scholarly journals Identification of Leishmania by Matrix-Assisted Laser Desorption Ionization–Time of Flight (MALDI-TOF) Mass Spectrometry Using a Free Web-Based Application and a Dedicated Mass-Spectral Library

2017 ◽  
Vol 55 (10) ◽  
pp. 2924-2933 ◽  
Author(s):  
Laurence Lachaud ◽  
Anna Fernández-Arévalo ◽  
Anne-Cécile Normand ◽  
Patrick Lami ◽  
Cécile Nabet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Leishmania Donovani ◽  
Identification System ◽  
Enzyme Electrophoresis ◽  
Mass Spectral Library ◽  
Spectral Library ◽  
Web Based ◽  
Content Type ◽  
Mass Spectral ◽  
Scalable Database

ABSTRACT Human leishmaniases are widespread diseases with different clinical forms caused by about 20 species within the Leishmania genus. Leishmania species identification is relevant for therapeutic management and prognosis, especially for cutaneous and mucocutaneous forms. Several methods are available to identify Leishmania species from culture, but they have not been standardized for the majority of the currently described species, with the exception of multilocus enzyme electrophoresis. Moreover, these techniques are expensive, time-consuming, and not available in all laboratories. Within the last decade, mass spectrometry (MS) has been adapted for the identification of microorganisms, including Leishmania . However, no commercial reference mass-spectral database is available. In this study, a reference mass-spectral library (MSL) for Leishmania isolates, accessible through a free Web-based application (mass-spectral identification [MSI]), was constructed and tested. It includes mass-spectral data for 33 different Leishmania species, including species that infect humans, animals, and phlebotomine vectors. Four laboratories on two continents evaluated the performance of MSI using 268 samples, 231 of which were Leishmania strains. All Leishmania strains, but one, were correctly identified at least to the complex level. A risk of species misidentification within the Leishmania donovani , L. guyanensis , and L. braziliensis complexes was observed, as previously reported for other techniques. The tested application was reliable, with identification results being comparable to those obtained with reference methods but with a more favorable cost-efficiency ratio. This free online identification system relies on a scalable database and can be implemented directly in users' computers.

scholarly journals N-Linked Glycopeptide Identification Based on Open Mass Spectral Library Search

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zhiwu An ◽  
Qingbo Shu ◽  
Hao Lv ◽  
Lian Shu ◽  
Jifeng Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Human Cancer ◽  
Cancer Cell Line ◽  
Peptide Identification ◽  
High Energy ◽  
Mass Spectral Library ◽  
Spectral Library ◽  
Data Set ◽  
Library Search ◽  
Mass Spectral

Confident characterization of intact glycopeptides is a challenging task in mass spectrometry-based glycoproteomics due to microheterogeneity of glycosylation, complexity of glycans, and insufficient fragmentation of peptide bones. Open mass spectral library search is a promising computational approach to peptide identification, but its potential in the identification of glycopeptides has not been fully explored. Here we present pMatchGlyco, a new spectral library search tool for intact N-linked glycopeptide identification using high-energy collisional dissociation (HCD) tandem mass spectrometry (MS/MS) data. In pMatchGlyco, (1) MS/MS spectra of deglycopeptides are used to create spectral library, (2) MS/MS spectra of glycopeptides are matched to the spectra in library in an open (precursor tolerant) manner and the glycans are inferred, and (3) a false discovery rate is estimated for top-scored matches above a threshold. The efficiency and reliability of pMatchGlyco were demonstrated on a data set of mixture sample of six standard glycoproteins and a complex glycoprotein data set generated from human cancer cell line OVCAR3.

scholarly journals Identifying Fentanyl with Mass Spectral Libraries

2021 ◽  
Author(s):  
Anthony J. Kearsley ◽  
Arun Moorthy
Keyword(s):  
Law Enforcement ◽  
Similarity Measures ◽  
Mass Spectral Library ◽  
Spectral Library ◽  
Mass Spectral ◽  
Fentanyl Analogs ◽  
Spectral Libraries ◽  
Mass Spectral Libraries

<div> <div> <div> <p>Synthesis, distribution and abuse of fentanyl, a synthetic opioid, has led to a critical worldwide epidemic. Mass spectral library searching for opioids remains unresolved despite being central to law-enforcement involving identification, monitoring and prosecution of opioid related crimes. In this article, two model problems are presented to illustrate difficulties associated with fentanyl identification. A collection of both currently-employed similarity measures and intuitive measures of dissimilarity are employed to simulate identifying fentanyl analogs with mass spectral library searching. </p> </div> </div> </div>

scholarly journals Global Proteomic Profiling ofSalmonellaInfection by a Giant Phage

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Susan T. Weintraub ◽  
Nurul Humaira Mohd Redzuan ◽  
Melissa K. Barton ◽  
Nur Amira Md Amin ◽  
Maxim I. Desmond ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Multidrug Resistant ◽  
Scaffold Protein ◽  
Gene Products ◽  
Proteomic Profiling ◽  
Content Type ◽  
Mass Spectral ◽  
Head Assembly ◽  
Infected Cells

ABSTRACTThe 240-kbSalmonellaphage SPN3US genome encodes 264 gene products, many of which are functionally uncharacterized. We have previously used mass spectrometry to define the proteomes of wild-type and mutant forms of the SPN3US virion. In this study, we sought to determine whether this technique was suitable for the characterization of the SPN3US proteome during liquid infection. Mass spectrometry of SPN3US-infected cells identified 232 SPN3US and 1,994Salmonellaproteins. SPN3US proteins with related functions, such as proteins with roles in DNA replication, transcription, and virion formation, were coordinately expressed in a temporal manner. Mass spectral counts showed the four most abundant SPN3US proteins to be the major capsid protein, two head ejection proteins, and the functionally unassigned protein gp22. This high abundance of gp22 in infected bacteria contrasted with its absence from mature virions, suggesting that it might be the scaffold protein, an essential head morphogenesis protein yet to be identified in giant phages. We identified homologs to SPN3US gp22 in 45 related giant phages, including ϕKZ, whose counterpart is also abundant in infected bacteria but absent in the virion. We determined the ϕKZ counterpart to be cleavedin vitroby its prohead protease, an event that has been observed to promote head maturation of some other phages. Our findings are consistent with a scaffold protein assignment for SPN3US gp22, although direct evidence is required for its confirmation. These studies demonstrate the power of mass spectral analyses for facilitating the acquisition of new knowledge into the molecular events of viral infection.IMPORTANCE“Giant” phages with genomes >200 kb are being isolated in increasing numbers from a range of environments. With hosts such asSalmonella enterica,Pseudomonas aeruginosa, andErwinia amylovora, these phages are of interest for phage therapy of multidrug-resistant pathogens. However, our understanding of how these complex phages interact with their hosts is impeded by the proportion (∼80%) of their gene products that are functionally uncharacterized. To develop the repertoire of techniques for analysis of phages, we analyzed a liquid infection ofSalmonellaphage SPN3US (240-kb genome) using third-generation mass spectrometry. We observed the temporal production of phage proteins whose genes collectively represent 96% of the SPN3US genome. These findings demonstrate the sensitivity of mass spectrometry for global proteomic profiling of virus-infected cells, and the identification of a candidate for a major head morphogenesis protein will facilitate further studies into giant phage head assembly.

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