Project description:<p>Clinical metabolic phenotyping employs metabolomics and lipidomics to detect and measure thousands of metabolites and lipids within human samples. This approach aims to identify metabolite and lipid changes between phenotypes (e.g. disease status) that aid understanding of biochemical mechanisms driving the phenotype. Sample preparation is a critical step in clinical metabolic phenotyping: it must be reproducible and give a high extraction yield of metabolites and lipids. Here, we assessed the extraction of polar metabolites from human urine and polar metabolites and lipids from human plasma for analysis by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) metabolomics and lipidomics. We evaluated several monophasic (urine and plasma) and biphasic (plasma) extractions, and we also tested alterations to (a) solvent-biofluid incubation time and temperature during monophasic extraction, and (b) phase partitioning time during biphasic extraction. Extracts were analysed by three UHPLC-MS assays: (i) HILIC for urine and plasma, (ii) C18 aqueous reversed phase for urine, and (iii) C18 reversed phase for plasma lipids, and the yield and reproducibility of each method was assessed. For HILIC UHPLC-MS plasma and urine analysis, monophasic 50:50 methanol:acetonitrile had the most detected putatively-identified polar metabolites. If lipid removal from the plasma polar HILIC extract is required, then the biphasic methanol/chloroform/water method is recommended. For C18 (aqueous) UHPLC-MS urine analysis, 50:50 methanol:water had high reproducibility and yield. For C18 UHPLC-MS plasma lipidomics, monophasic 100% isopropanol had the highest detection response of all annotated lipid classes. Increasing monophasic incubation time and temperature had little benefit on metabolite and lipid yield and reproducibility.</p>
Project description:Samples were subjected to LC–MS analysis using a dual pressure LTQ-Orbitrap Elite mass spectrometer (Thermo Fisher Scientific) connected to an electrospray ion source (Thermo Fisher Scientific) as recently described (PMID: 23017020). Peptide separation was carried out on an EASY nLC-1000 system (Thermo Fisher Scientific) equipped with a RP-HPLC column (75 μm × 30 cm) packed in-house with C18 resin (ReproSil-Pur C18–AQ, 1.9 μm resin, Dr. Maisch GmbH). A step-wise gradient from 95% solvent A (0.1% formic acid) and 5% solvent B (80% acetonitrile, 0.1% formic acid) to 50% solvent B over 60 min at a flow rate of 0.2 μl/min was used. Data acquisition mode was set to obtain one high resolution MS scan in the FT part of the mass spectrometer at a resolution of 240,000 full width at half-maximum (at m/z 400) followed by 20 MS/MS scans (TOP20) in the linear ion trap of the most intense ions using rapid scan speed. Unassigned and singly charged ions were excluded from analysis. Dynamic exclusion duration was set to 30 seconds.
Project description:Cells were treated with DMSO (biological triplicate) or degrader at indicated dose and time (Meta Treatment Table) and cells were harvested by centrifugation. Lysis buffer (8 M Urea, 50 mM NaCl, 50 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (EPPS) pH 8.5, Protease and Phosphatase inhibitors from Roche) was added to the cell pellets and homogenized by 20 passes through a 21 gauge (1.25 in. long) needle to achieve a cell lysate with a protein concentration between 1 - 4 mg/mL. A micro-BCA assay (Pierce) was used to determine the final protein concentration in the cell lysate. 200 µg of protein for each sample were reduced and alkylated as previously described1. Proteins were precipitated using methanol/chloroform. In brief, four volumes of methanol were added to the cell lysate, followed by one volume of chloroform, and finally three volumes of water. The mixture was vortexed and centrifuged to separate the chloroform phase from the aqueous phase. The precipitated protein was washed with three volumes of methanol, centrifuged and the resulting washed precipitated protein was allowed to air dry. Precipitated protein was resuspended in 4 M Urea, 50 mM HEPES pH 7.4, followed by dilution to 1 M urea with the addition of 200 mM EPPS, pH 8. Proteins were first digested with LysC (1:50; enzyme:protein) for 12 hours at room temperature. The LysC digestion was diluted to 0.5 M Urea with 200 mM EPPS pH 8 followed by digestion with trypsin (1:50; enzyme:protein) for 6 hours at 37 °C. Tandem mass tag (TMT) reagents (Thermo Fisher Scientific) were dissolved in anhydrous acetonitrile (ACN) according to manufacturer’s instructions. Anhydrous ACN was added to each peptide sample to a final concentration of 30% v/v, and labeling was induced with the addition of TMT reagent to each sample at a ratio of 1:4 peptide:TMT label. The 11 or 16-plex labeling reactions were performed for 1.5 hours at room temperature and the reaction quenched by the addition of hydroxylamine to a final concentration of 0.3% for 15 minutes at room temperature. Each of the sample channels were combined in a 1:1 ratio, desalted using C18 solid phase extraction cartridges (Waters) and analyzed by LC-MS for channel ratio comparison. Samples were then combined using the adjusted volumes determined in the channel ratio analysis and dried down in a speed vacuum. The combined sample was then resuspended in 1% formic acid and acidified (pH 2 - 3) before being subjected to desalting with C18 SPE (Sep-Pak, Waters). Samples were then offline fractionated into 96 fractions by high pH reverse-phase HPLC (Agilent LC1260) through an aeris peptide xb-c18 column (phenomenex) with mobile phase A containing 5% acetonitrile and 10 mM NH4HCO3 in LC-MS grade H2O, and mobile phase B containing 90% acetonitrile and 10 mM NH4HCO3 in LC-MS grade H2O (both pH 8.0). The 96 resulting fractions were then pooled in a non-continuous manner into 24 fractions and these fractions were used for subsequent mass spectrometry analysis. Data were collected using an Orbitrap Fusion Lumos mass spectrometer (Thermo Fisher Scientific, San Jose, CA, USA) coupled with a Proxeon EASY-nLC 1200 LC pump (Thermo Fisher Scientific) or an Orbitrap Eclipse Tribrid mass spectrometer (Thermo Fisher Scientific, San Jose, CA, USA) coupled with an UltiMate 3000 RSLCnano System. Peptides were separated on an EasySpray ES803a/ES803a.rev2 75 μm inner diameter microcapillary column (Thermo Fisher Scientific) or a 100 µm inner diameter microcapillary column packed with ~ 50 cm of Accucore C18 resin (2.6 µM, 100 Å, Thermo Fisher Scientific). Peptides were separated using a 190 min gradient of 6 - 27% acetonitrile in 1.0% formic acid with a flow rate of 300 or 350 nL/min. Each analysis used an MS3-based TMT method as described previously. The data were acquired using a mass range of m/z 340 – 1350, resolution 120,000, AGC target 5 x 105, maximum injection time 100 ms, dynamic exclusion of 120 seconds for the peptide measurements in the Orbitrap. Data dependent MS2 spectra were acquired in the ion trap with a normalized collision energy (NCE) set at 35%, AGC target set to 1.8 x 104 and a maximum injection time of 120 ms. MS3 scans were acquired in the Orbitrap with a HCD collision energy set to 55%, AGC target set to 2 x 105, maximum injection time of 150 ms, resolution at 50,000 and with a maximum synchronous precursor selection (SPS) precursors set to 10.
Project description:We performed LC-MSMS analysis using both CID and ETD for the identification of endogenous peptides. Endogenous peptides were extracted from mouse AtT 20 cells by acidified methanol method and all large molecules including proteins were removed by centrifugation. The supernatant containing endogenous peptides was freeze-dried. For LC-MSMS analysis, extracted peptides were resuspended and injected to Ultimate 3000 HPLC system and analysed on LTQ Orbitrap XL mass spectrometer. A 60 min gradient from 2% acetonitrile to 50% acetonitrile, both containing 0.1% formic acid was used to separate peptides on C18 column.The LTQ-Orbitrap mass spectrometer was operated in data-dependent mode, automatically switching between MS and MS/MS acquisition for the three most abundant peaks in a given MS spectrum. A chosen precursor ion was first fragmented by CID and ETD. Data processing: The raw data files were processed with Proteome Discoverer 1.3. The CID and ETD spectra were then written to Mascot generic files. OMSSA (version 2.1.9) was used and b- and y- ions were selected for CID data, and c-, y- and z- ions were used for ETD. The spectra were searched by setting the parent ion mass accuracy to +/- 0.02 Da. For fragment ions, the mass tolerance was set to +/- 0.4 Da. For the genome-wide peptide search, the mouse genomic sequence (NCBI build 37.61) was directly translated in its 6 reading frames, and used for spectral searching. No enzymatic cleavage was taken into account during the database searches. No variable PTMs were included.
Project description:30 µg proteins per sample were reduced (20 mM DTT Sigma, room temperature RT, 1 h) and S-alkylated (50 mM IAA Sigma, 1 h, dark). The remaining IAA was quenched with 20 mM DTT for 1 h in the dark. The proteins were digested with 1:50(w/w enzyme:protein) MS-grade trypsin/lys-C mix (Thermo Scientific) for 24 h at RT. The enzyme digestion was quenched by lowering the pH with formic acid (Fisher) and the sample was desalted with ZipTip C18 (Merck-Millipore) column. Samples were resuspended in 10 µl of 0.2% formic acid prior LC-MS/MS analysis.
Project description:Carfilzomib-sensitive (AMO1) and resistant (AMO1-CFZ) MM cells were grown in RPMI-1640 medium supplemented with 10 % FBS and 0.68 mM L-glutamine, in a humidified incubator at 5% CO2 and 37 °C. The AMO1-CFZ medium was additionally added 90 nM CFZ, while the CFZ sensitive AMO1 cells were added vehicle (0.009 % DMSO) only. AMO1-CFZ was either harvested directly or grown for 1 week in CFZ free medium (vehicle only) prior to harvest. AMO1 and carfilzomib-resistant AMO1-CFZ cells were resuspended in 100 µl 1% sodium deoxycholate, 100 mM Tris-HCl pH 8.5, 10 mM tris(2-carboxyethyl)phosphine (TCEP), 40 mM chloroacetamide (CAA), heated at 90 °C for 45 min and sonicated for 10 cycles (30 s ON/30 s OFF) using a Bioruptor pico sonicator. After centrifugation at 16000 × g for 10 min, 50 µg soluble protein from each sample was added 100 µl 0.1M ammonium bicarbonate, 0.5 µg trypsin and digested overnight at 37°C. Peptides were desalted using C18 spin columns, dried in a speedvac centrifuge and resuspended in 0.1% formic acid prior to MS analysis. Label-free quantitatative (LFQ) LC-MS/MS was performed on a timsTOF Pro (Bruker Daltonics) connected to a nanoElute (Bruker Daltonics) HPLC. Peptides were separated over a Bruker PepSep C18 (75 µm × 15 cm) column with running buffers A (0.1 % formic acid) and B (0.1 % formic acid in acetonitrile) using a 100 min gradient from 2 % B to 40 % B. The timsTof instrument was operated in the DDA PASEF mode with 10 PASEF scans per acquisition cycle and accumulation and ramp times of 100 ms each. The ‘target value’ was set to 20000 and dynamic exclusion was activated and set to 0.4 min. The quadrupole isolation width was set to 2 Th for m/z < 700 and 3 Th for m/z > 800.
Project description:The concentrations of twenty kinds of hormones in the follicular fluid were detected by high-performance liquid chromatography–mass spectrometry (HPLC-MS/MS). An Agilent 1200 series high-performance liquid chromatography (HPLC) instrument (Agilent, USA) was utilized. A PAL autosampler (CTC, Swiss) and a Gemini-NX-C18 column (2.0 mm×50 mm, 3 μm, Waters, USA) were used. The ion source was an API-4000 quadrupole electrostatic field orbit trap high-resolution mass spectrometer (Applied Biosystems, USA). The scanning mode was multiple reaction monitoring (MRM) (Agilent-1200 LC system coupled to an API400 mass spectrometer).
Project description:Bacteria was grown at 30C in 3 different conditions, i.e. SYN (syngas and minimal medium- ATCC no 1789), AC (0.3% acetate in minimal medium- ATCC no 1789) and TSB (tryptic soy broth). After harvesting by centrifugation, O. carboxidovorans pellets (1g) were lysed in 100 mM Tris-Cl pH 8.0, 2% Triton X-100, 2.6 mg/ml sodium azide, 8 mM PMSF by sonication on ice (4 pulses of 15 s duration each). For each condition of growth 4 samples (1g pellets) were separately treated (i.e. lysed and processed further). The supernatants were treated with 50% cold TCA, and the precipitated protein washed with acetone. The pellets were resuspended in solubilization buffer (7M urea, 20 mM tris-Cl, pH 8.0, 5 mM EDTA, 5 mM MgCl2, 4% CHAPS), and protein concentration was determined using the Plus One 2-D Quant Kit (Amersham) following the manufacturers instructions. Protein samples from each treatment were stored at -80 C. One hundred micrograms of each protein sample was resuspended in 0.1 M ammonium bicarbonate, 5% HPLC grade ACN, reduced in 5 mM DTT (65 C, 5 min), alkylated in 10 mM iodoacetamide (30 C, 30 min), and then trypsin digested until there was no visible pellet (1:50 w/w 37 C, 16 h). Peptides were desalted using a peptide microtrap (Michrom BioResources, Auburn, CA) and eluted using a 0.1% TFA, 95% ACN solution. Desalted peptides were dried in a vacuum centrifuge and resuspended in 20 ?l of 0.1% formic acid. Peptides were separated by strong cation exchange (SCX) liquid chromatography (LC) followed by reverse phase (RP) LC coupled directly in line with electrospray ionization (ESI) tandem mass spectrometry (MS/MS). 2DLC ESI MS/MS was done exactly as described (1). All searches were done using TurboSEQUEST (Bioworks Browser 3.2; Thermo Electron). Mass spectra and tandem mass spectra were searched against all annotated proteins from the strain OM5 including all the annotated plasmid-encoded proteins. Cysteine carbamidomethylation and methionine oxidation (single and double) were included in the search strategy. We used the reverse database functionality in Bioworks 3.2 and searched MS2 data against a reversed OM5 database using identical search criteria.