maldi-tofms

The sulfated polysaccharide from sterile alga Mastocarpus pacificus was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the extracted polysaccharides were only carrageenans. According to FT-IR- and NMR spectroscopy this polysaccharide was a hybrid kappa/iota-carrageenan with a predominance of kappa-type units. According to MALDI-TOFMS, oligosaccharide fragments obtained by mild acid hydrolysis had a polymerization degree of 1-9, while chains built up of galactose residues were up to 3...

The rapid identification and classification of pathogenic microorganisms, including Salmonella enterica, is important for the surveillance and prevention of foodborne diseases. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been shown to be an effective tool for the rapid identification of microorganisms. In a previous report, a mass database consisting of twelve biomarker proteins, S8, L15, L17, L21, L25, S7, superoxide dismutase (SodA), peptidylprolyl cis-trans isomerase C, Gns, YibT, YaiA and YciF, was introduced for the serotyping of Salmonella enterica via MALDI-MS (Applied Microbiology and Biotechnology, 2017, 101, 8557-8569)...

Matrix-Assisted Laser Desorption Ionization (MALDI) is a soft ionization technique that when used to analyze synthetic polymer analytes often requires the addition of a metal cationization agent (herein termed the "salt"). The choice of both the matrix and cationization agent need to be taken into account when considering the polymer under study; different polymers have shown different affinities toward different cationization agents, and their selectivity can change as the matrix changes. Salt-to-analyte (S/A) ratio plots are used in this work to investigate the effect of the quantity of cationization agent employed in the analysis of a polymethyl methacrylate (PMMA) analyte with different MALDI matrices...

The epithelial cadherin (CDH1) is an important determinant of tumor progression. Previous studies have indicated that the CDH1 -160C/A polymorphism was associated with the risk of colorectal cancer (CRC). However, they yielded conflicting results. Thus, we conducted this case-control study to evaluate the association between the CDH1 -160C/A polymorphism and susceptibility to CRC in a Chinese population. We recruited 351 cases and 411 controls in this case-control study. The genotype of the CDH1 -160C/A polymorphism was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS)...

Corynebacteria non-diphtheria and, in particular, C. pseudodiphtheriticum species that are closely related to C. propinquum and C. striatum form a group of new respiratory pathogens leading to the development of bronchitis, tracheitis, exacerbation of chronic obstructive pulmonary diseases, nosocomial pneumonia and other pathology. The goal is to analyze the frequency of the release of Сorynebacteria non-diphtheria from the upper respiratory tract of patients with various inflammatory diseases of the respiratory tract...

BACKGROUND: Helicobacter cinaedi is a microaerobic Gram-negative spiral-shaped bacterium that causes enteritis, cellulitis, and bacteremia in both immunocompromised and immunocompetent patients. While there have been increasing numbers of reported H. cinaedi infections recently, there has been no thyroid abscess case caused by H. cinaedi presenting with thyroid storm. CASE PRESENTATION: A 50-year-old Japanese man presented with a 9-day history of high fever associated with palpitations, dry cough, and chronic diarrhea...

AIM: To discuss the significance and applied value in the rapid identification and drug susceptibility test for blood stream infection (BSI) using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) combined with flow cytometry (FCM). METHODS: The bacteria were separated from the positive blood culture bottle using the separation gel-adsorption method system, and then applying MALDI-TOF MS combined with FCM to identify pathogen and drug susceptibility test quickly...

The family of staphylococcal superantigen-like proteins (SSLs) have a structure similar to bacterial superantigens but exhibit no superantigenic activity. These exoproteins have recently been shown to disturb the host immune defense system. One family member, SSL5, was reported to bind to human leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) and matrix metalloproteinase-9 (MMP-9) and to interfere with leukocyte trafficking. In the present study, we explored human plasma proteins bound by glutathione S-transferase (GST)-tagged recombinant SSL5 (GST-SSL5) and identified plasma protease C1 inhibitor (C1Inh) as a major SSL5-binding protein based on the results of peptide mass fingerprinting analysis with MALDI-TOFMS...

A method is developed to determine the position of ion formation along the flight axis of a MALDI TOFMS instrument using the image of the laser on the sample surface. Previous work (JASMS 2018, 29, 422-434) showed that misalignment of the sample stage in a Bruker Autoflex III MALDI TOFMS as well as multiple insertions/mountings of the target plate and differences in target plate shape itself produced reproducible changes in the measured ion time-of-flight which could be attributed to changes in the position of ion formation along the instrument flight axis...

RATIONALE: Quantification of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is challenging yet attractive, due to micro-scale procedural simplicity, high throughput and lack of memory effects. Since these features are important while analyzing trace elements in quality control schemes, MALDI-TOFMS was used for the determination of copper (Cu) and lead (Pb) in tequila with quantification carried out by partial least squares regression (PLS2) and by univariate calibration (UC)...

Overnight fasting is a routine procedure before surgery in clinical settings. Intermittent fasting is the most common diet/fitness trend implemented for weight loss and the treatment of lifestyle-related diseases. In either setting, the effects not directly related to parameters of interest, either beneficial or harmful, are often ignored. We previously demonstrated differential activation of cellular adaptive responses in 13 atrophied/nonatrophied organs of fasted mice by quantitative PCR analysis of gene expression...

The biological agents have been utilized as an affordable alternative to conventional costly metal remediation technologies for last few years. The present investigation introduces arsenic (As) resistant plant growth promoting rhizobacteria (PGPR) isolated from the As-contaminated agricultural field of West Bengal, India that alleviates arsenic-induced toxicity and exhibited many plant growth promoting traits (PGP). The isolated strain designated as AS6 has identified as Bacillus aryabhattai based on phenotypic characteristics, physio-biochemical tests, MALDI-TOFMS bio-typing, FAME analysis and 16S rDNA sequence homology...

The intrinsic binding ability of 7 natural peptides (oxytocin, arg8 -vasopressin, bradykinin, angiotensin-I, substance-P, somatostatin, and neurotensin) with copper in 2 different oxidation states (CuI/II ) derived from different Cu+/2+ precursor sources have been investigated for their charge-dependent binding characteristics. The peptide-CuI/II complexes, [M - (n-1)H + nCuI ] and [M - (2n-1)H + nCuII ], are prepared/generated by the reaction of peptides with CuI solution/Cu-target and CuSO4 solution and are analyzed by using matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry...

Frustrated by worse than expected error for both peak area and time-of-flight (TOF) in matrix assisted laser desorption ionization (MALDI) experiments using samples prepared by electrospray deposition, it was finally determined that there was a correlation between sample location on the target plate and the measured TOF/peak area. Variations in both TOF and peak area were found to be due to small differences in the initial position of ions formed in the source region of the TOF mass spectrometer. These differences arise largely from misalignment of the instrument sample stage, with a smaller contribution arising from the non-ideal shape of the target plates used...

In this study, thin-layer chromatography (TLC) hyphenated with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was developed for the screening of invertase substrates in complex matrices. BfrA, a specific β-D-fructofuranosidase from Leishmania major, was chosen as a model enzyme to screen biological activity in plant extracts due to its capacity to hydrolyze specific carbohydrates. TLC was considered to be a reliable technique for screening substrates (bioactive molecules) in plant extracts due to its quantitative capabilities whereas MALDI-TOFMS was particularly useful for rapid identification...

Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to obtain molecular images and data for principal component analysis (PCA)...

RATIONALE: Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. METHODS: To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively...

RATIONALE: Chronic kidney disease (CKD) and periodontitis (PD) are important health issues. There is a large variety of microorganisms related to the pathogenesis of periodontitis, and optimising the time and the cost of laboratory assays to detect these organisms is highly valuable in the medical field. METHODS: Bacteria were isolated from saliva and oral biofilm of 30 adolescents and young adults with definite medical and dental diagnosis of CKD and PD, respectively, and proteins were extracted for microorganism identification by means of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) technique...

RATIONALE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is frequently used to analyze homo- and copolymers, i.e. for computing copolymer fingerprints. However, the oligomer abundances are influenced by mass discrimination, i.e. mass- and composition-dependent ionization. We have developed a computational method to correct the abundance bias caused by the mass discrimination. METHODS: MALDI-TOFMS in combination with computational methods was used to investigate three random copolymers with different ratios of styrene and isoprene...

A fucoidan ScF from brown alga Saccharina cichorioides was extracted, purified and partially depolymerized by autohydrolysis at 37°C for 24, 48 and 72h. Supernatant (SN) and pellet (PL) fractions were obtained by ethanol precipitation of each sample. Unlike spectral data of ScF, NMR of PL derivatives clearly suggested the structure: 1,3-linked α-l-Fucp-4-OSO3 - repeating unit. Molecular weights (MWs) of PL fractions were 30, 26 and 18kDa for 24, 48 and 72h of autohydrolyis, respectively. MALDI-TOFMS, size-exclusion HPLC and carbohydrate polyacrylamide-gel electrophoresis (C-PAGE) indicated a similarity of SN mixtures...