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Mitsuo Takayama - One of the best experts on this subject based on the ideXlab platform.
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disappearance of interfering alkali metal adducted peaks from matrix assisted laser desorption ionization Mass Spectra of peptides with serine addition to alpha cyano 4 hydroxycinnamic acid matrix
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Takashi Nishikaze, Mitsuo TakayamaAbstract:It has been described that ion yield in both positive- and negative-ion matrix-assisted laser desorption/ionization Mass spectrometry (MALDI MS) of peptides is often inhibited by trace amounts of alkali metals and that the MALDI Mass Spectra are contaminated by the interfering peaks originating from traces of alkali metals, even when sample preparation is carefully performed. Addition of serine to the commonly used MALDI matrix alpha-cyano-4-hydroxycinnamic acid (CHCA) significantly improved and enhanced the signals of both protonated and deprotonated peptides, [M+H](+) and [M-H](-). The addition of serine to CHCA matrix eliminated the alkali-metal ion adducts, [M+Na](+) and [M+K](+), and the CHCA cluster ions from the Mass Spectra. Serine and serinephosphate as additives to CHCA enhanced and improved the formation of molecular-related ions of phosphopeptides in negative-ion MALDI Mass Spectra.
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disappearance of interfering alkali metal adducted peaks from matrix assisted laser desorption ionization Mass Spectra of peptides with serine addition to alpha cyano 4 hydroxycinnamic acid matrix
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Takashi Nishikaze, Mitsuo TakayamaAbstract:It has been described that ion yield in both positive- and negative-ion matrix-assisted laser desorption/ionization Mass spectrometry (MALDI MS) of peptides is often inhibited by trace amounts of alkali metals and that the MALDI Mass Spectra are contaminated by the interfering peaks originating from traces of alkali metals, even when sample preparation is carefully performed. Addition of serine to the commonly used MALDI matrix α-cyano-4-hydroxycinnamic acid (CHCA) significantly improved and enhanced the signals of both protonated and deprotonated peptides, [M+H]+ and [M−H]−. The addition of serine to CHCA matrix eliminated the alkali-metal ion adducts, [M+Na]+ and [M+K]+, and the CHCA cluster ions from the Mass Spectra. Serine and serinephosphate as additives to CHCA enhanced and improved the formation of molecular-related ions of phosphopeptides in negative-ion MALDI Mass Spectra. Copyright © 2007 John Wiley & Sons, Ltd.
Takashi Nishikaze - One of the best experts on this subject based on the ideXlab platform.
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disappearance of interfering alkali metal adducted peaks from matrix assisted laser desorption ionization Mass Spectra of peptides with serine addition to alpha cyano 4 hydroxycinnamic acid matrix
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Takashi Nishikaze, Mitsuo TakayamaAbstract:It has been described that ion yield in both positive- and negative-ion matrix-assisted laser desorption/ionization Mass spectrometry (MALDI MS) of peptides is often inhibited by trace amounts of alkali metals and that the MALDI Mass Spectra are contaminated by the interfering peaks originating from traces of alkali metals, even when sample preparation is carefully performed. Addition of serine to the commonly used MALDI matrix alpha-cyano-4-hydroxycinnamic acid (CHCA) significantly improved and enhanced the signals of both protonated and deprotonated peptides, [M+H](+) and [M-H](-). The addition of serine to CHCA matrix eliminated the alkali-metal ion adducts, [M+Na](+) and [M+K](+), and the CHCA cluster ions from the Mass Spectra. Serine and serinephosphate as additives to CHCA enhanced and improved the formation of molecular-related ions of phosphopeptides in negative-ion MALDI Mass Spectra.
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disappearance of interfering alkali metal adducted peaks from matrix assisted laser desorption ionization Mass Spectra of peptides with serine addition to alpha cyano 4 hydroxycinnamic acid matrix
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Takashi Nishikaze, Mitsuo TakayamaAbstract:It has been described that ion yield in both positive- and negative-ion matrix-assisted laser desorption/ionization Mass spectrometry (MALDI MS) of peptides is often inhibited by trace amounts of alkali metals and that the MALDI Mass Spectra are contaminated by the interfering peaks originating from traces of alkali metals, even when sample preparation is carefully performed. Addition of serine to the commonly used MALDI matrix α-cyano-4-hydroxycinnamic acid (CHCA) significantly improved and enhanced the signals of both protonated and deprotonated peptides, [M+H]+ and [M−H]−. The addition of serine to CHCA matrix eliminated the alkali-metal ion adducts, [M+Na]+ and [M+K]+, and the CHCA cluster ions from the Mass Spectra. Serine and serinephosphate as additives to CHCA enhanced and improved the formation of molecular-related ions of phosphopeptides in negative-ion MALDI Mass Spectra. Copyright © 2007 John Wiley & Sons, Ltd.
Peter Vandamme - One of the best experts on this subject based on the ideXlab platform.
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effects of growth medium on matrix assisted laser desorption ionization time of flight Mass Spectra a case study of acetic acid bacteria
Applied and Environmental Microbiology, 2014Co-Authors: Anneleen D Wieme, Katrien De Bruyne, Freek Spitaels, Maarten Aerts, Anita Van Landschoot, Peter VandammeAbstract:The effect of the growth medium used on the matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) Mass Spectra generated and its consequences for species and strain level differentiation of acetic acid bacteria (AAB) were determined by using a set of 25 strains. The strains were grown on five different culture media that yielded a total of more than 600 Mass Spectra, including technical and biological replicates. The results demonstrate that the culture medium can have a profound effect on the Mass Spectra of AAB as observed in the presence and varying signal intensities of peak classes, in particular when culture media do not sustain optimal growth. The observed growth medium effects do not disturb species level differentiation but strongly affect the potential for strain level differentiation. The data prove that a well-constructed and robust MALDI-TOF Mass spectrometry identification database should comprise Mass Spectra of multiple reference strains per species grown on different culture media to facilitate species and strain level differentiation.
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bacterial species identification from maldi tof Mass Spectra through data analysis and machine learning
Systematic and Applied Microbiology, 2011Co-Authors: Katrien De Bruyne, Bram Slabbinck, Willem Waegeman, Paul Vauterin, Bernard De Baets, Peter VandammeAbstract:At present, there is much variability between MALDI-TOF MS methodology for the characterization of bacteria through differences in e.g., sample preparation methods, matrix solutions, organic solvents, acquisition methods and data analysis methods. After evaluation of the existing methods, a standard protocol was developed to generate MALDI-TOF Mass Spectra obtained from a collection of reference strains belonging to the genera Leuconostoc, Fructobacillus and Lactococcus. Bacterial cells were harvested after 24h of growth at 28°C on the media MRS or TSA. Mass Spectra were generated, using the CHCA matrix combined with a 50:48:2 acetonitrile:water:trifluoroacetic acid matrix solution, and analyzed by the cell smear method and the cell extract method. After a data preprocessing step, the resulting high quality data set was used for PCA, distance calculation and multi-dimensional scaling. Using these analyses, species-specific information in the MALDI-TOF Mass Spectra could be demonstrated. As a next step, the Spectra, as well as the binary character set derived from these Spectra, were successfully used for species identification within the genera Leuconostoc, Fructobacillus, and Lactococcus. Using MALDI-TOF MS identification libraries for Leuconostoc and Fructobacillus strains, 84% of the MALDI-TOF Mass Spectra were correctly identified at the species level. Similarly, the same analysis strategy within the genus Lactococcus resulted in 94% correct identifications, taking species and subspecies levels into consideration. Finally, two machine learning techniques were evaluated as alternative species identification tools. The two techniques, support vector machines and random forests, resulted in accuracies between 94% and 98% for the identification of Leuconostoc and Fructobacillus species, respectively.
L F Sukhodub - One of the best experts on this subject based on the ideXlab platform.
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concentration dependence of nucleoside fast atom bombardment Mass Spectra
Rapid Communications in Mass Spectrometry, 1995Co-Authors: Sergey A Aksyonov, L F SukhodubAbstract:The quantitative investigation of the four RNA nucleosides (adenosine, guanosine, cytidine and uridine) using fast-atom bombardment Mass Spectra is reported. Nucleoside concentrations are varied in the 0.8–4% range. The nucleoside hydrogen-bonded complexes are shown to form primarily on the liquid matrix surface.
Emilio Scamporrino - One of the best experts on this subject based on the ideXlab platform.
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further application of a procedure for molecular weight and molecular weight distribution measurement of polydisperse polymers from their matrix assisted laser desorption ionization time of flight Mass Spectra
Macromolecules, 1997Co-Authors: Daniele Vitalini, Placido Mineo, Emilio ScamporrinoAbstract:A recently reported off-line procedure to estimate molecular weight (MW) averages and molecular weight distribution (MWD) index, also for polydisperse polymers, directly from their matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) Mass Spectra was applied here to poly(bisphenol A-carbonate) (PC), a poly(ether-sulfone) resin (PES), and poly(dimethylphenylene oxide) (PDMPO), all having a wide polydispersity index. The MW and MWD obtained values were compared with those determined by GPC or supplied by makers. A structural characterization of these polymers was also performed by examining their MALDI-TOF Mass Spectra.
