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Randall K Julian

Publications and source records attributed to Randall K Julian.

13 recordsLinked to original sources

Proteomic data exchange and storage: the need for common standards and public repositories.

The ever increasing volumes of proteomic data now being produced by laboratories across the world have resulted in major issues in data storage and accessibility. The further demands of multilaboratory initiatives has highlighted issues when collaborators cannot import data generated within the same project but generated by different hardware types and processed by laboratory-specific work flows and analyses packages. There is an increasing need for common data standards that will allow the interchange of data between different instrumentation, search engines, and between laboratory databases. This could then lead to the establishment of data repositories from where benchmark datasets could be accessed and reanalyzed. The Human Proteome Organization is currently supporting efforts to establish such standards. The work of the Proteomics Standards Initiative has lead to the development of the mzData XML interchange standard and is now broadening its scope to produce a spectral analysis output format, mzIdent. Accompanying controlled vocabularies allow the accurate, while systematic, representation of metadata throughout both schema.

Benchmarking↗

Comparison of the Paul ion trap to the linear ion trap for use in global proteomics.

A critical evaluation of the performance of a 2-D linear ion trap (IT) instrument to two 3-D quadrupole IT instruments with emphasis on identification of rat serum proteins by bottom-up LC-MS/MS is presented. The speed and sensitivity of each of the instruments were investigated, and the effects that each of these have on the bottom-up proteomics identification approach are discussed.

Animals↗

The work of the Human Proteome Organisation's Proteomics Standards Initiative (HUPO PSI).

This article describes the origins, working practices and various development projects of the HUman Proteome Organisation's Proteomics Standards Initiative (HUPO PSI), specifically, our work on reporting requirements, data exchange formats and controlled vocabulary terms. We also offer our view of the two functional genomics projects in which the PSI plays a role (FuGE and FuGO), discussing their impact on our process and laying out the benefits we see as accruing, both to the PSI and to biomedical science as a whole as a result of their widespread acceptance.

Humans↗

Statistical design of experiments as a tool in mass spectrometry.

This Tutorial is an introduction to statistical design of experiments (DOE) with focus on demonstration of how DOE can be useful to the mass spectrometrist. In contrast with the commonly used one factor at a time approach, DOE methods address the issue of interaction of variables and are generally more efficient. The complex problem of optimizing data-dependent acquisition parameters in a bottom-up proteomics LC-MS/MS analysis is used as an example of the power of the technique. Using DOE, a new data-dependent method was developed that improved the quantity of confidently identified peptides from rat serum.

Animals↗

Further steps towards data standardisation: the Proteomic Standards Initiative HUPO 3(rd) annual congress, Beijing 25-27(th) October, 2004.

The increasing volume of proteomics data currently being generated by increasingly high-throughput methodologies has led to an increasing need for methods by which such data can be accurately described, stored and exchanged between experimental researchers and data repositories. Work by the Proteomics Standards Initiative of the Human Proteome Organisation has laid the foundation for the development of standards by which experimental design can be described and data exchange facilitated. The progress of these efforts, and the direct benefits already accruing from them, were described at a plenary session of the 3(rd) Annual HUPO congress. Parallel sessions allowed the three work groups to present their progress to interested parties and to collect feedback from groups already implementing the available formats.

China↗

Further steps in standardisation. Report of the second annual Proteomics Standards Initiative Spring Workshop (Siena, Italy 17-20th April 2005).

The spring workshop of the HUPO-PSI convened in Siena to further progress the data standards which are already making an impact on data exchange and deposition in the field of proteomics. Separate work groups pushed forward existing XML standards for the exchange of Molecular Interaction data (PSI-MI, MIF) and Mass Spectrometry data (PSI-MS, mzData) whilst significant progress was made on PSI-MS' mzIdent, which will allow the capture of data from analytical tools such as peak list search engines. A new focus for PSI (GPS, gel electrophoresis) was explored; as was the need for a common representation of protein modifications by all workers in the field of proteomics and beyond. All these efforts are contextualised by the work of the General Proteomics Standards workgroup; which in addition to the MIAPE reporting guidelines, is continually evolving an object model (PSI-OM) from which will be derived the general standard XML format for exchanging data between researchers, and for submission to repositories or journals.

Mass Spectrometry↗

Common interchange standards for proteomics data: Public availability of tools and schema.

The Proteomics Standards Initiative (PSI) aims to define community standards for data representation in proteomics and to facilitate data comparision, exchange and verification. To this end, a Level 1 Molecular Interaction XML data exchange format has been developed which has been accepted for publication and is freely available at the PSI website (http.//psidev.sf.net/). Several major protein interaction databases are already making data available in this format. A draft XML interchange format for mass spectrometry data has been written and is currently undergoing evaluation whilst work is ongoing to develop a proteomics data integration model, MIAPE.

Computational Biology↗

Advances in the development of common interchange standards for proteomic data.

The generation of proteomics data is increasingly high-throughput and high volume. Both experimental design and the technologies used to produce and subsequently analyze the data are becoming ever more complex. An increasing need for methods by which such data can be accurately described, stored and exchanged between experimenters and data repositories has been recognised. Work by the Proteomics Standards Initiative of the Human Proteome Organisation has laid the foundation for the development of standards by which experimental design can be described and data exchange facilitated. At a recent workshop in Nice, participants gathered to review the progress made to date and assist in pushing the process still further forward.

Humans↗

High throughput screening of library compounds against an oligonucleotide substructure of an RNA target.

Approximately 300,000 compounds from selected libraries were screened against a subdomain of a hepatitis C viral (HCV) RNA using a high throughput flow injection mass spectrometry (FIA-MS) method with automated data storage and analysis. Samples contained 2 microM RNA target and 10 microM of each of up to ten ligands. Preliminary studies to optimize operational parameters used the binding of aminoglycosides to the A44 subdomain of bacterial RNA. Binding (confirmed by titration) and sensitivity were maximized within the constraints of the library and throughput. The mobile phase of 5 mM ammonium acetate in 50% isopropanol maintained the noncovalent complexes and provided good detection by electrospray mass spectrometry. Additionally, this composition maximized general solubility of the various classes of compounds including the oligonucleotide and organic library molecules. Cation adduction was insignificant in this screen although some solute and target dependent acetate adduction was observed. The ion trap mass spectrometer provided sufficient mass resolution to identify complexes of RNA with known components of the library. Converted mass spectral data (netCDF) were subjected to two types of statistical evaluation based on binding. The first algorithm identified noncovalent complexes that correlated with the molecular weights of the injected compounds. The second yielded the largest peak in the noncovalent complex region of the spectrum; this spectrum may or may not correlate with expected well components. Sixty-three compounds were confirmed to bind by more stringent secondary testing. Titrations, which were carried out with selected binding compounds, yielded a range of dissociation constants. Biological activity was observed for eleven confirmed binders.

Ligands↗

A common open representation of mass spectrometry data and its application to proteomics research.

A broad range of mass spectrometers are used in mass spectrometry (MS)-based proteomics research. Each type of instrument possesses a unique design, data system and performance specifications, resulting in strengths and weaknesses for different types of experiments. Unfortunately, the native binary data formats produced by each type of mass spectrometer also differ and are usually proprietary. The diverse, nontransparent nature of the data structure complicates the integration of new instruments into preexisting infrastructure, impedes the analysis, exchange, comparison and publication of results from different experiments and laboratories, and prevents the bioinformatics community from accessing data sets required for software development. Here, we introduce the 'mzXML' format, an open, generic XML (extensible markup language) representation of MS data. We have also developed an accompanying suite of supporting programs. We expect that this format will facilitate data management, interpretation and dissemination in proteomics research.

Database Management Systems↗

Further advances in the development of a data interchange standard for proteomics data.

The Protein Standards Initiative (PSI) aims to define community standards for data representation in proteomics and to facilitate data comparison, exchange and verification. Significant progress was made in advancing the design and implementation of a draft standard for exchanging experimental data from proteomics experiments involving mass spectrometry at the 51st Annual Conference of the American Society for Mass Spectrometry. In collaboration with the American Society for Tests and Measurements, the PSI propose to publish this first draft at the forthcoming HUPO 2nd World Congress in Montreal, 8-11 October 2003.

Computational Biology↗

Use of lysozyme as a standard for evaluating the effectiveness of a proteomics process.

Automated sequencing of unknowns in bottom-up proteomics makes the data produced susceptible to process control errors, which can be propagated into mistakes in analyte identification. Inclusion of an unintrusive internal standard, such as lysozyme, allows monitoring all phases of the proteomics process including sample preparation, enzymatic digestion, HPLC, mass spectrometry, and database searching. By using this internal standard, digestion issues including rearrangements, semi-tryptic fragments, and modifications were monitored. In addition, control of the HPLC process including column performance was achieved. The use of the lysozyme standard allowed easy optimization of mass spectral conditions including data dependent and collision induced dissociation settings. The use of this internal standard in a study of differential protein expression in rat serum samples is presented.

Animals↗