EarlyView Articles

Electric migration of α‐hemolysin in supported n ‐bilayers: A model for transmembrane protein microelectrophoresis

Published: Oct 1, 2013

Author(s): Frédéric Harb, Bernard Tinland

Journal: ELECTROPHORESIS

Proteome analysis involves separating proteins as a preliminary step toward their characterization. This paper reports on the translational migration of a model transmembrane protein (α‐hemolysin) in supported n‐bilayers (n, the number of bilayers, varies from 1 to around 500 bilayers) when an electric field parallel to the membrane plane is applied. The migration changes in direction as the charge on the protein changes its sign. Its electrophoretic...

Advances in chiral separations by nonaqueous capillary electrophoresis in pharmaceutical and biomedical analysis

Published: Oct 1, 2013

Author(s): Imran Ali, Mohd Marsin Sanagi, Hassan Y. Aboul‐Enein

Journal: ELECTROPHORESIS

NACE is an alternative technique to aqueous CE in the chiral separations of partially soluble racemates. Besides, partially water‐soluble or insoluble chiral selectors may be exploited in the enantiomeric resolution in NACE. The high reproducibility due to low Joule heat generation and no change in BGE concentration may make NACE a routine analytical technique. These facts attracted scientists to use NACE for the chiral resolution. The...

CE‐MS based on moving reaction boundary method for urinary metabolomic analysis of gastric cancer patients

Published: Oct 1, 2013

Author(s): Jin‐Lian Chen, Jing Fan, Xiao‐jie Lu

Journal: ELECTROPHORESIS

There is still a lack of satisfactory tumor markers for gastric cancer (GasC). This study is aimed at optimizing parameters in CE‐MS based on moving reaction boundary (MRB) so as to improve its sensitivity and stability, and at searching for potential tumor markers of GasC in patients’ urine samples via MRB‐CE‐MS. In this study, several parameters of MRB‐CE‐MS were investigated and optimized in order to gain optimal stability,...

Pumps for microfluidic cell culture

Published: Oct 1, 2013

Author(s): Chang Kyu Byun, Kameel Abi‐Samra, Yoon‐Kyoung Cho, Shuichi Takayama

Journal: ELECTROPHORESIS

In comparison to traditional in vitro cell culture in Petri dishes or well plates, cell culture in microfluidic‐based devices enables better control over chemical and physical environments, higher levels of experimental automation, and a reduction in experimental materials. Over the past decade, the advantages associated with cell culturing in microfluidic‐based platforms have garnered significant interest and have led to a plethora of...

Thin layer chromatography–densitometric determination of some non‐sedating antihistamines in combination with pseudoephedrine or acetaminophen in synthetic mixtures and in pharmaceutical formulations

Published: Sep 30, 2013

Author(s): Michael E. El‐Kommos, Samia M. El‐Gizawy, Noha N. Atia, Noha M. Hosny

Journal: Biomedical Chromatography

ABSTRACT The combination of certain non‐sedating antihistamines (NSA) such as fexofenadine (FXD), ketotifen (KET) and loratadine (LOR) with pseudoephedrine (PSE) or acetaminophen (ACE) is widely used in the treatment of allergic rhinitis, conjunctivitis and chronic urticaria. A rapid, simple, selective and precise densitometric method was developed and validated for simultaneous estimation of six synthetic binary mixtures and their...

In vitro evaluation of potential complexation between bovine insulin and bovine serum albumin

Published: Sep 30, 2013

Author(s): Hayder Al‐Domi, Muhammed Alzweiri, Imad Hamdan, Ziad Jaradat

Journal: Biomedical Chromatography

ABSTRACT The objective of this study was to examine the possible binding of bovine insulin (BI) with bovine serum albumin (BSA) to form a new potential diabetogenic irreversible complex protein. Several preparations of BSA and BI were prepared. Both capillary electrophoresis and spectrophotometric analysis were undertaken to test the possibility of complexation between BI and BSA. HPLC was used to test whether the potential complex...

Development and validation of a rapid and high‐sensitivity liquid chromatography–tandem mass spectrometry assay for the determination of neostigmine in small‐volume beagle dog plasma and its application to a pharmacokinetic study

Published: Sep 30, 2013

Author(s): Di Cao, Wenxue Li, Xin Zhao, Xiaolan Ye, Fanlu Sun, Jinying Li, Fenyun Song, Guorong Fan

Journal: Biomedical Chromatography

ABSTRACT A simple, rapid and high sensitive liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the determination of neostigmine in small‐volume beagle dog plasma was developed to assess the plasma pharmacokinetics of neostigmine. After protein precipitation in a Sirocco 96‐well filtration plate, the filtrate was directly injected into the LC‐MS/MS system. The analytes were separated on a Hanbon Hedera CN column...

Hair analysis as a tool to evaluate the prevalence of synthetic cannabinoids in different populations of drug consumers

Published: Sep 30, 2013

Author(s): A. Salomone, C. Luciano, D. Di Corcia, E. Gerace, M. Vincenti

Journal: Drug Testing and Analysis

Among the new psychoactive products, herbal mixtures containing synthetic cannabimimetics are likely the most abused worldwide. In this study, a specific ultra high performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS) method for the detection of 23 synthetic cannabinoids in hair samples was developed in order to (1) expand the number of screened compounds, coherent with new substances emerging in the European...

AOD‐9604 does not influence the WADA hGH isoform immunoassay

Published: Sep 30, 2013

Author(s): A. K. Orlovius, A. Thomas, W. Schänzer, M. Thevis

Journal: Drug Testing and Analysis

Drug‐facilitated sexual crime by use of ketamine and diazepam by a gynaecologist

Published: Sep 30, 2013

Author(s): Sarah M. R. Wille, Vincent Di Fazio, Nele Samyn

Journal: Drug Testing and Analysis

A review of the cultivation and processing of cannabis ( Cannabis sativa L.) for production of prescription medicines in the UK

Published: Sep 30, 2013

Author(s): David J. Potter

Journal: Drug Testing and Analysis

The quality demands of the pharmaceutical industry require prescription medicines to be consistent in their active ingredient content. Achieving this, using raw cannabis as a feedstock, is especially challenging. The plant material is extremely inhomogeneous, and the ratios of active ingredients are affected by a range of factors. These include the genetics of the plant, the growing and storage conditions, the state of maturity at...

Detection of the potential tumor marker of AFP using surface‐enhanced Raman scattering‐based immunoassay

Published: Sep 30, 2013

Author(s): Aijing Wang, Weidong Ruan, Wei Song, Lei Chen, Bing Zhao, Young Mee Jung, Xu Wang

Journal: Journal of Raman Spectroscopy

Abstract The development of rapid, highly sensitive detection methods for α‐fetoprotein (AFP) is very important. As hepatocellular carcinoma is closely related to the level of AFP in the blood, it is necessary to maintain an AFP concentration below the safety limit. In this paper, we propose a universal, rapid, sensitive, and highly specific immunoassay system utilizing gold nanoparticles (AuNPs) and surface‐enhanced Raman...

The succinated proteome

Published: Sep 30, 2013

Author(s): Eric D. Merkley, Thomas O. Metz, Richard D. Smith, John W. Baynes, Norma Frizzell

Journal: Mass Spectrometry Reviews

Abstract The post‐translational modifications (PTMs) of cysteine residues include oxidation, S‐glutathionylation, S‐nitrosylation, and succination, all of which modify protein function or turnover in response to a changing intracellular redox environment. Succination is a chemical modification of cysteine in proteins by the Krebs cycle intermediate, fumarate, yielding S‐(2‐succino)cysteine (2SC). Intracellular fumarate...

Protein carbonylation: Proteomics, specificity and relevance to aging

Published: Sep 30, 2013

Author(s): Elisa Cabiscol, Jordi Tamarit, Joaquim Ros

Journal: Mass Spectrometry Reviews

Abstract Detection and quantification of protein carbonyls present in biological samples has become a popular, albeit indirect, method to determine the existence of oxidative stress. Moreover, the rise of proteomics has allowed the identification of the specific proteins targeted by protein carbonylation. This review discusses these methodologies and proteomic strategies and then focuses on the relationship...

Mass spectrometry and redox proteomics: Applications in disease

Published: Sep 30, 2013

Author(s): D. Allan Butterfield, Liqing Gu, Fabio Di Domenico, Renã A.S. Robinson

Journal: Mass Spectrometry Reviews

Abstract Proteomics techniques are continuously being developed to further understanding of biology and disease. Many of the pathways that are relevant to disease mechanisms rely on the identification of post‐translational modifications (PTMs) such as phosphorylation, acetylation, and glycosylation. Much attention has also been focused on oxidative PTMs which include protein carbonyls, protein nitration, and...

C K‐edge NEXAFS study of fluorocarbon formation on carbon anodes in molten NaF–AlF ₃ –CaF ₂

Published: Sep 30, 2013

Author(s): Richard G. Haverkamp, Bruce C. C. Cowie

Journal: Surface and Interface Analysis

Operational instability from processes occurring at the anode during the production of aluminum in the commercial Hall‐Héroult process may lead to an increase in undesirable fluorocarbon emissions, higher energy use, and shorter plant life. One contribution to this instability may be the possible formation of a fluorocarbon film at the electrode interface. Here, the surface composition of graphite anodes after electrolysis in molten...

Depth profiling with SNMS and SIMS of Zn(O,S) buffer layers for Cu(In,Ga)Se ₂ thin‐film solar cells

Published: Sep 30, 2013

Author(s): Axel Eicke, Thomas Ciba, Dimitrios Hariskos, Richard Menner, Carsten Tschamber, Wolfram Witte

Journal: Surface and Interface Analysis

Zn(O,S) is a promising candidate to replace the commonly used CdS buffer layer for Cu(In,Ga)Se2 (CIGS) thin‐film solar cells due to its non‐toxicity and its potential to enhance the conversion efficiency of the CIGS solar cell. The composition of chemical bath deposited (CBD) and sputtered Zn(O,S) layers with thicknesses well below 100 nm was determined by sputtered neutral and secondary ion mass spectrometry (SNMS and SIMS). Despite numerous mass...

MR imaging of protein folding in vitro employing Nuclear‐Overhauser‐mediated saturation transfer

Published: Sep 25, 2013

Author(s): Moritz Zaiss, Patrick Kunz, Steffen Goerke, Alexander Radbruch, Peter Bachert

Journal: NMR in Biomedicine

MR Z‐spectroscopy allows enhanced imaging contrast on the basis of saturation transfer between the proton pools of cellular compounds and water, occurring via chemical exchange (chemical exchange saturation transfer, CEST) or dipole–dipole coupling (nuclear Overhauser effect, NOE). In previous studies, signals observed in the aliphatic proton region of Z‐spectra have been assigned to NOEs between protons in water molecules and protons at...

Development of a fast and efficient CE enzyme assay for the characterization and inhibition studies of α‐glucosidase inhibitors

Published: Sep 25, 2013

Author(s): Shoaib Iqbal, Nisar ur Rehman, Ulrich Kortz, Jamshed Iqbal

Journal: Journal of Separation Science

The inhibition of the α‐glucosidase enzyme plays an important role in the treatment of diabetes mellitus. We have established a highly sensitive, fast, and convenient CE method for the characterization of the enzyme and inhibition studies of α‐glucosidase inhibitors. The separation conditions were optimized; the pH value and concentration of the borate‐based separation buffer were optimized in order to achieve baseline separation of...

Tandem LC columns for the simultaneous retention of polar and nonpolar molecules in comprehensive metabolomics analysis

Published: Sep 25, 2013

Author(s): Kenneth R. Chalcraft, Brian E. McCarry

Journal: Journal of Separation Science

The tandem use of hydrophilic interaction LC columns with RP columns in series configuration has resulted in the retention of both polar and nonpolar components in complex biological samples (mouse serum) in a single analysis. This approach successfully coupled various columns with orthogonal separation characteristics, employed a single solvent gradient program compatible with the two columns and used ESI coupled to a TOF mass...