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Wu Z, Khan M, Mao S, Lin L, Lin JM. Combination of nano-material enrichment and dead-end filtration for uniform and rapid sample preparation in matrix-assisted laser desorption/ionization mass spectrometry. Talanta 2018; 181:217-223. [DOI: 10.1016/j.talanta.2018.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/30/2017] [Accepted: 01/07/2018] [Indexed: 11/15/2022]
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2
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Abstract
Drug analysis represents a large field in different disciplines. Plasma is commonly considered to be the biosample of choice for that purpose. However, concentrations often do not represent the levels present within deeper compartments and therefore cannot sufficiently explain efficacy or toxicology of drugs. MALDI-MS in drug analysis is of great interest for high-throughput quantification and particularly spatially resolved tissue imaging. The current perspective article will deal with challenges and opportunities of MALDI-MS drug analysis in different biological samples. A particular focus will be on hair samples. Recent applications were included, reviewed for their instrumental setup and sample preparation and pros and cons as well as future perspectives are critically discussed.
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3
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Determination of immunosuppressive drugs in human urine and serum by surface-assisted laser desorption/ionization mass spectrometry with dispersive liquid-liquid microextraction. Anal Bioanal Chem 2015; 408:629-37. [DOI: 10.1007/s00216-015-9145-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/08/2015] [Accepted: 10/22/2015] [Indexed: 11/27/2022]
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4
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Pabst M, Fagerer SR, Köhling R, Eyer K, Krismer J, Jefimovs K, Ibáñez AJ, Zenobi R. Quantification of saquinavir from lysates of peripheral blood mononuclear cells using microarrays and standard MALDI-TOF-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1083-1086. [PMID: 24711229 DOI: 10.1007/s13361-014-0875-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 02/19/2014] [Accepted: 02/22/2014] [Indexed: 06/03/2023]
Abstract
Drug monitoring is usually performed by liquid chromatography coupled with optical detection or electrospray ionization mass spectrometry. More recently, matrix-assisted laser desorption/ionization (MALDI) in combination with triple quadrupole or Fourier-transform (FT) mass analyzers has also been reported to allow accurate quantification. Here, we present a strategy that employs standard MALDI time-of-flight (TOF) mass spectrometry (MS) for the sensitive and accurate quantification of saquinavir from an extract of blood peripheral mononuclear cells. Unambiguous identification of saquinavir in the mass spectra was possible because of using internal mass calibration and by an overall low chemical noise in the low mass range. Exact mass determination of the constant background peaks of the cell extract, which were used for recalibration, was performed by an initial MALDI-FT-MS analysis. Fast and multiplexed sample analysis was enabled by microarray technology, which provided 10 replicates in the lower nL range for each sample in parallel lanes on a chip. In order to validate the method, we employed various statistical tests, such as confidence intervals for linear regressions, three quality control samples, and inverse confidence limits of the estimated concentration ratios.
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Affiliation(s)
- Martin Pabst
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
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5
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Pabst M, Fagerer SR, Köhling R, Küster SK, Steinhoff R, Badertscher M, Wahl F, Dittrich PS, Jefimovs K, Zenobi R. Self-Aliquoting Microarray Plates for Accurate Quantitative Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry. Anal Chem 2013; 85:9771-6. [DOI: 10.1021/ac4021775] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martin Pabst
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Stephan R. Fagerer
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Rudolf Köhling
- Sigma-Aldrich, Industriestrasse 25, 9471 Buchs, Switzerland
| | - Simon K. Küster
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Robert Steinhoff
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Martin Badertscher
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Fabian Wahl
- Sigma-Aldrich, Industriestrasse 25, 9471 Buchs, Switzerland
| | - Petra S. Dittrich
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Konstantins Jefimovs
- Swiss Federal Laboratories for Material Science and Technology EMPA, Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Renato Zenobi
- Department
of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
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6
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van Kampen JJA, Burgers PC, de Groot R, Gruters RA, Luider TM. Biomedical application of MALDI mass spectrometry for small-molecule analysis. MASS SPECTROMETRY REVIEWS 2011; 30:101-120. [PMID: 20169623 DOI: 10.1002/mas.20268] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is an emerging analytical tool for the analysis of molecules with molar masses below 1,000 Da; that is, small molecules. This technique offers rapid analysis, high sensitivity, low sample consumption, a relative high tolerance towards salts and buffers, and the possibility to store sample on the target plate. The successful application of the technique is, however, hampered by low molecular weight (LMW) matrix-derived interference signals and by poor reproducibility of signal intensities during quantitative analyses. In this review, we focus on the biomedical application of MALDI-MS for the analysis of small molecules and discuss its favorable properties and its challenges as well as strategies to improve the performance of the technique. Furthermore, practical aspects and applications are presented.
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Affiliation(s)
- Jeroen J A van Kampen
- Laboratories of Neuro-Oncology/Clinical and Cancer Proteomics, Department of Neurology, Erasmus MC, Rotterdam, The Netherlands
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7
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Rey M, Mrázek H, Pompach P, Novák P, Pelosi L, Brandolin G, Forest E, Havlíček V, Man P. Effective Removal of Nonionic Detergents in Protein Mass Spectrometry, Hydrogen/Deuterium Exchange, and Proteomics. Anal Chem 2010; 82:5107-16. [DOI: 10.1021/ac100171m] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Martial Rey
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Hynek Mrázek
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Petr Pompach
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Petr Novák
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Ludovic Pelosi
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Gérard Brandolin
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Eric Forest
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Vladimír Havlíček
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
| | - Petr Man
- Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), UMR 5092 CNRS-CEA-UJF, Grenoble, F-38054, France, Laboratory of Molecular Structure Characterization, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, CZ-142 20, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, CZ-12840, Czech Republic, Laboratoire de
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8
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Microfluidic Device for Coupling Capillary Electrophoresis and Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.jala.2009.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have designed and fabricated a polydimethylsiloxane (PDMS) microfluidic device for coupling capillary electrophoresis (CE) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). The coupling is advantageous in biological research because CE has the power of separating analytes in a sample based on mobility difference and MALDI-MS provides accurate and sensitive mass analysis of the analytes. The goal is realized by fractionating the separated analytes inside the microfluidic device and pushing the analyte fractions into open reservoirs. Each analyte fraction is then mixed with a matrix solution and deposited on a MALDI target for MALDI-MS. Therefore, a two-step analysis of analytes in the form of CE-MALDI-MS is achieved by using the microfluidic device.
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9
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Duncan MW, Roder H, Hunsucker SW. Quantitative matrix-assisted laser desorption/ionization mass spectrometry. BRIEFINGS IN FUNCTIONAL GENOMICS AND PROTEOMICS 2009; 7:355-70. [PMID: 19106161 DOI: 10.1093/bfgp/eln041] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This review summarizes the essential characteristics of matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF MS), especially as they relate to its applications in quantitative analysis. Approaches to quantification by MALDI-TOF MS are presented and published applications are critically reviewed.
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Affiliation(s)
- Mark W Duncan
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Denver, Mail Stop 8106, 12801 East 17th Avenue, Aurora, CO 80045, USA.
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Shrivas K, Wu HF. A rapid, sensitive and effective quantitative method for simultaneous determination of cationic surfactant mixtures from river and municipal wastewater by direct combination of single-drop microextraction with AP-MALDI mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:1637-44. [PMID: 17828802 DOI: 10.1002/jms.1266] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
A rapid, simple, sensitive, and effective quantitative method for simultaneous determination of cationic surfactants (CS(+)) from river and municipal wastewater by direct combination of single-drop microextraction (SDME) with atmospheric pressure (AP)-MALDI mass spectrometry has been successfully demonstrated without the requirements of tedious sample pre- or post-treatment or separation by high-performance liquid chromatography (HPLC), gas chromatography (GC), and capillary electrophoresis (CE). This quantitative method can greatly enhance the signal-to-noise ratio for analysis of small molecules of CS(+) owing to the strong suppression of matrix ions by the analytes. In addition, SDME assisted in the isolation and preconcentration of CS(+) from water samples, which could effectively reduce the background interferences from the matrices present in waste and river water. The SDME conditions were optimized for achieving high extraction efficiency of CS(+) from aqueous samples, in terms of solvent selection, stirring speed, extraction time, exposure volume of acceptor phase, and salt addition. The enrichment factors for CS(+) were found to be 40-64-folds for 7 min of extraction time with no salt addition and at room temperature. This method was found to yield a linear calibration curve in the concentration range from 50 to 1500 microg/l CS(+) with a limit of detection (LOD) of 10 microg/l. The relative recoveries in river and municipal wastewater were found to be 93.8-103.6% and 91.0-98.7%, respectively. These results indicate that the combination of SDME with AP-MALDI/MS is effective for the simultaneous determination of CS(+) from river and municipal wastewater. In addition, a comparison of enrichments and LOD values for this method with hollow-fiber liquid phase microextraction (HF-LPME) was also demonstrated. The present approach is easy to operate, rapid, sensitive, and suitable for high-throughput of analysis.
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Affiliation(s)
- Kamlesh Shrivas
- Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan
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11
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Charvat A, Gessler F, Niemeyer J, Bögehold A, Abel B. Rapid Quantitative Detection of Bovine Serum Albumin in Blood Serum with Seeded Liquid Beam Desorption Mass Spectrometry. ANAL LETT 2006. [DOI: 10.1080/00032710600752113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Charvat A, Bógehold A, Abel B. Time-Resolved Micro Liquid Desorption Mass Spectrometry: Mechanism, Features, and Kinetic Applications. Aust J Chem 2006. [DOI: 10.1071/ch05249] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Liquid water beam desorption mass spectrometry is an intriguing technique to isolate charged molecular aggregates directly from the liquid phase and to analyze them employing sensitive mass spectrometry. The liquid phase in this approach consists of a 10 µm diameter free liquid filament in vacuum which is irradiated by a focussed infrared laser pulse resonant with the OH-stretch vibration of bulk water. Depending upon the laser wavelength, charged (e.g. protonated) macromolecules are isolated from solution through a still poorly characterized mechanism. After the gentle liquid-to-vacuum transfer the low-charge-state aggregates are analyzed using time-of-flight mass spectrometry. A recent variant of the technique uses high performance liquid chromatography valves for local liquid injections of samples in the liquid carrier beam, which enables very low sample consumption and high speed sample analysis. In this review we summarize recent work to characterize the ‘desorption’ or ion isolation mechanism in this type of experiment. A decisive and interesting feature of micro liquid beam desorption mass spectrometry is that — under certain conditions — the gas-phase mass signal for a large number of small as well as supramolecular systems displays a surprisingly linear response on the solution concentration over many orders of magnitude, even for mixtures and complex body fluids. This feature and the all-liquid state nature of the technique makes this technique a solution-type spectroscopy that enables real kinetic studies involving (bio)polymers in solution without the need for internal standards. Two applications of the technique monitoring enzyme digestion of proteins and protein aggregation of an amyloid model system are highlighted, both displaying its potential for monitoring biokinetics in solution.
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Taguchi Y, Ishida Y, Matsubara H, Ohtani H. Quantitative analysis of an oligomeric hindered amine light stabilizer in polypropylene by matrix-assisted laser desorption/ionization mass spectrometry using a solid sampling technique. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:1345-50. [PMID: 16555367 DOI: 10.1002/rcm.2452] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A small amount of an oligomeric hindered amine light stabilizer (HALS) (Adekastab LA-68LD) in polypropylene (PP) materials was directly determined by solid sampling matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using an internal standard method. First the matrix reagent (dithranol), 20 mg, and the empirically selected internal standard, angiotensin I (MW = 1296.5), 5 microg, were premixed in the solid state. The matrix mixture was then co-ground with the PP sample containing the HALS in liquid nitrogen using a freezer mill. The powdered sample mixture was spotted on the sample plate, suspended in ion-exchanged water, dried to adhere on the plate, and subjected to MALDI-MS. Three series of the HALS components accompanied by the oxidized species were clearly observed as their molecular ions (M*+)) along with that of the internal standard in the mass spectra. A fairly good linear relationship (R2 = 0.9991) with a relative standard deviation of ca. 11% was observed between the relative peak intensities of the HALS components and the HALS contents ranging from 0.1-2.5 wt%, which could be used as the calibration line to determine the HALS content in PP composites directly by MALDI-MS. The UV-exposed PP composite samples were evaluated by this method to interpret the photostabilizing action of HALS in the PP materials based on the observed change in the relative abundances of the original and oxidized HALS components as a function of UV-exposure time.
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Affiliation(s)
- Yoshihiko Taguchi
- Organic Analysis Laboratories, Toray Research Center, Inc., Ohtsu 520-8567, Japan
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14
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Colgrave ML, Jones A, Craik DJ. Peptide quantification by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry: Investigations of the cyclotide kalata B1 in biological fluids. J Chromatogr A 2005; 1091:187-93. [PMID: 16395810 DOI: 10.1016/j.chroma.2005.07.094] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A rapid method has been developed for the quantification of the prototypic cyclotide kalata B1 in water and plasma utilizing matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry. The unusual structure of the cyclotides means that they do not ionise as readily as linear peptides and as a result of their low ionisation efficiency, traditional LC/MS analyses were not able to reach the levels of detection required for the quantification of cyclotides in plasma for pharmacokinetic studies. MALDI-TOF-MS analysis showed linearity (R2 > 0.99) in the concentration range 0.05-10 microg/mL with a limit of detection of 0.05 microg/mL (9 fmol) in plasma. This paper highlights the applicability of MALDI-TOF mass spectrometry for the rapid and sensitive quantification of peptides in biological samples without the need for extensive extraction procedures.
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Affiliation(s)
- Michelle L Colgrave
- Institutefor Molecular Bioscience, University of Queensland, ARC Special Research Centre for Functional and Applied Genomics, Brisbane 4072, Australia
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15
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Okuno S, Wada Y. Measurement of serum salicylate levels by solid-phase extraction and desorption/ionization on silicon mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2005; 40:1000-4. [PMID: 16059881 DOI: 10.1002/jms.859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The applicability of the matrix-free laser desorption/ionization on silicon mass spectrometry (DIOS-MS) to measuring serum drug levels was examined by analyzing serum salicylic acid. The optimized and simple solid-phase extraction (SPE) allowed good recovery, 88.9 +/- 5.8%, for 1.4 mM (200 mg/L) of salicylic acid in serum. The negative ion MS allowed measurements of deprotonated molecules without interference from other signals. Using a deuterium-labeled internal standard, good linearity was obtained in the 0.14 to 4.2 mM (20-600 mg/L) range, which was sufficient for monitoring the therapeutic anti-inflammatory dose. SPE followed by DIOS-MS is anticipated to be a method of measuring drug levels in blood and may allow high throughput analysis.
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Affiliation(s)
- Shoji Okuno
- Japan Science and Technology Agency, Innovation Plaza Osaka, Izumi, Osaka 594-1144, Japan
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16
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Bungert D, Heinzle E, Tholey A. Quantitative matrix-assisted laser desorption/ionization mass spectrometry for the determination of enzyme activities. Anal Biochem 2004; 326:167-75. [PMID: 15003557 DOI: 10.1016/j.ab.2003.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Indexed: 10/26/2022]
Abstract
Quantitative matrix-assisted laser desorption/ionization (MALDI) time-of-flight (ToF) mass spectrometry (MS) was applied for the determination of concentrations of low-molecular-weight (< 400Da) substrates and products of enzyme-catalyzed reactions. Isotope-labeled and fluorinated internal standards were used for the quantification. Automated quantitative MALDI-ToF MS analysis of quenched samples allowed the direct and simultaneous observation of time-dependent decrease of substrate concentration and increase of product concentration without any need for prepurification or desalting steps. The results showed good agreement with established but more elaborate analytical methods. MALDI-ToF MS thus is an interesting alternative tool for the determination of enzyme activities. Due to automated and miniaturized measurement it is especially suitable for the screening of biocatalysts.
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Affiliation(s)
- Ditte Bungert
- Technische Biochemie, Universität des Saarlandes, 66123 Saarbrücken, Germany
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17
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Hatsis P, Brombacher S, Corr J, Kovarik P, Volmer DA. Quantitative analysis of small pharmaceutical drugs using a high repetition rate laser matrix-assisted laser/desorption ionization source. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:2303-2309. [PMID: 14558130 DOI: 10.1002/rcm.1192] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this work, a high repetition rate laser matrix-assisted laser desorption/ionization (MALDI) source is studied on a quadrupole-time-of-flight (QqTOF) and a triple quadrupole (QqQ) mass spectrometer for rapid quantification of small pharmaceutical drugs. The high repetition rate laser allows an up to 100-fold higher pulse frequency as compared with regular MALDI lasers, resulting in much larger sample throughput and number of accumulated spectra. This increases the reproducibility of signal intensities considerably, with average values being around 5% relative standard deviation after taking into account the area ratio of the analyte to an internal standard. Experiments were conducted in MS/MS mode to circumvent the large chemical background due to MALDI matrix ions in the low mass range. The dynamic range of calibration curves on the QqTOF mass spectrometer extended over at least two orders of magnitude, whereas on the QqQ it extended over at least three orders of magnitude. Detection limits ranged from 60-400 pg/microL on the QqTOF and from 6-70 pg/microL on the QqQ for a series of benzodiazepines. The benzodiazepine content of commercial pill formulations was quantified, and less than 5% error was obtained between the present method and the manufacturer's certified values. Furthermore, a high sample throughput was achieved with this method, so that a single MALDI spot could be quantitatively scanned in as little as 15 s, and an entire 96-well MALDI plate in 24 min.
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Affiliation(s)
- Panos Hatsis
- Institute for Marine Biosciences, National Research Council, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
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18
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Bucknall M, Fung KYC, Duncan MW. Practical quantitative biomedical applications of MALDI-TOF mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2002; 13:1015-27. [PMID: 12322949 DOI: 10.1016/s1044-0305(02)00426-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) is used to obtain fast and accurate determinations of molecular mass, but quantitative determinations are generally made by other techniques. In this study we illustrate the practical utility of automated MALDI-TOFMS as a tool for quantifying a diverse array of biomolecules covering an extensive molecular weight range, and present in biological extracts and fluids. Growth hormone was measured in rat pituitary tissue; insulin in human pancreatic tissue; homovanillic acid in human urine; and LVV-hemorphin-7, epinephrine and norepinephrine in human adrenal and pheochromocytoma tissues. Internal standards including compounds of similar molecular weight, structural analogs or isotopomers were incorporated into each analysis. We report on the current practical limitations of quantitative MALDI-TOFMS and highlight some of the potential benefits of this technique as a quantitative tool.
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Affiliation(s)
- Martin Bucknall
- Ray Williams Biomedical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia
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Yan W, Gardella JA, Wood TD. Quantitative analysis of technical polymer mixtures by matrix assisted laser desorption/ionization time of flight mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2002; 13:914-920. [PMID: 12216731 DOI: 10.1016/s1044-0305(02)00388-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report quantitative MALDI-TOF measurements for polydimethylsiloxane (PDMS) of two different molecular weights using the relative ratio of the signal intensities of integrated oligomer distributions for these two molecular weight distributions. By reporting the ratio of intensities of the integrals of two oligomer distributions, we assume that the ionization and desorption efficiencies, crystallization conditions and other factors affecting intensity are similar. Poly(methyl methacrylate) (PMMA-33,000) was mixed with PDMS samples to show whether the presence of another material might affect the desorption efficiency. Quantitative values for the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersities (D) were calculated using the oligomer distributions. The results show a linear relationship between the analyte concentrations and the signal intensities in the range from 1,000 Da to 10,000 Da, and the desorption efficiency of these two PDMS materials was the same even in the presence of PMMA.
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Affiliation(s)
- Wenyan Yan
- Bausch and Lomb, Inc., Rochester, New York, USA
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20
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Walker AK, Rymar G, Andrews PC. Mass spectrometric imaging of immobilized pH gradient gels and creation of "virtual" two-dimensional gels. Electrophoresis 2001; 22:933-45. [PMID: 11332761 DOI: 10.1002/1522-2683()22:5<933::aid-elps933>3.0.co;2-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have developed a matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) based technique for the detection of intact proteins directly from immobilized pH gradient gels (IPGs). The use of this technique to visualize proteins from IPGs was explored in this study. Whole cell Escherichia coli extracts of various loadings were separated on IPGs. These IPGs were processed to remove contaminants and to achieve matrix/analyte cocrystallization on the surface of the gel. Mass spectra were acquired by scanning the surface of the gel and were assimilated into a "virtual" two dimensional (2-D) gel. This virtual 2-D gel is analogous to a "classical" 2-D gel, except that the molecular weight information is acquired by mass spectrometry rather than by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This mass spectrometry (MS) based technology exemplifies a number of desirable characteristics, some of which are not attainable with classical two-dimensional electrophoresis (2-DE). These include high sensitivity, high reproducibility, and an inherently higher resolution and mass accuracy than 2-D gels. Furthermore, there is a difference in selectivity exhibited between virtual 2-D gels and classical 2-D gels, as a number of proteins are visible in the virtual gel image that are not present in the stained gels and vice versa. In this report, virtual 2-D gels will be compared to classical 2-D gels to illustrate these features.
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Affiliation(s)
- A K Walker
- Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606, USA
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21
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Gordon EF, Muddiman DC. Impact of ion cloud densities on the measurement of relative ion abundances in Fourier transform ion cyclotron resonance mass spectrometry: experimental observations of coulombically induced cyclotron radius perturbations and ion cloud dephasing rates. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:195-203. [PMID: 11288202 DOI: 10.1002/jms.121] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fundamental research into the quantitative properties of Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) has yielded interesting observations, especially in terms of factors affecting the accuracy of relative ion abundances. However, most of the previous discussions have focused on theoretical systems, or systems of limited scope. In this paper, we document ion motion attributes of a 30 spectra (six samples, five replicates each) system previously established as linear over two orders of magnitude. Observed behaviors include the perturbation of one charged species (cyclosporin A, CsA) of low ion density to a cyclotron orbit of greater radius than that of an almost identical, but slightly mass-separated species (CsG) with a higher ion density. This radial perturbation is attributed to the coulombic repulsion between the two ion clouds as they interact during the excitation process, as previously proposed by Uechi and Dunbar. Magnitudes of the perturbation were confirmed by making cyclotron radii determinations utilizing the ratio of the third-to-first harmonics for the charged species of interest. It was found that these radial differences can account for as much as a 55% signal bias in favor of CsA for a single sample and a >20% positive bias in the slope of the regressed data set. A second behavior noted that also contributes to the potential inaccuracy of relative ion abundance measurements is the difference in signal decay rates for CsA and CsG. Damping constants and initial time domain signal amplitudes were evaluated using segmented Fourier transforms. Discrepancies in decay rates were not expected from two species that have essentially identical collisional cross-sections. However, it has been observed that the faster decay rates are observed by the species of lower ion cloud density. We have attributed this differential signal decay phenomenon to the rates of loss of phase coherence for the two ion clouds. Previously, others have reported that less dense ion clouds are more susceptible to shearing and other disruptive forces during the course of their excited cyclotron motion. Our experimental evidence supports that it is the loss of cloud coherence that accounts for the signal loss over time, with the less dense cloud de-phasing more quickly. As the ion populations of the two investigated species near equivalence, so do their time constants.
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Affiliation(s)
- E F Gordon
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, USA
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22
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Kang MJ, Tholey A, Heinzle E. Application of automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the measurement of enzyme activities. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:1327-33. [PMID: 11466793 DOI: 10.1002/rcm.376] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Sample preparation methods and data acquisition protocols were optimized for the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to high-throughput quantitative analysis of low molecular mass substrates and products of an enzyme-catalyzed reaction. Using a deuterlum-labeled internal standard, precise standard curves were obtained (r(2) = 0.9998) over two orders of magnitude of concentration of rac-1-phenylethylamine (PEA), which is converted to 2-methoxy-N-[(1R)-1-phenylethyl]acetamide (MET) by a lipase-catalyzed reaction with ethylmethoxyacetate (EMA) as second substrate. Reliable relative standard deviations were achieved (< or =5%) using automated analysis with peak intensity ratios between 0.2 and 5 of analyte to internal standard. This method permitted quantitative analysis of the lipase reaction, producing results comparable to those from gas chromatographic (GC) analysis in the dynamic range of GC. This work shows that MALDI-TOFMS can be applied for the high-throughput screening of enzymes.
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Affiliation(s)
- M J Kang
- Technische Biochemie, Saarland University, Im Stadtwald, Bldg. 2, D-66123 Saarbruecken, Germany
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23
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Horak J, Werther W, Schmid ER. Optimisation of the quantitative determination of chlormequat by matrix-assisted laser desorption/ionisation mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:241-248. [PMID: 11223954 DOI: 10.1002/rcm.217] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The plant growth regulator chlormequat, an involatile quaternary ammonium salt, has been quantified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). Restrictions for quantitative MALDI-TOFMS analysis, such as irreproducible crystallisation and unsatisfactory laser stability, have been overcome by the application of two synthesised isotopically labelled standards and the optimisation of the measurement protocol. Data acquisition at constant laser power was compared to data acquisition at approximately constant ion abundance of the relevant ions (analyte and internal standards). Data acquisition at constant ion abundance performed better and enabled a high number of consecutive firings to the same sample deposition area. Furthermore an increased sample-to-sample repeatability and a high reproducibility over several weeks without re-calibration have been attained by this method. Linearity over three orders of magnitude (0.05 to 30 ng/microL chlormequat), with a correlation coefficient of 0.9997, was achieved using [13C3]-chlormequat as internal standard. Limit of detection and limit of determination were determined to be in the low pg/microL range for pure standard solutions. Thin-layer chromatography was applied for the removal of high amounts of choline, which is often present in plant tissue extracts and can adversely affect the ionisation and detection of chlormequat by MALDI-TOFMS. The use of two internal standards ([13C3]- and [2H9]-chlormequat) enabled direct quantification and simultaneous control of the recovery.
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Affiliation(s)
- J Horak
- Institute of Analytical Chemistry, University of Vienna, Waehringerstrasse 38, A-1090 Vienna, Austria
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24
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Kang MJ, Tholey A, Heinzle E. Quantitation of low molecular mass substrates and products of enzyme catalyzed reactions using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2000; 14:1972-1978. [PMID: 11085406 DOI: 10.1002/1097-0231(20001115)14:21<1972::aid-rcm119>3.0.co;2-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Relative peak-height ratios of products to substrates determined by MALDI-TOFMS allow the quantitative analysis of enzyme catalyzed reactions for screening purposes. Two examples were investigated: the first one was a lipase catalyzed reaction which produces 2-methoxy-N-[(1R)-1-phenylethyl]acetamide (MET) using rac-alpha-phenylethylamine (PEA) as substrate. The second one was the pyruvate decarboxylase catalyzed formation of (1R)-1-hydroxy-1-phenyl-2-propanone (PAC) with benzaldehyde (BzA) as substrate. Here the corresponding oximes were analyzed after derivatization using hydroxylamine. The standard curves (r2 = 0.985 for MET, r2 = 0.991 for PAC) were linear over two orders of magnitude for MET and PAC concentrations. After optimization of the sample preparation an average relative standard deviation of 12.5% was obtained in both cases.
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Affiliation(s)
- M J Kang
- Technische Biochemie, University of the Saarland, Saarbruecken, Germany
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25
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MacPhee CE, Howlett GJ, Sawyer WH. Mass spectrometry to characterize the binding of a peptide to a lipid surface. Anal Biochem 1999; 275:22-9. [PMID: 10542105 DOI: 10.1006/abio.1999.4283] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The binding of an amphipathic alpha-helical peptide to small unilamellar lipid vesicles has been examined using chemical derivitization and mass spectrometry. The peptide is derived from the sequence of human apolipoprotein C-II (apoC-II), the protein activator of lipoprotein lipase (LpL). ApoC-II(19-39) forms approximately 60% alpha-helix upon binding to model egg yolk phosphatidylcholine small unilamellar vesicles. Measurement of the affinity of the peptide for lipid by spectrophotometric methods is complicated by the contribution of scattered light to optical signals. Instead, we characterize the binding event using the differential labeling of lysine residues by the lipid- and aqueous-phase cross-linkers, disuccinimidyl suberate (DSS) and bis(sulfosuccinimidyl) suberate (BS(3)), respectively. In aqueous solution, the three lysine residues of the peptide are accessible to both cross-linkers. In the presence of lipid, the C-terminal lysine residue becomes inaccessible to the lipid-phase cross-linker DSS, but remains accessible to the aqueous-phase cross-linker, BS(3). We use mass spectrometry to characterize this binding event and to derive a dissociation constant for the interaction (K(d) = 5 microM). We also provide evidence for the formation of dimeric cross-linked peptide when high densities of peptide are bound to the lipid surface.
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Affiliation(s)
- C E MacPhee
- Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, 3052, Australia
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26
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Guo J, Wu J, Siuzdak G, Finn MG. Bestimmung von Enantiomerenüberschüssen durch kinetische Racematspaltung und Massenspektrometrie. Angew Chem Int Ed Engl 1999. [DOI: 10.1002/(sici)1521-3757(19990614)111:12<1868::aid-ange1868>3.0.co;2-j] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Abstract
The continuing success of the combinatorial approach is heavily reliant on analytical methodologies, which allow for the rapid and accurate characterisation of medicinally relevant molecules from compound libraries. Mass spectrometry has recently been touted as the most suitable tool for a range of combinatorial applications such as structural elucidation and screening. The refinement of conventional methods, developments of techniques such as Fourier transform ion cyclotron resonance and new screening methodologies have allowed the medicinal chemist to tackle the growing analytical challenges posed by combinatorial chemistry.
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Affiliation(s)
- V Swali
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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Süssmuth RD, Jung G. Impact of mass spectrometry on combinatorial chemistry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 725:49-65. [PMID: 10226877 DOI: 10.1016/s0378-4347(98)00513-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the past few years, the emergence of combinatorial chemistry has drawn increasing attention and a great deal of analytical research has been centered around this new methodology. These new methods capable of producing vast numbers of samples, which are in many cases highly complex, demand fast and reliable analytical techniques able to provide high quality information concerning sample compositions. Mass spectrometry (MS) is the method of choice to face these analytical challenges. In particular, the introduction of electrospray ionization (ESI and matrix assisted laser desorption/ionization (MALDI) have been the driving forces for many of the recent innovations, not only within the fields of the biosciences, but also in combinatorial chemistry. These ionization techniques are extremely versatile for the characterization of both single compound collections and compound mixture collections. The high-throughput capabilities, as well as many possible couplings with separation techniques (HPLC, CE) have been thus facilitated. However, mass spectrometry is not only limited to use as an instrument for synthesis control, but also plays an increasing role in the identification of active compounds from complex libraries. Recently, new initiatives for library analysis and screening have arisen from the application of the latest developments in mass spectrometry, Fourier transform ion cyclotron resonance (FTICR).
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Affiliation(s)
- R D Süssmuth
- University of Tübingen, Institute of Organic Chemistry, Germany.
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29
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GHASSEMPOUR A, DANESHFAR R, MOSSEVI R, ARSHADI MR. Rapid and Sensitive Determination of Cyclosporins by Pyrolysis Mass Spectrometry. ANAL SCI 1999. [DOI: 10.2116/analsci.15.457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | - Reza MOSSEVI
- Department of Chemistry, Sharif University of Technology
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30
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31
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Wu J, Takayama S, Wong CH, Siuzdak G. Quantitative electrospray mass spectrometry for the rapid assay of enzyme inhibitors. CHEMISTRY & BIOLOGY 1997; 4:653-7. [PMID: 9331404 DOI: 10.1016/s1074-5521(97)90220-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Combinatorial chemistry has become an important method for identifying effective ligand-receptor binding, new catalysts and enzyme inhibitors. In order to distinguish the most active component of a library or to obtain structure-activity relationships of compounds in a library, an efficient quantitative assay is crucial. Electrospray mass spectrometry has become an indispensable tool for qualitatively screening combinatorial libraries and its use for quantitative analysis has recently been demonstrated. RESULTS This paper describes the use of quantitative electrospray mass spectrometry for screening libraries of inhibitors of enzymatic reactions, specifically the enzymatic glycosylation by beta-1,4-galactosyltransferase, which catalyzes the transfer of galactose from uridine-5'-diphosphogalactose to the 4-position of N-acetylglucosamine beta OBn (Bn: benzene) to form N-acetyllactosamine beta OBn. Our mass spectrometric screening approach showed that both nucleoside diphosphates and triphosphates inhibited galactosyltransferase while none of the nucleoside monophosphates, including uridine-5'-monophosphate, showed any inhibition. Additional libraries were generated in which the concentrations of the inhibitors were varied and, using mass spectrometry, uridine-5'-diphosphate-2-deoxy-2-fluorogalactose was identified as the best inhibitor. CONCLUSIONS This report introduces quantitative electrospray mass spectrometry as a rapid, sensitive and accurate quantitative assaying tool for inhibitor libraries that does not require a chromophore or radiolabeling. A viable alternative to existing analytical techniques is thus provided. The new technique will greatly facilitate the discovery of novel inhibitors against galactosyltransferase, an enzyme for which there are few potent inhibitors.
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Affiliation(s)
- J Wu
- Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037, USA
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