Project description:The aim of the work was to test relatively simple proteomics approach based on phenol extraction and two-dimensional gel electrophoresis (2-DE) with 7cm immobilized pH gradient strips for the determination of clinically relevant proteins in wheat grain. Using this approach, 157 2-DE spots were quantified in biological triplicate, out of which 55 were identified by MALDI-TOF/TOF mass spectrometry. Clinically relevant proteins associated with celiac disease, wheat dependent exercise induced anaphylaxis, baker´s asthma, and food allergy, were detected in 24 2-DE spots. However, alcohol-soluble gliadins were not detected with this approach. The comparison with recent quantitative study suggested that gel-based and gel-free proteomics approaches are complementary for the detection and quantification of clinically relevant proteins in wheat grain.
Project description:Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has exhibited advantages in rapid analysis of metabolites. This data set provides support to the discuss of influence of interferential species, matrix effect and instrument parameters on metabolite qualification and quantification.
2021-12-28 | PXD030653 | iProX
Project description:MALDI-TOF MS analysis of ruminal lipid A from TMR and pasture fed cows
Project description:The current technique used for microbial identification in hospitals is MALDI-TOF MS. However, it suffers from important limitations, in particular for closely-related species or when the database used for the identification lacks the appropriate reference. In this work, we set up a high throughput LC-MS/MS top-down proteomics platform dedicated to intact bacterial protein analysis. Using Escherichia coli as a model, all steps of the workflow were optimized: protein extraction, on-line liquid chromatographic separation, MS/MS fragmentation and data analysis. Using the optimized parameters, about 220 proteins, corresponding to more than 500 proteoforms, could be identified in a single run. We then demonstrated the suitability of the developed platform for the characterization and discrimination of enterobacterial pathogens rather undistinguishable by MALDI-TOF although leading to very different clinical outcomes. For each pathogen, we identified specific proteoforms that could potentially be used as biomarkers. We also improved the characterization of poorly described bacterial strains. Our results highlight the advantage of targeting proteoforms vs peptides for accurate bacterial characterization, and qualify top-down proteomics as a promising tool in clinical microbiology.
Project description:Vacuoles and lysosomes are single-membrane-bound organelles involved in diverse functions such as intracellular digestion and storage or secretion of metabolites. To understand their origin, evolution and fundamental features, the identification of proteins comprising these compartments in missing links would be invaluable. So, we isolated the vacuoles from Cyanidioschyzon merolae, which is considered to be one of the most primitive photosynthetic eukaryotes, and identified 46 proteins by matrix-assisted laser desorption/ionization time of flight-mass spectrometry. Keywords: peptide mass fingerprinting, MALDI-TOF
Project description:Chemoreception is based on the senses of smell and taste that are crucial for animals to find new food sources, shelter, and mates. The initial step in olfaction involves the translocation of odorants from the periphery through the aqueous lymph of the olfactory sensilla to the odorant receptors by chemosensory proteins (CSPs) or odorant binding proteins (OBPs).To better understand the roles of CSPs and OBPs in a coleopteran pest species, the red flour beetle Tribolium castaneum (Coleoptera, Tenebrionidae), we performed transcriptome analyses of male and female antennae, heads, mouthparts, legs, and bodies, which revealed that all 20 CSPs and 49 of the 50 previously annotated OBPs are transcribed. Only six of the 20 CSP are significantly transcriptionally enriched in the main chemosensory tissues (antenna and/or mouthparts), whereas of the OBPs all eight members of the antenna binding proteins II (ABPII) subgroup, 18 of the 20 classic OBP subgroup, the C+OBP, and only five of the 21 C-OBPs show increased chemosensory tissue expression. By MALDI-TOF-TOF MS protein fingerprinting, we confirmed three CSPs, four ABPIIs, three classic OBPs, and four C-OBPs in the antennae.Most of the classic OBPs and all ABPIIs are involved in chemoreception. A few are also present in other tissues like odoriferous glands and testes and may be involved in release or transfer of chemical signals. The majority of the CSPs as well as the C-OBPs are not enriched in antennae or mouthparts, suggesting a more general role in the transport of hydrophobic molecules. RNAseq data obtained from different body parts of adult males and females, as well as larvae
