Electrophoresis (Electrophoresis)

Publisher: Electrophoresis Society; International Electrophoresis Society, Wiley-VCH Verlag

Journal description

Attracting high-quality papers from the world's leading laboratories ELECTROPHORESIS has proved itself indispensable in the life sciences where electrophoresis is the most widely used method. ELECTROPHORESIS is the foremost journal for new analytical and preparative methods and for innovative applications on all aspects of electrophoresis. It has an international scope and publishes original papers short communications and review articles in the following areas: biochemistry molecular and cell biochemistry genetics immunology microbiology clinical chemistry forensics food science and many more. Special Issues Paper Symposium issues devoted to new developments prepared by an expert Guest Editor are published regularly with special emphasis on capillary electrophoresis (2-3 issues per year)and proteomics. The journal also publishes proceedings of international and national electrophoresis meetings.

Current impact factor: 3.16

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 3.161
2012 Impact Factor 3.261
2011 Impact Factor 3.303
2010 Impact Factor 3.569
2009 Impact Factor 3.077
2008 Impact Factor 3.509
2007 Impact Factor 3.609
2006 Impact Factor 4.101
2005 Impact Factor 3.85
2004 Impact Factor 3.743
2003 Impact Factor 4.04
2002 Impact Factor 4.325
2001 Impact Factor 4.282
2000 Impact Factor 3.385
1999 Impact Factor 3.447
1998 Impact Factor 3.054
1997 Impact Factor 2.848
1996 Impact Factor 2.467
1995 Impact Factor 2.73
1994 Impact Factor 2.274
1993 Impact Factor 1.842
1992 Impact Factor 2.159

Impact factor over time

Impact factor
Year

Additional details

5-year impact 2.87
Cited half-life 7.10
Immediacy index 0.48
Eigenfactor 0.03
Article influence 0.63
Website Electrophoresis website
Other titles Electrophoresis (Online), Electrophoresis, Proteomics reviews
ISSN 1522-2683
OCLC 43388561
Material type Periodical, Program, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Wiley-VCH Verlag

  • Pre-print
    • Author cannot archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • Upon funder agreement with publisher
  • Conditions
    • Pre-print may be deposited on personal intranet or institutional intranet repository, but not on a public repository
    • Pre-print must not updates with future versions
    • Published source must be acknowledged with set phrases (See policy)
    • Must link to publisher's site: http://www.interscience.wiley.com/
    • Publisher's version/PDF cannot be used
    • Some journal exceptions-check individual homepages
  • Classification
    ​ white

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Electrophoretic mobility of oil droplets of micron sizes in PBS and ionic surfactant solutions was measured in this paper. The experimental results show that, in addition to the applied electrical field, the speed and the direction of electrophoretic motion of oil droplets depend on the surfactant concentration and on if the droplet is in negatively charged Dodecylsulfate (SDS) solutions or in positively charged Hexadecyltrimethylammonium bromide (CTAB) solutions. The absolute value of the electrophoretic mobility increases with increased surfactant concentration before the surfactant concentration reaches to the critical micelle concentration (CMC). It was also found that there are two vortices around the oil droplet under the applied electrical field. The size of the vortices changes with the surfactant and with the electrical field. The vortices around the droplet directly affect the drag of the flow field to the droplet motion and should be considered in the studies of electrophoretic mobility of oil droplets. The existence of the vortices will also influence the determination and the interpretation of the zeta potential of the oil droplets based on the measured mobility data. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 07/2015; DOI:10.1002/elps.201500062
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    ABSTRACT: Design, fabrication, integration and feasibility test results of a novel microfluidic cell capture device is presented, exploiting the advantages of proton beam writing to make lithographic irradiations under multiple target tilting angles and UV lithography to easily reproduce large area structures. A cell capture device is demonstrated with a unique doubly tilted micropillar array design for cell manipulation in microfluidic applications. Tilting the pillars increased their functional surface, therefore, enhanced fluidic interaction when special bioaffinity coating was used, and improved fluid dynamic behavior regarding cell culture injection. The proposed microstructures were capable to support adequate distribution of body fluids, such as blood, spinal fluid, etc., between the inlet and outlet of the microfluidic sample reservoirs, offering advanced cell capture capability on the functionalized surfaces. The hydrodynamic characteristics of the microfluidic systems were tested with yeast cells (similar size as red blood cells) for efficient capture. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 07/2015; x:x. DOI:10.1002/elps.201500254
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    ABSTRACT: A novel fluorescence detection system for capillary electrophoresis (CE) was described and evaluated. Two miniature laser pointers were used as the excitation source. A Y-style optical fiber was used to transmit the excitation light and a four-branch optical fiber was used to collect the fluorescence. The optical fiber and optical filter were imported into a photomultiplier tube without any extra fixing device. A simplified PDMS detection cell was designed with guide channels through which the optical fibers were easily aligned to the detection window of separation capillary. According to different requirements, laser pointers and different filters were selected by simple switching and replacement. The fluorescence from four different directions was collected at the same detecting point. Thus, the sensitivity was enhanced without peak broadening. The fluorescence detection system was simple, compact, low-cost and highly sensitive, with its functionality demonstrated by the separation and determination of red dyes and fluorescent whitening agents. The detection limit of rhodamine 6G was 7.7 nM (S/N = 3). The system was further applied to determine illegal food dyes. The CE system is potentially eligible for food safety analysis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500265
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    ABSTRACT: In this work, double dispersant-assisted ionic liquid dispersive liquid-liquid microextraction coupled with micellar electrokinetic chromatography was developed to determine four UV filters (benzophenone, 4-hydroxybenzophenone, 2, 4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone). 1-Hexyl-3-methylimidazolium hexafluorophosphate was used as the extraction solvent. The main novelty of the present work was that acetonitrile-Triton X-114 was used as double disperser solvent. Parameters affected the extraction efficiency were investigated and optimized. Under the optimum conditions, enrichment factors were in the range of 25.3-40.5. The limits of detection and quantitation, calculated at a signal-to-noise ratio of three and ten, were 3.9-6.7 ng mL(-1) and 13.0-22.3 ng mL(-1) . The linearity of the method was in the range of 0.02-2 μg mL(-1) for 2, 4-dihydroxybenzophenone and 4-hydroxybenzophenone, 0.01-2 μg mL(-1) for benzophenone and 2-hydroxy-4-methoxybenzophenone, with correlation coefficient (R(2) ) of 0.9984-0.9991. The proposed method was successfully applied to the determination of four benzophenone-type UV filters in six kinds of sunscreen cosmetic products, with yielded relative recoveries ranging from 80.2 to 117.7%. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500004
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    ABSTRACT: This study reports a new method for establishing an open tubular immobilized pH gradient (IPG) in a microchip coupled with a whole column image detection (WCID) system for protein separation applications. This method allows a wider range of immobilized pH (2.6-9.5) to be established in a PDMS/quartz channel by controlling the diffusion of acidic and basic polymer solutions into the channel through well-designed channel dimensions. The developed pH gradient was experimentally validated by performing the separation of a mixture of standard pI markers. It was further validated by the separation of the hemoglobin control AFSC sample. This method is advantageous over existing IPG methods because it has a wider range of pH and maintains the open tubular feature which matches the UV WCID to improve the sensitivity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500041
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    ABSTRACT: One challenging point in analysing cellular secretome collected as conditioned medium is cross contamination by cell culture media components, especially bovine serum proteins. A common approach for serum removal is to wash the cells, an alternative is to grow cells using serum-free conditions. Given that the sample processing may influence the phenotype of cells and thus the secretome, it is important to establish the optimal protocol for each cell type. In this study, we compared two methods for preparing conditioned medium from human adipocytes derived from mesenchymal stem cells. Cells were either washed twice with PBS or cultured the last four days of differentiation in serum free adipogenic medium. Gene expression of the cells was evaluated by using real time PCR and one dimensional LC-MS/MS was used to compare secreted proteins present in the culture supernatants. Surprisingly, results showed significant differences in gene expression patterns of the cells and in protein content of the conditioned media and suggested that PBS washes induced severe modifications of the phenotype of cells and thus changes in protein secretion profiles. These data emphasize the significant variations in protein species related to cell manipulations and underline the importance of procedure optimization prior to any proteomic investigation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500086
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    ABSTRACT: To investigate genetic diversity in Chinese populations, 706 unrelated male individuals from five ethnic groups (Han, Korean, Hui, Mongolian and Tibetan, respectively) were analyzed with 17 Y-chromosomal short tandem repeats (STRs). The haplotype diversity was 0.99985 in the combined data. 675 distinct haplotypes were observed, of which 649 were unique. Y-chromosome haplogroup in the five groups were also predicted with Y-STR haplotypes. Genetic distance of the five studied ethnic groups and other published groups was analyzed by analysis of molecular variance (AMOVA) and visualized in a multi-dimensional scaling (MDS) plot. In conclusion, the 17 Y-STR loci are highly polymorphic markers in the five groups and hence are very useful in forensic application, population genetics and human evolution studies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500089
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    ABSTRACT: It has been shown that diverse strains of bacteria can be separated according to their characteristic surface properties by means of capillary electrophoresis (CE). We employed here this analytical technique to the study of colistin-resistance in Gram-negative bacteria, which involves the selection of mutants with modified outer membrane composition resulting in changes of surface cell properties. In the same way as with molecular entities, we performed firstly the validation of an isotachophoresis-based CE method for three common pathogenic Gram-negative bacteria namely Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Secondly, we compared the electrophoretic profiles of bacterial samples from a colistin-susceptible clinical isolate of K. pneumoniae and from the corresponding colistin-resistant derivative. By a simple CE run taking a few minutes, the coexistence of several bacterial subpopulations in the colistin-resistant derivative was clearly evidenced. This work encourages further research that would allow applications of CE in clinical laboratory for a daily monitoring of bacterial population in cared patients when "last-chance" colistin treatment is initiated against multidrug-resistant bacteria. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500064
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    ABSTRACT: Cytochrome P450 (CYP) enzymes catalyze the metabolism of both, the analgesic and anesthetic drug ketamine and the α2 -adrenergic receptor-agonist medetomidine which is used for sedation and analgesia. As racemic medetomidine or its active enantiomer dexmedetomidine are often coadministered with racemic or S-ketamine in animals and dexmedetomidine together with S- or racemic ketamine in humans, drug-drug interactions are likely to occur and have to be characterized. Enantioselective CE with highly sulfated γ-cyclodextrin as chiral selector was employed for analyzing in vitro (i) the kinetics of the N-demethylation of ketamine mediated by canine CYP3A12 and (ii) interactions occurring with racemic medetomidine and dexmedetomidine during coincubation with ketamine and canine liver microsomes (CLM), canine CYP3A12, human liver microsomes (HLM) and human CYP3A4. For CYP3A12 without an inhibitor, Michaelis-Menten kinetics was determined for the single enantiomers of ketamine and substrate inhibition kinetics for racemic ketamine. Racemic medetomidine and dexmedetomidine showed an inhibition of the N-demethylation reaction in the studied canine enzyme systems. Racemic medetomidine is the stronger inhibitor for CLM, whereas there is no difference for CYP3A12. For CLM and CYP3A12, the inhibition of dexmedetomidine is stronger for the R- compared to the S-enantiomer of ketamine, a stereoselectivity which is not observed for CYP3A4. Induction is observed at a low dexmedetomidine concentration with CYP3A4 but not with CYP3A12, CLM and HLM. Based on these results, S-ketamine combined with dexmedetomidine should be the best option for canines. The enantioselective CE assay with highly sulfated γ-cyclodextrin as chiral selector is an effective tool for determining kinetic and inhibition parameters of metabolic pathways. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500147
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    ABSTRACT: Oriented covalent immobilized β2 -adrenergic receptor (β2 -AR) capillary electrophoresis (OIRCE) was developed to determine the interactions between a set of natural extracts of Radix Paeoniae Rubra (NERPR) and β2 -AR, and to predict the activity of NERPR. The inner capillary surface is chemically bonded with stable β2 -AR coating via microwave-assisted technical synthesis. The modified capillaries were characterized via infrared spectroscopy and fluorescence microscopy. Furthermore, the bonding amounts of β2 -AR were first obtained via fluorescence spectroscopy method. In determining the amount of bonded β2 -AR, the regression equation A = 576 707C + 35.449 and the correlation coefficient 0.9995 were obtained. This result revealed an excellent linear relationship in the range of 2 × 10(-4) mg/mL to 1 × 10(-3) mg/mL. The normalized capacity factor (KRCE ) was obtained using OIRCE in evaluating drug-receptor interactions. Related theories and equations were used to calculate KRCE values from apparent migration times of a solute and electroosmotic flow (EOF). The order of KRCE and the binding constant (Kb ) values between drugs and β2 -AR was well consistent. The results confirmed that the OIRCE and KRCE values can be effectually used to investigate drug-receptor interactions, and OIRCE has the potential to predict drug activity and to select leading compounds from natural chemicals. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201400583
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    ABSTRACT: Preparation of proteins from salt-gland-rich tissues of mangrove plant is necessary for a systematic study of proteins involved in the plant's unique desalination mechanism. Extraction of high-quality proteins from the leaves of mangrove tree species, however, is difficult due to the presence of high levels of endogenous phenolic compounds. In our study, preparation of proteins from only a part of the leaf tissues (i.e., salt gland-rich epidermal layers) was required, rendering extraction even more challenging. By comparing several extraction methods, we developed a reliable procedure for obtaining proteins from salt gland-rich tissues of the mangrove species Avicennia officinalis. Protein extraction was markedly improved using a phenol-based extraction method. Greater resolution one-dimensional protein gel profiles could be obtained. More promising proteome profiles could be obtained through 1D-LC-MS/MS. The number of proteins detected was twice as much as compared to TUTS extraction method. Focusing on proteins that were solely present in each extraction method, phenol-based extracts contained nearly 10 times more proteins than those in the extracts without using phenol. The approach could thus be applied for downstream high-throughput proteomic analyses involving LC-MS/MS or equivalent. The proteomics data presented herein are available via ProteomeXchange with identifier PXD001691. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500023
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    ABSTRACT: Non-SELEX and other capillary based methods have grown in popularity for selection of aptamers since they provide a fast and efficient partitioning method when compared to classical techniques. Despite promising developments in these techniques, a major obstacle needs to be overcome for capillary based selections to be widely accepted. Due to the small injection volumes associated with capillary electrophoresis (CE), only a small proportion of the nucleic acid library can be partitioned at any one time. In this paper, we propose a new two-step method for the selection of aptamers which firstly incorporates a nitrocellulose membrane filter followed by capillary electrophoresis. This technique allows for non-binding sequences to be eliminated, reducing the library size before subsequent capillary based partitioning, while still reducing the time taken for aptamers to be selected. We demonstrated this technique on the selection of aptamers for cholesterol esterase and the highest binding truncated aptamer CES 4T displayed a KD of 203 ± 14 nM. In addition, an increase in the number of sequences partitioned was estimated using spectrophotometry and capillary injection volumes. The results suggested that for successful selection a two-step approach is needed. This hybrid technique could be used to select aptamers which bind to targets both in solution and immobilized onto a stationary phase, allowing the aptamers to be used in different binding environments. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201400540
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    ABSTRACT: This study concentrates on development of instrumentation for focusing and separation of analytes in continuous flow. It is based on bidirectional ITP working in wide pH range with separation space of closed void channel of trapezoidal shape and continuous supply of sample. The novel instrumentation is working with electrolyte system formulated previously and on the contrary to devices currently available, it allows preparative separation and concentration of cationic, anionic and amphoteric analytes simultaneously and in wide pH range. The formation of sharp edges at zone boundaries as well as low conductivity zones are avoided in suggested system and thus, local overheating is eliminated allowing for high current densities at initial stages of focusing. This results in high focusing speed and reduction of analysis time, which is particularly advantageous for separations performed in continuous flow systems. The closed void channel is designed to avoid basic obstacles related to liquid leakage, bubbles formation, contacts with electrodes, channel height and complicated assembling. The performance of designed instrumentation and focusing dynamics were tested by using colored low molecular mass pH indicators for local pH determination, focusing pattern and completion. In addition, feasibility and separation efficiency were demonstrated by focusing of cytochrome C and myoglobin. The collection of fractions at instrument output allows for subsequent analysis and identification of sample components that are concentrated and conveniently in form of solution for further processing. Since the instrumentation operates with commercially available simple defined buffers and compounds without need of carrier ampholytes background, it is economically favorable. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500223
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    ABSTRACT: Human, bovine and porcine insulins are small proteins with very closely related amino acid sequences, which makes their separation challenging. In this study, we took advantage of the high-resolution power of capillary electrophoresis, and more particularly of micellar electrokinetic chromatography, to separate those biomolecules. Among several surfactants, perfluorooctanoic acid ammonium salt was selected. Then, using a design of experiments approach, the optimal BGE composition was found to consist of 50 mM ammonium acetate pH 9.0, 65 mM PFOA and 4% MeOH. The three insulins could be separated within 12 minutes with a satisfactory resolution. This method could be useful to detect possible counterfeit pharmaceutical formulations. Indeed, it would be easy to determine if human insulin was replaced by bovine or porcine insulin. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500178
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    ABSTRACT: One of the main limitations of untargeted metabolomics analysis is the low detection coverage of analytical techniques such as NMR, LC-MS or GC-MS. In this research, the detection coverage of an automated approach configured by the on-line coupling of solid-phase extraction (SPE) to LC-MS/MS was evaluated by combination of sorbents based on different retention mechanisms. The approach was applied to the analysis of human serum using three types of sorbents: alkyl bonded silica, polymeric resins and mixed-mode ionic resins. The combination of four sorbents (C18, a modified polystyrene-divinylbenzene resin and two mixed-mode ionic resins) led to the best extraction results and, therefore, the best detection coverage, which is explained by their complementary retention mechanisms. However, some of the sorbents provide a high detection coverage by themselves, as is the case with C18, which can afford to retain almost 83% of all detected entities. Taking into account the complementarity between pairs of these sorbents (C18 and the polystyrene-divinylbenzene resin with the mixed-mode ionic resins), dual cartridge SPE-LC-MS/MS configurations were designed for serum analysis. These configurations allowed increasing the detection coverage up to 91% of the total number of molecular features detected with all sorbents tested. An additional benefit of the SPE-LC-MS/MS strategy was the improvement of sensitivity as compared to protein precipitation and fractionation with methanol and chloroform. Thus, an average preconcentration factor of 10-75 was obtained in the SPE-based approach versus the two-phase protocol for metabolites extraction. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500060
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    ABSTRACT: A simple and rapid detection of cerebrospinal fluid (CSF) leakage would benefit spine surgeons making critical post-operative decisions on patient care. We have assessed novel approaches to selectively determine CSF β2-transferrin (β2TF), an asialo-transferrin (aTF) biomarker, without interference from serum sialo-transferrin (sTF) in test samples. First, we performed mild periodate oxidation to selectively generate aldehyde groups in sTF for capture with magnetic hydrazide microparticles, and selective removal with a magnetic separator. Using this protocol sTF was selectively removed from mixtures of CSF and serum containing CSF aTF (β2TF) and serum sTF, respectively. Second, a two-step enzymatic method was developed with neuraminidase and galactose oxidase for generating aldehyde groups in sTF present in CSF and serum mixtures for magnetic hydrazide microparticle capture. After selectively removing sTF from mixtures of CSF and serum, ELISA could detect significant TF signal only in CSF, while the TF signal in serum was negligible. The new approach for selective removal of only sTF in test samples will be promising for the required intervention by a spine surgeon. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500128
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    ABSTRACT: Herein, we designed four peptides appended with different numbers of histidine (Hisn -peptide). We launched a systematic investigation on quantum dots (QDs) and Hisn -peptide self-assembly in solution using fluorescence coupled capillary electrophoresis (CE-FL). The results indicated that CE-FL was a powerful method to probe how ligands interaction on the surface of nanoparticles. The self-assembly of QDs and peptide was determined by the numbers of histidine. We also observed that longer polyhistidine tags (n ≤ 6) could improve the self-assembly efficiency. Furthermore, the formation and separation of QD-peptide assembly were also studied by CE-FL inside a capillary. The total time for the mixing, self-assembly, separation and detection was less than 10 min. Our method greatly expands the application of CE-FL in QDs-based biolabeling and bioanalysis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500205
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    ABSTRACT: Both poly and mono ADP-ribosylation are common post-translational protein modifications. For example, poly ADP-ribosylation is involved in DNA repair mechanisms through the poly (ADP-ribose) polymerase (PARP) family of enzymes. While mono ADP-ribosylation has been known to trigger cell death exhibited by many bacterial toxins. Because of the wide role of ADP-ribosylation, the detection and analysis are very important for further understanding of the PARP family of enzymes and the molecular mechanisms leading to cell toxicity in the presence of bacterial enzymes. Here we describe a novel technique utilizing a capillary electrophoresis (CE)-based Western technology to detect and analyze ADP-ribosylated proteins. The method is based on a nano-volume size separation that is automated, quantitative, offers great sensitivity, and is high-throughput for potential use in PARP drug screening inhibitor assays. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500173
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    ABSTRACT: Familial cases of amyotrophic lateral sclerosis (fALS) are related to mutations of copper-zinc superoxide dismutase (SOD1). Aggregation of SOD1 plays a central role in the pathogenesis of fALS and altered metallation of SOD1 mutants could be involved in this process. Using isoelectric focusing gel electrophoresis (IEF) under non-denaturating conditions and particle induced X-ray emission (PIXE) analysis we studied the pI distribution and metallation status of fALS SOD1 mutants (A4V, G93A, D125H) compared to human wild-type (hWT). SOD1 fALS mutants are characterized by a variable number of isoforms and higher pI compared to hWT, reflecting a reduced net charge that might explain their greater propensity to precipitation and aggregation. Cu/Zn ratios were slightly different for the predominant expressed isoforms of A4V, G93A and D125H mutants compared to hWT. Differences in metallation were observed within each genotype, the more basic isoforms exhibiting lower Cu/Zn ratios. Moreover, we revealed the existence of a pool of fALS mutants SOD1 pI isoforms, slightly expressed (<10%), with a low Cu/Zn ratio and high pI values. Overall, IEF-PIXE results suggest that the toxicity of SOD1 mutants should be studied at the pI isoform level with a particular attention to the species with the lowest charges. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500187
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    ABSTRACT: The operating parameters that affect the performance of the on-line preconcentration technique "analyte focusing by micelle collapse-micellar electrokinetic chromatography (AFMC-MEKC)" were examined using a multivariate approach involving experimental design to determine the sunscreen agents in cosmetics. Compared with the single variable approach, the advantage of the multivariate approach was that many factors could be investigated simultaneously to obtain the best separation condition. A fractional factorial design (fFD) was used to identify the fewest significant factors in the central composite design (CCD). The CCD was adopted for evaluating the location of the minimum or maximum response in this study. The influences of the experimental variables on the response were investigated by applying a chromatographic exponential function (CEF). The optimized condition and the relationship between the experimental variables were acquired using the JMP software. The ANOVA analysis indicated that the Tris pH value, SDS concentration and ethanol percentage influenced the separation quality and significantly contributed to the model. The optimized condition of the running buffer was 10 mM Tris buffer (pH 9.5) containing 60 mM SDS, 7 mM γ-CD and 20% (v/v) ethanol. The sample was prepared in 100 mM Tris buffer (pH 9.0) containing 7.5 mM SDS and 20% (v/v) ethanol. The SDS concentration in the sample matrix was slightly greater than the CMC value that makes the micelle be easily collapsed and the analytes be accumulated in the capillary. In addition, sunscreen agents in cosmetics after 1000-fold dilution were successfully determined by AFMC-MEKC. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Electrophoresis 06/2015; DOI:10.1002/elps.201500222