Effective ion‐pairing for the separation of basic proteins in capillary electrophoresis

Okafo, George; Vinther, Anders; Kornfelt, Troels; Camilleri, Patrick

doi:10.1002/elps.11501601316

Cited by 19 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other electrolyte additives such as various salts [84], zwitterions [85,86], and organic amines [87,88] can be used to compete for the adsorption sites on the capillary wall [89].…”

Section: Suppression Of Eof and Reduction Of Solute Adsorptionmentioning

confidence: 99%

Dual‐opposite‐injection CZE: Theoretical aspects and application to organic and pharmaceutical compounds

Weekley

Foley

2007

Electrophoresis

View full text Add to dashboard Cite

Several important figures of merit (migration time, efficiency, resolution, resolution per unit time, and electrophoretic selectivity) are quantitatively compared for the first time for conventional CZE and dual-opposite-injection CZE (DOI-CZE). Aspects of DOI-CZE relevant to the separation of organic and pharmaceutical ions (MW>120 Da) are also discussed. Two new approaches to resolve the codetection of anions and cations, hydrodynamic flow-modified DOI-CZE and polarity reversal in combination with asymmetric detector window positioning, are compared with the method of preliminary transport, a variable procedure within sequential sample introduction, using a six-component sample of organic and pharmaceutical compounds. The advantages of DOI-CZE for the simultaneous analysis of organic/pharmaceutical anions and cations are illustrated in a direct comparison of conventional CZE and DOI-CZE for the separation of a ten-component mixture of pharmaceutical ions (five ionized acids and five ionized bases).

show abstract

“…Other electrolyte additives such as various salts [84], zwitterions [85,86], and organic amines [87,88] can be used to compete for the adsorption sites on the capillary wall [89].…”

Section: Suppression Of Eof and Reduction Of Solute Adsorptionmentioning

confidence: 99%

Dual‐opposite‐injection CZE: Theoretical aspects and application to organic and pharmaceutical compounds

Weekley

Foley

2007

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…The addition of the dodecasodium salt of phytic acid to the separation buffer is known to allow the analysis of a number of basic proteins (pI w 9) by CE. [25][26][27] Some very basic proteins that totally adsorb to the capillary in the presence of buffer only can apparently be analysed as sharp signals in the electropherogram when the dodecasodium salt of phytic acid is included in the separation buffer. Phytic acid contains six phosphate groups with pK a values ranging from 1.9 to 9.5, which means that this molecule has a polyanionic character over a wide pH range.…”

Section: Nature Of the Separation Buffermentioning

confidence: 99%

Capillary electrophoresis hyphenated to inductively coupled plasma-sector field-mass spectrometry for the stoichiometric determination of Zn bound to Aeromonas hydrophila Zn beta-lactamase

Lierde

Chéry

Strijckmans

et al. 2004

J. Anal. At. Spectrom.

View full text Add to dashboard Cite

A method was developed for the determination of the stoichiometric Zn/protein ratio for the Aeromonas hydrophila metallo beta-lactamase AE036. Capillary electrophoresis (CE) was used to separate free Zn ions from the Zn bound to the metalloprotein, the only Zn-species which is biochemically relevant. An inductively coupled plasma-sector field-mass spectrometer (ICP-SF-MS), operated at a mass resolution of 3000, was used as an element-specific detector. If the primary structure of the protein and thus the number of sulfur-containing amino acids is known, as is the case for Aeromonas hydrophila Zn beta-lactamase, monitoring of both Zn and S with ICP-SF-MS permits the Zn/protein ratio to be determined. The method was optimised in order to obtain short migration times (less than 10 min) for the metallo beta-lactamase and for standards with bare fused silica capillaries. After optimisation, a 75 mmol L-1 bis-Tris background electrolyte buffered at a pH of 6.75 was used for the separation, a voltage of 30 kV was applied over a capillary with a total length of approximately 70 cm and the sample was introduced hydrodynamically at 1000 mbar s. Quantitative results (stoichiometric Zn/protein ratio of 1 and 2, before and after saturation of the enzyme with Zn, respectively) were obtained using external calibration with albumin as a S standard and ZnCl2 as a Zn standard. The method was also demonstrated to be precise with < 5% RSD on the Zn/protein ratio for n=3. An absolute limit of detection of 8 ng of A. hydrophila Zn beta-lactamase (calculated on the basis of sulfur) was obtained under these conditions

show abstract

“…In a separate paper, Preisler and Yeung imaged a 23-cm portion of the capillary to monitor changes in the PEO coating during electrophoresis by continuously monitoring the EOF (525). Phytic acid, which can reduce wall adsorption of proteins and serve as an effective ion-pair agent, is becoming a popular buffer additive for CE of proteins (526,527), peptides (528), oligosaccharides (529), and oligonucleotides (530).…”

Section: Separation Systemsmentioning

confidence: 99%

Capillary Electrophoresis

1998

View full text Add to dashboard Cite

This review represents the fifth in the series of fundamental reviews on capillary electrophoresis (CE) appearing in the journal. This review, which covers the period from October 1995 to October 1997, focuses on significant developments in the theory and practice of CE. Following the previously successful format, included here are papers covering capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis (CITP), and capillary electrochromatography (CEC). Within these separation systems we emphasize advances in the underlying principles and theory including performance optimization, instrumental configurations (sample introduction, CEC, microchips, etc.), and detection strategies. Publications that appeared during the covered period in which the emphasis was on specific applications of CE have not been included in this review. These can be easily accessed through various numbers of existing application reviews (1) or applicationsspecific literature searches.The review is not intended to provide a comprehensive compilation of the more than 3600 CE papers published between October 1995 and October 1997. The author's intent, rather, was to gather and present those papers representing fundamental developments across the CE landscape. It is hoped that the result will provide a flavor for the current directions in which CE is evolving, where CE has matured, and perhaps offer insight to some of the latent, untapped, promise of CE.

show abstract

Effective ion‐pairing for the separation of basic proteins in capillary electrophoresis

Cited by 19 publications

References 17 publications

Dual‐opposite‐injection CZE: Theoretical aspects and application to organic and pharmaceutical compounds

Dual‐opposite‐injection CZE: Theoretical aspects and application to organic and pharmaceutical compounds

Capillary electrophoresis hyphenated to inductively coupled plasma-sector field-mass spectrometry for the stoichiometric determination of Zn bound to Aeromonas hydrophila Zn beta-lactamase

Capillary Electrophoresis

Contact Info

Product

Resources

About