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).
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
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 ...
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:. ...
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
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 ...
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 ...
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
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. ...
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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 ...
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 ...
OBJECTIVE: A recent study using surface-enhanced laser desorption/ionization time-of-flight analysis of cerebrospinal fluid identified a 12.5kDa truncated isoform of cystatin C (CysC) as a specific biomarker for multiple sclerosis (MS). METHODS: Surface-enhanced laser desorption/ionization time-of-flight analysis of cerebrospinal fluid samples from 43 MS patients and 46 healthy control subjects. RESULTS: Full-length CysC (13.4kDa) concentration was similar in MS and control samples. The 12.5kDa CysC protein was produced from full-length CysC by N-terminal cleavage during storage at -20 degrees C. INTERPRETATION: The 12.5kDa CysC isoform is a storage-related artifact and is not useful as a diagnostic marker for MS. Ann Neurol 2007;62:193-196. ...
TY - GEN. T1 - APPLICATIONS OF LASER DESORPTION MASS SPECTROMETRY.. AU - Cotter, Robert J.. AU - Tabet, Jean Claude. AU - van Breemen, Richard. PY - 1984. Y1 - 1984. N2 - The laser desorption technique can be used for the mass spectral analysis of nonvolatile/thermally labile compounds such as peptides, oligosaccharides, glycolipids, etc. In our laboratory a laser desorption time-of-flight mass spectrometer has been used for structural confirmation of several glucuronic acid conjugates, synthesized by an immobilized-enzyme mediated technique. Laser desorption spectra of several small peptides produce both C-terminal and N-terminal fragments. The molecular ions are formed by cationization (alkali ion attachment) and the alakali ion is generally found on the C-terminal fragments, suggesting a ionization/fragmentation scheme similar to that observed by chemical ionization.. AB - The laser desorption technique can be used for the mass spectral analysis of nonvolatile/thermally labile compounds such ...
Bruker introduced the IVD-CE certified MALDI Biotyper solution in 2009 for clinical microbiology and since then it has quickly become established as the method of choice for routine clinical microbiology laboratories. The MALDI Biotyper is a microbial identification system based on MALDI-TOF mass spectrometry allowing unbiased identification of microorganisms within a few minutes down to the species level. The MALDI Biotyper is an easy, rapid, robust, high-throughput, cost-effective and efficient identification technology. Continued expansion of the IVD reference library ensures the inclusion of common clinical microorganisms as well as rare organisms. ...
The ability to accurately identify nematodes at the species level requires specific skills in nematode taxonomy. The most common approach used is microscopy, which takes time and requires specific training: molecular approaches to plant nematode identification can also be used. Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) is being used as a new approach to identify microorganisms. Identification is based on the characteristic protein profile of the organism generated by MALDI-TOF MS. In MALDI-TOF MS, pulses from a UV laser are absorbed by a crystalline matrix to which macromolecules have been adsorbed, and this results in relatively gentle desorption and ionization of the macromolecules, which are then accelerated using a high voltage and travel along the flight tube. The time taken to reach the detector is directly related to the mass/charge ratio of the molecule. MALDI-TOF is a promising approach for rapid identification of organisms because of ...
Continuous spray deposition (CSD) of aqueous solutions of partially depolymerised methyl cellulose was found to improve matrix-assisted laser desorption/ionisation (MALDI) sample preparation. One feature was that the sensitivity in MALDI time-of-flight mass spectrometry increased up to an order of magnitude compared with the standard sample preparation method. Another feature was that CSD provided targets for MALDI with homogeneously distributed analyte. This resulted in a more even signal intensity and a higher reproducibility than in the standard method. High-mass discrimination was more pronounced in CSD than in the standard method. Size-exclusion chromatography with aqueous eluent was coupled online to CSD onto matrix-precoated foils. The suitability for determination of the molar mass distribution of methyl cellulose was investigated.. ...
MALDI sample holders and methods of using and making the same are provided. The MALDI sample holders are configured for use in matrix assisted laser desorption/ionization and include a planar substrate having a surface and at least one fluid retaining structure present on the surface. The fluid retaining structure includes a material that changes from a first fluid state to a second solid state in response to a stimulus. Also provided are methods of using the subject MALDI sample holders in a matrix-assisted laser desorption/ionization protocol, as well as methods of producing the subject MALDI sample holders. Kits for use in practicing the subject methods are also provided.
Thermotolerant yeasts, which are expected to be applicable for high-temperature fermentation as an economical process, were isolated from four provinces in Laos. Of these yeasts, five isolates exhibited stronger fermentation abilities in a 16% sugars-containing medium of glucose, sucrose, sugarcane or molasses at 40°C than that of Kluyveromyces marxianus DMKU 3-1042, one of the most thermotolerant and efficient yeasts isolated previously in Thailand. One of the five strains, BUNL-17, exhibited the highest ethanol fermentation performance at 45°C. Yeast identification was achieved by whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) analysis as well as by nucleotide sequencing of the D1/D2 domain of the large subunit rRNA gene, revealing that the isolated strains can be categorized into Pichia kudriavzevii, Cyberlindnera rhodanensis and K. marxianus and that all of the five strains are K. marxianus. The results of this study showed that the ...
in Clinical Chemistry (2008), 54. BACKGROUND: SELDI-TOF mass spectrometry (MS) is a high-throughput proteomic approach with potential for identifying novel forms of serum biomarkers of arthritis. METHODS: We used SELDI-TOF MS to analyze ... [more ▼]. BACKGROUND: SELDI-TOF mass spectrometry (MS) is a high-throughput proteomic approach with potential for identifying novel forms of serum biomarkers of arthritis. METHODS: We used SELDI-TOF MS to analyze serum samples from patients with various forms of inflammatory arthritis. Several protein profiles were collected on different Bio-Rad Laboratories ProteinChip arrays (CM10 and IMAC-Cu(2+)) and were evaluated statistically to select potential biomarkers. RESULTS: SELDI-TOF MS analyses identified several calgranulin proteins [S100A8 (calgranulin A), S100A9 (calgranulin B), S100A9*, and S100A12 (calgranulin C)], serum amyloid A (SAA), SAA des-Arg (SAA-R), and SAA des-Arg/des-Ser (SAA-RS) as biomarkers and confirmed the results with other techniques, ...
Serum profiling using proteomic techniques has great potential to detect biomarkers that might improve diagnosis and predict outcome for breast cancer patients (BC). This study used surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) to identify differentially expressed proteins in sera from BC and healthy volunteers (HV), with the goal of developing a new prognostic biomarker panel. Training set serum samples from 99 BC and 51 HV subjects were applied to four adsorptive chip surfaces (anion-exchange, cation-exchange, hydrophobic, and metal affinity) and analyzed by time-of-flight MS. For validation, 100 independent BC serum samples and 70 HV samples were analyzed similarly. Cluster analysis of protein spectra was performed to identify protein patterns related to BC and HV groups. Univariate and multivariate statistical analyses were used to develop a protein panel to distinguish breast cancer sera from healthy sera, and its prognostic potential was evaluated.
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has established itself among the plethora of mass spectrometry applications. In the biomedical field, MALDI-MSI is being more frequently recognized as a new method for the discovery of biomarkers, targets of treatment, classification of diseased and healthy tissues or to predict the outcome of a pathology. The technology has been used to study the localization of proteolytic peptides directly on tissue sections. A direct correlation between the detected peptides and the distribution and identity of the original precursor protein is the ultimate goal of any MALDI-MSI experiment. Enzymatic digestion protocols are commonly used to reveal the protein signature of these complex tissues. Considerations that pertain to methods of sample preparation, on-tissue digestion, data analysis and visualization will be addressed. This review will also discuss selected applications of on-tissue digestion combined with the MALDI-MSI ...
The identification of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations. They are of a fairly low molecular weight (to allow easy vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the mass spectrometer. They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported.[16] They have a strong optical absorption in either the UV or IR range,[17] so that they rapidly and efficiently absorb the laser irradiation. This efficiency is commonly associated with chemical structures incorporating several conjugated double bonds, as seen in the structure of cinnamic acid. They are functionalized with polar groups, allowing their use in aqueous solutions. They typically contain a chromophore. The matrix solution is mixed with the analyte (e.g. protein-sample). A ...
Bacillus are aerobic spore-forming bacteria that are known to lead to specific diseases, such as anthrax and food poisoning. This study focuses on the characterization of these bacteria by the detection of lipids extracted from 33 well-characterized strains from the Bacillus and Brevibacillus genera, with the aim to discriminate between the different species. For the purpose of analysing the lipids extracted from these bacterial samples, two rapid physicochemical techniques were used: matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and liquid chromatography in conjunction with mass spectrometry (LC-MS). The findings of this investigation confirmed that MALDI-TOF-MS can be used to identify different bacterial lipids and in combination with appropriate chemometrics allows for the discrimination between these different bacterial species, which was supported by LC-MS. The average correct classification rate (CCR) for the 7 species of bacteria was 62.23% ...
Matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) MS protein analysis was carried out as previously described [34]. Briefly, a pipette tip was used to pick one isolated bacterial colony from a culture agar plate and spread it as a thin film on a MTP 384 MALDI-TOF target plate (Bruker Daltonics, Germany). Twelve distinct deposits from twelve isolated colonies were performed for strain JC301T. Each smear was overlaid with 2 µl of matrix solution (a saturated solution of alpha-cyano-4-hydroxycinnamic acid) in 50% acetonitrile, 2.5% trifluoracetic acid and allowed to dry for 5 minutes. Next, measurements were taken with a Microflex spectrometer (Bruker). The spectra were recorded using a positive linear mode for the mass range of 2,000 to 20,000 Da (parameter settings: ion source 1 (ISI), 20kV; IS2, 18.5 kV; lens, 7 kV). A spectrum was obtained after 675 shots with variable laser power. The time of acquisition was between 30 seconds and 1 minute per spot. The twelve JC301T ...
Considerable controversy exists in the literature as to the occurrence of intramolecular migration of amide hydrogens upon collisional activation of protonated peptides and proteins. This phenomenon has important implications for the application of CID as an experimental tool to obtain site-specific information about the incorporation of deuterium into peptides and proteins in solution. Using a unique set of peptides with their carboxyl-terminal half labeled with deuterium we have shown unambiguously that hydrogen (1H/2H) scrambling is such a dominating factor during low energy collisional activation of doubly protonated peptides that the original regioselective deuterium pattern of these peptides is completely erased (Jørgensen, T. J. D., Gårdsvoll, H., Ploug, M., and Roepstorff, P. (2005) Intramolecular migration of amide hydrogens in protonated peptides upon collisional activation. J. Am. Chem. Soc.127, 2785-2793). Taking further advantage of this unique test system we have now investigated ...
Author: Rapp, E. et al.; Genre: Journal Article; Published in Print: 2009-01-01; Title: Atmospheric pressure free liquid infrared MALDI mass spectrometry: toward a combined ESI/MALDI-liquid chromatography interface.
Titanium dioxide-modified target plates were developed to enhance intact bacteria analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The plates were designed to photocatalytically destroy the bacterial envelope structure and improve the ionization efficiency of intracel
Strains: 1, Paucisalibacillus algeriensis sp. nov. strain EB02T; 2, Paucisalibacillus globulusstrain B22T; 3, Ornithinibacillus californiensisstrain MB-9T; 4, Ornithinibacillus bavariensisstrain WSBC 24001T; 5, Ornithinibacillus scapharcaestrain TW25T; 6, Ornithinibacillus halophilusstrain G8BT; 7, Oceanobacillus caenistrain S-11T; 8, Oceanobacillus iheyensisstrain HTE831T ; 9, Virgibacillus halodenitrificansstrain SF 121T .. Matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) MS protein analysis was performed as previously described [12,44,45]. Briefly, strain EB02T was cultivated on 5% sheep blood-enriched Columbia agar (BioMerieux) and incubated for 24 h at 30°C. Isolated bacterial colonies were picked, and then deposited as a thin film in 12 replicates on a MALDI-TOF steel target plate (Bruker Daltonics, Bremen, Germany). The plates were allowed to dry at room temperature. Each deposit was overlaid with 1.5 µl of matrix solution containing α-cyano-hydroxycinnamic acid ...
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Liu, Y. , Mirza, U. , Tang, J. , Porter, F. , Nagabhushan, T. , and Pramanik, B. N. 2003. Proteomic study of recombinant adenovirus 5 encoding human p53 by matrix-assisted laser desorption/ionization mass spectrometry in combination with database search. Int. J. Mass Spectrom. 226: 55-69. 99. Mirza, U. , Liu, Y. , Tang, J. , Pramanik, B. , and Nagabhushan, T. L. 2000. Extraction and characterization of adenovirus proteins from sodium dodecylsulfide polyacrylamide gel electrophoresis by matrixassisted laser desorption/ionization mass spectrometry. 5 μL/min was ~25,000 from ~16 nA of electrospray current transmitted into the interface. 1 μL/min, the peak intensity was ~24,000 from only 3 nA of electrospray current. Even though the electrospray current transmitted into the mass spectrometer dropped by 80% when the flow rate was lowered to 100 nL/min, the amount of gas-phase calibrant ions in the mass spectrometer remained the same as indicated by the detector response. This observation indicates ...
Murine zymosan-induced peritonitis is a widely used model for studying the molecular and cellular events responsible for the initiation, persistence and/or resolution of inflammation. Among these events, it is becoming increasingly evident that changes in glycosylation of proteins, especially in the plasma and at the site of inflammation, play an important role in the inflammatory response. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based glycosylation profiling, we investigated the qualitative and quantitative effect of zymosan-induced peritonitis on N-glycosylation in mouse plasma and peritoneal fluid. Our results show that both N-glycomes exhibit highly similar glycosylation patterns, consisting mainly of diantennary and triantennary complex type N-glycans with high levels (,95 %) of galactosylation and sialylation (mostly NeuGc) and a medium degree of core fucosylation (30 %). Moreover, MS/MS structural analysis, assisted by ...
Hirsutella rhossiliensis, a nematophagous fungus belonging to the Ascomycota, is resistant to aureobasidin A (AbA). In this fungus, the biosynthetic pathway leading to mannosylinositolphosphoceramides, which is inhibited by AbA, was not detected. Instead, this fungus contains neutral complex glycosphingolipids (GSLs) and monoglycosylceramides. Except for monoglycosylceramides, neutral GSLs share a neogala-series core structure, Galβ1-6Galβ1-Cer. Among the GSLs of H. rhossiliensis, three novel GSLs with terminal Man and Glc residues on the sugar chain were elucidated. We analyzed GSL structure using compositional sugar, fatty acid, and sphingoid analyses, methylation analysis, matrix-assisted laser desorption ionization time-of-flight/mass spectrometry (MALDI-TOF MS), and 1H nuclear magnetic resonance spectroscopy (NMR). The following structures were determined: Man1-3Galβ1-6Galβ1-6Galβ1-Cer; Glc1-2Galβ1-6Galβ1-6Galβ1-Cer; and Man1-3Galβ1-6(Glc1-4)Galβ1-6Galβ1-Cer. In the ceramides, ...
After SDS-PAGE under non-reducing conditions (with ~20 μg MBP-ZP-N-6his/lane), gel spots were excised and alkylated with 30 mM iodoacetamide in 100 mM Tris-HCl pH 6.8 for 30 min at room temperature. The liquid was removed and samples were prepared for digestion by washing twice with 100 ml 50 mM Tris-HCl pH 6.8/30% acetonitrile (ACN) for 20 min with shaking, then with 100% ACN for 1-2 min. After removing the washes, gel pieces were dried for 30 min in a Speed-Vac concentrator. Individual gel pieces were digested by adding 80 μg modified trypsin or chymotrypsin (sequencing grade, Roche Molecular Biochemicals) in 13-15 ml 25 mM Tris-HCl pH 6.8 and leaving overnight at room temperature. Peptides were extracted with 2 × 50 ml 50% ACN/2% trifluoroacetic acid (TFA) and the combined extracts were divided in half, then dried. One half of the digest was dissolved in matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) matrix for immediate mass spectrometric ...
Aim: This Swedish study determined which species of coagulase-negative staphylococci (CoNS) were found in neonatal blood cultures and whether they included Staphylococcus capitis clones with decreased susceptibility to vancomycin. Methods: CoNS isolates (n = 332) from neonatal blood cultures collected at orebro University Hospital during 1987-2014 were identified to species level with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). The antibiotic susceptibility pattern of S. capitis isolates was determined by the disc diffusion test and Etest, and the presence of heterogeneous glycopeptide-intermediate S. capitis (hGISC) was evaluated. Results: Staphylococcus epidermidis (67.4%), Staphylococcus haemolyticus (10.5%) and S. capitis (9.6%) were the most common CoNS species. Of the S. capitis isolates, 75% were methicillin-resistant and 44% were multidrug-resistant. No isolate showed decreased susceptibility to vancomycin, but at least 59% displayed the ...
In this work, fast isoelectric focusing (IEF) was successfully implemented on an open paper fluidic channel for simultaneous concentration and separation of proteins from complex matrix. With this simple device, IEF can be finished in 10 min with a resolution of 0.03 pH units and concentration factor of 10, as estimated by color model proteins by smartphone-based colorimetric detection. Fast detection of albumin from human serum and glycated hemoglobin (HBA1c) from blood cell was demonstrated. In addition, off-line identification of the model proteins from the IEF fractions with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was also shown ...
Joana Mourão is a PeerJ user. Bio: • Pharmacist with a microbiology PhD, focused on the surveillance, epidemiology and molecular characterization of Salmonella non-typhoid and other pathogens (Enterococcus, E. coli) resistant to antibiotics and tolerant to metals/biocides from different clinical (hospital, community) and non-clinical settings (food products, animal and environment). • Experience in the detection, identification and typing of foodborne pathogens in diverse matrices (food products/bacterial strains) by potential alternative (quick and low-cost) methodologies, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). • 8 years evidenced experience across a range of classic (microbial detection and identification by culture methodologies, antimicrobial susceptibility assays, DNA extraction) and molecular (PCR, sequencing, Southern-Blot, hybridization, PFGE, RFLP, MLST) laboratory methodologies,
Most states mandate that cannabis testing labs analyze samples for any fungal or microbial growth resulting from production or handling, as well as for mycotoxins, which are toxins produced by fungi. With the potential to become lethal, continuous exposure to mycotoxins can lead to a buildup of progressively worse allergic reactions.. LCMS should be used to qualify and identify strains of mycotoxins. However, determining the amount of microorganisms present is another challenge. That testing can be done using enzyme linked immunosorbent assay (ELISA), quantitative polymerase chain reaction (qPCR) or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with each having their advantages and disadvantages.. For mycotoxin analysis, select a high-sensitivity LC-MS/MS instrument. In addition to standard LC, using an MS/MS selective detector enables labs to obtain limits of detection up to 1000 times greater than conventional LC-UV instruments.. For qPCR and its ...
The MALDI Biotyper is a microbial identification system based on MALDI-TOF mass spectrometry allowing unbiased identification of microorganisms within a few minutes down to the species level. The MALDI Biotyper is an easy, rapid, robust, high-throughput, cost-effective and efficient identification technology. Continued expansion of the reference library ensures that a broad range of microorganisms can be identified easily. The reference library now includes round close to 3,000 species of 540 microorganism genera. Download brochure ...
ABSTRACT: Ethylene glycol (EG), a frequently used lithogenic agent, causes calcium oxalate (CaOx) crystal deposition in the renal cortex. In this study, we compared the protein expression pattern in kidneys of rat with EG-induced renal lithiasis with that of normal rats. Ten male Sprague-Dawley rats were divided into 2 groups. In the control group (n=5), rats were fed with normal drinking water; in the EG group (n=5), rats were fed with 0.75% EG in drinking water. After 4 weeks, rats fed with EG showed CaOx deposition in the renal cortex. The renal cortex proteins were extracted and separated by two-dimensional electrophoresis (2-DE). Comparative analyses of the respective spot patterns from the 2-DE output were performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Among the proteins identified, reduced albumin in rat renal lithiasis was confirmed by immunohistochemical analysis. Our results demonstrated that the amount of albumin was reduced in EG-treated ...
We describe here a system for the rapid identification, assay development, and characterization of gene-based single nucleotide polymorphisms (SNPs). This system couples informatics tools that mine candidate SNPs from public expressed sequence tag resources and automatically designs assay reagents with detection by a chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. As a proof of concept of this system, a genomewide collection of reagents for 9,115 gene-based SNP genetic markers was rapidly developed and validated. These data provide preliminary insights into patterns of polymorphism in a genomewide collection of gene-based polymorphisms.. ...
As part of a project on environmental disasters (5), this study aimed to evaluate ethnic differences in genes involved in susceptibility to environmental agents. We described NAT2 genotypes, predicted haplotypes, and deduced phenotypes in a Central Asian (Kyrgyz) and a European (Romanian) study population. During the last decade, a high degree of variability in NAT2 alleles has been found at 15 nucleotide positions and documented in the NAT database. The SNP500Cancer Project verified 9 nucleotide positions of these 15 and an additional SNP in the 3′ flanking region. A first decision has therefore to be made on the selection of sequence variants in studies of genetic susceptibility (10). We selected all NAT2 sequence variants which were verified as polymorphic by the SNP500Cancer Project for genotyping with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Two variants (364G,A and 411A,T) turned out to be monomorphic in the Kyrgyz and Romanian study groups. No assay ...
Glycophthalocyanines: structural differentiation and isomeric differentiation by matrix-assisted laser desorption/ionization tandem mass spectrometry (pages 1019-1026). Ana R. M. Soares, Maria G. P. M. S. Neves, Sérgio M. Santos, João P. C. Tomé, Augusto C. Tomé, José A. S. Cavaleiro, Tomás Torres and M. Rosário M. Domingues. Version of Record online: 15 APR 2013 , DOI: 10.1002/rcm.6533. ...
A system for measuring small oil droplets in an oil-in-water (O/W) emulsion was developed using multiphoton ionization time-of-flight mass spectrometry. In the present study, a capillary column with an inner diameter of 15 µm was used for sample introduction. Moreover, a compact microscopic system was constructed for observing an emulsion flowing through a capillary column. As a result, the length for sample introduction was shortened, which is preferable for the direct evaluation of an emulsion. Using this system, the minimum diameter of a detectable toluene droplet in an O/W emulsion was decreased to 1.7 µm. The present system could be used to evaluate the local microenvironment and stability of an emulsion.
Tick-borne rickettsioses include mild to life-threatening diseases in humans worldwide. When removing an attached tick from the human body, patients and physicians may have two questions: 1) is the tick a known vector of a human infectious disease, and 2) is the tick infected by a pathogenic agent that could have been transmitted during the attachment period? The morphological identification of Ticks is difficult, and requires expertise and specific documentation. The use of Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has recently emerged as an effective, rapid and inexpensive tool to identify arthropods including Ticks. Here, we show the utility of MALDI-TOF MS for the dual identification of tick species and the rapid detection of Rickettsia spp in Ticks. Such results can be used to guide decisions related to specific patient monitoring or the administration of preventive treatment. Additionally, the low consumable costs, the minimum time required ...
Authors: Agostini, M. , Bedin, C. , Enzo, M.V. , Molin, L. , Traldi, P. , DAngelo, E. , Maschietto, E. , Serraglia, R. , Ragazzi, E. , Prevedello, L. , Foletto, M. , Nitti, D. Article Type: Research Article Abstract: BACKGROUND: Obesity is currently epidemic in many countries worldwide and is strongly related to diabetes and cardiovascular disease. Mass spectrometry, in particular matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) is currently used for detecting different pattern of expressed protein. This study investigated the differences in low molecular weight (LMW) peptide profiles between obese and normal-weight subjects in combination with multivariate statistical analysis. MATERIALS: Serum samples of 60 obese patients and 10 healthy …subjects were treated by cut-off membrane (30000 Da) to remove the most abundant proteins. The filtrates containing the LMW protein/peptides were analyzed by MALDI-TOF mass spectrometry. Dataset was elaborated to align and normalize ...
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Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) commonly coexist in smokers, and the presence of COPD increases the risk of developing LC. Cigarette smoke causes oxidative stress and an inflammatory response in lung cells, which in turn may be involved in COPD and lung cancer development. The aim of this study was to identify differential proteomic profiles related to oxidative stress response that were potentially involved in these two pathological entities. Protein content was assessed in the bronchoalveolar lavage (BAL) of 60 patients classified in four groups: COPD, COPD and LC, LC, and control (neither COPD nor LC). Proteins were separated into spots by two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and examined by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/TOF). A total of 16 oxidative stress regulatory proteins were differentially expressed in BAL samples from LC and/or COPD patients as compared with the control group.
Background Matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI TOF-MS) allows the identification of most bacteria and an increasing number of fungi. The potential for the highest clinical benefit of such methods would be in severe acute infections that require prompt treatment adapted to the infecting species. Our objective was to determine whether yeasts could be identified directly from a positive blood culture, avoiding the 1-3 days subculture step currently required before any therapeutic adjustments can be made. Methodology/Principal Findings Using human blood spiked with Candida albicans to simulate blood cultures, we optimized protocols to obtain MALDI TOF-MS fingerprints where signals from blood proteins are reduced. Simulated cultures elaborated using a set of 12 strains belonging to 6 different species were then tested. Quantifiable spectral differences in the 5000-7400 Da mass range allowed to discriminate between these species and to build a reference
β-elemene, the active component of elemene (1-methyl-1-vinyl-2,4-diisopropenyl-cyclohexane), is a naturally occurring compound isolated from the traditional Chinese medicinal herb Curcuma wenyujin. Studies have confirmed that β-elemene enhances the radiosensitivity of lung cancer cell lines such as A549, by multiple pathways; however, their underlying mechanisms and pathways are yet to be elucidated. In the present study, two-dimensional differential in-gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry were used to profile the different proteins in A549 cell xenograft models of both treatment groups. The protein/mRNA expression was assessed by reverse transcription-polymerase chain reaction and western blotting techniques in tumor samples from all treatment groups. As a critical player in redox regulation of cancer cells, inhibition of peroxiredoxin-1 (Prx-1) may be an effective option for enhancing the tumor response to radiation. We ...
TY - CHAP. T1 - Mass spectrometry imaging using the stretched sample approach. AU - Zimmerman, Tyler A.. AU - Rubakhin, Stanislav S.. AU - Sweedler, Jonathan V.. PY - 2010/12/1. Y1 - 2010/12/1. N2 - Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) can determine tissue localization for a variety of analytes with high sensitivity, chemical specificity, and spatial resolution. MS image quality typically depends on the MALDI matrix application method used, particularly when the matrix solution or powder is applied directly to the tissue surface. Improper matrix application results in spatial redistribution of analytes and reduced MS signal quality. Here we present a stretched sample imaging protocol that removes the dependence of MS image quality on the matrix application process and improves analyte extraction and sample desalting. First, the tissue sample is placed on a monolayer of solid support beads that are embedded in a hydrophobic membrane. Stretching the ...
Introduction: Early identification of microbial organisms from respiratory secretions of patients with cystic fibrosis (CF) is important to guide therapeutic decisions. The objective was to compare the accuracy of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) relative to the conventional phenotypic method in identifying common bacterial isolates, including nonfermenting Gram-negative bacteria, in a cohort of patients with CF. Methods: A total of 123 isolates from 50 patients with CF representing 14 bacterial species from respiratory specimens were identified using MALDI-TOF MS in parallel with conventional phenotypic methods. Discrepancies were confirmed by 16S ribosomal RNA (rRNA) gene sequencing in five Gram-negative isolates. Results: The MALDI-TOF MS managed to identify 122/123 (99.2%) bacterial isolates to the genus level and 118/123 (95.9%) were identified to the species level. The MALDI-TOF MS results were 100% consistent to the species level ...
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Figure 3.5 (a) Released glycans from bovine fetuin derivatized as methyl esters with methyl iodide. (b) The same glycans derivatized with methanol in the presence of DMT-MM. a2 ^ 6-linked sialic acids form methyl esters, whereas a2 ^ 3-linked acids produce lactones. The mass difference between these species allows the linkage to be determined.. Sulfated glycans are also unstable under MALDI conditions and eliminate sulfate easily [228]. Their sodium salts, however, are more stable [97, 229] and can be differentiated from phosphorylated glycans (phosphate and sulfate have the same nominal mass) by the observation that whereas phosphorylated glycans ionize as free acids, sulfated glycans are invariably seen in the positive ion spectra only as sodium salts [229]. In order to stabilize sulfates, ion pairing with the tripeptide Lys-Lys-Lys has been used [230] with the added advantage that it enables isobaric phosphates and sulfates to be differentiated by their fragmentation spectra [231]. Whereas ...
Glycosylation is an important and universal post-translational modification for many proteins, and regulates protein functions. However, simple and rapid methods to analyze glycans on individual proteins have not been available until recently. A new technique to analyze glycopeptides in a highly sensitive manner by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using the liquid matrix 3AQ/CHCA was developed recently and we optimized this technique to analyze a small amount of transmembrane protein separated by SDS-PAGE.. We used the MALDI-MS method to evaluate glycosylation status of membrane-type 1 matrix metalloproteinase (MT1-MMP). Glycosylation of MT1-MMP is reported to modulate its protease activity and thereby to affect cancer cell invasion. After in-gel tryptic digestion of the protein, a single droplet of the digest was applied directly to the liquid matrix on a MALDI target plate. Concentration of hydrophilic glycopeptides within the central area occurred due ...
A: Traditional methods did not have the accuracy to identify such unusual pathogens that were referred to MISU. I began to explore new technologies, especially mass spectrometry (MS). MS instruments have been used for a century by physicists and chemists to study the nature of matter. Their application in biology, however, posed major obstacles and had to await the development of techniques that enabled very large molecules, such as proteins, to change their state to a "gas" so they could now travel in a charged field for analysis. There are numerous types of mass spectrometers. The one we first used was Matrix-Assisted Laser Desorption/Ionisation Time of Flight Mass Spectrometer (MALDI-TOF-MS) at a company in Manchester. In the method we used, a bacterial/matrix admixture placed at one end of a tube under vacuum, was bombarded using a soft laser to create a plume of ions or charged fragments. These travel at rates - milliseconds - that are inversely proportional to their mass/charge ratios to ...
Imaging Mass Mpectrometry combines the chemical specificity and parallel detection of Mass Spectrometry with microscopic imaging capabilities. Imaging Mass Spectrometry is a technology that combines advanced analytical techniques for the analysis of Biomedical Chromatography with spatial fidelity. Imaging Mass Spectrometry is a technology that combines advanced analytical techniques for the analysis of Biomedical Chromatography with spatial fidelity. An effective approach for imaging biological specimens in this way utilizes Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS). ...
Background. Customer satisfaction is important for clinical microbiology laboratories and the most important service aspect is the reliability of responses. One important indicator of the quality of care is turnaround time for a sample referred to a laboratory.. Aim. This study describes and evaluates an improvement of the blood culture process and evaluates the staffs experiences of the changes brought by the improvement project.. Methods. The blood culture process during evenings and nights was re-designed in a cooperation project between the laboratories of clinical microbiology and clinical chemistry in a mid-size Swedish county council. Typing with matrix-assisted laser desorption/ionization time of flight (MALDI ToF) and rapid antibiotic susceptibility testing were also introduced. To describe staff experi-ences semi-structured interviews were performed with twelve of the staff involved.. Results. The time from sampling to susceptibility testing and typing, for patients with cefotaxime ...
Poster (2014, May). Objectives Clearly associated to neonatal meningitis, Group B streptococci (GBS) classified as sequence type-17 (ST-17) are defined as the "highly virulent" clone amongst GBS. The aim of this study was to ... [more ▼]. Objectives Clearly associated to neonatal meningitis, Group B streptococci (GBS) classified as sequence type-17 (ST-17) are defined as the "highly virulent" clone amongst GBS. The aim of this study was to evaluate an easy and rapid method, recently described to detect ST-17 and ST-1 GBS, based on distinguishing peak-shifts present on the protein spectrum of these 2 sequence types, using a Microflex (Bruker) matrix-assisted laser desorption/ionization time of flight mass spectrometer (MALDI-TOF MS). Methods This study was performed on 67 multi locus sequence typed (MLST) GBS originated from the Belgian and Czech National Reference Centers, including 18 ST-17 and 16 ST-1. After culture on blood agar, an ethanol/formic acid extraction was performed on each ...
Laboratory testing-Some antimicrobial stewardship (AMS) programs have already incorporated rapid diagnostic tests which can positively identify infectious agents in a matter of hours rather than days, dramatically reducing delays in implementation of effective therapies. Use of fluorescence in situ hybridization using peptide nucleic acid probes (PNA FISH®), for instance, has been shown to identify Enterococcus faecium 2.3 days earlier than conventional microbiological methods and reduces the time to initiation of effective therapy by 1.8 days in research conducted at the University of Maryland.2 Other research indicates that PNA FISH can contribute to decreased hospital costs and shorter lengths of stay for patients with Staphylococcus aureus and coagulase-negative staphylococci.3 Procalcitonin tests can quickly determine whether a patient has systemic bacterial infection. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric analysis detects the presence of ...
General interests encompass the investigation and development of ionization processes, methodologies, and instrumentation employed in mass spectrometry and the application of mass spectrometry to the elucidation of structural features that govern the functions of biological molecules and to the analysis of organic molecules found in environmental matrices. Individual studies entail development of tandem time-of-flight mass spectrometry (TOF MS/MS); development of electron capture ionization time-of-flight mass spectrometry (ECI TOF MS); investigation of electron capture dissociation of peptides and proteins; proteomics based on protein-function; investigation of protein/nucleic acid interaction; and environmental analysis of fluorinated alkyl substances.. ...
Saliva contains various proteins, particularly abundant are phosphoproteins, that may be related to disease occurrences and that play significant roles in a biological system. Thus, medical diagnostics will benefit tremendously if disease-related protein biomarkers are discovered from saliva. In this paper, we propose and demonstrate an approach using functional zinc oxide coated iron oxide magnetic nanoparticles ([email protected] MNPs) as affinity probes to selectively enrich phosphoproteins from complex saliva samples and as microwave absorbers to assist the enrichment and subsequent tryptic digestion of trapped proteins under microwave heating. The target species trapped by MNPs were characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) combined with protein database search. Entire analysis time was shortened to less than 20 min. The detection limit of this approach for a monophosphopeptide was as low as 250 pM (10 μL). [Figure not available: see fulltext ...
Integrin-mediated cell adhesion stimulates a cascade of signaling pathways that control cell proliferation, migration, and survival, mostly through tyrosine phosphorylation of signaling molecules. p130Cas, originally identified as a major substrate of v-Src, is a scaffold molecule that interacts with several proteins and mediates multiple cellular events after cell adhesion and mitogen treatment. Here, we describe a novel p130Cas-associated protein named p140Cap (Cas-associated protein) as a new tyrosine phosphorylated molecule involved in integrin- and epidermal growth factor (EGF)-dependent signaling. By affinity chromatography of human ECV304 cell extracts on a MBP-p130Cas column followed by mass spectrometry matrix-assisted laser desorption ionization/time of flight analysis, we identified p140Cap as a protein migrating at 140 kDa. We detected its expression in human, mouse, and rat cells and in different mouse tissues. Endogenous and transfected p140Cap proteins coimmunoprecipitate with ...
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The mass increment indicating the detection of FL and other fructosamine- modified peptides is +162 Da. Glycation of intact proteins and large peptide chains has been detected by electrospray positive ion mass spectrometry and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Roberts and coworkers detected and quantified fructosamine- modified a- and p-chains of hemoglobin by deconvolution of multiply charged ion series [84], shown in later studies by peptide mapping to reflect fructosa- mine formation at sites a-K61, P-V1, and P-K66 [28]. Increase in molecular mass of human serum albumin (HSA) glycated by glucose prepared in vitro was measured by MALDI-TOF. This revealed that preparations of glycated HSA had a large increase in mass due to the high extent of glycation, dissimilar from the low increase in mass of glycated HSA in plasma samples in vivo. For example, HSA from human plasma had a mean mass increment of +243 Da, whereas model glucose-modified ...
The mammalian adaptor protein Alix [ALG-2 (apoptosis-linked-gene-2 product)-interacting protein X] belongs to a conserved family of proteins that have in common an N-terminal Bro1 domain and a C-terminal PRD (proline-rich domain), both of which mediate partner protein interactions. Following our previous finding that Xp95, the Xenopus orthologue of Alix, undergoes a phosphorylation-dependent gel mobility shift during progesteroneinduced oocyte meiotic maturation, we explored potential regulation of Xp95/Alix by protein phosphorylation in hormone-induced cell cycle re-entry or M-phase induction. By MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS analyses and gel mobility-shift assays, Xp95 is phosphorylated at multiple sites within the N-terminal half of the PRD during Xenopus oocyte maturation, and a similar region in Alix is phosphorylated in mitotically arrested but not serum-stimulated mammalian cells. By tandem MS, Thr745 within this region, which localizes in a ...
HABA Matrix 25 mg $22.00. Pre-Weighed Ultrapure MALDI Matrix Tubes. 2-(4-Hydroxybenzeneazo)benzoic acid (HABA) can be used as a MALDI mass spectrometry (MALDI-MS) - HABA, 2-(4-Hydroxybenzeneazo)benzoic acid, is an effective MALDI mass spectrometry (MALDI-MS) matrix and has a strong absorbance at 337 nm. -
TY - JOUR. T1 - Testing the significance of microorganism identification by mass spectrometry and proteome database search. AU - Pineda, Fernando J.. AU - Lin, Jeffrey S.. AU - Fenselau, Catherine. AU - Demirev, Plamen A.. PY - 2000/8/15. Y1 - 2000/8/15. N2 - We derive and validate a simple statistical model that predicts the distribution of false matches between peaks in matrix-assisted laser desorption/ionization mass spectrometry data and proteins in proteome databases. The model allows us to calculate the significance of previously reported microorganism identification results. In particular, for Δm = ±1.5 Da, we find that the computed significance levels are sufficient to demonstrate the ability to identify microorganisms, provided the number of candidate microorganisms is limited to roughly three Escherichia coli-like or roughly 10 Bacillus subtilis-like microorganisms (in the sense of having roughly the same number of proteins per unit-mass interval). We conclude that, given the ...
We investigated the metabolic defect(s) of four children who presented with isolated cryptogenic chronic liver disease, coagulopathy, and abnormalities of several unrelated serum glycoproteins. Analysis of the patients serum glycoproteins and fibroblasts suggest they have a novel congenital disorder of glycosylation (CDG). All had abnormal transferrin (Tf) isoelectric focusing (IEF) profiles. More detailed analysis of Tf by electrospray ionization mass spectrometry (ESI-MS) showed a plethora of abnormal glycosylations that included loss of 1-2 sialic acids and 1-2 galactose units, typical of Group II defects. Tf from two patients also lacked 1-2 entire oligosaccharide chains, typical of Group One disorders. Total serum N-glycans were analyzed by HPLC and matrix-assisted laser desorption/ionization mass spectrometry and also showed increased proportion of neutral glycan chains lacking sialic acids and galactose units. Analysis of patient fibroblasts eliminated CDG-Ia, through CDG-Ih, -IL and ...
The immune system integrates critical information across multiple scales to develop an effective response against invading pathogens and cancer. Modern approaches, such as imaging mass spectrometry and state-of-the-art microscopy, are key technologies to understand the mechanisms that spatially regulate leukocyte function. Multimodal imaging approaches, such as microscopy and mass spectrometry, is capable to analyse the local regulation of immune responses in infections and cancer. Our interdisciplinary coregistration algorithm combines immunohistochemistry (IHC), matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) and liquid chromatography with tandem mass spectrometry (LC-MS/MS) to unravel the immunological landscapes in diseases to improve diagnosis and therapies ...
in Proteomics (2009), 9(8), 2163-2170. Asthma is a complex inflammatory disease of airways. A network of reciprocal interactions between inflammatory cells, peptidic mediators, extracellular matrix components, and proteases is thought to be ... [more ▼]. Asthma is a complex inflammatory disease of airways. A network of reciprocal interactions between inflammatory cells, peptidic mediators, extracellular matrix components, and proteases is thought to be involved in the installation and maintenance of asthma-related airway inflammation and remodeling. To date, new proteic mediators displaying significant activity in the pathophysiology of asthma are still to be unveiled. The main objective of this study was to uncover potential target proteins by using surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) on lung samples from mouse models of allergen-induced airway inflammation and remodeling. In this model, we pointed out several protein or peptide peaks ...
TY - JOUR. T1 - Differentially expressed proteins in nitric oxide-stimulated NIH/3T3 fibroblasts. T2 - Implications for inhibiting cancer development. AU - Shim, Dong Hwi. AU - Lim, Joo Weon. AU - Kim, Hyeyoung. PY - 2015/1/1. Y1 - 2015/1/1. N2 - Purpose: Recent evidence shows that nitric oxide (NO) may exhibit both pro-cancer and anti-cancer activities. The present study aimed to determine the differentially expressed proteins in NO-treated NIH/3T3 fibroblasts in order to investigate whether NO induces proteins with pro-cancer or anti-cancer effects. Materials and Methods: The cells were treated with 300 μM of an NO donor 3,3-bis-(aminoethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18) for 12 h. The changed protein patterns, which were separated by two-dimensional electrophoresis using pH gradients of 4‒7, were conclusively identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis of the peptide digests. Results: Seventeen differentially ...
Several studies have linked Infertility associated spermatotoxicty/spermato-mutagenesis of Adult male Wister dietary exposed to aflatoxin B, the dynamics may be as a result of chromosomal aberration or simply by its anti-spermatogenesis properties. To evaluate the protein composition of epididymal fluid and sperm extracts of the rats using a two-dimensional gel electrophoresis. Epididymal luminal fluid from the corpus and cauda regions of male animals rendered infertile by the anti spermal and mutagenic properties of aflatoxin B1 possessed a certain protein (contraception-associated protein 1, CAP1) which has a molecular mass of - 25 kDa and isoelectric point (pl) of 5.8; although it wasn t found in fluids, but was present in sperm, from fertile rats. Infrared matrix-assisted laser desorption/ionization mass spectrometry indicated that the molecular mass of CAP1 was 20 420 120 daltons. Homology of the hormone from a known insect (Acheta domesticus) was carried out by analysing 17 amino acids ...
Lipolysis involves a number of components including signaling pathways, droplet-associated proteins, and lipases such as hormone-sensitive lipase (HSL). We used surface enhanced laser desorption/ionization time-of-flight mass spectroscopy to identify cellular proteins that might interact with HSL and potentially influence lipolysis. Using recombinant HSL as bait on protein chips, clusters of proteins of 14.7-18.9, 25.8-26.8, 36.1, 44.3-49.1, and 53.7 kDa were identified that interact with HSL, particularly when lysates were examined from beta-agonist treated mouse adipocytes. The ability to detect these interacting proteins was markedly diminished when the adipocytes were treated with insulin. A very similar pattern of proteins was identified when anti-HSL IgG was used as the bait. Following immunocapture, the identification of the prominent 53.7 kDa protein was carried out by tryptic digestion and MS analysis and determined to be vimentin. The interaction of HSL with vimentin, and its hormonal ...
In osteoarthritis (OA), impairment of cartilage regeneration can be related to a defective chondrogenic differentiation of mesenchymal stromal cells (MSCs). Therefore, understanding the proteomic- and metabolomic-associated molecular events during the chondrogenesis of MSCs could provide alternative targets for therapeutic intervention. Here, a SILAC-based proteomic analysis identified 43 proteins related with metabolic pathways whose abundance was significantly altered during the chondrogenesis of OA human bone marrow MSCs (hBMSCs). Then, the level and distribution of metabolites was analyzed in these cells and healthy controls by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), leading to the recognition of characteristic metabolomic profiles at the early stages of differentiation. Finally, integrative pathway analysis showed that UDP-glucuronic acid synthesis and amino sugar metabolism were downregulated in OA hBMSCs during chondrogenesis compared to healthy ...
abstract = {Insects have developed an efficient host defense against microorganisms, which involves humoral and cellular mechanisms. Numerous data highlight similarities between defense responses of insects and innate immunity of mammals. The fruit fly, Drosophila melanogaster, is a favorable model system for the analysis of the first line defense against microorganisms. Taking advantages of improvements in mass spectrometry (MS), two-dimensional (2D) gel electrophoresis and bioinformatics, differential analyses of blood content (hemolymph) from immune-challenged versus control Drosophila were performed. Two strategies were developed: (i) peptidomic analyses through matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS and high performance liquid chromatography for molecules below 15 kDa, and (ii) proteomic studies based on 2D gel electrophoresis, MALDI-TOF fingerprinting and database searches, for compounds of greater molecular masses. The peptidomic strategy led to the ...
The traditional methods of bacterial identification are based on observation of either the morphology of single cells or colony characteristics. However, the adoption of newer and automated methods offers advantage in terms of rapid and reliable identification of bacterial species. The review provides a comprehensive appreciation of new and improved technologies such fatty acid profiling, sequence analysis of the 16S rRNA gene, matrix-assisted laser desorption/ionization time-of-flight (MALDI‑TOF), metabolic finger profiling using BIOLOG, ribotyping, together with the computational tools employed for querying the databases that are associated with these identification tools and high-throughput genomic sequencing in bacterial identification. It is evident that with the increase in the adoption of new technologies bacterial identification is becoming easier. Key words: Bacteria, Biolog, computational tools, fatty acids, Gram staining, identification, metagenomics, morphology, MALDI
L. Qiao, P. Yang, B. Liu, N. Lion and C. Roussel et al. Plate for matrix-assisted laser desorption ionization mass spectrometry for, e.g. analyzing peptide, has substrate that is covered with light sensitive matrix with light absorber, charge carrier, probe molecule and photo-sensitizer, US8080784, 2008.. Detailed record ...
A single photon ionization, molecular beam sampling, reflectron time-of-flight mass spectrometer (SPI/MBTOFMS) has been developed and used to study pyrolysis products from a selection of biomass materials. Spectra are characterized by high resolution and decreased fragmentation compared to electron-impact ionization mass spectra from related molecular beam mass spectrometer systems equipped with quadrupole mass analyzers.
HABA matrix 1 gram $235.00. 2-(4-Hydroxybenzeneazo)benzoic acid (HABA) can be used as a MALDI mass spectrometry (MALDI-MS) matrix and has a strong absorbance at 337 nm. HABA is recommended for use to analyze oligosacharides or intact proteins. - HABA, 2-(4-Hydroxybenzeneazo)benzoic acid, is an effective MALDI mass spectrometry (MALDI-MS) matrix and has a strong absorbance at 337 nm. -
Accurate and fast yeast identification is important when treating patients with invasive fungal disease as susceptibility to antifungal agents is highly species related. Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) provides a powerful tool with a clear potential to improve current diagnostic practice. Two MALDI-TOF-MS-systems (BioTyper/Bruker and Saramis/AXIMA) were evaluated using: (i) A collection of 102 archived, well characterised yeast isolates representing 14 different species and (ii) Prospectively collected isolates obtained from clinical samples at two participating laboratories. Of the 102 archived isolates, 81 (79%) and 92 (90%) were correctly identified by Saramis/AXIMA and BioTyper/Bruker respectively. Saramis/AXIMA was unable to separate Candida albicans, C. africana and C. dubliniensis in 13 of 32 isolates. After manual interpretation of the mass spectra output, all 13 isolates were correctly identified, resulting in an overall identification ...