Mass determination of major plasma proteins by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Biochemists at Lancaster Laboratories are successfully characterizing proteins, complex carbohydrates and nucleic acids by developing and validating new methods for determining molecular weights using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS).
Supplementary Materialsproteomes-04-00034-s001. at least several thousand genes encoding putative extracellular proteins [12]. Only a limited number of these extracellular proteins has so far been characterized for function, particularly concerning cell wall dynamics [9,13], and thus, a full picture of how cell wall dynamics result from the concerted action of such proteins is not yet attainable. Protoplasts isolated enzymatically from your cells and cultured Akt1 cells of vegetation are capable of forming fresh cell walls and therefore offer a unique opportunity to study various methods of cell wall construction and, using histochemical staining techniques and electron microscopy, observed cell wall dynamics in the cell surface during cell wall regeneration [14]. Furthermore, using two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and matrix-assisted laser desorption ionization-time-of-flight/mass spectrometry (MALDI-TOF/MS), we successfully recognized approximately three hundred ...
We used high-performance liquid chromatography to separate urine obtained from whole-body gamma-irradiated mice (4 Gy) before analyzing each fraction with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry to identify radiation-responsive molecules. We identified two candidates: hepcidin antimicrobial peptide 2 (hepcidin-2) and peptide fragments of kidney androgen-regulated protein (KAP). We observed that peak increases of hepcidin-2 in urine were delayed in a dose-dependent manner (1 Gy and above); however, the amount of KAP peptide fragments showed no correlation with radiation dose. In addition, an increase in hepcidin-2 after exposure to relatively low radiation doses (0.25 and 0.5 Gy, respectively) was biphasic (at 8-48 h and 120-168 h, respectively, after irradiation). The increase in hepcidin-2 paralleled an increase in hepcidin-2 gene (Hamp2) mRNA levels in the liver. These results suggest that radiation exposure directly or indirectly induces urinary excretion of
Analysis of human serum proteins by liquid phase isoelectric focusing and matrix-assisted laser desorption/ionization-mass spectrometry.
BACKGROUND Sequence type 131 (ST131) is a predominant lineage among extraintestinal pathogenic Escherichia coli. It plays a major role in the worldwide dissemination of extended-spectrum β-lactamase (ESBL)-producing E. coli. The ST131 pandemic is mainly the result of clonal expansion of the single well-adapted subclone H30-Rx, which is acquired in hospitals more frequently than other ESBL-producing E. coli clones. AIM To develop a rapid method using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify ST131 for infection control purposes. METHODS Peak biomarkers of ST131 were identified from the mass spectrum profiles of 109 E. coli isolates (including 50 ST131 isolates). FINDINGS The models accurately identified ST131 isolates from mass spectrum profiles obtained with and without protein extraction. CONCLUSIONS The rapid identification of ST131 isolates with MALDI-TOF MS can be easily implemented in the laboratory, and could help to target
An accurate method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been developed for quantitative analysis of calcitonin and insulin in different commercially available pharmaceutical products. Tryptic peptides derived from these polypeptides were chemically modified at their C-terminal lysine-residues with 2-methoxy-4,5-dihydro-imidazole (light tagging) as standard and deuterated 2-methoxy-4,5-dihydro-imidazole (heavy tagging) as internal standard (IS). The heavy modified tryptic peptides (4D-Lys tag), differed by four atomic mass units from the corresponding light labelled counterparts (4H-Lys tag). The normalized peak areas (the ratio between the light and heavy tagged peptides) were used to construct a standard curve to determine the concentration of the analytes. The concentrations of calcitonin and insulin content of the analyzed pharmaceutical products were accurately determined, and less than 5% error was obtained between the ...
A Household Microsporum canis Dermatophytosis Suggested by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry Analysis - Get your full text copy in PDF #930713
|em|Background|/em|: The non-dairy sector is growing, fermented alternatives to dairy are sparse. Adapted starter |br /|cultures to substituting raw materials needs to be developed.|br /||em|Objective|/em|: Aims of this study were to isolate, identify, and phenotypically characterize lactic acid bacteria (LAB) that inhabit Swedish legumes, and assess properties necessary for selecting strains with the ability to ferment a bean beverage and with potential health beneficial properties.|br /||em|Design|/em|: Isolates of presumed LAB were obtained from legumes collected at Öland, Sweden. Strain diversity was assessed by repetitive polymerase chain reaction (rep-PCR). The strains were identified using matrix- assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Species belonging to Enterococcus were predominant along with Pediococcus and closely related Bacillus. Strains were tested for |br /|tolerance to low pH, phenol, and bile as well as their bile salt hydrolase (BSH)
TY - JOUR. T1 - Structural characterization of multibranched oligosaccharides from seal milk by a combination of off-line high-performance liquid chromatography-matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and sequential exoglycosidase digestion. AU - Kinoshita, Mitsuhiro. AU - Ohta, Hiroko. AU - Higaki, Kanata. AU - Kojima, Yoko. AU - Urashima, Tadasu. AU - Nakajima, Kazuki. AU - Suzuki, Minoru. AU - Kovacs, Kit M.. AU - Lydersen, Christian. AU - Hayakawa, Takao. AU - Kakehi, Kazuaki. PY - 2009/5/15. Y1 - 2009/5/15. N2 - A complex mixture of diverse oligosaccharides related to the carbohydrates in glycoconjugates involved in various biological events is found in animal milk/colostrum and has been challenging targets for separation and structural studies. In the current study, we isolated oligosaccharides having high molecular masses (MW ∼ 3800) from the milk samples of bearded and hooded seals and analyzed their structures by off-line ...
TY - JOUR. T1 - Characterisation of bisphenol-A diglycidyl ether by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). AU - Li, Zhili. AU - Guo, Xinghua. AU - Liu, S.. AU - Ji, Y.. AU - Zhang, Y.. AU - Ji, K.. AU - You, Y.. PY - 1997. Y1 - 1997. M3 - Article. VL - 14. SP - 14. EP - 18. JO - Acta materiae compositae Sinica = Fuhe-cailiao-xuebao. JF - Acta materiae compositae Sinica = Fuhe-cailiao-xuebao. SN - 1000-3851. IS - 4. ER - ...
Despite the benefits of MALDI-TOF MS technology (Matrix-Assisted Laser Desorption-Ionization Time-Of-Flight Mass Spectrometry) reported worldwide and the continuous improving of the available databases, discrimination between Streptococcus pneumoniae and closely related species within the Streptococcus mitis group (SMG) using this methodology has been suboptimal. However, the accurate identification at the species level of this group of microorganisms is important for the appropriate management of infected patients. In this study, 216 SMG isolates -101 S. pneumoniae and 115 corresponding to 7 non-pneumococcal species within this group- were analysed. All the isolates had been previously identified by conventional methods (optochin and bile solubility tests) and non-pneumococcal isolates were confirmed by sequence analysis (sodA and plys genes) when required. The isolates were also identified with the MALDI Biotyper 3.1 (Bruker Daltonics, Bremen, Germany) using an updated library containing 6903 Main
We evaluated the performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), the MALDI Bruker Biotyper system (microflex LT; Bruker Daltonik GmbH, Bremen, Germany), on the identification of 50 isolates of clinically encountered molds, including Penicillium marneffei (n=28), Paecilomyces species (n=12), Fusarium solani (n=6), Rhizopus species (n=3), and Pseudallescheria boydii (n=1). The isolates were identified to species levels by sequence analysis of the internal transcribed spacer (ITS) regions using primers ITS1 and ITS4. None of the 28 genetically well characterized isolates of P. marneffei were identified as P. marneffei by MALDI-TOF MS, because P. marneffei was not present in either Bruker general library (DB 5627) or Bruker filamentous fungi library V1.0. However, the rate of accurate identification as P. marneffei (score value 2.000) was 85.7% based on newly-created database from one P. marneffei strain (NTUH-3370) by MALDI Biotyper system.
Discover how advances in mass spectrometry are fueling new discoveries across a broad range of research areas Electrospray and MALDI Mass Spectrometry brings both veteran practitioners and beginning scientists up to date with the most recent trends and findings in electrospray ionization and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. In particular, this Second Edition highlights how advances in electrospray and MALDI mass spectrometry are supporting important discoveries in new and emerging fields such as proteomics and metabolomics as well as in traditional areas of chemistry and physics research.. Electrospray AND MALDI Mass Spectrometry, SECOND EDITION is divided into five parts:. ...
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used successfully to detect phosphorylation sites in proteins. Applications may be limited by the low response of phosphopeptides compared to nonphosphorylated peptides in MALDI MS. The addition of ammonium salts to th …
The chemopreventive efficacy of cranberry juice concentrate in an experimental model of urinary bladder cancer was evaluated using female Fischer-344 rats. The animals received N-butyl-N-(4-hydroxybutyl)-nitrosamine (OH-BBN) for a period of eight weeks. Cranberry juice concentrate was administered at doses of 1.0 or 0.5 ml/rat/day beginning one week after the final OH-BBN treatment and continuing until the end of the study. The urinary bladders of all the rats were weighed and examined grossly for lesions, and all masses were submitted for pathological evaluation ...
Reads data files acquired by Bruker Daltonics matrix-assisted laser desorption/ionization-time-of-flight mass spectrometer of the *flex series.. ...
Wong, C., K.L.; Chan, T.W.Dominic, 1997: Cationization processes in matrix-assisted laser desorption/ionization mass spectrometry: Attachment of divalent and trivalent metal ions
Gruisen, J.A.E. (2019) Matrix-assisted laser desorption/ionisation mass spectrometry imaging for bone fracture hematoma analysis. Full text not available from this repository. ...
Gerl M. J, Bittl V, Kirchner S, Sachsenheimer T, Brunner HL, Lüchtenborg C, Ozbalci C, Wiedemann H, Wegehingel S, Nickel W, Haberkant P, Schultz C, Krüger M, Brügger B (2016). Sphingosine-1-phosphate lyase deficient cells as a tool to study Protein lipid interactions. PloS one. 11:e0153009. Callens N, Brügger B, Bonnafous P, Drobecq H, Gerl MJ, Krey T, Roman-Sosa G, Rümenapf T, Lambert O, Dubuisson J, Rouillé Y (2016). Morphology and molecular composition of purified bovine viral diarrhea virus envelope. PLoS Pathog. 12(3):e1005476. Hacke M, Bjorkholm P, Hellwig A, Himmels P, de Almodovar CR, Brügger B, Wieland F, Ernst AM (2015). Inhibition of Ebola virus glycoprotein-mediated cytotoxicity by targeting its transmembrane and cholesterol. Nat Commun. 6,7688, PMID 26158910. Gerl MJ, Sachsenheimer T, Grzybek M, Coskun U, Wieland FT, Brügger B (2014). Analysis of transmembrane domains and lipid modified peptides with matrix-assisted laser desorption ionization-time-of-flight mass ...
TY - JOUR. T1 - Design and synthesis of cleavable biotinylated dideoxynucleotides for DNA sequencing by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. AU - Qiu, Chunmei. AU - Kumar, Shiv. AU - Guo, Jia. AU - Yu, Lin. AU - Guo, Wenjing. AU - Shi, Shundi. AU - Russo, James J.. AU - Ju, Jingyue. PY - 2012/8/15. Y1 - 2012/8/15. N2 - Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based methods have been widely explored for DNA sequencing. We report here the design, synthesis, and evaluation of a novel set of chemically cleavable biotinylated dideoxynucleotides, ddNTPs-N 3-biotin, for the DNA polymerase extension reaction and its application in DNA sequencing by mass spectrometry (MS). These nucleotide analogs have a biotin moiety attached to the 5 position of the pyrimidines (C and U) or the 7 position of the purines (A and G) via a chemically cleavable azido-based linker, with different length linker arms serving as mass ...
TY - JOUR. T1 - Two-step matrix application technique to improve ionization efficiency for matrix-assisted laser desorption/ionization in imaging mass spectrometry. AU - Sugiura, Yuki. AU - Shimma, Shuichi. AU - Setou, Mitsutoshi. PY - 2006/12/15. Y1 - 2006/12/15. N2 - A novel matrix application protocol for direct tissue mass spectrometry is presented. Matrix-assisted laser desorption/ionization is a popular ionization procedure for direct tissue analysis and imaging mass spectrometry. Usually, matrixes are applied by dispensing droplets through either pipettes or automated dispensing machines, or by air-brushing. These techniques are very simple, but it was difficult to obtain uniform matrix crystals on the tissue surface, and nonuniform crystals degrade the spectrum qualities. Here we report a new matrix application protocol, which is a combination of spraying and dispensing droplets, and we have succeeded in overcoming these problems in conventional matrix applications on tissue surfaces. We ...
Archaea and a number of groups of environmentally important bacteria, e.g., sulfate-reducing bacteria, anoxygenic phototrophs, and some thermophiles, are difficult to characterize using current methods developed for phenotypically differentiating heterotrophic bacteria. We have evaluated matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-MS) as a rapid method for identifying different groups of extremophilic prokaryotes using a linear mass spectrometer (Micromass, UK). The instrument is designed to acquire mass-spectral patterns from prokaryotic cell-wall components between masses of 500 and 10,000 Da in a statistically robust manner and create a database that can be used for identification. We have tested 28 archaea (10 genera, 20 spp.) and 42 bacteria (25 genera, 37 spp.) and found that all species yield reproducible, unique mass-spectral profiles. As a whole, the profiles for the archaea had fewer peaks and showed less differentiation compared to the bacteria, perhaps ...
Black phosphorus-assisted laser desorption ionization mass spectrometry for the determination of low-molecular-weight compounds in biofluids.. PubMed. He, Xiao-Mei; Ding, Jun; Yu, Lei; Hussain, Dilshad; Feng, Yu-Qi. 2016-09-01. Quantitative analysis of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been a challenging task due to matrix-derived interferences in low m/z region and poor reproducibility of MS signal response. In this study, we developed an approach by applying black phosphorus (BP) as a matrix-assisted laser desorption ionization (MALDI) matrix for the quantitative analysis of small molecules for the first time. Black phosphorus-assisted laser desorption/ionization mass spectrometry (BP/ALDI-MS) showed clear background and exhibited superior detection sensitivity toward quaternary ammonium compounds compared to carbon-based materials. By combining stable isotope labeling (SIL) strategy with BP/ALDI-MS ...
Clinical demand for HCV genotyping is increasing because of the significance of HCV genotype as a predictor of treatment response and to enable use of more efficacious therapeutic options. Currently, genotyping is performed largely by sequence analysis and hybridization-based assays (16)(17)(18). Sequencing can give information on the majority species present in the viral populations but generally fails to detect species comprising less than 15%-50% of a viral population (26). It is thus necessary to analyze multiple clones to determine the genetic heterogeneity of a population. Assays based on hybridization have been widely used as surrogate genotyping methods, but such assays are labor-intensive, complicate identification of genotype variants or genotype mixtures, and are not suitable for screening large numbers of samples because of the complex protocols involved.. MS generates precise information on the molecular mass of the analyte, both DNA strands can be analyzed in parallel, and the ...
The techniques of supersonic molecular beam cooling and laser multiphoton ionisation (MPI) spectroscopy have been combined to give a potentially powerful analytical technique. Two methods of sample introduction into the molecular beam have been employed, namely resistive heating and laser desorption. The resistive heating method allowed 2-colour MPI spectra of naphthalene, anthracene and perylene to be recorded in a simple free jet apparatus. A sensitivity for anthracene of 600 ppb is estimated. A time-of-flight (TOF) mass spectrometer has been developed, incorporating both linear and reflecting-geometry (reflectron) flight tubes, to allow laser desorption MPI (LD-MPI) mass spectra to be recorded for a number of involatile and thermally unstable compounds. Mass resolutions of 300 (linear) and 850 (reflectron) have been obtained for aniline. The constraints affecting the mass resolving power of both spectrometer designs are discussed. Finally, the potential of LD-MPI mass spectrometry as a ...
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Hereditary transthyretin amyloidosis (ATTRv amyloidosis) is caused by a variant transthyretin (TTR), which is a serum protein secreted by the liver. Mass spectrometry (MS) is a useful tool that can detect variant TTRs in serum samples from patients with ATTRv amyloidosis. We previously reported several mass spectrometric methods to detect variant TTRs in serum samples. Those methods require cumbersome immunoprecipitation with anti-TTR antibodies and significant time to analyze the variant TTRs. In our study here, we developed a new simple and quick method to detect variant TTRs in serum samples by means of matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) MS without immunoprecipitation (direct MALDI). By using direct MALDI, we analyzed 288 serum samples obtained from patients who were clinically suspected having amyloidosis to investigate the usefulness of this direct MALDI method to detect variant TTRs in serum samples. The method completed the process within 30 min. We
SELDI-TOF-MS offers a unique platform for high throughput urine protein profiling; however, standardization of analysis conditions is critical, and both extrinsic and intrinsic factors must be taken into account for accurate data interpretation.
TY - JOUR. T1 - Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight (MALDI-QIT-TOF)-based imaging mass spectrometry reveals a layered distribution of phospholipid molecular species in the mouse retina. AU - Hayasaka, Takahiro. AU - Goto-Inoue, Naoko. AU - Sugiura, Yuki. AU - Zaima, Nobuhiro. AU - Nakanishi, Hiroki. AU - Ohishi, Kentaro. AU - Nakanishi, Setsuko. AU - Naito, Takayuki. AU - Taguchi, Ryo. AU - Setou, Mitsutoshi. PY - 2008/11/15. Y1 - 2008/11/15. N2 - We recently developed a matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight (MALDI-QIT-TOF)-based imaging mass spectrometry (IMS) system. This system enables us to perform structural analyses using tandem mass spectrometry (MS/MS), as well as to visualize phospholipids and peptides in frozen sections. In the retina, phototransduction is regulated by the light-sensitive interaction between visual pigment-coupled receptor proteins, such as rhodopsin, and G proteins, such as transducin. ...
Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) has revolutionized the identification of microorganisms in the clinical microbiology laboratory, and numerous studies have documented the superior analytical performance characteristics of MALDI-TOF MS compared to those of manual and automated biochemical methods for microorganism identification (1-4). Compared to biochemical-based identification, MALDI-TOF MS-based identification significantly reduces the cost and time to microbial identification while simultaneously enhancing favorable patient outcomes and reducing the cost and length of hospitalization (5-8).. Despite the implementation of MALDI-TOF MS in clinical microbiology laboratories, studies specifically designed to assess the reproducibility of MALDI-TOF MS platforms for microorganism identification are limited. As part of a multicenter study, using the manufacturers default unmodified settings, we assessed the ability of a MALDI-TOF MS ...
TY - JOUR. T1 - SELDI-TOF MS profiling of plasma proteins in ovarian cancer. AU - Wu, Shao Pai. AU - Lin, Ya Wen. AU - Lai, Hung Cheng. AU - Chu, Tang Yuan. AU - Kuo, Yu Liang. AU - Liu, Hang Seng. PY - 2006/3. Y1 - 2006/3. N2 - Objective: Proteomic profiling of plasma or serum is a technique to identify new biomarkers in disease. The objective of this study was to identify new plasma biomarkers in ovarian cancer patients using mass spectrometry protein profiling and artificial intelligence. Methods: A total of 65 plasma samples obtained from women with ovarian cancer (n = 35) and age-matched disease-free controls (n = 30) were applied to anion exchange protein chips for protein profiling by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Results: SELDI-TOF MS was highly reproducible in detecting ovarian tumor-specific protein profiles. One protein peak (relative molecular mass, Mr, 11,537 Da) was identified in plasma from women with ovarian cancer ...
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Pantoea agglomerans is an ecologically diverse taxon that includes commercially important plant-beneficial strains and opportunistic clinical isolates. Standard biochemical identification methods in diagnostic laboratories were repeatedly shown to run into false-positive identifications of P. agglomerans, a fact which is also reflected by the high number of 16S rRNA gene sequences in public databases that are incorrectly assigned to this species. More reliable methods for rapid identification are required to ascertain the prevalence of this species in clinical samples and to evaluate the biosafety of beneficial isolates. Whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) methods and reference spectra (SuperSpectrum) were developed for accurate identification of P. agglomerans and related bacteria and used to detect differences in the protein profile within variants of the same strain, including a ribosomal point mutation conferring streptomycin ...
Derivatisation for the characterisation of neutral oxosteroids by electrospray and matrix-assisted laser desorption/ionisation tandem mass spectrometry: The Girard P derivative / W.J. Griffiths; S. Liu; G. Alvelius; J. Sjövall; William Griffiths ...
The analytical utility of gold nanoparticles (AuNPs) for laser desorption/ionization mass spectrometry (LDI-MS) is examined here. An evaluation of the parameters that affect desorption/ionization show that careful treatments of AuNPs is needed, as subtle changes in the solution environment can result in subsequent changes in the mass spectra. A thorough evaluation of the parameters that affect desorption/ionization of peptides is presented here, and these parameters include: (i) AuNP-to-analyte ratio, (ii) AuNP size, (iii) solvent, (iv) AuNP surface composition, (v) pH and buffer effects, (vi) amino acid sequence, and (vii) additives such as fructose or glycerol. Specifically, controlling the AuNP-to-analyte ratio, pH, peptide composition, and AuNP size are important parameters for ionization. Additionally, effects of passivating the AuNP surface with halides or oxyanions was investigated. The presence of NaF, NaCl, NaBr, and NH4X (X = F, Cl, Br, I) were shown to not significantly affect analyte ...
TY - JOUR. T1 - Determination of methylation specificity of sequence-specific DNA methyltransferases using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. AU - Tamura, Takashi. AU - Araki, Yoshinori. AU - Yamaoka, Seiji. AU - Inagaki, Kenji. AU - Tanaka, Hidehiko. PY - 1997/10/15. Y1 - 1997/10/15. N2 - We describe here a sensitive and straightforward method for characterizing the methylation specificity of type II DNA methyltransferase (MTase) using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. DNA substrate, prepared by ligation of a commercially available oligonucleotide, was modified by the subject MTase, and was derivatized to a mixture of single-stranded oligonucleotides through endonuclease treatment, heat-denaturation and limited digestion by 3-terminus-specific phosphodiesterase I. MALDI-TOF mass spectrometry was used to determine the mass differences between the digestion products, and the methylated nucleotide ...
Background: Invasion and metastasis are two important hallmarks of malignant tumors caused by complex genetic and epigenetic alterations. The present study investigated the contribution of aberrant methylation profiles of cancer related genes, APC, BIN1, BMP6, BRCA1, CST6, ESR-b, GSTP1, P14 (ARF), P16 (CDKN2A), P21 (CDKN1A), PTEN, and TIMP3, in the matched axillary lymph node metastasis in comparison to the primary tumor tissue and the adjacent normal tissue from the same breast cancer patients to identify the potential of candidate genes methylation as metastatic markers. Methods: The quantitative methylation analysis was performed using the SEQUENOMs EpiTYPER (TM) assay which relies on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results: The quantitative DNA methylation analysis of the candidate genes showed higher methylation proportion in the primary tumor tissue than that of the matched normal tissue and the differences were significant for ...
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The ultimate aim of this site is to be a resource for applications of laser desorption ionization mass spectrometry (LDI MS). The site is maintained by members of the Venkat Panchagnula group. Our current research interests are in the broad areas of in bioanalysis, metabolomics, pesticide residue & food contaminant analysis, and surface chemistry.
The ultimate aim of this site is to be a resource for applications of laser desorption ionization mass spectrometry (LDI MS). The site is maintained by members of the Venkat Panchagnula group. Our current research interests are in the broad areas of in bioanalysis, metabolomics, pesticide residue & food contaminant analysis, and surface chemistry.
An integrated liquid sample handling system for matrix-assisted laser-desorption/ionization time-of-flight mass spectroscopy (MALDI-TF MS) is described. The integrated system comprises a miniaturized sample handling compartment containing a MALDI ionization surface for separating, chemically manipulating and detecting analytes by MALDI -TOF MS. The miniaturized integrated sample handling system disclosed herein is applicable to a wide range of analytical problems that require separation and/or chemical manipulation of a sample prior to mass analysis as part of the analytical procedure.
A refined sample preparation procedure for matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) was developed for the evaluation of the degree of substitution (DS) in partially depolymerised carboxymethyl cellulose (CMC). By adding ammonium sulphate to the sample mixture prior to the analysis, good quality mass spectra could be acquired. The usual time-consuming search for sweet-spots at the crystalline rim of the MALDI target spot was also avoided. This quality improvement made it possible to investigate whether various positions on the target spot generated mass spectra in which the measured DS varied. The accuracy and reproducibility of the sample preparation procedure were tested by applying it on three commercial CMCs. The study shows that the DS values that were calculated from the spectra acquired from the centre region of the MALDI target spot were in better agreement with the DS provided by the supplier than were the values obtained from the large ...
Two things were surprising about some recent research we reported. First, with regard to chemically impaired groundwater quality, it may not always be the chemicals that are most worrisome for human health impacts. Second, the primary methodology we used in that work for microorganism identification, matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS), is a vastly underappreciated tool, especially outside the clinical realm in areas such as environmental monitoring.
Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) may soon replace routine electrophoretic methods for monitoring monoclonal proteins in patients with multiple myeloma. To further evaluate the clinical utility of this assay, we compared the performance of MALDI-TOF-MS head-to-head with an established bone marrow-based measurable residual disease assay by flow cytometry (Flow-BM-MRD), using Memorial Sloan Kettering Cancer Centers 10-color, single-tube method. Our results suggest that MALDI-TOF-MS adds value to bone marrow-based MRD testing and may be most useful for early detection of relapse in peripheral blood compared to current electrophoretic methods.
Alterations in protein phosphorylation, a posttranslational modification (PTM) that regulates many-processes in living cells, is a fundamental mechanism of many diseases, including cancer. Phosphoproteomics, with the combined use of affinity chromatography and electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, is shedding light into phosphorylation signaling pathways at the proteome level and helps to solve difficulties related to sample complexity and phosphopeptide enrichment. One of the most frequent and efficient methods used to enrich samples for the phosphorylated components is titanium dioxide chromatography. Titanium dioxide has a high affinity for phosphopeptides and can also be selective in specific experimental conditions. Here, we describe a protocol for the use of a MALDI plate covered with titanium dioxide nanostructured film, a device developed for a rapid and efficient study of phosphorylated peptides. © 2011 Springer ...
The disulfide bonding patterns in the N-terminal (LN) domains of the basement membrane protein laminin beta 1 have not been investigated so far. We report an in-depth mass spectrometric analysis using offline nano-high-performance liquid chromatography/matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (nano-HPLC/MALDI-TOF/TOF-MS) for determining the disulfide bond patterns in the LN-domain of recombinant mouse laminin beta 1 chain for the first time. Mass spectra were recorded and the putatively disulfide-linked peptides were subjected to LIFT-TOF/TOF-MS to confirm the disulfide bond. Screening the fragment ion mass spectra of disulfide-linked peptides for characteristic 66-amu patterns (34 u +32 u), arising from symmetric and asymmetric cleavage of disulfide bonds, facilitated their identification. Using various enzymes for proteolytic digestion of a recombinant laminin beta 1 chain N-terminal protein fragment, a linear bonding pattern of the eight ...
BACKGROUND: Oligosaccharidoses, which belong to the lysosomal storage diseases, are inherited metabolic disorders due to the absence or the loss of function of one of the enzymes involved in the catabolic pathway of glycoproteins and indirectly of glycosphingolipids. This enzymatic deficiency typically results in the abnormal accumulation of uncompletely degraded oligosaccharides in the urine. Since the clinical features of many of these disorders are not specific for a single enzyme deficiency, unambiguous screening is critical to limit the number of costly enzyme assays which otherwise must be performed. METHODS: Here we provide evidence for the advantages of using a MALDI-TOF/TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometric (MS) method for screening oligosaccharidoses. Urine samples from previously diagnosed patients or from unaffected subjects were randomly divided into a training set and a blind testing set. Samples were directly analyzed without prior treatment.
Polyacrylonitrile/Nafion®/carbon nanotube (PAN/Nafion®/CNT) composite nanofibers were prepared using electrospinning. These electrospun nanofibers were studied as possible substrates for surface-assisted laser desorption/ionization (SALDI) and matrix-enhanced surface-assisted laser desorption/ionization time
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=On-line%20atmospheric%20pressure%20matrix-assisted%20laser%20desorption/ionization%20mass%20spectrometry&rft.jtitle=Analyst&rft.date=2004&rft.volume=129&rft.issue=7&rft.spage=574&rft.epage=578&rft.au=Daniel,%20J%C3%BCrg%20M.&Ehala,%20Sille&Friess,%20Sebastian%20D.&Zenobi,%20Renato&rft.genre=article& ...
We report a graphene-doped resin target fabricated via a 3D printing technique for laser desorption/ionization mass spectrometry analysis. The graphene doped in the target acts as an inherent laser absorber and ionization promoter, thus permitting the direct analysis of samples without adding matrix. This work reve
TY - JOUR. T1 - Detection of trace ink compounds in erased handwritings using electrospray-assisted laser desorption ionization mass spectrometry. AU - Kao, Yi Ying. AU - Cheng, Sy Chyi. AU - Cheng, Chu Nian. AU - Shiea, Jentaie. AU - Ho, Hsiu O.. PY - 2014. Y1 - 2014. N2 - Writings made with erasable pens on paper surfaces can either be rubbed off with an eraser or rendered invisible by changing the temperature of the ink. However, trace ink compounds still remain in the paper fibers even after rubbing or rendering. The detection of these ink compounds from erased handwritings will be helpful in knowing the written history of the paper. In this study, electrospray-assisted laser desorption ionization/mass spectrometry was used to characterize trace ink compounds remaining in visible and invisible ink lines. The ink compounds were desorbed from the paper surface by irradiating the handwritings with a pulsed laser beam; the desorbed analytes were subsequently ionized in an electrospray plume and ...
In this paper, we report on the functionalization of silicon nanostructured (NanoSi) surface with an organic layer of nitrilotriacetic acid (NTA) and its subsequent use as an affinity surface-assisted laser desorption/ionization mass spectrometry (SA
TY - JOUR. T1 - The characterisation of coumarins from selected structural classes by electrospray ionisation quadrupole time-of-flight tandem mass spectrometry. AU - Smyth, Franklin. AU - Morgan, Jason L.. AU - OKane, Edmund. AU - Millar, Tommy J.. AU - Ramachandran, Venkataraman N.. PY - 2011/5. Y1 - 2011/5. N2 - Electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS) has been used for characterisation of a selection of naturally occurring and synthetic coumarins from different structural classes. The product ions, suggested in earlier studies by electrospray ionisation ion trap mass spectrometry (ESI-MSn), are unequivocally established for the representative coumarins by virtue of accurate mass measurement. Synthetic coumarins that are unsubstituted in the heterocyclic ring give rise to a major product ion by loss of CO2, whereas those substituted in the heterocyclic ring generally undergo alternative fragmentation releasing neutral species such as ketene ...
Complete article is available online.. PDF version is available online.. Trueperella abortisuis is a gram-positive bacterium that has been previously identified in aborted porcine feti and placentae located in Asia and Europe. Routine microbiological screening of extended boar semen from a US mid-Atlantic stud identified delayed growth of very small white colonies on both brain-heart infusion and sheep-blood agars after 48 to 72 hours incubation at 37°C under aerobic conditions. Isolate identification was performed using matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry, with T abortisuis identified (MALDI biotyper score = 2.103). After storage at 16°C and 72 hours post collection, total and progressive motility parameters had decreased in extended semen samples positive for T abortisuis. Further work is needed to elucidate the role T abortisuis may play in extended boar semen quality, extended semen longevity, and sow reproductive performance.. Keywords: ...
Phosphatidylethanolamines (PEs) are one of the major constituents of cellular membranes, and, along with other phospholipid classes, have an essential role in the physiology of cells. Profiling of phospholipids in biological samples is currently done using mass spectrometry (MS). In this work we describe the MS fragmentation of sodium adducts of 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphatidylethanolamine (POPE) and 2-linoleoyl-1-palmitoyl-sn-glycero-3-phosphatidylethanolamine (PLPE). This study was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) using three different instruments and also by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). All MS/MS spectra show product ions related to the polar head fragmentation and product ions related to the loss of acyl chains. In ESI-MS/MS spectra, the product ions [M+Na-R1COOH-43]+ and [M+Na-R2COOH-43]+ show different relative abundance, as well as [M+Na-R1COOH]+ and [M+Na-R2COOH]+ product ions, ...
BACKGROUND: Dioscorins are the major storage proteins of yam tubers. However, the molecular nature of their heterogeneity in tubers has not been fully elucidated. In this study the authors isolated the dioscorin gene families of Dioscorea japonica and Dioscorea pseudojaponica, performed matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) and elucidated which dioscorin isoforms are the major constituents in tubers.. RESULTS: The dioscorin gene families of D. japonica (Dj-dioA1-Dj-dioA4, Dj-dioB1 and Dj-dioB2) and D. pseudojaponica (Dp-dioA1-Dp-dioA5 and Dp-dioB1) were cloned from cDNA libraries of yam tubers. The dioscorins isolated from Dioscorea alata (Da-dioscorins), D. japonica (Dj-dioscorins) and D. pseudojaponica (Dp-dioscorins) were mainly monomers, with a few dimers. The monomers contained one intramolecular disulfide bond (Cys28-Cys187) and belonged to Class A dioscorins with two cysteine residues. The dimers consisted of Class B dioscorins with ...
|i|Objective|/i|: Human neutrophil peptides (HNPs) -1, -2 and -3 are significantly upregulated and were reported as biomarkers in gastric cancer (GC). However, the tissue location and function of HNPs 1-3 are still unclear in GC, and the spatial distribution of the triad needs to be disclosed. The aims of this study were to investigate the distribution and relationships among HNPs-1, -2 and -3, and assess whether infiltrated neutrophils accumulate in gastric tumor.|i|Methods|/i|: In this study, paired samples (|i|n|/i|=33) of the GC tissues and adjacent normal tissues from the same patients were obtained from surgery. Expression of HNPs 1-3 were detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The distributions of the HNPs 1-3 in GC tissues were investigated. After verification of HNPs-1 by immunohistochemistry, infiltrated neutrophils were also detected. Then, an in vitro assay was used to observe the binding capacity and measure the cytotoxic
TY - JOUR. T1 - Biochemical profile of leaf, silk and grain samples of eight maize landraces (Zea Mays L.) cultivated in two low-input agricultural systems. AU - UARROTA , VIRGILIO GAVICHO. AU - Severino, Ricardo Brasil. AU - Malinowsky, Carina. AU - de Oliveira, Simone Kobe. AU - Kuhnen, Shirley. AU - Yunes, Rosendo Augusto. AU - Maraschin, Marcelo. PY - 2014/12/1. Y1 - 2014/12/1. N2 - This research aimed to determine the biochemical profile of leaf, silk and grain samples of eight maize landraces (Zea maysL.) cultivated in southern Brazil. To accomplish this, reverse-phase high performance liquid chromatography-UV-visible (RP-HPLC-UV-vis), UV-vis spectrophotometry, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and chemometrics were used to examine carotenoids and their isomers, anthocyanin and phenolic acids. Leaf tissue samples showed higher amounts of carotenoids (838.6μg/g - Língua de Papagaio variety), anthocyanins (405.8μg/g - Palha Roxa ...
Zhan, Q., Gusev, A., & Hercules, D. M. (1999). A novel interface for on-line coupling of liquid capillary chromatography with matrix-assisted laser desorption/ionization detection. Rapid Communications in Mass Spectrometry, 13(22), 2278-2283 ...
Diversity and dynamic changes of Anelloviruses in plasma following Allogeneic Hematopoietic Stem Cell Transplantation. Gimenez Quiles E, Monzo Cataluña C, Albert Vicent E, Fuentes Trillo A, Seda García E, Pinana J, Hernandez Boluda J, Solano Vercet C, Chaves Martínez F, Navarro Ortega D. Journal of Medical Virology. 2020 Nov 11. doi: 10.1002/jmv.26661. PMID: 33174620. Early adjustment of empirical antibiotic therapy of bloodstream infections on the basis of direct identification of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and Gram staining results. Torres Fink I, Pinto Plá C, Oltra Sempere R, Pascual Martín T, Carbonell Monleon N, Colomina Rodríguez F, Tormo Diaz M, Albert Vicent E, Aguilar Aguilar G, Solano Vercet C, Navarro Ortega D. Journal of Infection and Chemotherapy. 2020 Sep;26(9):963-969. doi: 10.1016/j.jiac.2020.04.019. PMID: 32386929. Early kinetics of Torque Teno virus DNA load and BK polyomavirus viremia after kidney ...
The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphologically similar taxa. This study aimed to assess if strains of four closely-related plant pathogens, i.e., accurately Alternaria dauci (ten strains), Alternaria porri (six), Alternaria solani (ten), and Alternaria tomatophila (ten) could be identified using multilocus phylogenetic analysis and Matrix-Assisted Laser Desorption Ionisation Time of Flight (MALDI-TOF) profiling of proteins. Phylogenetic analyses were performed on three loci, i.e., the internal transcribed spacer (ITS) region of rRNA, and the glyceraldehyde-3-phosphate dehydrogenase (gpd) and Alternaria major antigen (Alt a 1) genes. Phylogenetic trees based on ITS sequences did not differentiate strains of A. solani, A. tomatophila, and ...
Unfixed tissue specimens most frequently are stored for long term research uses at either -80° C or in vapor phase liquid nitrogen (VPLN). There is little information concerning the effects such long term storage on tissue RNA or protein available for extraction. Aliquots of 49 specimens were stored for 5-12 years at -80° C or in VPLN. Twelve additional paired specimens were stored for 1 year under identical conditions. RNA was isolated from all tissues and assessed for RNA yield, total RNA integrity and mRNA integrity. Protein stability was analyzed by surface-enhanced or matrix-assisted laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS, MALDI-TOF-MS) and nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS). RNA yield and total RNA integrity showed significantly better results for -80° C storage compared to VPLN storage; the transcripts that were preferentially degraded during VPLN storage were these involved in antigen ...
TY - JOUR. T1 - MALDI-TOF MS analysis of the extracellular polysaccharides released by the diatom Thalassiosira pseudonana under various nutrient conditions. AU - Ai, Xin Xin. AU - Liang, Jun Rong. AU - Gao, Ya Hui. AU - Lo, Chun Lap Samuel. AU - Lee, Fred Wang Fat. AU - Chen, Chang Ping. AU - Luo, Chun Shan. AU - Du, Chao. PY - 2015/4/1. Y1 - 2015/4/1. N2 - Investigation of the production and structural characteristics of the extracellular polysaccharides (ECPS) released by diatoms according to nutrient status is urgently necessary for our understanding of the roles of ECPS in aquatic ecosystem. In this study, the effects of N and P depletion and variable nutrient sources on the production and structural characterization of the soluble ECPS released by the marine diatom Thalassiosira pseudonana in batch culture were examined. The abundance of the soluble ECPS produced under N (NO3 −) depletion was higher than that obtained in the P (PO4 3−) depletion and control treatments. NH4 + rather ...
TY - JOUR. T1 - Peptide profiling in epithelial tumor plasma by the emerging proteomic techniques. AU - Caputo, Emilia. AU - Lombardi, Maria Luisa. AU - Luongo, Vincenza. AU - Moharram, Ramy. AU - Tornatore, Pete. AU - Pirozzi, Giuseppe. AU - Guardiola, John. AU - Martin, Brian M.. PY - 2005/5/5. Y1 - 2005/5/5. N2 - The plasma peptide component (PPC) from ten melanoma (Mel), breast cancer (BC) and healthy individuals was examined by a combination of RP-HPLC, surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and tandem mass spectrometry. A three peak pattern (2023, 2039, 2053.5 m/z) was primarily observed in melanoma. Two peaks (2236.1 and of 2356.3 m/z) were found only in BC samples. Fibrinogen alpha and inter-α-trypsin inhibitor heavy chain H4 fragments were absent in both tumor samples.. AB - The plasma peptide component (PPC) from ten melanoma (Mel), breast cancer (BC) and healthy individuals was examined by a combination of RP-HPLC, surface ...
To explore the proteins regulated by cyclooxygenase-2 (COX-2) in gastric cancer, the expression plasmid of COX-2siRNA was constructed and transfected into gastric cancer cell line SGC7901. Then, two-dimensional electrophoresis and the PDQuest software analysis were applied to discover the differentially expressed proteins. The differential protein spots were analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Fourteen differentially expressed proteins between the two cell lines were identified. 15-Hydroxyprostaglandin dehydrogenase [NAD+] (15-PGDH), a key enzyme in prostaglandin degradation, was identified as an upregulated protein in SGC7901 cells transfected with the COX-2siRNA plasmid. To further explore whether the 15-PGDH is regulated by COX-2, western blotting and immunocytochemical assay were performed to detect the expression of 15-PGDH in different cell lines with different expression level of COX-2. The results showed that the expression of 15-PGDH ...
TY - JOUR. T1 - Declining plasma fibrinogen alpha fragment identifies HER2-positive breast cancer patients and reverts to normal levels after surgery. AU - Shi, Qian. AU - Harris, Lyndsay N.. AU - Lu, Xin. AU - Li, Xiaochun. AU - Hwang, Justin. AU - Gentleman, Robert. AU - Iglehart, J. Dirk. AU - Miron, Alexander. N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.. PY - 2006/11. Y1 - 2006/11. N2 - Breast cancer is the most common nonskin malignancy affecting women. Currently, no simple, blood-based diagnostic test exists to complement radiological screening and increase sensitivity of detection. To screen plasma specimens and identify biomarkers that detect HER2-positive breast cancer, automated robotic sample processing followed by surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF) mass spectroscopy was used. Multiple statistical algorithms were used to select biomarkers that segregate cancer patients versus controls and produced average CV rates ranging ...
Lymph node status is not part of the staging system for cervical cancer, but provides important information for prognosis and treatment. We investigated whether lymph node status can be predicted with proteomic profiling. Serum samples of 60 cervical cancer patients (FIGO I/II) were obtained before primary treatment. Samples were run through a HPLC depletion column, eliminating the 14 most abundant proteins ubiquitously present in serum. Unbound fractions were concentrated with spin filters. Fractions were spotted onto CM10 and IMAC30 surfaces and analyzed with surface-enhanced laser desorption time of flight (SELDI-TOF) mass spectrometry (MS). Unsupervised peak detection and peak clustering was performed using MASDA software. Leave-one-out (LOO) validation for weighted Least Squares Support Vector Machines (LSSVM) was used for prediction of lymph node involvement. Other outcomes were histological type, lymphvascular space involvement (LVSI) and recurrent disease. LSSVM models were able to determine LN
Barley thioredoxin h isoforms HvTrxh1 and HvTrxh2 differ in temporal and spatial distribution and in kinetic properties. Target proteins of HvTrxh1 and HvTrxh2 were identified in mature seeds and in seeds after 72 h of germination. Improvement of the established method for identification of thioredoxin-targeted proteins based on two-dimensional electrophoresis and fluorescence labelling of thiol groups was achieved by application of a highly sensitive Cy5 maleimide dye and large-format two-dimensional gels, resulting in a 10-fold increase in the observed number of labelled protein spots. The technique also provided information about accessible thiol groups in the proteins identified in the barley seed proteome. In total, 16 different putative target proteins were identified from 26 spots using tryptic in-gel digestion, matrix-assisted laser-desorption ionization-time-of-flight MS and database search. HvTrxh1 and HvTrxh2 were shown to have similar target specificity. Barley α-amylase/subtilisin ...
In this study, a comprehensive review of the literature was carried out to identify all Treponema species isolated from human samples. We determined that, to date, 284 strains from 13 different Treponema species, including T. pectinovorum, T. socranskii, T. denticola, T. vincentii, T. maltophilum, T. medium, T. amylovorum, T. lecithinolyticum, T. parvum, T. putidum, T. phagedenis, T. minutum, and T. refringens, have been isolated from human oral and skin samples. Metagenomic studies have demonstrated the presence of uncultivated Treponema species in the human oral cavity and gut (9, 14-17). In our laboratory, we have paid particular attention to the culture of this bacterial genus, to develop and to implement a new method for the detection, isolation, and identification of Treponema strains. We have combined three different techniques, namely, the use of a new electron microscope (Hitachi TM4000) to detect the presence of Treponema in clinical specimens, a new culture technique based on passive ...
The aim of the present study was to identify potential serum biomarkers for insulin resistance (IR) in patients with polycystic ovary syndrome (PCOS) by comparing the differences in serum protein expression levels between PCOS patients with and without IR. PCOS patients aged from 18 to 35 years were recruited at Guangdong Women and Childrens Hospital from January, 2013 to February, 2014. A total of 218 PCOS patients were enrolled and divided into the insulin resistance (PCOS‑IR) and non‑insulin resistance (PCOS‑NIR) groups according to their homeostasis model assessment of insulin resistance. Two‑dimensional difference gel electrophoresis (2D‑DIGE) and matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry (MALDI‑TOF‑MS/MS) techniques were used to identify differences in protein expression levels between the PCOS‑IR and PCOS‑NIR groups. The present study demonstrated that the total cholesterol (TCH), triglycerides (TG), low‑density lipoprotein ...
Viridans streptococci (VS) are responsible for several systemic diseases, such as endocarditis, abscesses, and septicemia. Unfortunately, species identification by conventional methods seems to be more difficult than species identification of other groups of bacteria. The aim of the present study was to evaluate the use of cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the rapid identification of 10 different species of VS. A total of 99 VS clinical isolates, 10 reference strains, and 20 strains from our in-house culture collection were analyzed by MALDI-TOF-MS. To evaluate the mass-spectrometric discrimination results, all strains were identified in parallel by phenotypic and genotypic methods. MALDI-TOF-MS identified 71 isolates as the mitis group, 23 as the anginosus group, and 5 as Streptococcus salivarius. Comparison of the species identification results obtained by the MALDI-TOF-MS analyses and with the phenotypic/genotypic ...
A pancreatic adenocarcinoma cell line (Paca44) was treated with trichostatin-A (TSA), a potent inhibitor of histone deacetylases, in order to evaluate the effect of this drug on protein expression. Master maps of control and treated Paca44 cells were generated by analysis with the PDQuest software. The comparison between such maps showed up- and downregulation of 51 polypeptide chains, out of a total of 700 spots detected by a medium-sensitivity stain, micellar Coomassie Brilliant Blue. Fingerprinting by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)-mass spectrometry analysis enabled the identification of 22 of these spots. Among these proteins, of particular interest are the two downregulated proteins nucleophosmin and translationally controlled tumor protein, as well as the upregulated proteins programmed cell death protein 5 (also designated as TFAR19) and stathmin (oncoprotein 18). The modulation of these four proteins is consistent with our observation that TSA is ...
CHCA MALDI Matrix 25 mg $22.00 - α-Cyano-4-hydroxycinnamic acid (CHCA) is a commonly used MALDI-MS reagent. CHCA is a good first choice for MALDI- MS with proteins and peptides less than 10 kDa. -
Peptides derived from frog skin secretion have great potential as drug leads as they exhibit many bioactive functions. In this study, the precursor peptide of Lividin-AW was identified from the skin secretion of the Chinese torrent frog (Amolops wuyiensis) by using shotgun cloning and its encoded mature peptide, sequenced as AVPLIYNRPGVYVTKRPK-NH2, was synthesised by Fmoc-solid phase peptide synthesis. The structure of the synthetic peptide was confirmed by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry and purified by reversed-phase high performance liquid chromatography (RP-HPLC). To determine the bioactive function of Lividin-AW, a series of bioactivity assays, including antimicrobial assays, cell viability assays, a trypsin inhibition assay and a haemolysis assay, were conducted and the results showed that Lividin-AW exhibited weak antimicrobial activity against Candida albicans (MIC=128µM), Staphylococcus aureus (MIC=512 µM) and Escherichia coli ...
Title: Serum Amyloid Beta Peptides in Patients with Dementia and Age-Matched Non-Demented Controls as Detected by Surface-Enhanced Laser Desorption Ionisation-Time of Flight Mass Spectrometry (SELDI-TOF MS). VOLUME: 3 ISSUE: 3. Author(s):Suzanne V. Frankfort, Jos P.C.M. van Campen, Linda R. Tulner and Jos H. Beijnen. Affiliation:Department of Pharmacy&Pharmacology, Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands.. Keywords:Serum Amyloid Beta Peptides, dementia, SELDI-TOF MS, Alzheimers Disease, CSF profile, diagnosis, DNA Isolation, Genotype Analysis. Abstract: Background: By using surface enhanced laser desorption/ionisation- time of flight mass spectrometry (SELDITOF MS) an amyloid ß (Aß) profile was shown in cerebrospinal fluid (CSF) of patients with dementia. Objective: To investigate the Aβ-profile in serum with SELDI-TOF MS, to evaluate if this profile resembles CSF profiles and to investigate the correlation between intensity of Aβ-peptide-peaks in serum and ...
Thymoquinone is one of the main components present in Nigella sativa seeds and is known to have various biological functions in inflammation, oxidative stress, tumors, aging, and in lowering blood glucose levels. Few studies have focused on its neuroprotective effects and its regulation of small-molecule metabolites during cerebral ischemia reperfusion injury. In this study, transient middle cerebral occlusion (tMCAO) was used to establish the rat model of cerebral ischemia reperfusion injury. We investigated the effects of thymoquinone using matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) in a model of ischemia reperfusion injury to explore the changes in small-molecule metabolites in the brain. We found that that thymoquinone significantly improved neurobehavioral scores, reduced the cerebral infarct area, alleviated brain edema, and increased the number of normal neurons following injury. MALDI-MSI revealed that thymoquinone reduced abnormal accumulations of glucose,
Human Cayman ataxia and mouse or rat dystonia are linked to mutations in the genes ATCAY (Atcay) that encode BNIP-H or Caytaxin, a brain-specific member of the BNIP-2 family. To explore its possible role(s) in neuronal function, we used protein precipitation and matrix-assisted laser desorption/ionisation mass spectrometry and identified kidney-type glutaminase (KGA) as a novel partner of BNIP-H. KGA converts glutamine to glutamate, which could serve as an important source of neurotransmitter. Co-immunoprecipitation with specific BNIP-H antibody confirmed that endogenous BNIP-H and KGA form a physiological complex in the brain, whereas binding studies showed that they interact with each other directly ...
Cation Exchange ProteinChip Arrays from Ciphergen,Ciphergens ProteinChip arrays have been developed for affinity capture of proteins from biological samples. A variety of ProteinChip chemical surfaces allow differential capture of proteins according to their unique biochemical properties. Each chip has eight different spots, allowing side-by-side,biological,biology supply,biology supplies,biology product
Cation Exchange ProteinChip Arrays from Ciphergen,Ciphergens ProteinChip arrays have been developed for affinity capture of proteins from biological samples. A variety of ProteinChip chemical surfaces allow differential capture of proteins according to their unique biochemical properties. Each chip has eight different spots, allowing side-by-side,biological,biology supply,biology supplies,biology product
An on-plate specific enrichment method is presented for the direct analysis of peptides phosphorylation. An array of sintered TiO2 nanoparticle spots was prepared on a stainless steel plate to provide porous substrate with a very large specific surface and durable functions. These spots were used to selectively capture phosphorylated peptides from peptide mixtures, and the immobilized phosphopeptides could then be analyzed directly by MALDI MS after washing away the nonphos- phorylated peptides. Qiao, L.; Roussel, C.; Wan, J.; Yang, P.; Girault, H. H.; Liu, B.
Background: Airway inflammation in cystic fibrosis (CF) is exaggerated and characterized by neutrophil-mediated tissue destruction, but its genesis and mechanisms remain poorly understood. To further define the pulmonary inflammatory response, we conducted a proteome-based screen of bronchoalveolar lavage fluid (BALF) collected from young children with and without CF experiencing endobronchial infection.. Methods: We collected BALF samples from 45 children younger than 5 years and grouped them according to the presence of respiratory pathogens: 1 x 105 colony-forming units (CFU)/mL BALF (18 and 12 samples with and without CF, respectively) and ,1 x 105 CFU/mL (23 and 15 samples). BALF proteins were analyzed with SELDI-TOF mass spectrometry (MS) and H4 ProteinChips®. Proteins were identified and characterized using trypsin digestion, tandem MS, Fourier transform ion cyclotron resonance MS, immunoblotting, and ELISA.. Results: The SELDI-TOF MS BALF profiles contained 53 unique, reliably detected ...
Electrospray ionization time of flight mass spectrometry (ESI-ToF-MS) is a powerful characterization technique for large nonvolatile compounds, but has found limited applicability in the synthetic polymer field. Two factors currently limit the utility of ESI-ToF-MS for synthetic polymer characterization: 1) Electrospray ionization often results in multiply charged species for each component in the sample. Synthetic polymers contain a distribution of many compounds with close, uniformly spaced masses. The presence of multiple m/z peaks for each mass typically results in data that is complicated and becomes increasingly complicated as the average molar mass of the sample increases. 2) Electrospray ionization is best suited for polar, easily ionized species dissolved in polar solvents. The vast majority of synthetic polymers are relatively non-polar, do not ionize easily and are not soluble in the polar solvents most often used for ESI. By adding easily ionizable, surface active quaternary ammonium ...
A low-mass-ion discriminant equation (LOME) was constructed to investigate whether systematic low-mass-ion (LMI) profiling could be applied to ovarian cancer (OVC) screening. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry was performed to obtain mass spectral data on metabolites detected as LMIs up to a mass-to-charge ratio (m/z) of 2500 for 1184 serum samples collected from healthy individuals and patients with OVC, other types of cancer, or several types of benign tumor. Principal component analysis-based discriminant analysis and two search algorithms were employed to identify discriminative low-mass ions for distinguishing OVC from non-OVC cases. OVC LOME with 13 discriminative LMIs produced excellent classification results in a validation set (sensitivity, 93.10 %; specificity, 100.0 %). Among 13 LMIs showing differential mass intensities in OVC, 3 metabolic compounds were identified and semi-quantitated. The relative amount of LPC 16:0 was somewhat
A low-mass-ion discriminant equation (LOME) was constructed to investigate whether systematic low-mass-ion (LMI) profiling could be applied to ovarian cancer (OVC) screening. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry was performed to obtain mass spectral data on metabolites detected as LMIs up to a mass-to-charge ratio (m/z) of 2500 for 1184 serum samples collected from healthy individuals and patients with OVC, other types of cancer, or several types of benign tumor. Principal component analysis-based discriminant analysis and two search algorithms were employed to identify discriminative low-mass ions for distinguishing OVC from non-OVC cases. OVC LOME with 13 discriminative LMIs produced excellent classification results in a validation set (sensitivity, 93.10 %; specificity, 100.0 %). Among 13 LMIs showing differential mass intensities in OVC, 3 metabolic compounds were identified and semi-quantitated. The relative amount of LPC 16:0 was somewhat
Whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a rapid method for identification of microorganisms that is increasingly used in microbiology laboratories. This identification is based on the comparison of the tested isolate mass spectrum with reference databases. Using Neisseria meningitidis as a model organism, we showed that in one of the available databases, the Andromas database, 10 of the 13 species-specific biomarkers correspond to ribosomal proteins. Remarkably, one biomarker, ribosomal protein L32, was subject to inter-strain variability. The analysis of the ribosomal protein patterns of 100 isolates for which whole genome sequences were available, confirmed the presence of inter-strain variability in the molecular weight of 29 ribosomal proteins, thus establishing a correlation between the sequence type (ST) and/or clonal complex (CC) of each strain and its ribosomal protein pattern. Since the molecular weight of three of the variable
Esophageal carcinoma is a common malignancy worldwide, with a low 5‑year survival rate. As the majority of cases are diagnosed at an advanced stage, there is an urgent need for an effective biomarker for early diagnosis of esophageal cancer patients. Surface‑enhanced laser desorption ionization time‑of‑flight mass spectrometry (SELDI‑TOF‑MS) was applied to detect the serum protein expression in esophageal cancer patients using ProteinChip software, and the results were analyzed and screened using Biomarker Patterns and SPSS16.0 software. The ELISA method was conducted to determine the concentration of anaphylatoxin C3a, which is one of the complement proteins, in the serum of esophageal cancer patients and non‑esophageal cancer participants. A total of 144 effective differential expression protein peaks in the window of 1‑10 kDa were obtained ( ...
Matrix assisted laser desorption ionisation ion mobility separation mass spectrometry imaging (MALDI-IMS-MSI) has been employed to image the distribution of proteins in ex-vivo human skin. Using a bottom-up proteomics approach employing on-tissue digestion the distribution of abundant skin proteins; collagen, keratin, decorin and serum albumin could be mapped. Images have been recorded at 150 and 30 μm spatial resolution. Multivariate statistical analysis of the data has been employed to associate specific proteins with layers of the skin. The improved specificity given by the use of ion mobility separation in mass spectrometric imaging has been demonstrated by separation of peptide ions from phospholipids.. ...
Efficient identification methods for laboratory testing, active surveillance and screening of patients are therefore in high need to avoid spreading of CRKP. The MBT Subtyping Module looks automatically for a blaKPC related peak in the sample spectrum after successful identification of the Enterobacteriaceae listed below. If present, the MALDI Biotyper will report this sample as a presumptive blaKPC positive. ...
Detail záznamu - Tandem mass spectrometry identification and LC-MS quantification of intact cytokinin nucleotides in K-562 human leukemia cells - Detail záznamu - Knihovna Akademie věd České republiky
The discovery of single-nucleotide polymorphisms (SNPs) has important implications in a variety of genetic studies on human diseases and biological functions. One valuable approach proposed for SNP discovery is based on base-specific cleavage and mass spectrometry. However, it is still very challenging to achieve the full potential of this SNP discovery approach. In this study, we formulate two new combinatorial optimization problems. While both problems are aimed at reconstructing the sample sequence that would attain the minimum number of SNPs, they search over different candidate sequence spaces. The first problem, denoted as , limits its search to sequences whose in silico predicted mass spectra have all their signals contained in the measured mass spectra. In contrast, the second problem, denoted as
Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract. The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions, if any, did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin. The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight (MALDI ToF) mass spectrometry. Reactions between the two materials did appear to occur, with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the disappearance of ionic bonds. The linkages between the two materials appeared to be by amination of the phenolic -OHs of the tannin by the amino groups of the non-skeletal side chains of arginine, and by esterification by the -COOH groups of glutamic and aspartic acid of the aliphatic alcohol-OH on the C3 site of
The last two decades have seen a number of significant advances in the methodology for evaluating the molecular weight distributions of polydispersed macromolecular systems in solution at the molecular level. This reference presents reviews on the progress in different analytical and characterization methods of biopolymers. Readers will find useful information about combinations of complex biopolymer analysis such as chromatographic or membrane based fractionation procedures combined with multiple detectors on line (multi-angle laser light scattering or MALLS). Key topics include: • refractive index, UV-Vis absorbance and intrinsic viscosity detection systems, • advances in SEC-MALLS (size exclusion chromatography coupled to multi-angle laser light scattering) and FFF-MALLS (field flow fractionation coupled on line to MALLS), • HPSEC-A4F-MALLS, matrix-assisted laser-desorption ionization (MALDI) • electrospray ionization (ESI) mass spectrometry • nuclear magnetic resonance (NMR) ...
OUTLINE: Patients are stratified according to disease (cervical cancer vs ovarian epithelial, fallopian tube, and primary peritoneal cancer). (Open to accrual for cervical cancer patients only as of 4/5/2005). Patients receive oral gefitinib daily. Treatment continues every 28 days in the absence of disease progression or unacceptable toxicity.. Biopsies of a sentinel lesion (with CT guidance or laparoscopy) are obtained at baseline and at 4 weeks. Skin biopsies of unaffected areas are also obtained at these time points. Tissue is examined using immunohistochemical methods. Proteomic profiling using surface-enhanced laser desorption/ionization with time-of-flight (SELDI-TOF) mass spectrometry is conducted on serum at baseline and then every 4 weeks.. Patients are followed monthly.. PROJECTED ACCRUAL: A total of 30-40 patients (15-20 per stratum) will be accrued for this study within 10-12 months. (Open to accrual for cervical cancer patients only as of 4/5/2005) ...
Alzheimers disease (AD) is the most common form of dementia found in all human populations worldwide, while vascular dementia (VaD) is the second most common form of dementia. New biomarkers for early and specific diagnosis of AD and VaD are needed to achieve greater insight into changes occurring in the brain and direct therapeutic strategies. The objective of this explorative study was to discover candidate protein biomarkers for the differential diagnosis between VaD and AD. Surface-enhanced laser desorption/ionization (SELDI) TOF-MS was used to differentially profile proteins and peptides in CSF samples from 28 AD patients and 21 patients with VaD. A combination of univariate (Kruskal-Wallis) and multivariate (independent component analysis) statistical approaches produced a list of 27 proteins and peptides that could differentiate between VaD and AD. These markers represent various physiological processes, such as protein degradation (ubiquitin), protease inhibition (cystatin C and alpha-1