Assays for serum cholinesterase activity by capillary electrophoresis and an amperometric flow injection choline biosensor

Hsieh, Bo-Chuan; Hsiao, Hsien-Yi; Cheng, Tzong‐Jih; Chen, Richie L.C.

doi:10.1016/j.aca.2008.06.008

Cited by 15 publications

(2 citation statements)

References 21 publications

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“…Due to its high separation efficiency and sensitivity, extremely small sample requirement, rapid analysis and utilization of various detection modes, it is increasingly being used in biochemical assays for determining a wide range of different compounds in biological samples. 1,2 CE has been employed in enzyme assays for studying enzyme kinetics, [3][4][5][6] evaluating enzyme activity, [7][8][9] and for inhibitor screening. [10][11][12] Usually, the catalytic activity of an enzyme decreases gradually with time, e.g.…”

Section: Introductionmentioning

confidence: 99%

Advances in immobilized enzyme microbioreactors in capillary electrophoresis

Iqbal

Müller

2013

Analyst

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Miniaturized bioanalytical systems are increasingly being used in the field of biochemical research. Immobilized enzyme microbioreactors in capillary electrophoresis (CE) have been constructed and used to fulfill the increasing demands for miniaturized bioanalytical systems. This manipulation permits low sample consumption, reduced costs, short analysis times and efficient analyses. This review provides an overview of the distinct characteristics of immobilized microbioreactors in CE. After an introduction on miniaturized microreactors, the various methods of enzyme immobilization will be discussed. The emphasis will be on two common constructions of microreactors in CE, i.e. CE-coupled microreactors, and microreactors directly integrated into the CE capillary. Such microbioreactors offer straightforward automation of reaction steps followed by separation in the same capillary.

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Section: Introductionmentioning

confidence: 99%

Advances in immobilized enzyme microbioreactors in capillary electrophoresis

Iqbal

Müller

2013

Analyst

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“…Because of its unique advantages, such as high efficiency and sensitivity, rapid analysis, extremely low sample volume requirements, and the ability to utilize several detection methods, capillary electrophoresis (CE) has become a powerful tool for the quantitative study of enzyme-catalyzed reactions and has been widely applied in nearly all aspects of enzyme assays, , including the evaluation of enzymatic activity, − enzyme kinetics, , enzyme inhibition and activation, , and the investigation of enzyme-mediated metabolic pathways. , For enzyme assays, online monitoring of the enzymatic reaction from beginning to end is vitally important to fully understand the metabolic enzyme functions and to determine their uses for clinical diagnostics. Online monitoring of the enzymatic reaction requires that the substrate and product be sequentially injected into the capillary without any physical disturbance of the capillary inlet so that both substrate and product may be simultaneously monitored once the reaction occurs.…”

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confidence: 99%

Method for the Sequential Online Analysis of Enzyme Reactions Based on Capillary Electrophoresis

Chen

Zhao

et al. 2012

Anal. Chem.

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We have developed an easy-to-operate and effective method for performing the sequential online analysis of enzyme reactions based on capillary electrophoresis (CE). The system was constructed by passing two capillaries through a sample vial at a distance of 5 μm between the capillary ends. Direct online sample injection and sequential CE analysis were achieved by periodically switching the high-voltage power supply off and on, without any physical disturbance of the capillary inlet. The sample was injected via concentration diffusion with in-column derivatization of the amino acids occurring at the interface of the capillaries. High reproducibility of the sequential injections was demonstrated with relative standard deviation values (n = 20) of 1.01%, 1.25%, and 0.80% for peak height, peak area, and migration time, respectively. Sequential online CE enzyme assay of a glutamate pyruvate transaminase catalyzed enzyme reaction was carried out by simultaneously monitoring the substrate consumption and the product formation every 30 s from the beginning to the end of the reaction. The Michaelis constants for the reaction were obtained and were found to be in good agreement with the results of traditional off-line enzyme assays. Our method has great potential for usage in sequential online CE analysis of chemical reactions with in-column chemical derivatization of the analytes for ultraviolet or laser-induced fluorescence detection.

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Capillary Electrophoretic Enzyme Assays

Scriba

Abromeit

Hense³

et al. 2013

Capillary Electrophoresis of Biomolecules

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In the past years, capillary electrophoresis has become a frequently used technique for enzyme assays due to the high separation efficiency and versatility as well as small sample size and low consumption of chemicals. The capillary electrophoresis assays can be divided into two general categories: pre-capillary (or offline) assays and in-capillary (or online) assays. In pre-capillary assays, the incubation is performed offline and substrate(s) and product(s) are subsequently analyzed by capillary electrophoresis. In in-capillary assays enzyme reaction and separation of the analytes are performed inside the same capillary. In such assays the enzyme is either immobilized or in solution. The latter techniques is also referred to as electrophoretically mediated microanalysis (EMMA) indicating that the individual steps of the incubation as well as analysis are performed via electrophoretic phenomena. This chapter describes both techniques using the deacetylation of acetyl-lysine residues in model peptides by sirtuin enzymes as well as the hydrolysis of acetylthiocholine by acetylcholinesterase as examples.

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Assays for serum cholinesterase activity by capillary electrophoresis and an amperometric flow injection choline biosensor

Cited by 15 publications

References 21 publications

Advances in immobilized enzyme microbioreactors in capillary electrophoresis

Advances in immobilized enzyme microbioreactors in capillary electrophoresis

Method for the Sequential Online Analysis of Enzyme Reactions Based on Capillary Electrophoresis

Capillary Electrophoretic Enzyme Assays

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