Amphoteric, isoelectric immobiline membranes for preparative isoelectric focusing

Wenger, Pierre; Zuanni, Maxime de; Javet, Philippe; Gelfi, Cecilia; Righetti, Pier Giorgio

doi:10.1016/0165-022x(87)90004-2

Cited by 48 publications

(21 citation statements)

References 11 publications

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“…Wenger et al synthesized amphoteric, isoelectric membranes and demonstrated their use as good buffers at their respective pIs (25). These membranes are created with the same technology used to make IPG strips.…”

Section: Mu Ul Lt Ti Ic Co Om Mp Pa Ar Rt Tm Me En Nt T E El Le Ec mentioning

confidence: 99%

Peer Reviewed: Prefractionation Techniques in Proteome Analysis

Righetti¹,

Castagna²,

Herbert³

2001

Anal. Chem.

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100

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Section: Mu Ul Lt Ti Ic Co Om Mp Pa Ar Rt Tm Me En Nt T E El Le Ec mentioning

confidence: 99%

Peer Reviewed: Prefractionation Techniques in Proteome Analysis

Righetti¹,

Castagna²,

Herbert³

2001

Anal. Chem.

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100

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“…Additionally the experimental set-up of Lee and Hong (1987) is complicated by the fact that their membranes are negatively charged, producing an electroosmotic flow and inducing protein adsorption to the charge groups on the membranes. Our system is immune from such drawbacks: Isoelectric membranes do not produce electroosmosis (in fact they are used to cure it) (Wenger et al, 1987) and, due to their isoelectric state, do not have any tendency to absorb proteins. At the same time the membranes prevent very well the loss of enzyme from the reaction chamber.…”

Section: Discussionmentioning

confidence: 99%

Isoelectrically trapped enzymatic bioreactors in a multimembrane cell coupled to an electric field: Theoretical modeling and experimental validation with urease

Nembri

Bossi

Ermakov

et al. 1997

Biotechnol. Bioeng.

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A novel type of immobilized enzyme reactor operating under an electric field is here reported: a multicompartment immobilized enzyme reactor (MIER). In this experimental set‐up, the enzyme and zwitterionic buffering ions are trapped in between two isoelectric membranes, having isoelectric point (pl) values so far apart as to trap the enzyme by an isoelectric mechanism, while allowing operation at pH optima, even when the latter pH value is quite removed from the enzyme pl. As an example, urease (pl 4.9) is trapped between a pl 4.0 and a pl 8.0 membranes, thus permitting operation (via suitable amphoteric ions buffering at pH 7.5) at the pH of optimum of activity (pH 7.5). The charged product (ammonium ions) quickly leaves the enzyme chamber under the influence of the electric field, thus allowing sustained activity for much longer time periods than in conventional reactors. As an example, while in a batch reactor 90% of original enzyme activity is lost in 200 min, only 2% activity is lost in the same period in the MIER reactor. As an additional bonus, the MIER reactor allows conversion rates of ∼95% in a wide range of substrate concentrations, whereas batch‐type reactors rarely achieve better than 50% conversion under comparable experimental conditions. © 1997 John Wiley & Sons, Inc.

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“…Isoelectric trapping (IET) protein separations in multicompartmental electrolyzers, pioneered by Martin et al [1], Faupel et al [2,3], and Righetti et al [4,5], became important alternatives to chromatographic methods of protein purification [6]. Earlier achievements of this powerful preparative separation technology and instrumentation [7] in the general area of laboratory-scale preparative protein purification have been reviewed extensively, such as in [8,9].…”

Section: Introductionmentioning

confidence: 99%

“…The quintessential feature of classical IET [1][2][3][4][5] is that the purified proteins are isolated in the form of isoionic solutions in compartments that are formed by buffering membranes [1] (also known as isoelectric membranes [2][3][4][5][14][15][16] and zwitterionic membranes [17,18]), whose pH (pI) values bracket the pI of the target protein. Typically, the solutions containing the proteins are recirculated through the separation compartments.…”

Section: Introductionmentioning

confidence: 99%

Hydrolytically stable, diaminocarboxylic acid‐based membranes buffering in the pH range from 6 to 8.5 for isoelectric trapping separations

Fleisher

Vigh

2005

Electrophoresis

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Diaminocarboxylic acid carrier ampholytes, such as L-histidine, 2,3-diaminopropionic acid, L-ornithine, and L-lysine, were reacted with glycerol-1,3-diglycidyl ether (GDGE) and poly(vinyl alcohol) (PVA) in the presence of sodium hydroxide to produce hydrolytically and mechanically stable hydrogels, supported on a PVA substrate, for use as buffering membranes in isoelectric trapping (IET) separations. The pH values of the DACAPVA membranes were determined with the help of small-molecule pI markers and proteins and were found to be in the 6 < pH < 8.5 range. The membranes were successfully used to isoelectrically trap small ampholytes, desalt ampholyte solutions in IET mode, and effect the binary separation of chicken egg white proteins.

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Amphoteric, isoelectric immobiline membranes for preparative isoelectric focusing

Cited by 48 publications

References 11 publications

Peer Reviewed: Prefractionation Techniques in Proteome Analysis

Peer Reviewed: Prefractionation Techniques in Proteome Analysis

Isoelectrically trapped enzymatic bioreactors in a multimembrane cell coupled to an electric field: Theoretical modeling and experimental validation with urease

Hydrolytically stable, diaminocarboxylic acid‐based membranes buffering in the pH range from 6 to 8.5 for isoelectric trapping separations

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