Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds:  Capillary Electrophoresis Study

Guillaume, Yves Claude; Peyrin, Eric

doi:10.1021/ac980848u

Cited by 34 publications

(15 citation statements)

References 42 publications

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“…Finally, when K is equal to unity, molecules spend equal fractions of time traveling as both species A and B and the velocity of the solute zone is the numerical average of v A und v B . This dependence of velocity on K is supported by previous expressions for the apparent electrophoretic mobility of reactive solute zones in CE [3,72].…”

Section: Effects Of Equilibrium Constantsupporting

confidence: 82%

“…Previous experimental investigations of thermodynamic contributions to separation in CE include complexation reactions of imidazoles with cyclodextrins [3] and metals with polyazamacrocyclic chelating agents [4] as well as peptide isomerization [5][6][7] and denaturation [8]. Evaluation of kinetic rate constants for dissociation of metals complexed with azo-dye ligands [9] and peptide isomerization [5][6][7] from CE measurements has also been reported.…”

Section: Introductionmentioning

confidence: 99%

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Stochastic simulation of reactive separations in capillary electrophoresis

Newman

McGuffin

2005

Electrophoresis

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A stochastic (Monte Carlo) simulation is used to investigate thermodynamic and kinetic contributions from the reversible A <--> B reaction in capillary electrophoresis (CE). The effects of equilibrium constant, rate constant, and electrophoretic mobility on the molecular zone profiles and the corresponding statistical moments are evaluated. As the reaction approaches steady state, the velocity of the zone is governed by the equilibrium constant and the electrophoretic mobilities of the reacting molecules. When the equilibrium constant is less than unity, the mean zone velocity is more similar to that of the reactant A. Conversely, when the equilibrium constant is greater than unity, the velocity is more similar to that of the product B. The extent of zone-broadening and asymmetry at steady state is dependent upon the equilibrium constant, the characteristic reaction lifetime, and the electrophoretic mobility difference between reacting molecules. If all other parameters are held constant, the plate height is greatest and skew is least when the equilibrium constant is unity. The plate height increases linearly with the characteristic reaction lifetime and electrophoretic mobility difference, whereas the skew is independent of these parameters. These conclusions have important implications for the elucidation of thermodynamic and kinetic information from experimental data.

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Section: Effects Of Equilibrium Constantsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Stochastic simulation of reactive separations in capillary electrophoresis

Newman

McGuffin

2005

Electrophoresis

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“…Temperature dependence of the binding constants can be described by a van't Hoff plot equation as follows [28,31,47]:…”

Section: Temperature Effect and Thermodynamic Studymentioning

confidence: 99%

“…As described by Guillaume and Peyrin [47], the information of the analyte-CD inclusion complexation mechanism can be illustrated by thermodynamic data. Figure 5 depicts the van't Hoff plots of ln K versus T 21 for these seven alkylnaphthalene derivatives at the temperatures from 15 to 407C, as determined by Eq.…”

Section: Temperature Effect and Thermodynamic Studymentioning

confidence: 99%

Application of cyclodextrin-mediated capillary electrophoresis to determine the apparent binding constants and thermodynamic parameters of the alkylnaphthalene derivatives

Wang

2005

Electrophoresis

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The separation and migration behavior of seven positional and structural neutral alkylnaphthalene derivatives in cyclodextrin-mediated capillary electrophoresis were systematically investigated. The effective separation conditions were to use 10 mM phosphate buffer with negatively charged carboxymethyl-beta-cyclodextrin (CM-beta-CD) at pH 6.0. The guest-host interactions with 1:1 or both 1:1 and 1:2 binding stoichiometries for various derivatives were evaluated by comparing their apparent binding constants. The results reveal that the substituent group(s) attached to the naphthalene ring significantly affected the inclusion stoichiometric behaviors. Alkylnaphthalene derivatives with the substituent(s) at the 1-position(s), such as 1-ethylnaphthalene, 1,4-dimethylnaphthalene, may undergo complexation with one and two CM-beta-CD molecules. The binding constants of these derivatives were consistent with the data obtained by a spectrophotometric method. The thermodynamic parameters were also calculated in order to improve our understanding of the interaction between the neutral alkylnaphthalene derivatives and CM-beta-CD at various temperatures. The positive entropy (deltaS degrees) values of the alkylnaphthalenes with the substituent(s) at the 2-position(s) indicate that the inclusion of the guest molecule into the cavity of CM-beta-CD is favored at all temperatures.

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“…In this paper, focus will be on DNA aptamer complexes with adenosine (A), adenosine diphosphate (ADP) and adenosine triphosphate (ATP), which are important cofactors involved in the production of readily available energy used by living systems. The apparent association constant K of the aptamer-ligand binding can be analyzed with the change in the electrophoretic mobility m of the injected ligand (L) on complexation with aptamer (Apt) present in the run buffer using the following equation [29,30]:…”

Section: Introductionmentioning

confidence: 99%

Aptamer–oligonucleotide binding studied by capillary electrophoresis: Cation effect and separation efficiency

2005

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Novel features of DNA structure, recognition and discrimination have been recently elucidated through the solution structural characterization of DNA aptamers that bind cofactors, amino acids and peptides with high affinity and specificity. Multidimensional nuclear magnetic resonance methodologies have been successfully applied to solve the solution structures. In this work, it was demonstrated that capillary electrophoresis was a powerful tool allowing the fundamental study of the binding mechanism between a DNA aptamer and three ligands, adenosine and adenylate compounds, i.e., adenosine diphosphate (ADP) and adenosine triphosphate (ATP). In order to gain further insight into this binding, thermodynamic measurements under different values of parameters (such as salt nature and its concentration (x) in the run buffer) were carried out. The results showed that dehydration at the binding interface, van der Waals interactions, H-bonding and adjustment of the aptamer recognition surface were implied in the aptamer-ligand association. As well, it was demonstrated that the addition in the medium of the sodium monovalent cation Na(+) or the nickel divalent cation Ni(2+) decreased the complex formation. Separation efficiency and peak shape can also be improved by Mg(2+) divalent cation, which increased the mass transfer kinetics during the ligand-aptamer binding process. A significant separation for the worst separated pair of peaks on the electropherogram ((ADP, ATP) peak pair) was thus achieved.

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Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds: Capillary Electrophoresis Study

Cited by 34 publications

References 42 publications

Stochastic simulation of reactive separations in capillary electrophoresis

Stochastic simulation of reactive separations in capillary electrophoresis

Application of cyclodextrin-mediated capillary electrophoresis to determine the apparent binding constants and thermodynamic parameters of the alkylnaphthalene derivatives

Aptamer–oligonucleotide binding studied by capillary electrophoresis: Cation effect and separation efficiency

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