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At least 631 records · Page 35Linked to original sources
PubMed2003

Protein feature based identification of cell cycle regulated proteins in yeast.

DNA microarrays have been used extensively to identify cell cycle regulated genes in yeast; however, the overlap in the genes identified is surprisingly small. We show that certain protein features can be used to distinguish cell cycle regulated genes from other genes with high confidence (features include protein phosphorylation, glycosylation, subcellular location and instability/degradation). We demonstrate that co-expressed, periodic genes encode proteins which share combinations of features, and provide an overview of the proteome dynamics during the cycle. A large set of novel putative cell cycle regulated proteins were identified, many of which have no known function.

Cell Cycle↗
PubMed2003

Public access for teaching genomics, proteomics, and bioinformatics.

When the human genome project was conceived, its leaders wanted all researchers to have equal access to the data and associated research tools. Their vision of equal access provides an unprecedented teaching opportunity. Teachers and students have free access to the same databases that researchers are using. Furthermore, the recent movement to deliver scientific publications freely has presented a second source of current information for teaching. I have developed a genomics course that incorporates many of the public-domain databases, research tools, and peer-reviewed journals. These online resources provide students with exciting entree into the new fields of genomics, proteomics, and bioinformatics. In this essay, I outline how these fields are especially well suited for inclusion in the undergraduate curriculum. Assessment data indicate that my students were able to utilize online information to achieve the educational goals of the course and that the experience positively influenced their perceptions of how they might contribute to biology.

Computational Biology↗
PubMed2004

[Preliminary proteome analysis for Saccharomyces cerevisiae under different culturing conditions].

For the investigation of the metabolic regulation of Saccharomyces cerevisiae under different culture conditions, the proteins of cell utilizing various carbon sources were separated by two-dimensional electrophoresis with immobilized pH gradients as the first dimension and SDS-PAGE as the second. Samples were taken in the log phase of batch culture using glucose or lactic acid as carbon source, while another sample was taken from the broth when glucose was consumed up and ethanol accumulated in the previous phase was further metabolized. After electrophoresis, the protein spots were detected by silver-stain in a Hoefer Automated Gel Stainer with a protein silver staining kit. Silver-stained gels were scanned and digitized to create computer images. About 500 protein spots were detected by employing the 2D proteome image analysis system Image Master 2D Elite and SWISS-2DPAGE proteome database. Most of the protein expressed and involved in the glycolysis, pentose phosphate (PP) pathway, anaplerotic pathway, as well as TCA cycle were analyzed. The metabolism regulation of protein level for Saccharomyces cerevisiae under various carbon sources, as well as during different phase of growth, was studied. The expression of several glycolytic enzymes (glk, pgi, pgk, eno, pyk) was up-regulated while the expression of enzymes in oxidative pentose phosphate pathway (zwf, gnd) was down-regulated when ethanol and lactic acid were taken as carbon source. Simultaneously, frucotose 1,6-biphosphatase was found to be up-regulated due to the gluconeogenic requirement. Citrate synthase and Malate dehydrogenase do not exhibit significant difference, indicating TCA cycle is necessary when utilizing glucose, ethanol or lactic acid as carbon source. Thus, the NADPH loss due to the repressed pentose phosphate pathway could be compensated by TCA cycle in cases of ethanol and lactic acid. The expression of malic enzyme and isocitrate lyase are activated to a large extent when metabolizing ethanol, indicating glyoxylate shunt is essential in transferring ethanol to generate four carbon precursors for the biosynthesis and the NADP-dependent malic enzyme could also serve as compensation mechanism for NADPH loss in this case.

Carbon↗
PubMed2004

Two-dimensional gel electrophoresis and immunoblot analysis of Neospora caninum tachyzoites.

Identification of expressed protein profiles and antigenic determination are some of the most challenging aspects of proteomics. Two-dimensional gel electrophoresis (2-DE) combined with immunoblot analysis were employed to study the N. caninum proteome. Protein sample preparation was carried out by first conducting sonication, followed by adding lysis buffer containing 7M urea plus 2M thiourea to the purified tachyzoites in order to complete disruption. A total of 335 differentially expressed protein spots were detected using pH 4-7 IPG strip (7 cm) that were run in a 56 kVh isoelectric focusing (IEF) system. Of the spots analyzed, 64 were identified as antigenic spots on immunoblot profile. Major antigenic spots appeared at 65 kDa (pI 5.2-5.3), 51 kDa (pI 5.5), 38 kDa (pI 5.1), 33 kDa (pI 4.4), 29 kDa (pI 5.6) and 15.5 kDa (pI 5.0) were observed to be significantly distinct compared to the rest of the antigenic spots. The results indicate that combination of 2-DE and immunoblotting methods were thought as very useful tools in defining both proteins and antigens of N. caninum tachyzoites. Additionally, present 2-DE profiles may be valuable in further proteomic approaches and study of the pathogen.

Animals↗
PubMed2005

PRIDE: the proteomics identifications database.

The advent of high-throughput proteomics has enabled the identification of ever increasing numbers of proteins. Correspondingly, the number of publications centered on these protein identifications has increased dramatically. With the first results of the HUPO Plasma Proteome Project being analyzed and many other large-scale proteomics projects about to disseminate their data, this trend is not likely to flatten out any time soon. However, the publication mechanism of these identified proteins has lagged behind in technical terms. Often very long lists of identifications are either published directly with the article, resulting in both a voluminous and rather tedious read, or are included on the publisher's website as supplementary information. In either case, these lists are typically only provided as portable document format documents with a custom-made layout, making it practically impossible for computer programs to interpret them, let alone efficiently query them. Here we propose the proteomics identifications (PRIDE) database (http://www.ebi.ac.uk/pride) as a means to finally turn publicly available data into publicly accessible data. PRIDE offers a web-based query interface, a user-friendly data upload facility, and a documented application programming interface for direct computational access. The complete PRIDE database, source code, data, and support tools are freely available for web access or download and local installation.

Computational Biology↗
PubMed2006

VAMP: visualization and analysis of array-CGH, transcriptome and other molecular profiles.

MOTIVATION: Microarray-based CGH (Comparative Genomic Hybridization), transcriptome arrays and other large-scale genomic technologies are now routinely used to generate a vast amount of genomic profiles. Exploratory analysis of this data is crucial in helping to understand the data and to help form biological hypotheses. This step requires visualization of the data in a meaningful way to visualize the results and to perform first level analyses. RESULTS: We have developed a graphical user interface for visualization and first level analysis of molecular profiles. It is currently in use at the Institut Curie for cancer research projects involving CGH arrays, transcriptome arrays, SNP (single nucleotide polymorphism) arrays, loss of heterozygosity results (LOH), and Chromatin ImmunoPrecipitation arrays (ChIP chips). The interface offers the possibility of studying these different types of information in a consistent way. Several views are proposed, such as the classical CGH karyotype view or genome-wide multi-tumor comparison. Many functionalities for analyzing CGH data are provided by the interface, including looking for recurrent regions of alterations, confrontation to transcriptome data or clinical information, and clustering. Our tool consists of PHP scripts and of an applet written in Java. It can be run on public datasets at http://bioinfo.curie.fr/vamp AVAILABILITY: The VAMP software (Visualization and Analysis of array-CGH,transcriptome and other Molecular Profiles) is available upon request. It can be tested on public datasets at http://bioinfo.curie.fr/vamp. The documentation is available at http://bioinfo.curie.fr/vamp/doc.

Algorithms↗
PubMed2003

GlobPlot: Exploring protein sequences for globularity and disorder.

A major challenge in the proteomics and structural genomics era is to predict protein structure and function, including identification of those proteins that are partially or wholly unstructured. Non-globular sequence segments often contain short linear peptide motifs (e.g. SH3-binding sites) which are important for protein function. We present here a new tool for discovery of such unstructured, or disordered regions within proteins. GlobPlot (http://globplot.embl.de) is a web service that allows the user to plot the tendency within the query protein for order/globularity and disorder. We show examples with known proteins where it successfully identifies inter-domain segments containing linear motifs, and also apparently ordered regions that do not contain any recognised domain. GlobPlot may be useful in domain hunting efforts. The plots indicate that instances of known domains may often contain additional N- or C-terminal segments that appear ordered. Thus GlobPlot may be of use in the design of constructs corresponding to globular proteins, as needed for many biochemical studies, particularly structural biology. GlobPlot has a pipeline interface--GlobPipe--for the advanced user to do whole proteome analysis. GlobPlot can also be used as a generic infrastructure package for graphical displaying of any possible propensity.

Algorithms↗
PubMed2005

CHASE, a charge-assisted sequencing algorithm for automated homology-based protein identifications with matrix-assisted laser desorption/ionization time-of-flight post-source decay fragmentation data.

We describe CHASE, a novel algorithm for automated de novo sequencing based on the mass spectrometric (MS) fragmentation analysis of tryptic peptides. This algorithm is used for protein identification from sequence similarity criteria and consists of four steps: (1) derivatization of tryptic peptides at the N-terminus with a negatively charged reagent; (2) post-source decay (PSD) fragmentation analysis of peptides; (3) interpretation of the mass peaks with the CHASE algorithm and reconstruction of the amino acid sequence; (4) transfer of these data to software for protein identifications based on sequence homology (Basic Local Alignment Search Tool, BLAST). This procedure deduced the correct amino acid sequence of tryptic peptide samples and also was able to deduce the correct sequence from difficult mass patterns and identify the amino acid sequence. This allows complete automation of the process starting from MS fragmentation of complex peptide mixtures at low concentration (e.g. from silver-stained gel bands) to identification of the protein. We also show that if PSD data are collected in a single spectrum (instead of the segmented mode offered by conventional matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instrumentation), the complete workflow from MS-PSD data acquisition to similarity-based identification can be completely automated. This strategy may be applied to proteomic studies for protein identification based on automated de novo sequencing instead of MS or tandem MS patterns. We describe the Charge Assisted Sequencing Engine (CHASE) algorithm, the working protocol, the performance of the algorithm on spectra from MALDI-TOFMS and the data comparison between a TOF and a TOF-TOF instrument.

Algorithms↗
PubMed2002

Oolemmal proteomics.

Fertilization is defined as a series of gametic interactions in which capacitated sperm must first penetrate the egg vestments and then bind to and fuse with the egg plasma membrane (oolemma). The molecular basis of sperm-egg binding and fusion has yet to be elucidated due, in part, to how little is known about the array of proteins residing on the oolemma. Proteomics is an emerging area of research that directly evaluates protein expression by resolving, identifying, quantitating, and characterizing proteins utilizing a variety of techniques including high resolution two-dimensional polyacrylamide gel electrophoresis (2D PAGE), tandem mass spectrometry, and computer analysis. Our research group has utilized 2D PAGE to begin building a mouse oocyte proteomic database, with over 500 silver-stained proteins being resolved and digitized to date. Cell-surface labeling with biotin has identified a subset of 80 putative egg surface proteins. Amino acid microsequences from over 30 of the surface-labeled proteins has been obtained by tandem mass spectrometry. Sequences from eight of these proteins do not match any sequences from protein and DNA databanks, indicating that these proteins are novel. Our major current research goal is to clone, characterize, and express the novel proteins that are shown to be ovary-specific and investigate their functional roles in sperm-egg interaction.

Animals↗
PubMedDate not supplied

e-molecular shapes and properties.

Due to recent computer technology advances, shape analysis has gained importance in all domains. In drug design and proteomics, molecular surfaces (van der Waals surface, solvent accessible surface, solvent excluded surface, polar surface area, electron density surface, separating surface, etc.), buried surfaces (gap, cleft, cavity, etc.) as well as shape properties of these surfaces, can be easily computed and visualized via the Internet. Freely available resources from the Internet for academic use, are reviewed.

Computer Simulation↗
PubMed2005

Expansion of the BioCyc collection of pathway/genome databases to 160 genomes.

The BioCyc database collection is a set of 160 pathway/genome databases (PGDBs) for most eukaryotic and prokaryotic species whose genomes have been completely sequenced to date. Each PGDB in the BioCyc collection describes the genome and predicted metabolic network of a single organism, inferred from the MetaCyc database, which is a reference source on metabolic pathways from multiple organisms. In addition, each bacterial PGDB includes predicted operons for the corresponding species. The BioCyc collection provides a unique resource for computational systems biology, namely global and comparative analyses of genomes and metabolic networks, and a supplement to the BioCyc resource of curated PGDBs. The Omics viewer available through the BioCyc website allows scientists to visualize combinations of gene expression, proteomics and metabolomics data on the metabolic maps of these organisms. This paper discusses the computational methodology by which the BioCyc collection has been expanded, and presents an aggregate analysis of the collection that includes the range of number of pathways present in these organisms, and the most frequently observed pathways. We seek scientists to adopt and curate individual PGDBs within the BioCyc collection. Only by harnessing the expertise of many scientists we can hope to produce biological databases, which accurately reflect the depth and breadth of knowledge that the biomedical research community is producing.

Animals↗
PubMed2006

Ions of the interactome: the role of MS in the study of protein interactions in proteomics and structural biology.

The role of MS in the study of protein-protein interactions in solution is described from a proteomics perspective, in terms of high-throughput analyses of protein complexes in vivo, through to chemical and biochemical treatments ahead of MS analysis in the context of complementary experimental approaches in structural biology. The use of MS to characterise protein-protein interactions is described following the single and tandem affinity purification of protein complexes and assemblies of expressed proteins in host cells, the isolation and preservation of protein complexes on surfaces and microarrays, and their prior treatment with chemical and biochemical probes by hydrogen exchange, radical probe, chemical cross-linking, and limited proteolysis. The advantages and disadvantages of each of the approaches are presented. These new and emerging applications, which further demonstrate the power of MS, continue to ensure that the mass spectrometer will remain at the heart of discoveries in proteomics in the foreseeable future.

Animals↗
PubMedDate not supplied

Feature based fuzzy matching of 2D gel electrophoresis images.

Automatic alignment (matching) of two-dimensional gel electrophoresis images is of primary interest in the evolving field of proteomics. In the present study, feature-based matching techniques, in their classical and robust versions, are described, and an automatic method of fuzzy alignment (FA) is introduced. This method allows automatic matching of two gel images with different numbers of features with unknown correspondence. Performance of FA is tested on simulated and real data sets.

Automation↗
PubMed2004

Scoring hidden Markov models to discriminate beta-barrel membrane proteins.

A new method is presented for identification of beta-barrel membrane proteins. It is based on a hidden Markov model (HMM) with an architecture obeying these proteins' construction principles. Once the HMM is trained, log-odds score relative to a null model is used to discriminate beta-barrel membrane proteins from other proteins. The method achieves only 10% false positive and false negative rates in a six-fold cross-validation procedure. The results compare favorably with existing methods. This method is proposed to be a valuable tool to quickly scan proteomes of entirely sequenced organisms for beta-barrel membrane proteins.

Algorithms↗
PubMed2007

Multivariate data analysis of proteome data.

We present the background for multivariate data analysis on proteomics data with a hands-on section on how to transfer data between different software packages. The techniques can also be used for other biological and biochemical problems in which structures have to be found in a large amount of data. Digitalization of the 2D gels, analysis using image processing software, transfer of data, multivariate data analysis, interpretation of the results, and finally we return to biology.

Electrophoresis, Gel, Two-Dimensional↗
PubMedDate not supplied

[Genomics. Proteomics. Bioinformatics. What else?].

The biology of the past century was, undoubtedly, reductionist. Its general trend was expressed in the appearance and burst of scientific disciplines, such as biochemistry, biophysics, molecular biology, molecular genetics, virology, cell biology, and bioorganic chemistry. All these disciplines are united by an aspiration to explain the phenomena of life through the description of the properties of molecules, first of all, biopolymers, which constitute the living organisms. In current science, all these directions are often united under the general heading "physicochemical biology", while classical biological disciplines, such as zoology, botany, embryology, etc., are referred to as "general biology".

Animals↗
PubMed2004

YETI: Yeast Exploration Tool Integrator.

UNLABELLED: Yeast Exploration Tool Integrator (YETI) is a novel bioinformatics tool for the integrated visualization and analysis of functional genomic data sets from the budding yeast Saccharomyces cerevisiae. AVAILABILITY: YETI is freely available for use over the WWW, or download under license, at http://www.bru.ed.ac.uk/~orton/yeti.html

Computer Graphics↗