Download or read book Protein Sequencing and Identification Using Tandem Mass Spectrometry written by Michael Kinter and published by John Wiley & Sons. This book was released on 2005-04-12 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: How to design, execute, and interpret experiments for protein sequencing using mass spectrometry The rapid expansion of searchable protein and DNA databases in recent years has triggered an explosive growth in the application of mass spectrometry to protein sequencing. This timely and authoritative book provides professionals and scientists in biotechnology research with complete coverage of procedures for analyzing protein sequences by mass spectrometry, including step-by-step guidelines for sample preparation, analysis, and data interpretation. Michael Kinter and Nicholas Sherman present their own high-quality, laboratory-tested protocols for the analysis of a wide variety of samples, demonstrating how to carry out specific experiments and obtain fast, reliable results with a 99% success rate. Readers will get sufficient experimental detail to apply in their own laboratories, learn about the proper selection and operation of instruments, and gain essential insight into the fundamental principles of mass spectrometry and protein sequencing. Coverage includes: * Peptide fragmentation and interpretation of product ion spectra * Basic polyacrylamide gel electrophoresis * Preparation of protein digests for sequencing experiments * Mass spectrometric analysis using capillary liquid chromatography * Techniques for protein identification by database searches * Characterization of modified peptides using tandem mass spectrometry And much more

Download or read book Algorithms for Peptide Identification by Tandem Mass Spectrometry written by Franz Roos and published by . This book was released on 2006 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Peptide Identification by Tandem Mass Spectrometry a Tag oriented Open modification Search Method written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dans la majorité des projets de recherche en protéomique, il faut, à un moment ou un autre, déterminer l'identité des protéines présentes dans l'échantillon biologique étudié. Généralement, la méthode utilisée est la corrélation de spectres obtenus par spectrométrie de masse avec des séquences protéiques répertoriées dans des banques de données. Nous avons développé une méthode pour identifier des protéines portant des modifications non attendues. Lorsque les spectres contiennent suffisamment d'information, il est possible de spécifier la position et la nature des modifications présentes.

Download or read book Peptide Identification of Tandem Mass Spectrometry from Quadrupole Time of flight Mass Spectrometers written by Kuang-Ying Hsi and published by . This book was released on 2009 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tandem mass spectrometry (MS2) is widely used for peptide and protein identification. One of the most fundamental problems for peptide identification in MS2 is to score peptide annotations against the spectrum which is produced by the peptide. In this thesis, a Bayesian network model is proposed for scoring peptides from Q-TOF mass spectrometers. The research is based on the Bayesian network probabilistic methodology used by InsPecT software, which exploits a hybrid strategy of both database search and de novo algorithms for peptide identification. Initially we focused on the connections of InsPecT scoring model without any changes of nodes. We attempted to determine the connections between nodes for Q-TOF by their dependencies. In order to prove that we need the complete set of nodes as the original InsPecT scoring model, we reduced the number of nodes and surprisingly caused significant improvement in peptide identification performance. The 18-node model was reduced to 10-node models for both charge 2 and charge 3 ions, and we obtained the percentage gain in spectra identification 37.51% for charge 2 and 57.68% for charge 3 ions compared to the InsPecT software 2006.10.20 version. The simplified model also leads to computation time reduction. Currently InsPecT does not perform as well as Mascot on Q-TOF data. Reason for that may be that InsPecT was originally trained for LTQ data and in this thesis we only focused our improvement on the InsPecT scoring stage. Deficiencies may occur in the initial tagging and final calculation of the score. Further research may do an exhaustive combination of fragment ions to derive a set of most discriminative and informative ions.

Download or read book Biological Evolution and Statistical Physics written by M. Lässig and published by Springer. This book was released on 2008-01-11 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: This set of lecture notes gives a first coherent account of a novel aspect of the living world that can be called biological information. The book presents both a pedagogical and state-of-the art roadmap of this rapidly evolving area and covers the whole field, from information which is encoded in the molecular genetic code to the description of large-scale evolution of complex species networks. The book will prove useful for all those who work at the interface of biology, physics and information science.

Download or read book Effective Strategies for Improving Peptide Identification with Tandem Mass Spectrometry written by Han, Xi and published by . This book was released on 2011 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tandem mass spectrometry (MS/MS) has been routinely used to identify peptides from protein mixtures in the field of proteomics. However, only about 30% to 40% of current MS/MS spectra can be identified, while many of them remain unassigned, even though they are of reasonable quality. The ubiquitous presence of post-translational modifications (PTMs) is one of the reasons for current low spectral identification rate. In order to identify post-translationally modified peptides, most existing software requires the specification of a few possible modifications. However, such knowledge of possible modifications is not always available. In this thesis, we describe a new algorithm for identifying modified peptides without requiring users to specify the possible modifications before the search routine; instead, all modifications from the Unimod database are considered. Meanwhile, several new techniques are employed to avoid the exponential growth of the search space, as well as to control the false discoveries due to this unrestricted search approach. A software tool, PeaksPTM, has been developed and it has already achieved a stronger performance than competitive tools for unrestricted identification of post-translationally modified peptides. Another important reason for the failure of the search tools is the inaccurate mass or charge state measurement of the precursor peptide ion. In this thesis, we study the precursor mono-isotopic mass and charge determination problem, and propose an algorithm to correct precursor ion mass error by assessing the isotopic features in its parent MS spectrum. The algorithm has been tested on two annotated data sets and achieved almost 100 percent accuracy. Furthermore, we have studied a more complicated problem, the MS/MS preprocessing problem, and propose a spectrum deconvolution algorithm. Experiments were provided to compare its performance with other existing software.

Download or read book Algorithms for Peptide Identification Via Tandem Mass Spectrometry written by Thomas Tschager and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Peptide Identification by Tandem Mass Spectrometry written by Patricia Hernandez (informaticienne.) and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dans la majorité des projets de recherche en protéomique, il faut, à un moment ou un autre, déterminer l'identité des protéines présentes dans l'échantillon biologique étudié. Généralement, la méthode utilisée est la corrélation de spectres obtenus par spectrométrie de masse avec des séquences protéiques répertoriées dans des banques de données. Nous avons développé une méthode pour identifier des protéines portant des modifications non attendues. Lorsque les spectres contiennent suffisamment d'information, il est possible de spécifier la position et la nature des modifications présentes.

Download or read book Expanding the Toolbox of Tandem Mass Spectrometry with Algorithms to Identify Mass Spectra from More Than One Peptide written by Jian Wang and published by . This book was released on 2013 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: In high-throughput proteomics the development of computational methods and novel experimental strategies often rely on each other. In several areas, mass spectrometry methods for data acquisition are ahead of computational methods to interpret the resulting tandem mass (MS/MS) spectra. While there are numerous situations where two or more peptides are co-fragmented in the same MS/MS spectrum, nearly all mainstream computational approaches still make the ubiquitous assumption that each MS/MS spectrum comes from only one peptide. In this thesis we addressed problems in three emerging areas where computational tools that relax the above assumption are crucial for the success application of these approaches on a large-scale. In the first chapter we describe algorithms for the identification of mixture spectra that are from more than one co-eluting peptide precursors. The ability to interpret mixture spectra not only improves peptide identification in traditional data-dependent-acquisition (DDA) workflows but is also crucial for the success application of emerging data-independent-acquisition (DIA) techniques that have the potential to greatly improve the throughput of peptide identification. In chapter two, we address the problem of identification of peptides with complex post-translational modification (PTM). Detection of PTMs is important to understand the functional dynamics of proteins. Complex PTMs resulted from the conjugation of another macromolecule onto the substrate protein. The resultant modified peptides not only generate spectrum that contains a mixture of fragment ions from both the PTM and the substrate peptide but they also display substantially different fragmentation patterns as compared to conventional, unmodified peptides. We describe a hybrid experimental and computational approach to build search tools that capture the specific fragmentation patterns of modified peptides. Finally in chapter three we address the problem of identification of linked peptides. Linked peptides are two peptides that are covalently linked together. The generation and identification of linked peptides has recently been demonstrated to be a versatile tool to study protein-protein interactions and protein structures, however the identification of linked peptides face many challenges. We integrate lessons learned in the previous chapters to build an efficient and sensitive tool to identify linked peptides from MS/MS spectra.

Download or read book Plant Systems Biology written by Sacha Baginsky and published by Springer Science & Business Media. This book was released on 2007-06-25 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume aims to provide a timely view of the state-of-the-art in systems biology. The editors take the opportunity to define systems biology as they and the contributing authors see it, and this will lay the groundwork for future studies. The volume is well-suited to both students and researchers interested in the methods of systems biology. Although the focus is on plant systems biology, the proposed material could be suitably applied to any organism.

Download or read book Ultrafast and Real time Peptide Identification from Tandem Mass Spectra written by Benjamin J. Diament and published by . This book was released on 2011 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Novel Data Analysis Methods and Algorithms for Identification of Peptides and Proteins by Use of Tandem Mass Spectrometry written by Hua Xu and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Tandem mass spectrometry is one of the most important tools for protein analysis. This thesis is focused on the development of new methods and algorithms for tandem mass spectrometry data analysis. A database search engine, MassMatrix, has also been developed that incorporates these methods and algorithms. The program is publicly available both on the web server at www.massmatrix.net and as a deliverable software package for personal computers. Three different scoring algorithms have been developed to identify and characterize proteins and peptides by use of tandem mass spectrometry data. The first one is targeted at the next generation of tandem mass spectrometers that are capable of high mass accuracy and resolution. Two scores calculated by the algorithm are sensitive to high mass accuracy due to the fact that this new algorithm explicitly incorporates mass accuracy into scoring potential peptide and protein matches for tandem mass spectra. The algorithm is further improved by employing Monte Carlo Simulations to calculate ion abundance based scores without any assumptions or simplifications. For high mass accuracy data, MassMatrix provides improvements in sensitivity over other database search programs. The second scoring algorithm based on peptide sequence tags inferred from tandem mass spectra further improves the performance of MassMatrix for low mass accuracy tandem mass spectrometry data. The third algorithm is the first automated data analysis method that uses peptide retention times in liquid chromatography to evaluate potential peptide matches for tandem mass spectrometry data. The algorithm predicts reverse phase liquid chromatography retention times of peptides by their hydrophobicities and compares the predicted retention times with the observed ones to evaluate the peptide matches. In order to handle low quality data, a new method has also been developed to reduce noise in tandem mass spectra and screen poor quality spectra. In addition, a data analysis method for identification of disulfide bonds in proteins and peptides by tandem mass spectrometry data has been developed and incorporated in MassMatrix. By this new approach, proteins and peptides with disulfide bonds can be directly identified in tandem mass spectrometry with high confidence without any chemical reduction and/or other derivatization.

Download or read book Proteome Informatics written by Conrad Bessant and published by Royal Society of Chemistry. This book was released on 2016-11-15 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of proteomics has developed rapidly over the past decade nurturing the need for a detailed introduction to the various informatics topics that underpin the main liquid chromatography tandem mass spectrometry (LC-MS/MS) protocols used for protein identification and quantitation. Proteins are a key component of any biological system, and monitoring proteins using LC-MS/MS proteomics is becoming commonplace in a wide range of biological research areas. However, many researchers treat proteomics software tools as a black box, drawing conclusions from the output of such tools without considering the nuances and limitations of the algorithms on which such software is based. This book seeks to address this situation by bringing together world experts to provide clear explanations of the key algorithms, workflows and analysis frameworks, so that users of proteomics data can be confident that they are using appropriate tools in suitable ways.

Download or read book Proteome Research Mass Spectrometry written by Peter James and published by Springer Science & Business Media. This book was released on 2000-10-26 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in large scale DNA sequencing technology have made it possible to sequence the entire genome of an organism. Attention is now turning to the analysis of the product of the genome, the proteome, which is the set of proteins being expressed by a cell. Mass spectrometry is the method of choice for the rapid large-scale identification of these proteomes and their modifications. This is the first book to extensively cover the applications of mass spectrometry to proteome research.

Download or read book Algorithms for Peptide Identification from Mixture Tandem Mass Spectra written by Yi Liu and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The large amount of data collected in an mass spectrometry experiment requires effective computational approaches for the automated analysis of those data. Though extensive research has been conducted for such purpose by the proteomics community, there are still remaining challenges, among which, one particular challenge is that the identification rate of the MS/MS spectra collected is rather low. One significant reason that contributes to this situation is the frequently observed mixture spectra, which result from the concurrent fragmentation of multiple precursors in a single MS/MS spectrum. However, nearly all the mainstream computational methods still take the assumption that the acquired spectra come from a single precursor, thus they are not suitable for the identification of mixture spectra. In this research, we focused on developing effective algorithms for the purpose of interpreting mixture tandem mass spectra, and our research work is mainly comprised of two components: de novo sequencing of mixture spectra and mixture spectra identification by database search. For the de novo sequencing approach, firstly we formulated the mixture spectra de novo sequencing problem mathematically, and proposed a dynamic programming algorithm for the problem. Additionally, we use both simulated and real mixture spectra datasets to verify the efficiency of the algorithm described in the research. For the database search identification, we proposed an approach for matching mixture tandem mass spectra with a pair of peptide sequences acquired from the protein sequence database by incorporating a special de novo assisted filtration strategy. Besides the filtration strategy, we also introduced in the research a method to give an reasonable estimation of the mixture coefficient which represents the relative abundance level of the co-sequenced precursors. The preliminary experimental results demonstrated the efficiency of the integrated filtration strategy and mixture coefficient estimating method in reducing examination space and also verified the effectiveness of the proposed matching scheme.

Download or read book Mass Spectrometry of Proteins and Peptides written by John R. Chapman and published by Springer Science & Business Media. This book was released on 2008-02-05 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Little more than three years down the line and I am already writing the Preface to a second volume to follow Protein and Peptide Analysis by Mass . What has happened in between these times to make this second venture worthwhile? New types of mass spectrometric instrumentation have appeared so that new techniques have become possible and existing techniques have become much more feasible. More particularly, however, the newer ionization te- niques, introduced for the analysis of high molecular weight materials, have now been thoroughly used and studied. As a result, there has been an en- mous improvement in the associated sample handling technology so that these methods are now routinely applied to much smaller sample amounts as well as to more intractable samples. Again, this particular community of mass spectrometry users has both increased in number and diversified. And, riding this wave of acceptance, leaders in the field have set their sights on more complex problems: molecular interaction, ion structures, quantitation, and kinetics are just a few of the newer areas reported in Mass Spectrometry of Proteins and Peptides. As with the first volume, one purpose of this collection, Mass Spectr- etry of Proteins and Peptides, is to show the reader what can be done by the application of mass spectrometry, and perhaps even to encourage the reader to venture down new paths.

Download or read book Protein Identification Via Assembly of Tandem Mass Spectra written by Adrian Lewis Guthals and published by . This book was released on 2015 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-throughput proteomics is made possible by a combination of modern mass spectrometry instruments capable of generating many millions of tandem mass (MS2 or MS/MS) spectra on a daily basis and the increasingly sophisticated associated software for their automated identification. Despite the growing accumulation of collections of identified spectra and the regular generation of MS2 data from related peptides, the mainstream approach for peptide identification is still the nearly two decades old approach of matching one MS2 spectrum at a time against a database of protein sequences. These traditional approaches fail for the identification of spectra from unknown proteins such as antibodies or proteins from organisms with un-sequenced genomes. Furthermore, attempts to identify MS/MS spectra against large databases (e.g., the human microbiome or 6-frame translation of the human genome) face a search space that is 10-100 times larger than the human proteome, where it becomes increasingly challenging to separate between true and false peptide matches. First, we describe techniques to utilize networks of spectra from related peptides to rigorously compute the joint spectral probability of multiple spectra being matched to peptides with overlapping sequences, thus improving peptide identification by 30-62% against large search spaces. We then introduce methods that dramatically improve de novo sequencing of unknown proteins using novel spectral network assembly algorithms and incorporating alternative MS/MS acquisition protocols. Finally, we describe an interesting end-goal biological problem for which the described advances in de novo sequencing can usher in a new era of therapeutic drug discovery.