Project description:Proteomic analysis of chick vestibualr hair bundles purified using the twist-off method. See Description.doc. Utricle hair bundles were purified from E20–21 chicks using the twist-off method (Gillespie & Hudspeth J Cell Biol 112, 625-640, 1991; Shin et al. Neuron 53, 371-386, 2007). NuPAGE LDS sample buffer (Invitrogen) with 50 mM dithiothreitol was added to a combined final volume of 80 µl per 100 utricles' worth of bundles; samples were heated to 70°C for 15 min. Epithelial proteins were similarly solubilized with sample buffer. Proteins were separated by running ~1 cm into a NuPAGE 4–12% Bis-Tris gel (1.5 mm x 10 well; one or two lanes per bundle sample); gels were rinsed with water, then stained with Imperial Protein Stain (Thermo Scientific). The 1 cm of gel with separated proteins was manually sliced into six pieces. Gel pieces were transferred to siliconized tubes and washed and destained in 200 µl 50% methanol overnight. The gel pieces were dehydrated in acetonitrile, rehydrated in 30 µl of 10 mM dithiothreitol in 0.1 M ammonium bicarbonate and reduced at room temperature for 0.5 h. The DTT solution was removed and the sample alkylated in 30 µl 50 mM iodoacetamide in 0.1 M ammonium bicarbonate at room temperature for 0.5 h. The reagent was removed and the gel pieces dehydrated in 100 µl acetonitrile. The acetonitrile was removed and the gel pieces rehydrated in 100 µl 0.1 M ammonium bicarbonate. The pieces were dehydrated in 100 µl acetonitrile, the acetonitrile removed and the pieces completely dried by vacuum centrifugation. The gel pieces were rehydrated in 20 ng/µl trypsin (Sigma-Aldrich T6567 proteomics grade, from porcine pancreas, dimethylated) in 50 mM ammonium bicarbonate on ice for 10 min. Any excess enzyme solution was removed and 20 µl 50 mM ammonium bicarbonate added. The sample was digested overnight at 37°C and the peptides formed extracted from the polyacrylamide in two 30 µl aliquots of 50% acetonitrile/5% formic acid. These extracts were combined and evaporated to 15 µl for MS analysis. For the gel slice immediately adjacent to the agarose, peptides were purified away from interfering polymers by SCX. A single experiment's worth of hair bundles or epithelium was analyzed by six LC-MS/MS runs, corresponding to the six gel pieces. The LC-MS/MS system consisted of a Thermo Electron Orbitrap Velos ETD mass spectrometer system with a Protana nanospray ion source, which was interfaced to a reversed-phase capillary column of 8 cm length x 75 µm internal diameter, self-packed with Phenomenex C18 Jupiter of 10 µm particle size. An extract aliquot (7.5 µl) was injected and peptides eluted from the column by an acetonitrile/0.1 M acetic acid gradient at a flow rate of 0.5 µl/min over 1.2 hr. The nanospray ion source was operated at 2.5 kV. The digest was analyzed using the data-dependent capability of the instrument, acquiring—in sequential scans—a single full scan mass spectrum in the Orbitrap detector at 60,000 resolution to determine peptide molecular weights, and 20 product-ion spectra in the ion trap to determine amino acid sequence. MaxQuant version 1.2.2.5 software was used for protein identification and quantitation. The default contaminants file associated with the MaxQuant download was edited to remove entries known to be present in hair bundles (e.g., actin) and to add additional impurities that entered the bundle-purification workflow (keratins, hemoglobins, egg white components). Mass spectrometry data were searched against Ensembl version 66 (released February, 2012) using Andromeda; the Ensembl FASTA file was edited by replacing several sequences with longer or full-length sequences, including actin gamma 1 (NP_001007825.1), actin beta (NP_990849.1), fascin 1 (NP_001171603), fascin 2 (NP_001171209), ATP synthase beta (NP_001026562.1), peptidylprolyl isomerase A (NP_001159798.1), calbindin 2 (NP_990647.1), PDZD7 (XP_003641537.1), espin (XP_417532.3), and CACNA2D2 (XP_427707.3). Protein identifications were reported with an FDR of 1%. If a set of peptides for a protein was identical to or completely contained within that of another protein, MaxQuant groups those proteins together ("redundant groups"); the entry with the largest number of peptides was used to identify the redundant group. Redundant groups that shared more than 20% of their identified peptides were further grouped in our analysis ("shared-peptide groups"); the entry with the greatest intensity associated with it was used to identify the shared-peptide group.

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.

Project description:Female Sprague-Dawley rats were randomly separated into two groups: i) trained (Ex group) and ii) sedentary (Cont group). Animals from the Ex group were adapted to treadmill exercise for two consecutive weeks, involving a gradual increase in the running time till 60 min/day at 20 m/min, 0% grade, 5 days/week. This exercise program remained constant until the end of the 54 weeks. Mitochondria isolation from 10 animals (5 Ex group and 5 Cont group) was performed using the conventional methods of differential centrifugation. Mitochondrial protein extracts were reduced with dithiothreitol, alkylated with iodoacetamide and digested with trypsin using the FASP procedure (18). Briefly, each sample was solubilized in 4 % SDS, 0.1 M DTT, 0.1 M HEPES and incubated for 30 min at 60 C. Then, samples were mixed with 0.2 mL of a solution of 8 M Urea, 0.1 M HEPES, pH 8.5 (UH solution), loaded into the filtration devices (3k Microcon, Millipore), centrifuged at 14,000 g for 20 min, and washed twice with UH solution. After centrifugation, the concentrates were alkylated with 50 mM iodoacetamide in UH solution (dark, 25 C, 20 min), and washed twice with UH solution. The concentrate was diluted with 0.1 mL of 50 mM ammonium bicarbonate (ABC) and digested overnight (37 C) with the addition of 2 ug of trypsin diluted in 30 uL of 50 mM ABC. The resulting tryptic peptides were collected by centrifugation and the filter were washed twice with 50 uL of 50 mM ABC. Eluted peptides were acidified with 10 uL of formic acid and cleaned up on a homemade Empore C18 column (3M, St. Paul, MN, USA) (ref) for subsequent phospho-enrichment and/or analysis by LC-MS/MS. The dried protein digest was dissolved with 10 uL (3 % ACN, 0.1 % TFA), diluted 1:5 with loading buffer (1 M glycolic acid, 5 % TFA, 80 % ACN) and phosphopeptides were enriched on TiO2-beads as previously described (19). Briefly 5 mg of "Titansphere TiO2 5 um" were suspended in 100 uL of 100 % ACN, immobilized in a pipette-column and washed using 5 uL of loading buffer. Each sample was loaded in each pipette-column and then washed with 30 uL of washing buffer (1 % TFA, 80 % ACN). Phosphopeptides were eluted from the beads with 25 uL of 25 % ACN (v/v) containing 25 % NH4OH (m/v), acidified with 10 uL of 10 % TFA and vacuum- concentrated to approximately 4 uL. Samples were finally diluted to 10 uL with H2O + 0.1% formic acid prior to injection. The peptides mixtures were analyzed by online nanoflow liquid chromatography tandem mass spectrometry (nanoLC-MS/MS) on an EASY-nLC system (Proxeon Biosystems, Odense, Denmark) connected to the LTQ Orbitrap Velos instrument (Thermo Fisher Scientific, Bremen, Germany) through a nanoelectrospray ion source. Six microliters of the peptide mixture were auto-sampled directly onto the analytical HPLC column (120 mm x75 um I.D., 3 um particle size (Nikkyo Technos Co., Ltd.) with a 120-min gradient from 5 % to 50 % ACN in 0.1 % FA. The effluent from the HPLC column was directly electrosprayed into the mass spectrometer. The LTQ Orbitrap Velos instrument was operated in data-dependent acquisition mode to automatically switch between full scan MS and MS/MS acquisition. The MS survey scan was performed in the FT cell recording a window between 350 and 2000 m/z. The resolution was set to 60 000, and the automatic gain control was set to 1,000,000 ions with a maximal acquisition time of 400 ms. The 20 most intense peptide ions with charge states great than or equal to 2 were sequentially isolated to a target value of 5,000 and fragmented in the high-pressure linear ion trap by low-energy CID with normalized collision energy of 35% Q value of 0.25, and an activation time of 10 ms. Raw files were processed using Proteome Discoverer version 1.3 (Thermo Fisher Scientific, Bremen). Peak lists were searched using Mascot software version 2.3 (Matrix Science, UK) against a SwissProt database containing entries corresponding to Rattus norvegicus (version of July 2012), a list of common contaminants, and all the corresponding decoy entries. Trypsin was chosen as enzyme and a maximum of two miscleavages were allowed. Carbamidomethylation (C) was set as a fixed modification, whereas oxidation (M) and phosphorylation (STY) were used as variable modifications. Searches were performed using a peptide tolerance of 7 ppm, a product ion tolerance of 0.5 Da. Resulting data files were filtered for FDR less than 1 % at peptide level.

Project description:Some molecular and cellular mechanisms of fertilization are still not completely described. The role of the acrosomal matrix (AM), the particulate compartment within the acrosome, is one of them. Here, we proposed that amyloids, highly ordered protein aggregates, by their physical and chemical properties could contribute to AM roles in fertilization. Purified AM were exposed to a two-step extraction to sequentially strip off soluble proteins. The remaining insoluble material (core) was subjected to a mass spectrometry analysis. Preparation of samples for MS analysis: Three different approaches were used to optimize identification of peptides in the AM core. For in-gel digestion, core samples were resuspended in 13.2mM SA pH3 containing 8M urea and 100 mM DTT and incubated for 1 hr at RT. Proteins were separated on a hand casted 12% polyacrylamide Tris-glycine gel. After silver staining, visible bands were cut from the gel, destained and washed with ddH2O (2 X 5 min) then with 50% ethanol (2 X 5 min) before stored at -20 degrees C. Gel pieces were tryptically digested in 25mM triethylammonium bicarbonate buffer at 37 degrees C overnight with trypsin. For in-solution digestion, core samples were resuspended in 13.2mM SA pH3/ 8M urea/ 100mM DTT and incubated for 1 h at RT followed by 15 min at 70 degrees C. Iodoacetamide was added to 10mM and proteins were alkylated by incubation for 15 min at RT in the dark. Samples were added to a pre-rinsed spin filter and centrifuged at 14,000 X g. Samples were washed with 9M urea then with 25mM ammonium bicarbonate. Samples were digested with trypsin in 25mM ammonium bicarbonate overnight. After digestion, samples were spin at 14,000 X g and washed 2 times with 25mM ammonium bicarbonate. The retentate was transferred to a new tube and air dried. For on-membrane digestion, the samples were dotted on nitrocellulose membrane and digested by trypsin. Briefly, core samples were resuspended and treated as for in-solution digestion. Then, samples were dotted by gravity on the membrane. Wells were rinsed with 20mM SA pH3 followed by TBS. Dots were cut and air-dried. After the protein digestion with trypsin in 25mM ammonium bicarbonate the membranes were dissolved with acetone and the precipitated peptides were air-dried. All digested peptides were reconstituted in 2% acetonitrile/ 0.1% formic acid for MS analysis. MS data acquisition: Protein identification by liquid chromatography tandem mass spectrometry (LCMS/MS) analysis of peptides was performed using an LTQ Orbitrap Velos MS interfaced with a 2D nanoLC system. Protein and Peptide Identification: MS/MS spectra were extracted using the ProteoWizard Toolkit. The spectra were analyzed using the GPM Manager with X!Tandem to search against a home made mouse database containing 213,054 nonredundant protein sequences created by using mouse sequences from Ensembl database (files Mus_musculus.GRCm38.73.pep.all & Mus_musculus.GRCm38.73.pep.abinitio) and from NCBI database (file nr downloaded on 09/19/2013) . Search was performed using fully tryptic enzyme specificity (See deposited MS data for details). Peptides and proteins that have an expectation value of log10 (e) <= -2 were included in the results. Curated results were obtained by keeping only proteins with at least one mouse-specific matching peptide (peptide match = 100% identities and 100% coverage on a unique mouse protein and <100% identities and/or <100% coverage on human proteins). In addition, trypsin-like proteins were kept if at least one peptide was not matching on exogenous pig trypsins.

Project description:Mitochondrial fraction was obtained using the mitochondrial isolation kit (KC010100, BioChain Institute). Each tissue was finely chopped and homogenized 40 strokes in two volumes of mitochondrial isolation buffer, and then centrifuged at 600×g for 10 min. The supernatant was collected and centrifuged at 12,000×g for 15 min. The supernatant was used as cytosolic fraction containing lysosomes and microsomes. The mitochondrial fraction was obtained from the pellet and resuspended in mitochondrial isolation buffer. The suspended mitochondria were sonicated (TOMY, Ultrasonic disruptor UD-100, output level 30, 30 sec×2) and centrifuged at 105,000×g for 30 min. The supernatant was used as the mitochondrial soluble fractions, containing mitochondrial intermembrane space (IMS) and matrix (MAT). The pellet was resuspended in RIPA buffer and centrifuged at 20,000×g for 30 min. The supernatant was used as the mitochondrial membrane fractions, containing mitochondrial outer membrane (OM) and inner membrane (IM). All the procedures were performed at 4°C. Mitochondrial and cytosolic fractions of WT and ES1-KO mouse brain were isolated as described 2.1 in 1% triton x-100 in 20 mM Tris-HCl. These samples were concentrated by SDS-PAGE and cut out from gels. The sectioned gels were finely chopped and washed with water. Then, the gel pieces were destained 50% methanol and vortexed in 25 mM ammonium bicarbonate containing 50% acetonitrile for 5 min. The supernatant was removed and the gel pieces were soaked 100% acetonitrile for 1 min. After removing the solution, the gel pieces were dried in vacuo, and rehydrated with a reducing solution (50 mM ammonium bicarbonate and 25 mM dithiothreitol), and incubated for 40 min at 56°C. The reducing buffer was removed and gel pieces were soaked in an alkylating solution (50 mM ammonium bicarbonate containing 55 mM iodoacetamide) for 30 min at room temperature in the dark. After removing the alkylation solution, the gel pieces were washed twice with water and vortexed in 25 mM ammonium bicarbonate containing 50% acetonitrile for 5 min, and then soaked 100% acetonitrile for 1 min. After removing the solution, the gel pieces were dried in vacuo and rehydrated with 50 mM ammonium bicarbonate containing 4 ng/μL sequencing grade trypsin and 0.01% Protease Max Surfactant. After incubating 10 min on ice, an equivalent volume of 50 mM ammonium bicarbonate containing 0.01% Protease Max Surfactant was added and incubated for 3 h at 37°C to digest the proteins in the gels with a protease. The equivalent volume of 1% trifluoroacetic acid was added and vortexed for 10 min for extraction of the tryptic fragments. After centrifuged at 12,000×g for 15 min, the peptide solutions were obtained from the supernatant. Ten microliters of each peptide solution were diluted with 190 μL of 100 mM ammonium bicarbonate and filtered on with a 0.22 μm using the amicon ultrafiltration unit (Amicon Ultra, 3 kDa, Millipore, MA, USA). Concentrated samples were denatured with an equivalent volume of trifluoroethanol (25 μL) and reduced with 1 μL of 200 mM dithiothreitol (DTT). The samples were incubated at 90°C for 30 min and cooled to room temperature. Free cysteine residues were alkylated with 4 μL of 200 mM iodoacetamide for 60 min at room temperature in the dark and the remaining iodoacetamide was quenched by adding 1 μL of 200 mM DTT. The samples were then mixed with 300 μL of 100 mM ammonium bicarbonate. Fifteen microliters of the sample were diluted with 85 μL of 100 mM ammonium bicarbonate and incubated with 1 μg trypsin (TPCK treated, AB Sciex, Framingham, MA, USA) at 37 °C for 18 h. The samples were desalted with C18 ZipTip (Millipore, Bedford, MA, USA) and eluted with H2O/acetonitrile (5/5; v/v). The ZipTip eluates were dried in a vacuum centrifuge. Desalted samples were rehydrated in 0.1% formic acid (FA) and were analyzed by LC-MS using a nanoLC Eksigent 400 system (Eksigent, AB Sciex), coupled online to a TripleTOF6600 mass spectrometer (AB Sciex). Peptide separation was performed using liquid chromatography with a trap and elution conﬁguration using a nano trap column (350 μm×0.5 mm, 3 μm, 120 Å, AB Sciex) and a nano ChromXP C18 reverse-phase column (75 μm×15 cm, 3 μm, 120 Å, AB Sciex) at 300 nL/min with a 90 min linear gradient of 8-30% acetonitrile in 0.1% FA, and then, with a 10 min linear gradient of 30% to 40% acetonitrile in 0.1% FA. The mass spectrometer was operated in information-dependent acquisition (IDA) mode, scanning full spectra (400–1500 m/z) for 250 ms, followed by up to 30 MS/MS scans (100–1800 m/z for 50 ms each), for a cycle time of 1.8 s. Candidate ions with a charge state between +2 and + 5 and counts above a minimum threshold of 125 counts per second were isolated for fragmentation, and one MS/MS spectrum was collected before adding those ions to the exclusion list for 12 s. The rolling collision energy was used with a collision energy spread of 15. The mass spectrometer was operated using the Analyst TF 1.7.1 software program (AB Sciex). For data-dependent acquisition (DDA, SWATH acquisition), the parameters were set as follows: 100 ms TOF MS scan, followed by 200 variable SWATH windows each at 50 ms accumulation time for m/z 400–1250. MS/MS SWATH scans were set at 5 Da window overlapping by 1 Da for m/z 400–1250 and varied on each side of the mass range. The total cycle time was 9.6 s. Rolling collision energy (CE) parameter script was used to automatically control the CE. Acquired spectra were searched against the UniProt reviewed database using the Paragon algorithm embedded in the ProteinPilot 5.0.1 software program (AB Sciex), with the following search parameters: (i) sample type: identiﬁcation, (ii) Cys alkylation: iodoacetamide, (iii) digestion: trypsin, (iv) instrument: TripleTOF 6600, (v) species: Mus musculus, (vi) ID focus: biological modiﬁcations, (vii) detected protein threshold: > 0.05 (10% conﬁdence). The detected protein threshold was set to the minimum level to enhance the number of wrong answers to enable the curve ﬁtting by an independent FDR analysis. This was carried out by the target-decoy approach provided with the ProteinPilot software program, which was used to assess the quality of the identiﬁcations. Positive identiﬁcations were considered when identiﬁed proteins and peptides reached a 1% local FDR. The resulting group file was loaded into Peakview (v2.2.0, AB Sciex) and peaks from SWATH runs were extracted with a peptide confidence threshold of 99% and a false discovery rate <1%. The SWATH ﬁles were then exported to the MarkerView software program (version 1.3.0.1; AB Sciex) and the peak areas of individual peptides were normalized to the sum of the peak areas of all detected peptides.

Project description:The experiment consists of M.hyp 232 cultures digests analyzed on two mass specs, LTQ Velos Pro and LTQ FT Ultra LTQ Velos Pro: Six cell culture replicates of M.hyo 232 were hydrophobically separated using tree detergents: Digitonin, Tween, and SDS. Each francion, including the insoluble pellet, was trypsin digested and then cleaned using an SCX trap follwed by a RP trap to remove detergents. Each fraction was sepated using a Dionex U3000 splitless nanoflow system operating at 333 nl per minute using a gradient of 2% ACN to 50% ACN in 4 hours. Eluate was analyzed using an LTQ Velos Pro mass spectrometer with 20 MS/MS scans of the 20 most intense peaks from each MS scan. Dynamic exclusion was enable for 3 minutes for each m/z with a repeat count of 1. LTQ FT Ultra: Two cell pellets for high resolution analysis were lysed and trypsin digested. Digested peptides were dried, resuspended in 20 mM KH2PO4, 20% ACN, pH 3 (Buffer A) in 2.5 µL and transferred to low retention vials in preparation for separation using an Ultimate 3000 configured for 2D-LC. Each sample was loaded at 15 µl/min onto an SCX microtrap for the first dimension of separation, involving SCX steps of Buffer A + 0, 5, 10, 15, 20, 25, 30, 40, 50, 100, 250, 500, and 1000 mM KCl. For the second dimension of separation, each eluted salt step was desalted with an inline peptide microtrap with 2% ACN, 0.1% FA at 5 µl/min. Once desalted, the microtrap was switched into line with a fritless nano column (75µm x ~10cm) containing C18 media (5µ, 200 Å Magic, Michrom). Peptides were eluted using a gradient of 2% to 36% ACN, 0.1% FA at 350 nl/min over 60 min and electrospray ionized for analysis using an LTQ FT Ultra mass spectrometer. A survey scan m/z 350-1750 was acquired in the FT ICR cell (Resolution = 100,000 at m/z 400, with an accumulation target value of 1,000,000 ions). Up to the 6 most abundant ions (>3,000 counts) with charge states > +2 were sequentially isolated and fragmented within the linear ion trap using collisionally induced dissociation with an activation q = 0.25 and activation time of 30 ms at a target value of 30,000 ions. M/z ratios selected for MS/ MS were dynamically excluded for 30 seconds. Analysis: X!tandem searches were performed using the Mycoplasma hyopneumoniae strain 232 reference protein set from NCBI. The only difference between the searches for the LTQ Velos and LTQ FT was the precursor mass tolenance being set to +-1500ppm and +-24ppm respectively. Decoy searches were performed and the data filtered at e-value <= 0.01 with single peptide proteins discarded. These results are included in the submission as two tab-delimited text files.

Dataset Information

Cyanophora paradoxa muroplast LC-MSMS

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Proteomic analysis of the Cyanophora paradoxa muroplast provides clues on early events in plastid endosymbiosis.

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