Determination of limiting mobilities and dissociation constants of 21 amino acids by capillary zone electrophoresis at very low pH

Zusková, Iva; Novotná, Alena; Včeláková, Kateřina; Gaš, Bohuslav

doi:10.1016/j.jchromb.2006.03.015

Cited by 40 publications

(40 citation statements)

References 31 publications

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“…Mobility corrections on electrolytes and proteins have been investigated in the past [28,29,31]. Gas and his colleagues [28] used Onsager-Debye-Huckel theory to report the effect of ionic strength on the electrophoretic mobility of small ions such as background electrolyte in CZE.…”

Section: Resultsmentioning

confidence: 99%

“…For dilute aqueous solutions (less than 100 mM of ionic strength), the effective mobility, ( m i h i) can be expressed as [28] …”

Section: Mobility Corrections For Ampholytesmentioning

confidence: 99%

“…The corrected mobility of species (m i1 and m i1 À ) is given by the Onsager-Debye-Huckel equation as [28,29] …”

Section: Mobility Corrections For Ampholytesmentioning

confidence: 99%

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Dispersion of protein bands in a horseshoe microchannel during IEF

2009

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Ampholyte-based IEF is simulated for a 2-D horseshoe microchannel. The IEF model takes into account ionic-strength-dependent mobility corrections for both proteins and ampholytes. The Debye-Huckel-Henry model is employed to correct the protein mobilities and the Onsager-Debye-Huckel model is used to obtain effective mobilities of ampholytes from their limiting mobility. IEF simulations are conducted in the presence of 25 ampholytes (DeltapK=3.0) within a pH range of 6-9 under an electric field of 300 V/cm and using four proteins (pIs=6.49, 7.1, 7.93 and 8.6) focused in a 1-cm-long microchannel. The numerical results show that the concentrations of proteins and ampholytes are different when mobility corrections are considered but that the focusing positions remain the same regardless of mobility corrections. Our results also demonstrate that, unlike linear electrophoresis in which the bands deform significantly as they traverse a bend, during the transient portion of IEF racecourse dispersion is mitigated by focusing and, at focused-state, those bands that focus in the bend show no radial concentration dependence, i.e. they completely recover from racecourse dispersion, even within a tight turn.

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Section: Resultsmentioning

confidence: 99%

“…For dilute aqueous solutions (less than 100 mM of ionic strength), the effective mobility, ( m i h i) can be expressed as [28] …”

Section: Mobility Corrections For Ampholytesmentioning

confidence: 99%

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Dispersion of protein bands in a horseshoe microchannel during IEF

2009

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“…Values of E j were determined using limiting conductivities, as well as conductivities at 0.1 M and 0.5 M ionic strength where interionic forces play a larger role. The latter values were calculated using the Onsager limiting law in the form used by Zusková et al [18], even though it is known that the Onsager limiting law is valid for ionic strengths of at most 0.1 M and at higher concentrations the predicted mobilities are too low [3]. We noted that the E j values calculated were (i) essentially the same using the two equations for this junction, (ii) larger than those observed experimentally when using conductivities calculated at 0.1 M and 0.5 M ionic strength, and surprisingly (iii) comparable to experimental data when limiting conductivities were used.…”

Section: Theoretically Modelled E J Vs Ph Relationshipmentioning

confidence: 99%

A Novel Approach to Monitoring of the Diffusion Junction Potential in Speciation Studies by Polarography Under very Acidic Conditions. Part I: The Reversible Cd(II)‐Picolinic Acid System

Billing¹,

Cukrowski²,

Jordan³

2013

Electroanalysis

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A new polarographic procedure has been developed for the study of metal-ligand equilibria at pH < 2 by applying an insitu monitoring of the diffusion junction potential by introducing a non-complexing witness metal ion, Tl(I). As a case study, this procedure was applied to the Cd(II)-picolinic acid (pyridine-2-carboxylic acid) system; DC TAST polarography was employed at 25°C and ionic strength of 0.25-0.5 M (H,Na)NO 3 . Log b values of 4.26±0.03, 7.86±0.11 and 10.47±0.12 were obtained for the ML, ML 2 and ML 3 complexes, respectively, and compare well to literature values. The first log b (6.27±0.07) value for the MLH species was successfully determined, for which a crystal structure has been reported recently.

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“…[12][13][14][15][16] Gong et al 17 demonstrated that the determination of the enantiomers of non-UV-absorbing amino acids is possible by CE-C 4 D using a combination of the noncharged additives hydroxypropyl-b-cyclodextrin and (1)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18C6H 4 ) as the chiral separators. It has furthermore been shown that capillary electrophoresiscapacitively coupled contactless conductivity detection (CE-C 4 D) may be used for the monitoring of enzymatic reactions when the species involved are not detectable by optical means.…”

Section: -11mentioning

confidence: 99%

Following the lipase catalyzed enantioselective hydrolysis of amino acid esters with capillary electrophoresis using contactless conductivity detection

Schuchert‐Shi

Hauser

2009

Chirality

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The progress of the enzymatic hydrolysis of racemic mixtures of the enantiomers of the methyl esters of serine and threonine was monitored. This was possible in a reaction vessel of 1.5 mL by direct sampling of volumes in the nanoliter-range directly into an electrophoresis capillary. Contactless conductivity detection was used for quantification as the analytes are not accessible by UV-detection in capillary electrophoresis. Porcine pancreatic lipase and wheat germ lipase both showed a preference for the L-enantiomers of both amino acid esters. The selectivity of the porcine lipase between the two L-esters of the two amino acids was also studied and it was found that the production of L-threonine had priority over L-serine. Chirality 22:331-335, 2010. V V C 2009 Wiley-Liss, Inc.

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Determination of limiting mobilities and dissociation constants of 21 amino acids by capillary zone electrophoresis at very low pH

Cited by 40 publications

References 31 publications

Dispersion of protein bands in a horseshoe microchannel during IEF

Dispersion of protein bands in a horseshoe microchannel during IEF

A Novel Approach to Monitoring of the Diffusion Junction Potential in Speciation Studies by Polarography Under very Acidic Conditions. Part I: The Reversible Cd(II)‐Picolinic Acid System

Following the lipase catalyzed enantioselective hydrolysis of amino acid esters with capillary electrophoresis using contactless conductivity detection

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