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Thankan Jayasekharan, Shyam L Gupta, Vikas Dhiman
The intrinsic binding ability of seven natural peptides (oxytocin, arg8 -vasopressin, bradykinin, angiotensin-I, substance-P, somatostatin, and neurotensin) with copper in two 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 using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS)...
January 15, 2018: Journal of Mass Spectrometry: JMS
Brian J Malys, Michelle L Piotrowski, Kevin G Owens
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...
February 2018: Journal of the American Society for Mass Spectrometry
Justine Ferey, David Da Silva, Pierre Lafite, Richard Daniellou, Benoît Maunit
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...
August 1, 2017: Talanta
Chengzhi Li, Dong Ma, Kaifei Deng, Yijiu Chen, Ping Huang, Zhenyuan Wang
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)...
September 2017: Journal of Forensic Sciences
Makiko Fujii, Rie Shishido, Takaya Satoh, Shigeru Suzuki, Jiro Matsuo
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...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Levy Anderson César Alves, Rafael Celestino Souza, Taciana Mara Couto da Silva, Andreia Watanabe, Meriellen Dias, Maria Anita Mendes, Ana Lídia Ciamponi
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...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Martin S Engler, Sarah Crotty, Markus J Barthel, Christian Pietsch, Ulrich S Schubert, Sebastian Böcker
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...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Stanislav D Anastyuk, Natalia M Shevchenko, Roza V Usoltseva Menshova, Artyom S Silchenko, Pavel A Zadorozhny, Pavel S Dmitrenok, Svetlana P Ermakova
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...
February 10, 2017: Carbohydrate Polymers
Faten Alchab, Estelle Sibille, Laurent Ettouati, Emilie Bana, Zouhair Bouaziz, Angélique Mularoni, Elodie Monniot, Denyse Bagrel, Joachim Jose, Marc Le Borgne, Patrick Chaimbault
Quinones and quinones-like compounds are potential candidates for the inhibition of CDC25 phosphatases. The combination of MALDI-MS analyses and biological studies was used to develop a rapid screening of a targeted library of indeno[1,2-b]indoloquinone derivatives. The screening protocol using MALDI-TOFMS and MALDI-FTICRMS highlighted four new promising candidates. Biological investigations showed that only compounds 5c-f inhibited CDC25A and -C phosphatases, with IC50 values around the micromolar range. The direct use of a screening method based on MALDI-MS technology allowed achieving fast scaffold identification of a new class of potent inhibitors of CDC25 phosphatases...
2016: Journal of Enzyme Inhibition and Medicinal Chemistry
Masashi Sasaki, Tadashi Nakamura, Kentaro Hirayama, Kenji Fukuda, Tadao Saito, Tadasu Urashima, Sadaki Asakuma
The milk/colostrum of some mammalian species is known to contain sugar nucleotides including uridine diphosphate (UDP) oligosaccharides in addition to lactose and milk oligosaccharides, but the detailed structures of these UDP oligosaccharides have not so far been clarified. In this study we isolated two UDP-sialyl N-acetyllactosamines from ovine colostrum and characterized them using (1)H-NMR and MALDI-TOFMS spectroscopies. Their structures were found to be Neu5Gc(α2-3)Gal(β1-4)GlcNAcα1-UDP and Neu5Gc(α2-6)Gal(β1-4)GlcNAcα1-UDP...
October 2016: Glycoconjugate Journal
Shyam L Gupta, Vikas Dhiman, T Jayasekharan, N K Sahoo
RATIONALE: The increased use of silver nanoparticles (AgNPs) for various biological applications, and over-expression of various peptide receptors in different tumors/cancer cells, necessitate the need for dedicated investigations on the intrinsic binding ability of Ag with various biologically important peptides for better understanding of AgNPs-peptide interactions and for the future development of contrasting agents as well as drugs for imaging/biomedical applications. METHODS: The [M+(Ag)n ](+) complexes are prepared and characterized using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS)...
June 15, 2016: Rapid Communications in Mass Spectrometry: RCM
G G Kharseeva, N A Voronina, A Yu Mironov, E L Alutina
The comparative analysis was carried out concerning effectiveness of three techniques of identification of Corynebacterium non diphtheriae: bacteriological, molecular genetic (sequenation on 16SpRNA) andmass-spectrometric (MALDI-ToFMS). The analysis covered 49 strains of Corynebacterium non diphtheriae (C.pseudodiphheriticum, C.amycolatum, C.propinquum, C.falsenii) and 2 strains of Corynebacterium diphtheriae isolated under various pathology form urogenital tract and upper respiratory ways. The corinbacteria were identified using bacteriologic technique, sequenation on 16SpRNA and mass-spectrometric technique (MALDIToF MS)...
December 2015: Klinicheskaia Laboratornaia Diagnostika
Hideyuki Kajiwara, Norihide Hinomoto, Tetsuo Gotoh
RATIONALE: Discrimination of spider mite species is still performed using morphological information, although DNA and other biological approaches have been attempted for identification purposes. These techniques need much time, are expensive, and require specialist staff. As an alternative, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis is applied for rapid discrimination of spider mite species. METHODS: Spider mites were analyzed using MALDI-TOFMS after extraction with 70% formic acid and acetonitrile...
April 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Kun Jia, Wei Li, Feng Wang, Haixia Qu, Yuanyuan Qiao, Lanping Zhou, Yulin Sun, Qingwei Ma, Xiaohang Zhao
Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant neoplasms worldwide. Patients are often diagnosed at advanced stages with poor prognosis due to the absence of obvious early symptoms. Here, we applied a high-throughput serum peptidome analysis to identify circulating peptide markers of ESCC. Weak cationic exchange magnetic beads coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for two-stage proteotypic peptide profiling in complex serum samples collected from 477 cancer patients and healthy controls...
April 26, 2016: Oncotarget
Solomon T Gizaw, Tetsu Ohashi, Masakazu Tanaka, Hiroshi Hinou, Shin-Ichiro Nishimura
BACKGROUND: Understanding of the significance of posttranslational glycosylation in Alzheimer's disease (AD) is of growing importance for the investigation of the pathogenesis of AD as well as discovery research of the disease-specific serum biomarkers. METHODS: We designed a standard protocol for the glycoblotting combined with MALDI-TOFMS to perform rapid and quantitative profiling of the glycan parts of glycoproteins (N-glycans) and glycosphingolipids (GSLs) using human AD's post-mortem samples such as brain tissues (dissected cerebral cortices such as frontal, parietal, occipital, and temporal domains), serum and cerebrospinal fluid (CSF)...
August 2016: Biochimica et Biophysica Acta
Clifton K Fagerquist, William J Zaragoza
RATIONAL: Analysis of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) often relies upon sample preparation methods that result in cell lysis, e.g. bead-beating. However, Shiga toxin-producing Escherichia coli (STEC) can undergo bacteriophage-induced cell lysis triggered by antibiotic exposure that may allow greater selectivity of the proteins extracted. METHODS: We have developed a sample preparation method for selective extraction of bacteriophage-encoded proteins and specifically Shiga toxins 1 and 2 (Stx1 & 2) expressed from STEC strains induced by DNA-damaging antibiotics...
March 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Kanae Teramoto, Mitsuo Suga, Takafumi Sato, Takayuki Wada, Atsushi Yamamoto, Nagatoshi Fujiwara
Mycolic acids (MAs) are characteristic components of bacteria in the suborder Corynebacterineae, such as Mycobacterium. MAs are categorized into subclasses based on their functional bases (cyclopropane ring, methoxy, keto, and epoxy group). Since MAs have heterogeneity among bacterial species, analyzing of MAs are required in the chemotaxonomic field. However, their structural analysis is not easy because of their long carbon-chain lengths and several functional groups. In this study, total fatty acid (FA) methyl ester (ME) fraction of M...
2015: Mass Spectrometry
Rosita Russo, Camilla Rega, Angela Chambery
RATIONALE: The improvement and development of novel technologies and analytical tools are an important first line of defence for both detecting and deterring food frauds. In order to protect the authenticity of traditional foods and safeguard geographical indications and traditional specialities at European level, Protected Designation of Origin (PDO) legislation has been introduced as a guarantee of quality (Council Regulation ECC 2081/92). Dairy products, especially those certified as PDO products, are amongst the most common targets of fraudulent activities...
February 28, 2016: Rapid Communications in Mass Spectrometry: RCM
Rhiannon S McBean, Catherine A Hyland, Robert L Flower
Matrix-assisted laser desorption/ionization, time-of-flight mass spectrometry (MALDI-TOF MS), is a sensitive analytical method capable of resolving DNA fragments varying in mass by a single nucleotide. MALDI-TOF MS is applicable to blood group genotyping, as the majority of blood group antigens are encoded by single nucleotide polymorphisms. Blood group genotyping by MALDI-TOF MS can be performed using a panel (Hemo ID Blood Group Genotyping Panel, Agena Bioscience Inc., San Diego, CA) that is a set of genotyping assays that predict the phenotype for 101 antigens from 16 blood group systems...
2015: Immunohematology
David R Barnidge, Thomas P Krick, Timothy J Griffin, David L Murray
RATIONALE: Use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to monitor serum and urine samples for endogenous monoclonal immunoglobulins. MALDI-TOFMS is faster, fully automatable, and provides superior specificity compared to protein gel electrophoresis (PEL). METHODS: Samples were enriched for immunoglobulins in 5 min using Melon Gel™ followed by reduction with dithiothreitol for 15 min to separate immunoglobulin light chains and heavy chains...
November 15, 2015: Rapid Communications in Mass Spectrometry: RCM
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