Photoresponsive Macrocycles for Selective Binding and Release of Sulfate

2021 ◽  
Author(s):  
Shenglun Xiong ◽  
Qing He
Keyword(s):  
Binding Sites ◽  
Anion Binding ◽  
Anion Receptors ◽  
Selective Binding

A series of new photoresponsive macrocyclic anion receptors were synthesized via integration of an azobenzene unit and multiple anion binding sites. They exhibited highly selective binding to dianionic sulfate over...

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>

Neutral Anion Receptors with Multiple Urea-Binding Sites

2000 ◽  
Vol 2000 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Bianca H. M. Snellink-Ruël ◽  
Martijn M. G. Antonisse ◽  
Johan F. J. Engbersen ◽  
Peter Timmerman ◽  
David N. Reinhoudt
Keyword(s):  
Binding Sites ◽  
Anion Receptors

New Polydentate Macrocyclic Ligands of Hybrid Amine-Imine and Amide-Imine Types as Artificial Anion Receptors. Synthesis and Study of Anion Binding.

ChemInform ◽  
2005 ◽  
Vol 36 (52) ◽  
Author(s):  
E. A. Katayev ◽  
G. D. Pantos ◽  
V. M. Lynch ◽  
J. L. Sessler ◽  
M. D. Reshetova ◽  
...  
Keyword(s):  
Macrocyclic Ligands ◽  
Anion Binding ◽  
Anion Receptors

scholarly journals The fluoride permeation pathway and anion recognition in Fluc family fluoride channels

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Benjamin C McIlwain ◽  
Roja Gundepudi ◽  
B Ben Koff ◽  
Randy B Stockbridge
Keyword(s):  
Binding Sites ◽  
Anion Recognition ◽  
Anion Binding ◽  
Structural Studies ◽  
Planar Bilayer ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molecular Determinants ◽  
Cytoplasmic Accumulation ◽  
Oriented System

Fluc family fluoride channels protect microbes against ambient environmental fluoride by undermining the cytoplasmic accumulation of this toxic halide. These proteins are structurally idiosyncratic, and thus the permeation pathway and mechanism have no analogy in other known ion channels. Although fluoride binding sites were identified in previous structural studies, it was not evident how these ions access aqueous solution, and the molecular determinants of anion recognition and selectivity have not been elucidated. Using x-ray crystallography, planar bilayer electrophysiology and liposome-based assays, we identify additional binding sites along the permeation pathway. We use this information to develop an oriented system for planar lipid bilayer electrophysiology and observe anion block at one of these sites, revealing insights into the mechanism of anion recognition. We propose a permeation mechanism involving alternating occupancy of anion binding sites that are fully assembled only as the substrate approaches.

The red cell band 3 protein: its role in anion transport

1982 ◽  
Vol 299 (1097) ◽  
pp. 497-507 ◽  
Keyword(s):  
Binding Sites ◽  
Band 3 ◽  
Anion Transport ◽  
Anion Binding ◽  
Hydrophobic Residues ◽  
Ping Pong ◽  
Hydrophilic Residues ◽  
Aqueous Core ◽  
Positively Charged

Studies of anion transport across the red blood cell membrane fall generally into two categories: (1) those concerned with the operational characterization of the transport system, largely by kinetic analysis and inhibitor studies; and (2) those concerned with the structure of band 3, a transmembrane peptide identified as the transport protein. The kinetics are consistent with a ping-pong model in which positively charged anion-binding sites can alternate between exposure to the inside and outside compartments but can only shift one position to the other when occupied by an anion. The structural studies on band 3 indicate that only 60 % of the peptide is essential for transport. That particular portion is in the form of a dimer consisting of an assembly of membrane-crossing strands (each monomer appears to cross at least five times). The assembly presents its hydrophobic residues toward the interior of the bilayer, but its hydrophilic residues provide an aqueous core. The transport involves a small conformational change in which an anion-binding site (involving positively charged residues) can alternate between positions that are topologically in and topologically out.

Interactions between transport inhibitors at the anion binding sites of the band 3 dimer

Biochemistry ◽  
1981 ◽  
Vol 20 (18) ◽  
pp. 5095-5105 ◽  
Author(s):  
Ian G. Macara ◽  
Lewis C. Cantley
Keyword(s):  
Binding Sites ◽  
Band 3 ◽  
Anion Binding ◽  
Transport Inhibitors

Use of ionic and zwitterionic (Tris/BisTris and HEPES) buffers in studies on hemoglobin function

1992 ◽  
Vol 72 (4) ◽  
pp. 1611-1615 ◽  
Author(s):  
R. E. Weber
Keyword(s):  
Binding Sites ◽  
Ionic Composition ◽  
Oxygen Affinity ◽  
Chloride Concentration ◽  
Anion Binding ◽  
Chloride Binding ◽  
Ph Values ◽  
Two Temperatures ◽  
Ethanesulfonic Acid ◽  
Chloride Concentrations

The functional characteristics of hemoglobin (Hb) depend on oxygenation-linked proton and anion binding and thus on solvent buffer groups and ionic composition. This study compares the oxygenation properties of human Hb in ionic [tris(hydroxymethyl)aminomethane (Tris) and BisTris] buffers with those in zwitterionic N-2-hydroxy-ethylpiperazine-N′-2-ethanesulfonic acid (HEPES) buffer under strictly controlled chloride concentrations at different pH values, two temperatures, and in the absence and presence of the erythrocytic cofactor, 2,3-diphosphoglycerate (DPG). In contrast to earlier studies (carried out at the same or different chloride concentrations) it shows only small buffer effects that are manifested at low chloride concentration and high pH. These observations suggest chloride binding to the Tris buffers, which reduces the interaction with specific chloride binding sites in the Hb. The findings indicate that HEPES allows for more accurate assessment of Hb-oxygen affinity and its anion and temperature sensitivities than ionic buffers and advocates standard use of HEPES in studies on Hb function. Precise oxygen affinities of Hb dissolved in both buffers are defined under standard conditions.

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