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Barakat F, Gaudin K, Vialet B, Bathany K, Benizri S, Barthélémy P, Ferey L. Analysis of lipid-oligonucleotide conjugates by cyclodextrin-modified capillary zone electrophoresis. Talanta 2020; 219:121204. [PMID: 32887111 DOI: 10.1016/j.talanta.2020.121204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 01/28/2023]
Abstract
Lipid-oligonucleotide (LONs) based bioconjugates represent an emerging class of therapeutic agents, allowing the delivery of therapeutic oligonucleotide sequences. The LON development requests accurate and efficient analytical methods. In this contribution, LON analysis methods were developed in cyclodextrin-modified capillary zone electrophoresis (CD-CZE). The LONs selected in this study feature different structures, including i) the oligonucleotide length (from 10 to 20 nucleotides), ii) the inter-nucleotide linkage chemistry (phosphodiester PDE or phosphorothioate PTO), and iii) the lipidic part: single- (LONsc) or double-chain (LONdc) lipids. In CD-CZE, the effect of several parameters on the electrophoretic peaks was investigated (buffer, CD, and capillary temperature). The binding interaction between LON and Me-β-CD was studied in affinity capillary electrophoresis and revealed a 1:1 LON:CD complex. Non-linear regression and three usual linearization methods (y-reciprocal, x-reciprocal, and double-reciprocal) were used to determine the binding constants (K values of 2.5.104 M-1 and 2.0.104 M-1 for LON PDE and LON PTO, respectively). Quantitative methods with good performances and analysis time lower than 5 min were achieved. Importantly, the developed analysis allows a separation between the i) full-length sequence LONs and their truncated sequences, (n-1), (n-2), and (n-4)-mers and ii) LONsc, LONdc and their corresponding unconjugated oligonucleotides. This work highlights the interest of CD-CZE methods for LON analysis.
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Affiliation(s)
- Fatima Barakat
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France
| | - Karen Gaudin
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France.
| | - Brune Vialet
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France
| | - Katell Bathany
- Chimie et Biologie des Membranes et Nanoobjets (CBMN) UMR 5248 CNRS, Université de Bordeaux, 33600, Pessac, France
| | - Sebastien Benizri
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France
| | - Philippe Barthélémy
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France.
| | - Ludivine Ferey
- ARNA INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, 33076, France.
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2
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Miyabe K. Moment analysis for reaction kinetics of intermolecular interactions. Electrophoresis 2018; 39:3032-3039. [PMID: 30156042 DOI: 10.1002/elps.201800218] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/23/2018] [Accepted: 08/19/2018] [Indexed: 01/05/2023]
Abstract
Moment equations were developed on the basis of the principle of relativity for analyzing elution peak profiles measured by ACE to analytically determine the association (ka ) and dissociation (kd ) rate constants of intermolecular interactions. Basic equations representing the mass balance, mass transfer rate, and reaction kinetics in ACE system in a Galilean coordinate system S were transformed to those in another coordinate system S', which imaginarily moved with respect to S. Moment equations for ACE peaks in S' in the time domain were derived from the analytical solution of the modified basic equations in the Laplace domain. Moment equations for ACE peaks in S were derived from those in S' by the inverse Galilean transformation. The moment equations were used for analyzing some ACE data previously published to determine ka and kd values. It was demonstrated that the moment equations were effective for extracting the information about affinity kinetics of intermolecular interactions from the elution peak profiles measured by ACE. The moment equations were also used to discuss the influence of mass transfer and reaction kinetics on ACE peak profiles. Some results of the numerical calculations are also indicated in Supporting Information.
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Affiliation(s)
- Kanji Miyabe
- Department of Chemistry, Faculty of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
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3
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Singh G, Rani S, Gawri S, Sinha S, Sehgal R. Adamantylated organosilatranes: design, synthesis, and potential appraisal in surface modification and anti-protozoal activity. NEW J CHEM 2017. [DOI: 10.1039/c7nj01456b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A series of organosilatranes tethered with the privileged adamantane motif has been prepared and their pharmacokinetic profiles were scrutinized.
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Affiliation(s)
| | - Sunita Rani
- Department of Chemistry
- Panjab University
- Chandigarh
- India
| | | | - Shweta Sinha
- Department of Medical Parasitology
- Research Block-A
- PGIMER
- Chandigarh
- India
| | - Rakesh Sehgal
- Department of Medical Parasitology
- Research Block-A
- PGIMER
- Chandigarh
- India
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Dubský P, Dvořák M, Ansorge M. Affinity capillary electrophoresis: the theory of electromigration. Anal Bioanal Chem 2016; 408:8623-8641. [DOI: 10.1007/s00216-016-9799-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/04/2016] [Accepted: 07/14/2016] [Indexed: 12/19/2022]
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5
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Brinet D, Kaffy J, Oukacine F, Glumm S, Ongeri S, Taverna M. An improved capillary electrophoresis method for in vitro monitoring of the challenging early steps of Aβ1-42 peptide oligomerization: application to anti-Alzheimer's drug discovery. Electrophoresis 2014; 35:3302-9. [PMID: 25219962 DOI: 10.1002/elps.201400271] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 08/22/2014] [Accepted: 08/22/2014] [Indexed: 11/06/2022]
Abstract
We report an improved CE method to monitor in vitro the self-assembly of monomeric amyloid β-peptide (42 amino acids amyloid β-peptide, Aβ1-42 ) and in particular the crucial early steps involved in the formation of the neurotoxic oligomers. In order to start the kinetics from the beginning, sample preparation was optimized to provide samples containing exclusively the monomeric form. The CE method was also improved using a dynamic coating and by reducing the separation distance. Using this method, the disappearance of the monomer as well as the progressive formation of four species during the self-assembly process can now be monitored and quantified over time. The hydrodynamic radius of the species present at the initial kinetics step was estimated around 1.8 nm by Taylor dispersion analysis while SDS-PAGE analyses showed the predominance of the monomer. These results confirmed that the Aβ1-42 species present at this initial time was the monomer. Methylene blue, an anti-Alzheimer disease candidate, was then evaluated. In spite of an oligomerization inhibition, the enhanced disappearance of the Aβ1-42 monomer provoked by methylene blue was demonstrated for the first time. This method, allowing the monomeric and smallest oligomeric species to be monitored, represents a new accurate and precise way to evaluate compounds for drug discovery.
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Affiliation(s)
- Dimitri Brinet
- Protéines et Nanotechnologies en Sciences Séparatives, Institut Galien de Paris Sud, Faculté de Pharmacie, Université Paris-Sud, Châtenay-Malabry, France; Molécules Fluorées et Chimie Médicinale, Faculté de Pharmacie, Université Paris-Sud, Châtenay-Malabry, France
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6
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Poitevin M, Tranquart F, Cherkaoui S. Use of capillary electrophoresis as a versatile tool to measure interaction constants between a KDR-binding PEGylated lipopeptide and pegylated phospholipid micelles. Electrophoresis 2014; 36:326-34. [DOI: 10.1002/elps.201400280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/29/2014] [Accepted: 09/04/2014] [Indexed: 11/06/2022]
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7
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Müllerová L, Dubský P, Svobodová J, Gaš B. Determination of effective mobilities of EOF markers in BGE containing sulfated β-cyclodextrin by a two-detector method. Electrophoresis 2013. [DOI: 10.1002/elps.201200490] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ludmila Müllerová
- Faculty of Science; Department of Physical and Macromolecular Chemistry; Charles University in Prague; Prague; Czech Republic
| | - Pavel Dubský
- Faculty of Science; Department of Physical and Macromolecular Chemistry; Charles University in Prague; Prague; Czech Republic
| | - Jana Svobodová
- Faculty of Science; Department of Physical and Macromolecular Chemistry; Charles University in Prague; Prague; Czech Republic
| | - Bohuslav Gaš
- Faculty of Science; Department of Physical and Macromolecular Chemistry; Charles University in Prague; Prague; Czech Republic
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8
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Al Azzam KM, Saad B, Aboul-Enein HY. Determination of the binding constants of modafinil enantiomers with sulfated β-cyclodextrin chiral selector by capillary electrophoresis using three different linear plotting methods. Electrophoresis 2010; 31:2957-63. [DOI: 10.1002/elps.201000266] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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Wang B, He J, Bianchi V, Shamsi SA. Combined use of chiral ionic liquid and CD for MEKC: Part II. Determination of binding constants. Electrophoresis 2010; 30:2820-8. [PMID: 19691050 DOI: 10.1002/elps.200800852] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A competitive inhibition mechanism is proposed to investigate the interactions among 2,3,6-tri-O-methyl-beta-CD (TM-beta-CD), cationic ionic liquid type surfactants, N-undecenoxy-carbonyl-L-leucinol bromide (L-UCLB) and profens using affinity CE. The apparent binding constant of TM-beta-CD to L-UCLB was estimated by nonlinear and linear plotting methods. The binding constants of one representative profen (e.g. fenoprofen) to TM-beta-CD and L-UCLB were estimated by a secondary plotting approach. The R- and S-fenoprofens have different binding constant values, resulting in the enantioseparation due to the synergistic effect of the two chiral selectors, TM-beta-CD and L-UCLB.
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Affiliation(s)
- Bin Wang
- Department of Chemistry, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, USA
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11
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Goldberg MD, Lo RC, Abele S, Macka M, Gomez FA. Development of microfluidic chips for heterogeneous receptor-ligand interaction studies. Anal Chem 2009; 81:5095-8. [PMID: 19441833 DOI: 10.1021/ac9006649] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A simple microfluidic-based technique to quantitate the binding affinity between the glycopeptide antibiotics teicoplanin from Actinoplanes teicomyceticus and vancomycin from Streptomyces orientalis and 5-carboxyfluorescein-D-Ala-D-Ala-D-Ala (5-FAM-(DA)(3)) is described. In this work, (3-aminopropyl)triethoxysilane is used to modify the surfaces of a series of microchannels, and each channel is subsequently exposed to a solution of antibiotic for a few minutes. The antibiotic is retained after washing through electrostatic interactions, and the series of channels are subsequently exposed to an increasing concentration of 5-FAM-(DA)(3) followed by washing to exclude any nonspecific binding. The extent of fluorescence is quantified using a microscope fitted with a CCD camera. The binding constants for the interaction of teicoplanin and vancomycin with the fluorescent peptide were determined to be 6.03 +/- 0.97 x 10(4) and 4.93 +/- 1.13 x 10(4) M(-1), respectively, in good agreement with previous data. The ease of quantifying the extent of interaction in this microchip technique may prove powerful for exploration of a myriad of receptor-ligand pairs.
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Affiliation(s)
- Mark D Goldberg
- Department of Chemistry and Biochemistry, California State University, Los Angeles, 5151 State University Drive, Los Angeles, California 90032-8202, USA
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12
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Chen Z, Lu D, Weber SG. High-throughput phase-distribution method to determine drug-cyclodextrin binding constants. J Pharm Sci 2009; 98:229-38. [PMID: 18428984 DOI: 10.1002/jps.21396] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A high-throughput method has been developed to measure drug-cyclodextrin binding constants. It measures the distribution ratio of a drug between a polymer film [polyvinyl chloride (PVC) with 67% (w/w) dioctyl sebacate (DOS)] and a cyclodextrin-containing buffer in a 96-well format. Measurements of distribution ratios at several cyclodextrin concentrations lead to binding constants. Binding constants for econazole with six CDs have been determined in one 96-well microplate with four replications of each condition in 10 h. The K(1:1)/10(3) M(-1) values are 3.98 +/- 0.13, 3.90 +/- 0.22, 29.3 +/- 2.2, 0.66 +/- 0.04, 1.78 +/- 0.30, 4.08 +/- 0.50, with (2-hydroxyethyl)-beta-cyclodextrin, (2-hydroxypropyl)-beta-cyclodextrin, 2,6-di-O-methyl-beta-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin, alpha-cyclodextrin, beta-cyclodextrin, respectively. It is likely that 1:2 complexes are also formed in some cases. This method has also been applied to study the binding behavior as a function of the drug concentration and pH. Binding weakens at higher drug concentration which may be due to the self-association of the drug. An acidic environment decreases the binding constant of CD with the basic econazole. The formation of the 1:2 complexes is completely suppressed in acid as well. This protocol is faster than the phase-solubility method. Moreover, the material requirement is up to four orders of magnitude lower.
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Affiliation(s)
- Zhi Chen
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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13
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Chalumot G, Yao C, Pino V, Anderson JL. Determining the stoichiometry and binding constants of inclusion complexes formed between aromatic compounds and β-cyclodextrin by solid-phase microextraction coupled to high-performance liquid chromatography. J Chromatogr A 2009; 1216:5242-8. [DOI: 10.1016/j.chroma.2009.05.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 04/28/2009] [Accepted: 05/08/2009] [Indexed: 11/26/2022]
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14
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Chen Z, Weber SG. Determination of binding constants by affinity capillary electrophoresis, electrospray ionization mass spectrometry and phase-distribution methods. Trends Analyt Chem 2008; 27:738-748. [PMID: 19802330 PMCID: PMC2600677 DOI: 10.1016/j.trac.2008.06.008] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Many methods for determining intermolecular interactions have been described in the literature in the past several decades. Chief among them are methods based on spectroscopic changes, particularly those based on absorption or nuclear magnetic resonance (NMR) [especially proton NMR ((1)H NMR)]. Recently, there have been put forward several new methods that are particularly adaptable, use very small quantities of material, and do not place severe requirements on the spectroscopic properties of the binding partners. This review covers new developments in affinity capillary electrophoresis, electrospray ionization mass spectrometry (ESI-MS) and phasetransfer methods.
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Affiliation(s)
- Zhi Chen
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
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15
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Parker KM, Stalcup AM. Affinity capillary electrophoresis and isothermal titration calorimetry for the determination of fatty acid binding with beta-cyclodextrin. J Chromatogr A 2008; 1204:171-82. [DOI: 10.1016/j.chroma.2008.02.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 02/01/2008] [Accepted: 02/05/2008] [Indexed: 10/22/2022]
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Montes RE, Hanrahan G, Gomez FA. Use of chemometric methodology in optimizing conditions for competitive binding partial filling affinity capillary electrophoresis. Electrophoresis 2008; 29:3325-32. [DOI: 10.1002/elps.200700693] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Poon KHN, Cheng YL. A quartz crystal microbalance study of β-cyclodextrin self assembly on gold and complexation of immobilized β-cyclodextrin with adamantane derivatives. J INCL PHENOM MACRO 2007. [DOI: 10.1007/s10847-007-9380-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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18
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Holm R, Nicolajsen HV, Hartvig RA, Westh P, Ostergaard J. Complexation of tauro- and glyco-conjugated bile salts with three neutral β-CDs studied by ACE. Electrophoresis 2007; 28:3745-52. [PMID: 17893938 DOI: 10.1002/elps.200700311] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Complexation of the bile salts (BS) taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate common in rat, dog, and man with natural beta-CD and the chemically modified beta-CDs 2-hydroxypropyl-beta-CD and 2-O-methyl-beta-CD was studied using mobility shift ACE. The CDs were selected due to their frequent use in preformulation and drug formulation as oral excipients for the solubilization of drug substances with low aqueous solubility. ACE was demonstrated to be a feasible and efficient technique for investigation of the interactions between BS and beta-CDs. All the investigated BS possessed affinity for the three CDs with stability constants ranging from 2x10(3) to 4x10(5) M(-) (1). The requirements and assumptions related to the use of ACE for estimating high affinity stability constants were discussed. The extent and pattern of hydroxylation significantly influenced the affinity of the glyco- and tauro-conjugated BS toward the beta-CDs (chenodeoxycholates >> deoxycholates > cholates) whereas the nature of the beta-CD derivatization and BS conjugation played a minor role only. The results indicate that displacement of drug substances from beta-CD inclusion complexes is likely to occur in the small intestine where BS are present potentially influencing drug bioavailability.
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Affiliation(s)
- René Holm
- Preformulation, H. Lundbeck A/S, Valby, Denmark
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Mahammad S, Roberts GW, Khan SA. Cyclodextrin-hydrophobe complexation in associative polymers. SOFT MATTER 2007; 3:1185-1193. [PMID: 32900040 DOI: 10.1039/b700167c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We develop a new rheology-based method to study the complexation of cyclodextrins with hydrophobes in hydrophobically modified associative polymer solutions. The associative polymers have comb-like structure with hydrophobic groups randomly attached to the polymer backbone. Intermolecular interactions between the hydrophobic groups form a transient network resulting in thickening of the polymer solutions. On addition of cyclodextrins (CD) to the solution, the hydrophobes are encapsulated within the hydrophobic cavity of the cyclodextrins. This reduces viscoelastic properties of the polymer solution by several orders of magnitude. We exploit the existence of a dynamic equilibrium between CD adsorbed to the hydrophobes and free CD in the solution, to develop a rheology-based Langmuir-type adsorption isotherm for estimating the binding constant for molecular complexation. The model is based on the assumption that the amount of CD adsorbed is proportional to the reduction in elastic modulus of the polymer solution due to the encapsulation of the network junctions by CD. The effects of temperature on binding constant are studied to estimate the enthalpy and entropy of complexation. Experiments are conducted with both α-and β-CD at different polymer concentrations and temperatures to estimate the relative strength of binding of the CDs. At a given temperature and a polymer concentration, α-CD has a lower binding constant compared to that of β-CD, indicating higher affinity of α-CD to adsorb onto the hydrophobes. Since α-CDs have a smaller ring size, they can snugly fit to the hydrophobes and the association leads to higher enthalpy and entropy change.
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Affiliation(s)
- Shamsheer Mahammad
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA.
| | - George W Roberts
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA.
| | - Saad A Khan
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA.
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Hanrahan G, Montes RE, Pao A, Johnson A, Gomez FA. Implementation of chemometric methodology in ACE: Predictive investigation of protein–ligand binding. Electrophoresis 2007; 28:2853-60. [PMID: 17640087 DOI: 10.1002/elps.200600523] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An ACE predictive investigation of protein-ligand binding using a highly effective chemometric response surface design technique is presented. Here, K(d) was estimated using one noninteracting standard which relates to changes in the electrophoretic mobility of carbonic anhydrase B (CAB, EC 4.2.1.1) on complexation with the ligand 4-carboxybenzenesulfonamide (CBSA) present in the electrophoresis buffer. Experimental factors including injection time, capillary length, and applied voltage were selected and tested at three levels in a Box-Behnken design. Statistical analysis results were used to create a mathematical model for response surface prediction via contour and surface plots at a given target response (K(d) = 1.19x10(-6) M). As expected, there were a number of predicted solutions that reached our target response based on the significance of each factor at appropriate levels. The adequacy of the model was validated by experimental runs with the predicted model solution (capillary length = 47 cm, voltage = 11 kV, injection time = 0.01 min) presented in detail as an example.
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Affiliation(s)
- Grady Hanrahan
- Department of Chemistry and Biochemistry, California State University, Los Angeles, CA 90032, USA
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Karakasyan C, Millot MC, Jaulmes A, Vidal-Madjar C. Retention properties of hydrophobically end-capped poly(ethylene glycol)s on a beta-cyclodextrin support. J Chromatogr A 2006; 1127:108-16. [PMID: 16828487 DOI: 10.1016/j.chroma.2006.05.097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 05/03/2006] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
High-performance liquid chromatography (HPLC) was used to examine the retention behavior of monomethoxypoly(ethylene glycol)s bearing one hydrophobic naphthyl end group (Nap-MPEG) on beta-cyclodextrin polymer (poly-beta-CD) immobilized on a silica support, under isocratic elution conditions and using water as mobile phase. Studies of retentions and theoretical plate heights H were conducted at infinite dilution by comparing the behavior of Nap-MPEGs having different molecular weight (750, 1000 and 5000 g/mol). The larger is its molecular size, the lower is the retention of the polymer. The linear increase of H with mobile phase velocity reveals slow mass-transfer kinetics arising from the restricted diffusion into the pores of the support. The complexation constants between the Nap-MPEGs and beta-CD in solution (around 500M(-1)) were determined from the decrease of retention observed by adding increasing concentrations of hydroxypropyl beta-CD into the eluent. The peak profiles in mass-overload conditions were studied by fitting a model based upon bi-Langmuir kinetics which assumes a non-uniform support having two types of binding sites and apparent adsorption rate constants are used to describe mass-transfer kinetics. A three-parameter adsorption equilibrium isotherm was sufficient to account for the modifications of peak shapes observed when increasing amounts of polymer were injected. This result indicates an interaction with a heterogeneous poly-beta-CD support mainly composed of low affinity groups, non-saturable in the range of polymer concentration studied. An upper limit was estimated for the equilibrium constant (<1000 M(-1)) characterizing the affinity of Nap-MPEG for the non-saturable sites of the poly-beta-CD support. Large affinity constants (8-9 x 10(4)M(-1)) were found for the interaction of Nap-MPEGs with a small percentage of active sites.
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Affiliation(s)
- Carole Karakasyan
- Laboratoire de Recherche sur les Polymères, CNRS-Université Paris 12, 2 rue Henry Dunant, 94320 Thiais, France
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Abstract
Systems biology depends on a comprehensive assignment and characterization of the interactions of proteins and polypeptides (functional proteomics) and of other classes of biomolecules in a given organism. High‐capacity screening methods are in place for ligand capture and interaction screening, but a detailed dynamic characterization of molecular interactions under physiological conditions in efficiently separated mixtures with minimal sample consumption is presently provided only by electrophoretic interaction analysis in capillaries, affinity CE (ACE). This has been realized in different fields of biology and analytical chemistry, and the resulting advances and uses of ACE during the last 2.5 years are covered in this review. Dealing with anything from small divalent metal ions to large supramolecular assemblies, the applications of ACE span from low‐affinity binding of broad specificity being exploited in optimizing selectivity, e.g., in enantiomer analysis to miniaturized affinity technologies, e.g., for fast processing immunoassay. Also, approaches that provide detailed quantitative characterization of analyte–ligand interaction for drug, immunoassay, and aptamer development are increasingly important, but various approaches to ACE are more and more generally applied in biological research. In addition, the present overview emphasizes that distinct challenges regarding sensitivity, parallel processing, information‐rich detection, interfacing with MS, analyte recovery, and preparative capabilities remain. This will be addressed by future technological improvements that will ensure continuing new applications of ACE in the years to come.
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Affiliation(s)
- Christian Schou
- Department of Autoimmunology, Statens Serum Institute, Copenhagen, Denmark
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Zavaleta J, Chinchilla D, Martinez K, Gomez FA. Multiple-injection affinity capillary electrophoresis to examine binding constants between glycopeptide antibiotics and peptides. J Chromatogr A 2006; 1105:59-65. [PMID: 16325833 DOI: 10.1016/j.chroma.2005.10.062] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 10/21/2005] [Accepted: 10/27/2005] [Indexed: 11/25/2022]
Abstract
Multiple-injection affinity capillary electrophoresis (MIACE) was used to determine binding constants (K(b)) between vancomycin, ristocetin, and teicoplanin from Streptomyces orientalis, Nocardia lurida, and Actinoplanes teichomyceticus, respectively, and fluorenylmethoxycarbonyl (Fmoc)-(Gly, Ala, Val, and Phe)-D-Ala-D-Ala peptides. In this technique, separate plugs of sample containing non-interacting standards, peptide one, buffer, and peptide two, were injected into the capillary column and electrophoresed. Peptides migrate through the column at similar electrophoretic mobilities but remain as distinct zones due to the buffer plug between peptides. The electrophoresis is then carried out in an increasing concentration of antibiotic in the running buffer. Continued electrophoresis results in a shift in the migration time of the peptides upon binding to the antibiotic. Analysis of the change in the relative migration time ratio (RMTR) of the resultant complexes relative to the non-interacting standards, as a function of the concentration of antibiotic yields a value for K(b). MIACE is a versatile technique that can be used to measure affinity constants between ligands of similar relative molecular mass and charge without the need of separate binding experiments. The findings described, herein, demonstrate the advantages of using MIACE to estimate binding parameters between ligands and receptors.
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Affiliation(s)
- Jose Zavaleta
- Department of Chemistry and Biochemistry, California State University, 5151 State University Drive, Los Angeles, 90032-8202, USA
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Du X, Lu W, Ding N, Dai H, Teng X, Deng H. Spectral properties and supramolecular inclusion complexes of β-cyclodextrin with flexible amphiphilic and rigid compounds. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2005.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Schipper BR, Ramstad T. Determination of the binding constant between alprostadil and alpha-cyclodextrin by capillary electrophoresis: implications for a freeze-dried formulation. J Pharm Sci 2005; 94:1528-37. [PMID: 15920771 DOI: 10.1002/jps.20380] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The binding constant between alprostadil (PGE1) and alpha-cyclodextrin (alpha-CD) was determined at three temperatures by capillary electrophoresis. alpha-CD is an excipient material in Caverject Dual Chamber Syringe (DCS), added to enhance stability. The binding constant was used to calculate the amount of PGE1 free upon reconstitution and injection, the latter of which is critical to product performance. Measurement was made in a pH 7.2 separation buffer to ensure a negative charge on PGE1. The concentration of PGE1 was fixed while the concentration of alpha-CD was varied over a suitable range. As the amount of PGE1 bound to alpha-CD increases, the weighted average of the resultant mobility decreases, thereby allowing a binding isotherm to be generated from which the stability constant was extracted via nonlinear regression analysis. A value of 708 +/- 64 M(-1) was obtained at 27 degrees C, while at physiological temperature (37 degrees C) the value was 537 +/- 27 M(-1). These results compare favorably to values previously obtained by NMR. Calculation of the percent PGE1 free upon reconstitution and injection show it to be near the desired outcome of 100%. Hence, we were able to conclude that the amount of free drug delivered by Caverject DCS is nominally the same as for Caverject S. Po., an earlier-developed product that contains no alpha-CD.
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Sano D, Omura T. Construction of a cloning system for the mass production of a virus-binding protein specific for poliovirus type 1. Appl Environ Microbiol 2005; 71:2608-15. [PMID: 15870352 PMCID: PMC1087535 DOI: 10.1128/aem.71.5.2608-2615.2005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In our previous study, virus-binding proteins (VBPs) demonstrating the ability to strongly bind poliovirus type 1 (PV1) were recovered from a bacterial culture derived from activated sludge. The isolated VBPs would be useful as viral adsorbents for water and wastewater treatments. The VBP gene of activated sludge bacteria was isolated, and the cloning system of the VBP was established. The isolation of the VBP gene from DNA libraries for activated sludge bacteria was achieved with the colony hybridization technique. The sequence of the VBP gene consisted of 807 nucleotides encoding 268 amino acids. Fifteen amino acid sequences were retrieved from 2,137,877 sequences by a homology search using the BLAST server at the National Center for Biotechnology Information. The protein encoded in the isolated genome was considered to be a newly discovered protein from activated sludge culture, because any sequences in protein databases were not perfectly matched with the sequence of the VBP. It was confirmed that Escherichia coli BL21 transformed by pRSET carrying the isolated VBP gene could extensively produce the VBP clones. Enzyme-linked immunosorbent assay (ELISA) revealed that the VBP clone exhibited the binding ability with intact particles of PV1. The equilibrium binding constant between PV1 and VBP in the ELISA well was estimated to be 2.1 x 10(7) (M(-1)), which also indicated that the VBP clones have a high affinity with the PV1 particle. The VBP cloning system developed in this study would make it possible to produce a mass volume of VBPs and to utilize them as a new material of the specific adsorbent in several technologies, including virus removal, concentration, and detection.
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Affiliation(s)
- Daisuke Sano
- Department of Civil Engineering, Graduate School of Engineering, Tohoku University, Aoba, Sendai 980-8579, Japan.
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Gayton-Ely M, Pappas TJ, Holland LA. Probing affinity via capillary electrophoresis: advances in 2003–2004. Anal Bioanal Chem 2005; 382:570-80. [PMID: 15703915 DOI: 10.1007/s00216-004-3033-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Accepted: 12/09/2004] [Indexed: 10/25/2022]
Abstract
This review addresses recent advances in capillary electrophoresis of biological-based molecular interaction from a broader perspective, based on applications reported during the period 2003-2004. These capillary electrophoresis-based studies of molecular interactions include affinity capillary electrophoresis, electrokinetic chromatography, and free zone electrophoresis. The review is written as a general synopsis of applications and does not cover the theory or protocol involved in the implementation of the analyses.
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Affiliation(s)
- Melissa Gayton-Ely
- Department of Chemistry, West Virginia University, 217 Clark Hall, P.O.Box 6045, Morgantown, WV 26506, USA
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