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Melfi MT, Kanawati B, Schmitt-Kopplin P, Macchia L, Centonze D, Nardiello D. Investigation of fennel protein extracts by shot-gun Fourier transform ion cyclotron resonance mass spectrometry. Food Res Int 2021; 139:109919. [PMID: 33509486 DOI: 10.1016/j.foodres.2020.109919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/03/2020] [Accepted: 11/21/2020] [Indexed: 10/22/2022]
Abstract
A rapid shot-gun method by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is proposed for the characterization of fennel proteins. After enzymatic digestion with trypsin, few microliters of extract were analyzed by direct infusion in positive ion mode. A custom-made non-redundant fennel-specific proteome database was derived from the well-known NCBI database; additional proteins belonging to recognized allergenic sources (celery, carrot, parsley, birch, and mugwort) were also included in our database, since patients hypersensitive to these plants could also suffer from fennel allergy. The peptide sequence of each protein from that derived list was theoretically sequenced to produce calculated m/z lists of possible m/z ions after tryptic digestions. Then, by using a home-made Matlab algorithm, those lists were matched with the experimental FT-ICR mass spectrum of the fennel peptide mixture. Finally, Peptide Mass Fingerprint searches confirmed the presence of the matched proteins inside the fennel extract with a total of 70 proteins (61 fennel specific and 9 allergenic proteins).
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Affiliation(s)
- Maria Teresa Melfi
- Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Via Napoli, 25, 71122 Foggia, Italy
| | - Basem Kanawati
- Research Unit Analytical BioGeoChemistry (BGC), Helmholtz Zentrum München, Ingolstaedter Landstrasse, 85764 Neuherberg, Germany.
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry (BGC), Helmholtz Zentrum München, Ingolstaedter Landstrasse, 85764 Neuherberg, Germany; Chair of Analytical Food Chemistry, Technical University of Munich, Alte Akademie 10, D-85354 Freising, Germany
| | - Luigi Macchia
- Dipartimento dell'Emergenza e dei Trapianti di Organi, Sezione di Allergologia ed Immunologia Clinica, Università degli Studi di Bari, Piazza G. Cesare, 11, 70124 Bari, Italy
| | - Diego Centonze
- Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Via Napoli, 25, 71122 Foggia, Italy
| | - Donatella Nardiello
- Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Via Napoli, 25, 71122 Foggia, Italy.
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Kolli V, Schumacher KN, Dodds ED. Ion mobility-resolved collision-induced dissociation and electron transfer dissociation of N-glycopeptides: gathering orthogonal connectivity information from a single mass-selected precursor ion population. Analyst 2018; 142:4691-4702. [PMID: 29119999 DOI: 10.1039/c7an01196b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glycopeptide-level mass spectrometry (MS) and tandem mass spectrometry (MS/MS) analyses are commonly performed to establish site-specific protein glycosylation profiles that are of central importance to gaining structure-function insights on glycoproteins. Confoundingly, the complete characterization of glycopeptide connectivity usually requires the acquisition of multiple MS/MS fragmentation spectra. Complementary ion fragmentation techniques such as collision-induced dissociation (CID) and electron transfer dissociation (ETD) are often applied in concert to address this need. While structurally informative, the requirement for acquisition of two MS/MS spectra per analyte places considerable limitations upon the breadth and depth of large-scale glycoproteomic inquiry. Here, a previously developed method of multiplexing CID and ETD is applied to the study of glycopeptides for the first time. Integration of the two dissociation methods was accomplished through addition of an ion mobility (IM) dimension that disperses the two stages of MS/MS in time. This allows the two MS/MS spectra to be acquired within a few milliseconds of one another, and to be deconvoluted in post-processing. Furthermore, the method allows both fragmentation readouts to be obtained from the same precursor ion packet, thus reducing the inefficiencies imposed by separate CID and ETD acquisitions and the relatively poor precursor ion to fragment ion conversion typical of ETD. N-Linked glycopeptide ions ranging in molecular weight from 1.8 to 6.5 kDa were generated from four model glycoproteins that collectively encompassed paucimannosidic, high mannose, and complex types of N-glycosylation. In each case, IM-resolved CID and ETD events provided complete coverage of the glycan topology and peptide sequence coverages ranging from 48.4% (over 32 amino acid residues) to 85.7% (over eight amino acid residues). The potential of this method for large-scale glycoproteomic analysis is discussed.
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Affiliation(s)
- Venkata Kolli
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588-0304, USA.
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Li Y, Zhuang Y. fmpRPMF: A Web Implementation for Protein Identification by Robust Peptide Mass Fingerprinting. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2017; 15:1728-1731. [PMID: 29035223 DOI: 10.1109/tcbb.2017.2762682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Peptide mass fingerprinting continues to play an important role in current proteomics studies based on its good performance in sample throughput, specificity for single peptides, and insensitive to unexpected post-translational modifications as compared with . Here, we proposed and evaluated the use of feature-matching pattern-based support vector machines (SVMs) for robust protein identification. This approach is now facilitated with an updated web server (fmpRPMF) incorporated with several newly developed or improved modules and workflows allowing identification of proteins from data.
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Fesenko I, Khazigaleeva R, Kirov I, Kniazev A, Glushenko O, Babalyan K, Arapidi G, Shashkova T, Butenko I, Zgoda V, Anufrieva K, Seredina A, Filippova A, Govorun V. Alternative splicing shapes transcriptome but not proteome diversity in Physcomitrella patens. Sci Rep 2017; 7:2698. [PMID: 28578384 PMCID: PMC5457400 DOI: 10.1038/s41598-017-02970-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022] Open
Abstract
Alternative splicing (AS) can significantly impact the transcriptome and proteome of a eukaryotic cell. Here, using transcriptome and proteome profiling data, we analyzed AS in two life forms of the model moss Physcomitrella patens, namely protonemata and gametophores, as well as in protoplasts. We identified 12 043 genes subject to alternative splicing and analyzed the extent to which AS contributes to proteome diversity. We could distinguish a few examples that unambiguously indicated the presence of two or more splice isoforms from the same locus at the proteomic level. Our results indicate that alternative isoforms have a small effect on proteome diversity. We also revealed that mRNAs and pre-mRNAs have thousands of complementary binding sites for long non-coding RNAs (lncRNAs) that may lead to potential interactions in transcriptome. This finding points to an additional level of gene expression and AS regulation by non-coding transcripts in Physcomitrella patens. Among the differentially expressed and spliced genes we found serine/arginine-rich (SR) genes, which are known to regulate AS in cells. We found that treatment with abscisic (ABA) and methyl jasmonic acids (MeJA) led to an isoform-specific response and suggested that ABA in gametophores and MeJA in protoplasts regulate AS and the transcription of SR genes.
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Affiliation(s)
- Igor Fesenko
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
| | - Regina Khazigaleeva
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ilya Kirov
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Moscow, Russia
| | - Andrey Kniazev
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Oksana Glushenko
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical Medicine, Moscow, Russia
| | - Konstantin Babalyan
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Georgij Arapidi
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Tatyana Shashkova
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical Medicine, Moscow, Russia
| | - Ivan Butenko
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical Medicine, Moscow, Russia
| | - Victor Zgoda
- Institute of Biomedical Chemistry, Moscow, Russian Federation
| | - Ksenia Anufrieva
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Anna Seredina
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Anna Filippova
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Vadim Govorun
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical Medicine, Moscow, Russia
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Koehler CJ, Bollineni RC, Thiede B. Application of the half decimal place rule to increase the peptide identification rate. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:227-233. [PMID: 27806443 DOI: 10.1002/rcm.7780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/21/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Many MS2 spectra in bottom-up proteomics experiments remain unassigned. To improve proteome coverage, we applied the half decimal place rule (HDPR) to remove non-peptidic molecules. The HDPR considers the ratio of the digits after the decimal point to the full molecular mass and results in a relatively small permitted mass window for most peptides. METHODS First, the HDPR mass filter was calculated for the human and other proteomes. Subsequently, the HDPR was applied to three technical replicates of an in-solution tryptic digest of HeLa cells which were analysed by liquid chromatography/mass spectrometry (LC/MS) using a quadrupole-orbitrap mass spectrometer (Q Exactive). In addition, the same sample was analysed three times with a fixed exclusion list. The exclusion list was based on only choosing doubly charged ions for fragmentation. RESULTS The peptide spectrum match (PSM) rate increased by 2-4% applying HDPR filters from 0.1-0.25 Da and 75-150 ppm, respectively. Excluding all MS2 events by applying an HDPR filter of doubly charged ions, we were able to improve PSMs by 0.9% and the PSM rate by 2.5%. CONCLUSIONS An algorithm to filter precursors based on the HDPR was established to improve the targeting of the acquisition of MS2 spectra in data-dependent acquisition (DDA) experiments. According to our data, a total gain of PSMs of 1-5% might be achievable if the HPDR filter would already be applied during MS data acquisition. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
| | | | - Bernd Thiede
- Department of Biosciences, University of Oslo, Oslo, Norway
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Rocha LADO, Oliveira KS, Migliolo L, Franco OL. Effect of Moderate Exercise on Mitochondrial Proteome in Heart Tissue of Spontaneous Hypertensive Rats. Am J Hypertens 2016; 29:696-704. [PMID: 26391256 DOI: 10.1093/ajh/hpv160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 08/19/2015] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Hypertension is a multifactorial disease and an important independent risk factor for cardiovascular diseases. Exercise training is one of the most important non-pharmacological therapeutic strategies for treating hypertension; however, mitochondrial adaptations in the hypertensive heart as a result of exercise remain obscure. METHODS Aiming to explore the effects of exercise training of moderate intensity on the mitochondrial proteome in hypertensive animal models before and after the pathology developed, 20 isogenic male spontaneous hypertensive rats (SHRs) were randomly divided into 2 groups, 1 with animals of 6 and 40 weeks of age. Animals were submitted to exercise training on a treadmill for 30 minutes, 5 days per week for 4 weeks at 90% of the anaerobic threshold (AT). A mitochondrial sample extract from the left ventricle was prepared and further analyzed using LC-MS/MS. RESULTS Proteomics analyses led to the identification of 143 proteins in all groups. The data showed a considerable and clear increase in the abundance of NADH dehydrogenase and ATP synthase, as well as voltage-dependent anion channel (VDAC) type 1 decrease in exercise groups. When exercise effects were compared, differential proteins expressed only in exercise increased, such as cytochrome c oxidase, alcohol dehydrogenase, and NADH dehydrogenase [ubiquinone] 1 alpha subcomplex. CONCLUSIONS The results support the proposition that moderate exercise induces a beneficial adaptation in left ventricle myocardial mitochondria in order to attenuate the decrease in ATP production in hypertensive models.
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Affiliation(s)
- Luiz Antonio de Oliveira Rocha
- Curso de Educação Física, Universidade Católica de Brasilia, Brasília, DF, Brazil; Curso de pós-graduação em Patologia Molecular, Universidade de Brasília, Brasília, DF, Brazil; Centro de Analises Proteomicas e Bioquimicas, Curso de Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil
| | - Kleber Souza Oliveira
- Centro de Analises Proteomicas e Bioquimicas, Curso de Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Catolica Dom Bosco, Campo Grande, MS, Brazil
| | - Ludovico Migliolo
- Centro de Analises Proteomicas e Bioquimicas, Curso de Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Catolica Dom Bosco, Campo Grande, MS, Brazil
| | - Octavio Luiz Franco
- Curso de pós-graduação em Patologia Molecular, Universidade de Brasília, Brasília, DF, Brazil; Centro de Analises Proteomicas e Bioquimicas, Curso de Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Catolica Dom Bosco, Campo Grande, MS, Brazil.
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Engaging challenges in glycoproteomics: recent advances in MS-based glycopeptide analysis. Bioanalysis 2015; 7:113-31. [PMID: 25558940 DOI: 10.4155/bio.14.272] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The proteomic analysis of glycosylation is uniquely challenging. The numerous and varied biological roles of protein-linked glycans have fueled a tremendous demand for technologies that enable rapid, in-depth structural examination of glycosylated proteins in complex biological systems. In turn, this demand has driven many innovations in wide ranging fields of bioanalytical science. This review will summarize key developments in glycoprotein separation and enrichment, glycoprotein proteolysis strategies, glycopeptide separation and enrichment, the role of mass measurement accuracy in glycopeptide detection, glycopeptide ion dissociation methods for MS/MS, and informatic tools for glycoproteomic analysis. In aggregate, this selection of topics serves to encapsulate the present status of MS-based analytical technologies for engaging the challenges of glycoproteomic analysis.
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8
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Szabo Z, Janaky T. Challenges and developments in protein identification using mass spectrometry. Trends Analyt Chem 2015. [DOI: 10.1016/j.trac.2015.03.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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9
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Wouters B, Vanhoutte DJ, Aarnoutse P, Visser A, Stassen C, Devreese B, Kok WT, Schoenmakers PJ, Eeltink S. Visualization procedures for proteins and peptides on flat-bed monoliths and their effects on matrix-assisted laser-desorption/ionization time-of-flight mass spectrometric detection. J Chromatogr A 2013; 1286:222-8. [DOI: 10.1016/j.chroma.2013.02.064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 01/25/2013] [Accepted: 02/18/2013] [Indexed: 11/26/2022]
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Li Y, Hao P, Zhang S, Li Y. Feature-matching pattern-based support vector machines for robust peptide mass fingerprinting. Mol Cell Proteomics 2011; 10:M110.005785. [PMID: 21775775 DOI: 10.1074/mcp.m110.005785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peptide mass fingerprinting, regardless of becoming complementary to tandem mass spectrometry for protein identification, is still the subject of in-depth study because of its higher sample throughput, higher level of specificity for single peptides and lower level of sensitivity to unexpected post-translational modifications compared with tandem mass spectrometry. In this study, we propose, implement and evaluate a uniform approach using support vector machines to incorporate individual concepts and conclusions for accurate PMF. We focus on the inherent attributes and critical issues of the theoretical spectrum (peptides), the experimental spectrum (peaks) and spectrum (masses) alignment. Eighty-one feature-matching patterns derived from cleavage type, uniqueness and variable masses of theoretical peptides together with the intensity rank of experimental peaks were proposed to characterize the matching profile of the peptide mass fingerprinting procedure. We developed a new strategy including the participation of matched peak intensity redistribution to handle shared peak intensities and 440 parameters were generated to digitalize each feature-matching pattern. A high performance for an evaluation data set of 137 items was finally achieved by the optimal multi-criteria support vector machines approach, with 491 final features out of a feature vector of 35,640 normalized features through cross training and validating a publicly available "gold standard" peptide mass fingerprinting data set of 1733 items. Compared with the Mascot, MS-Fit, ProFound and Aldente algorithms commonly used for MS-based protein identification, the feature-matching patterns algorithm has a greater ability to clearly separate correct identifications and random matches with the highest values for sensitivity (82%), precision (97%) and F1-measure (89%) of protein identification. Several conclusions reached via this research make general contributions to MS-based protein identification. Firstly, inherent attributes showed comparable or even greater robustness than other explicit. As an inherent attribute of an experimental spectrum, peak intensity should receive considerable attention during protein identification. Secondly, alignment between intense experimental peaks and properly digested, unique or non-modified theoretical peptides is very likely to occur in positive peptide mass fingerprinting. Finally, normalization by several types of harmonic factors, including missed cleavages and mass modification, can make important contributions to the performance of the procedure.
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Affiliation(s)
- Youyuan Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, P R China
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11
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Birdsall RE, Kiley MP, Segu ZM, Palmer CD, Madera M, Gump BB, MacKenzie JA, Parsons PJ, Mechref Y, Novotny MV, Bendinskas KG. Effects of lead and mercury on the blood proteome of children. J Proteome Res 2011; 9:4443-53. [PMID: 20681587 DOI: 10.1021/pr100204g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heavy metal exposure in children has been associated with a variety of physiological and neurological problems. The goal of this study was to utilize proteomics to enhance the understanding of biochemical interactions responsible for the health problems related to lead and mercury exposure at concentrations well below CDC guidelines. Blood plasma and serum samples from 34 children were depleted of their most abundant proteins using antibody-based affinity columns and analyzed using two different methods, LC-MS/MS and 2-D electrophoresis coupled with MALDI-TOF/MS and tandem mass spectrometry. Apolipoprotein E demonstrated an inverse significant association with lead concentrations (average being one microgram/deciliter) as deduced from LC-MS/MS and 2-D electrophoresis and confirmed by Western blot analysis. This coincides with prior findings that Apolipoprotein E genotype moderates neurobehavioral effects in individuals exposed to lead. Fifteen other proteins were identified by LC-MS/MS as proteins of interest exhibiting expressional differences in the presence of environmental lead and mercury.
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Fuchs B, Süss R, Schiller J. An update of MALDI-TOF mass spectrometry in lipid research. Prog Lipid Res 2010; 49:450-75. [PMID: 20643161 DOI: 10.1016/j.plipres.2010.07.001] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Revised: 06/29/2010] [Accepted: 07/01/2010] [Indexed: 10/19/2022]
Abstract
Although matrix-assisted laser desorption and ionization (MALDI) mass spectrometry (MS)--often but not exclusively coupled with a time-of-flight (TOF) mass analyzer--is primarily established in the protein field, there is increasing evidence that MALDI MS is also very useful in lipid research: MALDI MS is fast, sensitive, tolerates sample impurities to a relatively high extent and provides very simple mass spectra without major fragmentation of the analyte. Additionally, MALDI MS devices originally purchased for "proteomics" can be used also for lipids without the need of major system alterations. After a short introduction into the method and the related ion-forming process, the MALDI mass spectrometric characteristics of the individual lipid (ranging from completely apolar hydrocarbons to complex glycolipids with the focus on glycerophospholipids) classes will be discussed and the progress achieved in the last years emphasized. Special attention will be paid to quantitative aspects of MALDI MS because this is normally considered to be the "weak" point of the method, particularly if complex lipid mixtures are to be analyzed. Although the detailed role of the matrix is not yet completely clear, it will be also explicitly shown that the careful choice of the matrix is crucial in order to be able to detect all compounds of interest. Two rather recent developments will be highlighted: "Imaging" MS is nowadays widely established and significant interest is paid in this context to the analysis of lipids because lipids ionize particularly well and are, thus, more sensitively detectable in tissue slices than other biomolecules such as proteins. It will also be shown that MALDI MS can be very easily combined with thin-layer chromatography (TLC) allowing the spatially-resolved screening of the entire TLC plate and the detection of lipids with a higher sensitivity than common staining protocols.
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Affiliation(s)
- Beate Fuchs
- University of Leipzig, Medical Department, Institute of Medical Physics and Biophysics, Härtelstrasse 16-18, Germany
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Froehlich JW, Dodds ED, Barboza M, McJimpsey EL, Seipert RR, Francis J, An HJ, Freeman S, German JB, Lebrilla CB. Glycoprotein expression in human milk during lactation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:6440-8. [PMID: 20415418 PMCID: PMC2882031 DOI: 10.1021/jf100112x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
While milk proteins have been studied for decades, strikingly little effort has been applied to determining how the post-translational modifications (PTMs) of these proteins may change during the course of lactation. PTMs, particularly glycosylation, can greatly influence protein structure, function, and stability and can particularly influence the gut where their degradation products are potentially bioactive. In this work, previously undiscovered temporal variations in both expression and glycosylation of the glycoproteome of human milk are observed. Lactoferrin, one of the most abundant glycoproteins in human milk, is shown to be dynamically glycosylated during the first 10 days of lactation. Variations in expression or glycosylation levels are also demonstrated for several other abundant whey proteins, including tenascin, bile salt-stimulated lipase, xanthine dehydrogenase, and mannose receptor.
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Affiliation(s)
| | - Eric D. Dodds
- Department of Chemistry, University of California, Davis, CA 95616
| | - Mariana Barboza
- Department of Chemistry, University of California, Davis, CA 95616
| | | | | | - Jimi Francis
- Department of Biochemistry, University of Nevada, Reno, NV 89557
| | - Hyun Joo An
- Department of Chemistry, University of California, Davis, CA 95616
| | - Samara Freeman
- Department of Food Science and Technology, University of California, Davis, CA 95616
| | - J. Bruce German
- Department of Food Science and Technology, University of California, Davis, CA 95616
| | - Carlito B. Lebrilla
- Department of Chemistry, University of California, Davis, CA 95616
- School of Medicine, University of California, Davis, CA 95616
- To whom correspondence should be addressed: Dr. Carlito B. Lebrilla, Department of Chemistry, One Shields Avenue, Davis, CA 95616, , Telephone: 1-530-752-6364; Fax: 1-530-754-5609
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14
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Bajrami B, Shi Y, Lapierre P, Yao X. Shifting unoccupied spectral space in mass spectrum of peptide fragment ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2009; 20:2124-2134. [PMID: 19682925 DOI: 10.1016/j.jasms.2009.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 07/06/2009] [Accepted: 07/06/2009] [Indexed: 05/28/2023]
Abstract
Ions near the high-end border of a mass defect distribution plot for native peptide fragment ions have potential as signature markers that are based on mass-to-charge ratio determination. The specificity of these marker ions, including phosphoryl ions, can be improved by removing interfering isobaric ions from the border region on the distribution plot. These interfering ions are rich in Asp and Glu content. The masses of amino acid residues and peptides are rescaled from the IUPAC scale (12C = 12 u as the mass reference) to the averagine scale (averagine mass = 111 u* as the mass reference with zero mass defect; u*: the mass unit on the averagine scale), using a scaling factor of 0.999493894. It is theoretically predicted that esterification of Asp and Glu side-chain carboxylates with n-butanol can achieve a sufficient retreat of the high-end border on a mass defect distribution plot based on the use of mass spectrometers with better-than-medium resolution. Theoretical calculations and laboratory experiments are performed to examine effects of various esterifications on the averagine-scale mass defect distribution of peptide fragment ions and on the specificity of two positive phosphoryl ions: the phosphotyrosine immonium ion and a cyclophosphoramidate ion.
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Affiliation(s)
- Bekim Bajrami
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA
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