Analysis of solutes and metabolites in single plant cell vacuoles by capillary electrophoresis

Lochmann, H.; Bazzanella, A.; Bächmann, K.

doi:10.1016/s0021-9673(98)00383-5

Cited by 26 publications

(9 citation statements)

References 45 publications

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“…The remainder are unable to provide ACC in the ripening fruit because they are expressed elsewhere, restricted by their tissue specific expression. Determination of the AdoMet concentration in single cells or group of cells using laser capture microdissection (76) coupled with nanocapillary electrophoresis (77,78) will provide additional experimental support to elucidate these relationships. Nearly 25 years ago Harris (79) put forward a similar concept regarding multilocus enzymes in man: "Although in general the different isozymes which make up these various multilocus sets are very similar to one another in their catalytic functions, differences in their kinetics, their inhibition characteristics and other properties such as stability have been noted in quite a number of cases.…”

Section: Resultsmentioning

confidence: 99%

Biochemical Diversity among the 1-Amino-cyclopropane-1-Carboxylate Synthase Isozymes Encoded by the Arabidopsis Gene Family

Yamagami

Tsuchisaka

Yamada

et al. 2003

Journal of Biological Chemistry

312

289

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1-Amino-cyclopropane-1-carboxylate synthase (ACS, EC 4.4.1.14) is the key enzyme in the ethylene biosynthetic pathway in plants. The completion of the Arabidopsis genome sequence revealed the presence of twelve putative ACS genes, ACS1-12, dispersed among five chromosomes. ACS1-5 have been previously characterized. However, ACS1 is enzymatically inactive whereas ACS3 is a pseudogene. Complementation analysis with the Escherichia coli aminotransferase mutant DL39 shows that ACS10 and 12 encode aminotransferases. The remaining eight genes are authentic ACS genes and together with ACS1 constitute the Arabidopsis ACS gene family. All genes, except ACS3, are transcriptionally active and differentially expressed during Arabidopsis growth and development. IAA induces all ACS genes, except ACS7 and ACS9; CHX enhances the expression of all functional ACS genes. The ACS genes were expressed in E. coli, purified to homogeneity by affinity chromatography, and biochemically characterized. The gas ethylene has been known since the beginning of the century to be used by plants as a signaling molecule for regulating a variety of developmental processes and stress responses (1). These include seed germination, leaf and flower senescence, fruit ripening, cell elongation, nodulation, wounding and pathogen responses. Ethylene production is induced by a variety of external factors, including wounding, viral infection, elicitors, auxin treatment, and Li ϩ ions (2-7). Ethylene is biosynthesized from methionine, which is converted to AdoMet 1 by the enzyme AdoMet synthetase. AdoMet is converted by the enzyme ACS to ACC, the precursor of ethylene (5, 7-9). ACC is oxidized to ethylene by ACO. ACS is a pyridoxal phosphate-containing enzyme (2, 5, 10) and its activity is regulated at the transcriptional (11-18) and posttranscriptional levels (19 -21). The ethylene biosynthetic enzymes, AdoMet synthetase, ACS, and ACO, are encoded by multigene families in various plant species (5,9,16,17,(22)(23)(24)(25). The crystal structures of apple and tomato Le-ACS2 isozymes were recently elucidated (26, 27). The structures show that the enzyme is a homodimer, and its overall fold and active sites are similar to those of aminotransferases even though the two enzymes have completely different catalytic activities. The tertiary structures together with available biochemical data explain the catalytic roles of the conserved and non-conserved active site residues (28 -31).The sequencing of the Arabidopsis genome revealed that ACS genes are putatively encoded by twelve genes (32). The question immediately arises as to why there are so many ACS isozymes for synthesizing ethylene in Arabidopsis. It has been postulated that the presence of ACS isozymes may reflect tissue-specific expression that satisfies the biochemical environment of the cells or tissues in which each isozyme is expressed (15). For example, a group of cells or tissues with low concentration of the ACS substrate, AdoMet, would express a high affinity (low K m ) ACS isozyme. Accordingly, the ...

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Section: Resultsmentioning

confidence: 99%

Biochemical Diversity among the 1-Amino-cyclopropane-1-Carboxylate Synthase Isozymes Encoded by the Arabidopsis Gene Family

Yamagami

Tsuchisaka

Yamada

et al. 2003

Journal of Biological Chemistry

312

289

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“…In some respects, this problem is paradoxical as the low analytical sample size is also regarded as a major advantage of the technique, e.g., for the determination of analytes in a single cell [144,145]. A number of approaches have been adopted to overcome these limitations including: modification of injection technique, on-line preconcentration and increasing detector sensitivity (see [67] and references therein).…”

Section: Isotachophoretic Enantiomeric Analysis Of 2-apasmentioning

confidence: 99%

Enantiomeric resolution of 2‐arylpropionic acid nonsteroidal anti‐inflammatory drugs by capillary electrophoresis: Methods and applications

Patel¹,

Hanna-Brown²,

Hadley³

et al. 2004

Electrophoresis

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The 2-arylpropionic acids (2-APAs) are an important group of nonsteroidal anti-inflammatory drugs. These agents, the majority of which are available as racemates, exhibit stereoselectivity in both their action and disposition. Developments in stereoselective separation science methodology, mainly chromatographic, have facilitated an evaluation of the pharmacological properties of the individual enantiomers of these drugs and contributed to our understanding of both their mode(s) of action and disposition. While a number of electrophoretic techniques, including capillary electrophoresis, capillary electrochromatography and isotachophoresis, have been applied to the stereoselective resolution and stereospecific analysis of these agents using a variety of chiral selectors, e.g., cyclodextrins, oligosaccharides, macrocyclic antibiotics, and proteins, the number of published applications in pharmaceutical and biomedical analysis remains relatively limited. However, the utility of electrophoretic techniques for stereospecific analysis may be illustrated using the 2-APAs as typical examples of chiral acidic pharmaceuticals. Applications include: determination of enantiomeric composition following biosynthetic stereoselective hydrolysis; examination of both achiral and chiral impurity profiles in bulk drugs and formulated products; determination of enantiomeric impurities in both bulk drugs and formulated products; examination of configurational stability following stress testing of formulated products; determination of enantiomeric composition and metabolite profile in biological fluids following administration of the racemates and individual enantiomers. It may be anticipated that future exploitation of electrophoretic approaches to the stereospecific analysis of these agents will result in further contributions to our understanding of their stereoselective biological properties and therapeutic use.

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“…As the background noise of the electrolyte was sufficiently low, the detection of micromolar concentrations of saccharides was possible [26]. These are conditions which are difficult to realize on-column.…”

Section: On-capillary Derivatizationmentioning

confidence: 99%

Derivatization trends in capillary electrophoresis

Lingeman²,

et al. 2000

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This survey gives an overview of recent derivatization protocols, starting from 1996, in combination with capillary electrophoresis (CE). Derivatization is mainly used for enhancing the detection sensitivity of CE, especially in combination with laser-induced fluorescence. Derivatization procedures are classified in tables in pre-, on- and postcapillary arrangements and, more specifically, arranged into functional groups being derivatized. The amine and reducing ends of saccharides are reported most frequently, but examples are also given for derivatization of thiols, hydroxyl, carboxylic, and carbonyl groups, and inorganic ions. Other reasons for derivatization concern indirect chiral separations, enhancing electrospray characteristics, or incorporation of a suitable charge into the analytes. Special attention is paid to the increasing field of research using on-line precapillary derivatization with CE and microdialysis for in vivo monitoring of neurotransmitter concentrations. The on-capillary derivatization can be divided in several approaches, such as the at-inlet, zone-passing and throughout method. The postcapillary mode is represented by gap designs, and membrane reactors, but especially the combination of separation, derivatization and detection on a chip is a new emerging field of research. This review, which can be seen as a sequel to our earlier reported review covering the years 1991-1995, gives an impression of current derivatization applications and highlights new developments in this field.

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Analysis of solutes and metabolites in single plant cell vacuoles by capillary electrophoresis

Cited by 26 publications

References 45 publications

Biochemical Diversity among the 1-Amino-cyclopropane-1-Carboxylate Synthase Isozymes Encoded by the Arabidopsis Gene Family

Biochemical Diversity among the 1-Amino-cyclopropane-1-Carboxylate Synthase Isozymes Encoded by the Arabidopsis Gene Family

Enantiomeric resolution of 2‐arylpropionic acid nonsteroidal anti‐inflammatory drugs by capillary electrophoresis: Methods and applications

Derivatization trends in capillary electrophoresis

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