◽  
Vol 261 (6) ◽  
pp. 2690-2696 ◽  
Author(s):  
B Schobert ◽  
J K Lanyi ◽  
D Oesterhelt
Keyword(s):  
Anion Binding

Pyrrole-bridged quinones: π-electronic systems that modulate electronic structures by tautomerism and deprotonation

2021 ◽  
Author(s):  
Shinya Sugiura ◽  
Hiromitsu Maeda
Keyword(s):  
Infrared Absorption ◽  
Electronic Structures ◽  
Near Infrared ◽  
Ion Pairing ◽  
Anion Binding ◽  
Electronic Systems

A new series of π-extended quinone derivatives containing a pyrrole bridge exhibited NH/OH-type tautomerization and anion binding along with deprotonation that induced near-infrared absorption and ion-pairing assemblies.

scholarly journals Anion binding in metal-organic frameworks

2021 ◽  
pp. 213708
Author(s):  
Xin Wu ◽  
Lauren K. Macreadie ◽  
Philip A. Gale
Keyword(s):  
Metal Organic Frameworks ◽  
Anion Binding ◽  
Metal Organic

scholarly journals Doubling the Carbonate-Binding Capacity of Nanojars by the Formation of Expanded Nanojars

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3083
Author(s):  
Wisam A. Al Isawi ◽  
Gellert Mezei
Keyword(s):  
Co2 Fixation ◽  
Binding Capacity ◽  
Coordination Complexes ◽  
Anion Binding ◽  
Ionization Mass ◽  
X Ray ◽  
Carbonate Ion ◽  
Carbonate Ions ◽  
Supramolecular Coordination ◽  
Hydration Energies

Anion binding and extraction from solutions is currently a dynamic research topic in the field of supramolecular chemistry. A particularly challenging task is the extraction of anions with large hydration energies, such as the carbonate ion. Carbonate-binding complexes are also receiving increased interest due to their relevance to atmospheric CO2 fixation. Nanojars are a class of self-assembled, supramolecular coordination complexes that have been shown to bind highly hydrophilic anions and to extract even the most hydrophilic ones, including carbonate, from water into aliphatic solvents. Here we present an expanded nanojar that is able to bind two carbonate ions, thus doubling the previously reported carbonate-binding capacity of nanojars. The new nanojar is characterized by detailed single-crystal X-ray crystallographic studies in the solid state and electrospray ionization mass spectrometric (including tandem MS/MS) studies in solution.

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