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MALDI and matrix

Martin Köhler, Christoph Neff, Camilo Perez, Cyrill Brunner, Els Pardon, Jan Steyaert, Gisbert Schneider, Kaspar P Locher, Renato Zenobi
The application of nanobodies as binding partners for structure stabilization in protein x-ray crystallography is taking an increasingly important role in structural biology. However, the addition of nanobodies to the crystallization matrices might complicate the optimization of the crystallization process, which is why analytical techniques to screen and characterize suitable nanobodies are useful. Here, we show how chemical cross-linking combined with high-mass matrix-assisted laser/desorption ionization mass spectrometry can be employed as a fast screening technique to determine binding specificities of intact nanobody•membrane protein complexes...
March 21, 2018: Analytical Chemistry
Shengli Chen, Huafang Hao, Ping Zhao, Wenheng Ji, Mingxia Li, Yongsheng Liu, Yuefeng Chu
Mycoplasma bovis is a major bovine pathogen that causes considerable economic losses in the cattle industry worldwide. Moreover, M. bovis biofilm can persist in the environment and its host. To date, M. bovis biofilm antigens recognized by bovine convalescent sera and their comparison with planktonic cells have not yet been explored. This study utilized an immunoproteomic approach using two-dimensional electrophoresis, immunoblotting using convalescent bovine serum, and subsequent matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) to identify the immunoreactive proteins expressed in biofilm- and planktonic-grown M...
2018: Frontiers in Microbiology
Adrian Arendowski, Justyna Szulc, Joanna Nizioł, Beata Gutarowska, Tomasz Ruman
Surface-assisted laser desorption/ionization mass spectrometry on gold nanoparticle enhanced target (AuNPET) technique was used for metabolomic analysis and secondary metabolites detection of two mould strains - Aspergillus versicolor and Penicillium chrysogenum in model conditions on microbiological malt extract agar medium. Results obtained with the use of AuNPET-based mass spectrometry technique were compared with traditional matrix-assisted laser desorption/ionization (MALDI) method based on α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) matrices...
March 16, 2018: Analytical Biochemistry
Sahar Sallam, Ivan Dolog, Bradford A Paik, Xinqiao Jia, Kristi L Kiick, Chrys Wesdemiotis
The sequence and helical content of two alanine-rich peptides (AQK18 and GpAQK18, Gp: L-propargylglycine) and their conjugates with poly(ethylene glycol) (PEG) have been investigated by multidimensional mass spectrometry (MS), encompassing electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) interfaced with tandem mass spectrometry (MS2 ) fragmentation and shape-sensitive separation via ion mobility mass spectrometry (IM-MS). The composition, sequence, and molecular weight distribution of the peptides and bioconjugates were identified by MS and MS2 experiments, which also confirmed the attachment of PEG at the C-terminus of the peptides...
March 19, 2018: Biomacromolecules
M Moreno, A Zacarias, A Porzel, L Velasquez, G Gonzalez, M Alegría-Arcos, F Gonzalez-Nilo, E K U Gross
Emerging and re-emerging epidemic diseases pose an ongoing threat to global health. Currently, Enterobactin and Enterobactin derivatives have gained interest, owing to their potential application in the pharmaceutical field. As it is known [J. Am. Chem. Soc (1979) 101, 20, 6097-6104], Enterobactin (H6 EB) is an efficient iron carrier synthesized and secreted by many microbial species. In order to facilitate the elucidation of enterobactin and its analogues, here we propose the creation of a H6 EB standard set using Density Functional Theory Infrared (IR) and NMR spectra...
March 2, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Zhao-Lian Lu, Ying-Jian Chen, Xin-Yan Jing, Na-Na Wang, Ting Zhang, Cheng-Jin Hu
BACKGROUND Papillary thyroid cancer (PTC) is currently the most commonly diagnosed endocrine malignancy. In addition, the sex- and age-adjusted incidence of PTC has exhibited a greater increase over the last 2 decades than in many other malignancies. Thus, discovering noninvasive specific serum biomarker to distinguish PTC from cancer-free controls in its early stages remains an important goal. MATERIAL AND METHODS Serum samples from 88 PTC patients and 80 cancer-free controls were randomly allocated into training or validation sets...
March 17, 2018: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Shelley N Jackson, Ludovic Muller, Aurelie Roux, Berk Oktem, Eugene Moskovets, Vladimir M Doroshenko, Amina S Woods
Matrix-assisted laser/desorption ionization (MALDI) mass spectrometry imaging (MSI) is widely used as a unique tool to record the distribution of a large range of biomolecules in tissues. 2,6-Dihydroxyacetophenone (DHA) matrix has been shown to provide efficient ionization of lipids, especially gangliosides. The major drawback for DHA as it applies to MS imaging is that it sublimes under vacuum (low pressure) at the extended time necessary to complete both high spatial and mass resolution MSI studies of whole organs...
March 16, 2018: Journal of the American Society for Mass Spectrometry
Jiaqiang Luo, Cheryl Taylor, Thomas Nebl, Ken Ng, Louise E Bennett
Animal and aquatic meats represent important sources of dietary protein and micro-nutrients. Although red and processed meats carry some risks for human health, sensory and nutritional advantages drive meat consumption. Therefore, it is important to understand how meat processing and cooking influence healthiness. The research aim was to investigate relationships of meat composition (proximates, amino acids and minerals) and cooking conditions (raw, 90 s microwave, 200 °C oven for 10 or 30 min) on protein digestibility, for a selection of four animal (beef, chicken, pork, kangaroo) and four aquatic meats (salmon, trout, prawn, oyster)...
July 15, 2018: Food Chemistry
David Bonnel, Raphaël Legouffe, André H Eriksson, Rasmus W Mortensen, Fabien Pamelard, Jonathan Stauber, Kim T Nielsen
Generation of skin distribution profiles and reliable determination of drug molecule concentration in the target region are crucial during the development process of topical products for treatment of skin diseases like psoriasis and atopic dermatitis. Imaging techniques like mass spectrometric imaging (MSI) offer sufficient spatial resolution to generate meaningful distribution profiles of a drug molecule across a skin section. In this study, we use matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to generate quantitative skin distribution profiles based on tissue extinction coefficient (TEC) determinations of four different molecules in cross sections of human skin explants after topical administration...
March 15, 2018: Analytical and Bioanalytical Chemistry
A C M Veloo, H Jean-Pierre, U S Justesen, T Morris, E Urban, I Wybo, M Kostrzewa, A W Friedrich
Within the ENRIA project, several 'expertise laboratories' collaborated in order to optimize the identification of clinical anaerobic isolates by using a widely available platform, the Biotyper Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Main Spectral Profiles (MSPs) of well characterized anaerobic strains were added to one of the latest updates of the Biotyper database db6903; (V6 database) for common use. MSPs of anaerobic strains nominated for addition to the Biotyper database are included in this validation...
March 12, 2018: Anaerobe
Sarah Caughlin, Shikhar Maheshwari, Yuksel Agca, Cansu Agca, Aaron J Harris, Kristina Jurcic, Ken K-C Yeung, David F Cechetto, Shawn N Whitehead
BACKGROUND: Accumulation of simple gangliosides GM2 and GM3, and gangliosides with longer long-chain bases (d20:1) have been linked to toxicity and the pathogenesis of Alzheimer's disease (AD). Conversely, complex gangliosides, such as GM1, have been shown to be neuroprotective. Recent evidence using matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS) has demonstrated that a-series gangliosides are differentially altered during normal aging, yet it remains unclear how simple species are shifting relative to complex gangliosides in the prodromal stages of AD...
March 12, 2018: Biochimica et Biophysica Acta
Lu Hu, Wuchao Zhao, Jianghua He, Yuetao Zhang
This work reveals the silyl ketene acetal (SKA)/B(C₆F₅)₃ Lewis pair-catalyzed room-temperature group transfer polymerization (GTP) of polar acrylic monomers, including methyl linear methacrylate (MMA), and the biorenewable cyclic monomers γ-methyl-α-methylene-γ-butyrolactone (MMBL) and α-methylene-γ-butyrolactone (MBL) as well. The in situ NMR monitored reaction of SKA with B(C₆F₅)₃ indicated the formation of Frustrated Lewis Pairs (FLPs), although it is sluggish for MMA polymerization, such a FLP system exhibits highly activity and living GTP of MMBL and MBL...
March 15, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Jiekai Yu, Yanqin Huang, Chen Lin, Xiaofen Li, Xuefeng Fang, Chenhan Zhong, Ying Yuan, Shu Zheng
The serum protein markers of colorectal adenoma in patients with a family history of colorectal cancer have been rarely reported. Serum samples from colorectal adenoma patients with or without a family history of colorectal cancer and healthy controls were profiled using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS). The model to distinguish colorectal adenoma patients with a family history of colorectal cancer from atypical hereditary colorectal families (CRA-H) and sporadic colorectal adenoma patients without a family history of colorectal cancer (CRA-S) was established with 85...
2018: Journal of Cancer
Amy N Jacobson, Biswa P Choudhury, Michael A Fischbach
Lipopolysaccharide (LPS), a cell-associated glycolipid that makes up the outer leaflet of the outer membrane of Gram-negative bacteria, is a canonical mediator of microbe-host interactions. The most prevalent Gram-negative gut bacterial taxon, Bacteroides , makes up around 50% of the cells in a typical Western gut; these cells harbor ~300 mg of LPS, making it one of the highest-abundance molecules in the intestine. As a starting point for understanding the biological function of Bacteroides LPS, we have identified genes in Bacteroides thetaiotaomicron VPI 5482 involved in the biosynthesis of its lipid A core and glycan, generated mutants that elaborate altered forms of LPS, and used matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry to interrogate the molecular features of these variants...
March 13, 2018: MBio
Noriko Takeuchi, Shunsuke Segawa, Naruhiko Ishiwada, Misako Ohkusu, Sachio Tsuchida, Mamoru Satoh, Kazuyuki Matsushita, Fumio Nomura
Haemophilus influenzae is a major pathogenic bacteria causing invasive disease, which is classified into six capsular serotypes (a-f) and non-typeable (NT) strains. Capsular serotyping of H. influenzae is traditionally determined by serological methods and more recently by PCR methods. However, these methods are time-consuming and expensive. In the present study, matrix-associated laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated as an alternative method for capsular serotyping of H...
March 10, 2018: Journal of Infection and Chemotherapy: Official Journal of the Japan Society of Chemotherapy
Hsin-Yao Wang, Tzong-Yi Lee, Yi-Ju Tseng, Tsui-Ping Liu, Kai-Yao Huang, Yung-Ta Chang, Chun-Hsien Chen, Jang-Jih Lu
Methicillin-resistant Staphylococcus aureus (MRSA), one of the most important clinical pathogens, conducts an increasing number of morbidity and mortality in the world. Rapid and accurate strain typing of bacteria would facilitate epidemiological investigation and infection control in near real time. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry is a rapid and cost-effective tool for presumptive strain typing. To develop robust method for strain typing based on MALDI-TOF spectrum, machine learning (ML) is a promising algorithm for the construction of predictive model...
2018: PloS One
Manikandan Muthu, Sechul Chun, Hui-Fen Wu, Mark W Duncan, Judy Gopal
The practice of laser desorption/ionization (LDI) mass spectrometry continues to evolve. In the most commonly adopted manifestation of LDI, matrix assisted laser desorption/ionization (MALDI), attention continues to be directed towards novel sample application strategies and modifications to the sample plate. Specifically, researchers continue to explore adaptations to the conventional, stainless steel sample plate that is the centerpiece of conventional LDI. Numerous variants of LDI-MS have been reported based on modifications of the plate surface, but none of these is widely adopted, either by end-users or instrument manufacturers...
March 13, 2018: Journal of Mass Spectrometry: JMS
Anastasia A Andrianova, Thomas DiProspero, Clayton Geib, Irina P Smoliakova, Evguenii I Kozliak, Alena Kubátová
The capability to characterize lignin, lignocellulose, and their degradation products is essential for the development of new renewable feedstocks. Electrospray ionization high-resolution time-of-flight mass spectrometry (ESI-HR TOF-MS) method was developed expanding the lignomics toolkit while targeting the simultaneous detection of low and high molecular weight (MW) lignin species. The effect of a broad range of electrolytes and various ionization conditions on ion formation and ionization effectiveness was studied using a suite of mono-, di-, and triarene lignin model compounds as well as kraft alkali lignin...
March 12, 2018: Journal of the American Society for Mass Spectrometry
Massimiliano Magro, Mattia Zaccarin, Giovanni Miotto, Laura Da Dalt, Davide Baratella, Piero Fariselli, Gianfranco Gabai, Fabio Vianello
Surface active maghemite nanoparticles (SAMNs) are able to recognize and bind selected proteins in complex biological systems, forming a hard protein corona. Upon a 5-min incubation in bovine whey from mastitis-affected cows, a significant enrichment of a single peptide characterized by a molecular weight at 4338 Da originated from the proteolysis of aS1 -casein was observed. Notably, among the large number of macromolecules in bovine milk, the detection of this specific peptide can hardly be accomplished by conventional analytical techniques...
March 12, 2018: Analytical and Bioanalytical Chemistry
Samantha J Lawton, Allison M Weis, Barbara A Byrne, Heather Fritz, Conor C Taff, Andrea K Townsend, Bart C Weimer, Asli Mete, Sarah Wheeler, Walter M Boyce
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was compared to conventional biochemical testing methods and nucleic acid analyses (16S rDNA sequencing, hippurate hydrolysis gene testing, whole genome sequencing [WGS]) for species identification of Campylobacter isolates obtained from chickens ( Gallus gallus domesticus, n = 8), American crows ( Corvus brachyrhynchos, n = 17), a mallard duck ( Anas platyrhynchos, n = 1), and a western scrub-jay ( Aphelocoma californica, n = 1)...
March 1, 2018: Journal of Veterinary Diagnostic Investigation
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