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In the last two decades, biological mass spectrometry has become the gold standard for the identification of proteins in biological samples. The technological advancement of mass spectrometers and the development of methods for ionization, gas phase transfer, peptide fragmentation as well as for acquisition of high-resolution mass spectrometric data marked the success of the technique. This chapter introduces peptide-based mass spectrometry as a tool for the investigation of protein complexes. It provides an overview of the main steps for sample preparation starting from protein fractionation, reduction, alkylation and focus on the final step of protein digestion. The basic concepts of biological mass spectrometry as well as details about instrumental analysis and data acquisition are described. Finally, the most common methods for data analysis and sequence determination are summarized with an emphasis on its application to protein-protein complexes.
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Peptídeos , Proteínas , Peptídeos/química , Espectrometria de Massas/métodos , Proteínas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodosRESUMO
With the tourism industry continuing to boom, the importance of tourism mascots in promoting and publicizing tourism destinations is becoming increasingly prominent. Three core dimensions, market trend, appearance design, and audience feedback, are numerically investigated for deeply iterating tourism mascot design. Further, a subjective and objective evaluation weighting model based on the hierarchical analysis method (AHP) and entropy weighting method is proposed, aiming to utilize the advantages of these methods and ensure the entireness and correctness of results. Taking the mascots of six famous tourist attractions in Xi'an as an example, the feasibility and effectiveness of the evaluation model are verified. Data analysis and modeling results confirm that the three core evaluation indexes of scalability, innovation, and recommendation should be focused on in the design of tourism mascots in the three dimensions of market trends, appearance design, and audience feedback. The evaluation index scores are 0.1235, 0.1170, and 0.1123, respectively, which further illustrates the priority of mascot design. The evaluation model constructed by the research provides decision-makers with a comprehensive evaluation tool from the perspective of tourist experience, and also effectively assists the optimization process of mascot design. In addition, the model has good versatility and adaptability in structural design and evaluation logic and can be widely used in the optimization and evaluation research of brand mascots.
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Unconventional epitopes presented by HLA class I complexes are emerging targets for T cell targeted immunotherapies. Their identification by mass spectrometry (MS) required development of novel methods to cope with the large number of theoretical candidates. Methods to identify post-translationally spliced peptides led to a broad range of outcomes. We here investigated the impact of three common database search engines - that is, Mascot, Mascot+Percolator, and PEAKS DB - as final identification step, as well as the features of target database on the ability to correctly identify non-spliced and cis-spliced peptides. We used ground truth datasets measured by MS to benchmark methods' performance and extended the analysis to HLA class I immunopeptidomes. PEAKS DB showed better precision and recall of cis-spliced peptides and larger number of identified peptides in HLA class I immunopeptidomes than the other search engine strategies. The better performance of PEAKS DB appears to result from better discrimination between target and decoy hits and hence a more robust FDR estimation, and seems independent to peptide and spectrum features here investigated.
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Peptídeos , Ferramenta de Busca , Epitopos , Espectrometria de Massas , Peptídeos/química , SoftwareRESUMO
The development of an easy-to-attach electroencephalograph (EEG) would enable its frequent use for the assessment of neurodevelopment and clinical monitoring. In this study, we designed a two-channel EEG headband measurement device that could be used safely and was easily attachable and removable without the need for restraint or electrode paste or gel. Next, we explored the use of this device for neurofeedback applications relevant to education or neurocognitive development. We developed a prototype visual neurofeedback game in which the size of a familiar local mascot changes in the PC display depending on the user's brain wave activity. We tested this application at a local children's play event. Children at the event were invited to experience the game and, upon agreement, were provided with an explanation of the game and support in attaching the EEG device. The game began with a consecutive number visual discrimination task which was followed by an open-eye resting condition and then a neurofeedback task. Preliminary linear regression analyses by the least-squares method of the acquired EEG and age data in 30 participants from 5 to 20 years old suggested an age-dependent left brain lateralization of beta waves at the neurofeedback stage (p = 0.052) and of alpha waves at the open-eye resting stage (p = 0.044) with potential involvement of other wave bands. These results require further validation.
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Neurorretroalimentação , Adolescente , Adulto , Encéfalo , Córtex Cerebral , Criança , Desenvolvimento Infantil , Pré-Escolar , Eletroencefalografia/métodos , Humanos , Neurorretroalimentação/métodos , Descanso , Adulto JovemRESUMO
The Earth's moon is currently an object of interest of many space agencies for unmanned robotic missions within this decade. Besides future prospects for building lunar gateways as support to human space flight, the Moon is an attractive location for scientific purposes. Not only will its study give insight on the foundations of the Solar System but also its location, uncontaminated by the Earth's ionosphere, represents a vantage point for the observation of the Sun and planetary bodies outside the Solar System. Lunar exploration has been traditionally conducted by means of single-agent robotic assets, which is a limiting factor for the return of scientific missions. The German Aerospace Center (DLR) is developing fundamental technologies towards increased autonomy of robotic explorers to fulfil more complex mission tasks through cooperation. This paper presents an overview of past, present and future activities of DLR towards highly autonomous systems for scientific missions targeting the Moon and other planetary bodies. The heritage from the Mobile Asteroid Scout (MASCOT), developed jointly by DLR and CNES and deployed on asteroid Ryugu on 3 October 2018 from JAXA's Hayabusa2 spacecraft, inspired the development of novel core technologies towards higher efficiency in planetary exploration. Together with the lessons learnt from the ROBEX project (2012-2017), where a mobile robot autonomously deployed seismic sensors at a Moon analogue site, this experience is shaping the future steps towards more complex space missions. They include the development of a mobile rover for JAXA's Martian Moons eXploration (MMX) in 2024 as well as demonstrations of novel multi-robot technologies at a Moon analogue site on the volcano Mt Etna in the ARCHES project. Within ARCHES, a demonstration mission is planned from the 14 June to 10 July 2021,1 during which heterogeneous teams of robots will autonomously conduct geological and mineralogical analysis experiments and deploy an array of low-frequency antennas to measure Jovian and solar bursts. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades'.
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Organizational change is a complex and critical issue in higher education today. Changes experienced across institutional systems have both short-term and long-term impact, making this phenomenon ripe for educational leadership research. Many universities and colleges have applied Kotter's (1995) eight-step change model prescriptively to implement academic initiatives, curriculum revisions, and strategic vision. However, Kotter's (1995) model has not previously explored ad hoc changes over time and has not been used to study a college live mascot program. Although a decreasing campus tradition, college live mascots have a relationship and impact on a student's experience and college identification, as well as university engagement with alumni and the public. Therefore, understanding how change is identified and experienced by campus stakeholders of a college live mascot program describe the various complexities and issues that initiate a climate for institutional change. To explain the evolution of a college live mascot program, oral histories across twenty years of campus stakeholders, including student trainers, campus administrators, and external consultants were analyzed using Kotter's (1995) model. The findings of this study affirmed that the steps associated with Kotter's (1995) change model, with a specific focus on the first three steps, are relevant for ad hoc changes, and offer implications for higher education change.
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Proteome profiling of human testicular biopsies was performed using tandem mass spectrometry with electrospray ionization. Protein identification results were compared for the Mascot commercial search engine, the SearchGUI noncommercial package, and their analog IdentiProt based on the open-source IdentiPy algorithm (http://hg.theorchromo.ru/identipy). A feature of IdentiPy is an automatic optimization of MS/MS search parameters. A set of protein identifications obtained with IdentiPy was consequently greater by one third than the sets with the other search engines. For the first time, an IdentiPy/IdentiProt search was conducted within the Progenesis LC-MS framework, which allows spectrum alignment, and the proteome profile obtained with alignment was compared with that obtained using the ProteoWizard converter. A total of 16 human chromosome 18 proteins were identified, including the myelin basic protein, which is not characteristic of testicular tissue.
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Algoritmos , Proteômica , Espectrometria de Massas em Tandem , Testículo/patologia , Biópsia , Bases de Dados de Proteínas , Humanos , Masculino , SoftwareRESUMO
Collision energy is a key parameter determining the information content of beam-type collision induced dissociation tandem mass spectrometry (MS/MS) spectra, and its optimal choice largely affects successful peptide and protein identification in MS-based proteomics. For an MS/MS spectrum, quality of peptide match based on sequence database search, often characterized in terms of a single score, is a complex function of spectrum characteristics, and its collision energy dependence has remained largely unexplored. We carried out electrospray ionization-quadrupole-time of flight (ESI-Q-TOF)-MS/MS measurements on 2807 peptides from tryptic digests of HeLa and E. coli at 21 different collision energies. Agglomerative clustering of the resulting Mascot score versus energy curves revealed that only few of them display a single, well-defined maximum; rather, they feature either a broad plateau or two clear peaks. Nonlinear least-squares fitting of one or two Gaussian functions allowed the characteristic energies to be determined. We found that the double peaks and the plateaus in Mascot score can be associated with the different energy dependence of b- and y-type fragment ion intensities. We determined that the energies for optimum Mascot scores follow separate linear trends for the unimodal and bimodal cases with rather large residual variance even after differences in proton mobility are taken into account. This leaves room for experiment optimization and points to the possible influence of further factors beyond m/ z.
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Fragmentos de Peptídeos/análise , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Proteínas de Escherichia coli , Células HeLa , Humanos , Distribuição Normal , Espectrometria de Massas por Ionização por Electrospray , Tripsina/metabolismoRESUMO
Confident identification of sites of protein phosphorylation by mass spectrometry (MS) is essential to advance understanding of phosphorylation-mediated signaling events. However, the development of novel instrumentation requires that methods for MS data acquisition and its interrogation be evaluated and optimized for high-throughput phosphoproteomics. Here we compare and contrast eight MS acquisition methods on the novel tribrid Orbitrap Fusion MS platform using both a synthetic phosphopeptide library and a complex phosphopeptide-enriched cell lysate. In addition to evaluating multiple fragmentation regimes (HCD, EThcD, and neutral-loss-triggered ET(ca/hc)D) and analyzers for MS/MS (orbitrap (OT) versus ion trap (IT)), we also compare two commonly used bioinformatics platforms, Andromeda with PTM-score, and MASCOT with ptmRS for confident phosphopeptide identification and, crucially, phosphosite localization. Our findings demonstrate that optimal phosphosite identification is achieved using HCD fragmentation and high-resolution orbitrap-based MS/MS analysis, employing MASCOT/ptmRS for data interrogation. Although EThcD is optimal for confident site localization for a given PSM, the increased duty cycle compared with HCD compromises the numbers of phosphosites identified. Finally, our data highlight that a charge-state-dependent fragmentation regime and a multiple algorithm search strategy are likely to be of benefit for confident large-scale phosphosite localization.
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Espectrometria de Massas/métodos , Osteoblastos/metabolismo , Fragmentos de Peptídeos/análise , Fosfoproteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Algoritmos , Benchmarking , Linhagem Celular Tumoral , Humanos , Espectrometria de Massas/instrumentação , Osteoblastos/citologia , Fosfoproteínas/química , Fosforilação , SoftwareRESUMO
We identified tryptic peptides in yeast cell lysates that map to translation initiation sites downstream of the annotated start sites using the peptide-spectrum matching algorithms OMSSA and Mascot. To increase the accuracy of peptide-spectrum matching, both algorithms were run using several standardized parameter sets, and Mascot was run utilizing a, b, and y ions from collision-induced dissociation. A large fraction (22%) of the detected N-terminal peptides mapped to translation initiation downstream of the annotated initiation sites. Expression of several truncated proteins from downstream initiation in the same reading frame as the full-length protein (frame 1) was verified by western analysis. To facilitate analysis of the larger proteome of Drosophila, we created a streamlined sequence library from which all duplicated trypsin fragments had been removed. OMSSA assessment using this "stripped" library revealed 171 peptides that map to downstream translation initiation sites, 76% of which are in the same reading frame as the full-length annotated proteins, although some are in different reading frames creating new protein sequences not in the annotated proteome. Sequences surrounding implicated downstream AUG start codons are associated with nucleotide preferences with a pronounced three-base periodicity N1^G2^A3.
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Bases de Dados de Proteínas/normas , Proteínas de Drosophila/análise , Proteínas Fúngicas/análise , Peptídeos/análise , Proteômica/métodos , Espectrometria de Massas em Tandem/normas , Algoritmos , Sequência de Aminoácidos , Animais , Códon de Iniciação , Anotação de Sequência Molecular , Proteômica/normas , Fases de Leitura , Padrões de ReferênciaRESUMO
Data processing, management and visualization are central and critical components of a state of the art high-throughput mass spectrometry (MS)-based proteomics experiment, and are often some of the most time-consuming steps, especially for labs without much bioinformatics support. The growing interest in the field of proteomics has triggered an increase in the development of new software libraries, including freely available and open-source software. From database search analysis to post-processing of the identification results, even though the objectives of these libraries and packages can vary significantly, they usually share a number of features. Common use cases include the handling of protein and peptide sequences, the parsing of results from various proteomics search engines output files, and the visualization of MS-related information (including mass spectra and chromatograms). In this review, we provide an overview of the existing software libraries, open-source frameworks and also, we give information on some of the freely available applications which make use of them. This article is part of a Special Issue entitled: Computational Proteomics in the Post-Identification Era. Guest Editors: Martin Eisenacher and Christian Stephan.
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Proteômica , Espectrometria de Massas em Tandem/métodos , Biologia Computacional , SoftwareRESUMO
Bayesian phylogeographic inference is a powerful tool in molecular epidemiological studies, which enables reconstruction of the origin and subsequent geographic spread of pathogens. Such inference is, however, potentially affected by geographic sampling bias. Here, we investigated the impact of sampling bias on the spatiotemporal reconstruction of viral epidemics using Bayesian discrete phylogeographic models and explored different operational strategies to mitigate this impact. We considered the continuous-time Markov chain (CTMC) model and two structured coalescent approximations (Bayesian structured coalescent approximation [BASTA] and marginal approximation of the structured coalescent [MASCOT]). For each approach, we compared the estimated and simulated spatiotemporal histories in biased and unbiased conditions based on the simulated epidemics of rabies virus (RABV) in dogs in Morocco. While the reconstructed spatiotemporal histories were impacted by sampling bias for the three approaches, BASTA and MASCOT reconstructions were also biased when employing unbiased samples. Increasing the number of analyzed genomes led to more robust estimates at low sampling bias for the CTMC model. Alternative sampling strategies that maximize the spatiotemporal coverage greatly improved the inference at intermediate sampling bias for the CTMC model, and to a lesser extent, for BASTA and MASCOT. In contrast, allowing for time-varying population sizes in MASCOT resulted in robust inference. We further applied these approaches to two empirical datasets: a RABV dataset from the Philippines and a SARS-CoV-2 dataset describing its early spread across the world. In conclusion, sampling biases are ubiquitous in phylogeographic analyses but may be accommodated by increasing the sample size, balancing spatial and temporal composition in the samples, and informing structured coalescent models with reliable case count data.
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Medicinal plants are the basic source of medicinal compounds traditionally used for the treatment of human diseases. Calotropis gigantea is a medicinal plant belonging to the family of Apocynaceae in the plant kingdom and subfamily Asclepiadaceae usually bearing multiple medicinal properties to cure a variety of diseases. BACKGROUND: The Peptide Mass Fingerprinting (PMF) identifies the proteins from a reference protein database by comparing the amino acid sequence that is previously stored in the database and identified. OBJECTIVE: The purpose of the study is to identify the peptides having anti-cancerous properties by in silico peptide mass fingerprinting. METHODS: The calculation of in silico peptide masses is done through the ExPASy PeptideMass and these masses are used to identify the peptides from the MASCOT online server. Anticancer probability is calculated by iACP server, docking of active peptides is done by CABS-dock the server. RESULTS: The anti-cancer peptides are identified with the MASCOT peptide mass fingerprinting server, the identified peptides are screened and only the anti-cancer are selected. De-novo peptide structure prediction is used for 3D structure prediction by PEP-FOLD 3 server. The docking results confirm strong bonding with the interacting amino acids of the receptor protein of breast cancer BRCA1 which shows the best peptide binding to the active chain, the human leukemia protein docking with peptides shows the accurate binding. CONCLUSION: These peptides are stable and functional and are the best way for the treatment of cancer and many other deadly diseases.
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Calotropis , Simulação por Computador , Mapeamento de Peptídeos/métodos , Extratos Vegetais/química , Plantas Medicinais , Proteômica/métodos , Sequência de Aminoácidos , Antineoplásicos/química , Extratos Vegetais/genética , Estrutura Secundária de Proteína , Estrutura Terciária de ProteínaRESUMO
Cannabis research has taken off since the relaxation of legislation, yet proteomics is still lagging. In 2019, we published three proteomics methods aimed at optimizing protein extraction, protein digestion for bottom-up and middle-down proteomics, as well as the analysis of intact proteins for top-down proteomics. The database of Cannabis sativa proteins used in these studies was retrieved from UniProt, the reference repositories for proteins, which is incomplete and therefore underrepresents the genetic diversity of this non-model species. In this fourth study, we remedy this shortcoming by searching larger databases from various sources. We also compare two search engines, the oldest, SEQUEST, and the most popular, Mascot. This shotgun proteomics experiment also utilizes the power of parallel digestions with orthogonal proteases of increasing selectivity, namely chymotrypsin, trypsin/Lys-C and Asp-N. Our results show that the larger the database the greater the list of accessions identified but the longer the duration of the search. Using orthogonal proteases and different search algorithms increases the total number of proteins identified, most of them common despite differing proteases and algorithms, but many of them unique as well.
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The N-glycans in Toxicodendron vernicifluum (Rhus vernicifera) lacquer laccase was elucidated for the first time through a combination of enzymatic digestion and subsequent mass spectrometry measurements using LC-MS/MS and MALDI-TOF MS. Lacquer laccase was isolated from a Japanese lacquer acetone powder from consecutive Sephadex C-50 and DEAE A-50 column chromatography. Trypsin and chymotrypsin digestions of the lacquer laccase resulted in a mixture of peptides and N-glycopeptides, which were treated with peptide-N-glycosidases and then Nα-(aminooxyacetyl)tryptophanylarginine methyl ester (aoWR) to give the aoWR-labelled N-glycans. The MS measurements revealed that GlcNAc4Hex5Fuc3Xyl1 N-glycan was attached at 12â¯N-glycosylation sites (Asn 5, 14, 180, 194, 233, 274, 284, 347, 364, 381, 398, and 519), GlcNAc3Hex4Fuc2Xyl1 N-glycan at two sites (Asn 124 and 454), and GlcNAc3Hex6Fuc1Xyl1 N-glycan at one site (Asn 28). A database search (Mascot search) of the peptides also suggested the presence of N-glycans at the 15 potential N-glycosylation sites (Asn-X-Ser/Thr).
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Glicopeptídeos/análise , Lacase/química , Proteínas de Plantas/química , Polissacarídeos/química , Toxicodendron/química , Sequência de Aminoácidos , Sequência de Carboidratos , Cromatografia em Gel , Quimotripsina/química , Glicopeptídeos/química , Glicosídeo Hidrolases/química , Glicosilação , Lacase/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Proteólise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tripsina/químicaRESUMO
MASCOT, a small 11â¯kg prototype Asteroid Lander on-board JAXA's Hayabusa2 space probe, was launched on December 3rd, 2014, and arrived at its destined target asteroid (162173) Ryugu on June 27, 2018. MASCOT was separated from its mother spacecraft and successfully landed on October 3rd, 2018, accomplishing the first ever landing of a European spacecraft on the surface of an asteroid. To catch this particular launch opportunity its development timeline needed to be heavily compressed. In particular, the kick-off for hardware production was released in February 2012, only 2 years before the initially planned delivery of the flight unit. Due to this compact schedule, current and well established verification processes could not be followed in order to finalize the project in the given time. But by applying a unique mix of conventional and tailored model philosophies it was possible to dynamical adapt the test program to accomplish for the shortest planning and a suitable weighing of costs and risks. A strategy of Concurrent Assembly, Integration and Verification (C-AIV) helped to identify and mitigate design and manufacturing issues and shortened the test timeline further from a general 4-5 year C/D-phase down to 2,5 year C/D-phase. This short article outlines the general idea of the applied method which could be used by AIV and System Engineers in a general tailoring process for projects of similar nature which could be run in an alternative and much faster way, if the circumstances would call for it. â¢Concurrent AIV, a new agile methodology to hard tailor test and model philosophies for space projects is presented,â¢The methodology is based on parallelization of test activities, creation of independent unique test threads and synergizing their dependencies at key points,â¢On the baseline of the asteroid lander MASCOT, this methodology has been successfully applied to shorten the overall test and implementation schedule to only 2.5 years.
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Peptide identification relies in the majority of mass spectrometry-based proteomics experiments on matching of experimental data against peptide and fragment ion masses derived from in silico digests of protein databases. One of the main drawbacks of this approach is that modifications have to be defined for database searching and therefore no unexpected modifications can be identified in a standard setup. Consequently, in many bottom-up proteomics experiments, unexpected modifications are not identified, even if high-quality fragment ion spectra of the modified peptides were acquired. It is therefore often not straightforward to identify unexpected modifications. In this protocol, we describe a stepwise procedure to identify unexpected modifications at peptides using the database search algorithm Mascot. The workflow includes parallel searches for the identification of known modifications at unexpected amino acids, error tolerant searches for modifications unexpected in the sample but known to the community, and mass tolerant searches for entirely unknown modifications. Furthermore, we suggest a follow-up strategy consisting of (1) verification of identified modifications in the initial dataset and (2) targeted experiments using synthetic peptides.
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Proteínas/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem , Aminoácidos/química , Animais , Cromatografia Líquida , Biologia Computacional/métodos , Análise de Dados , Bases de Dados de Proteínas , Células HeLa , Humanos , Peptídeos/química , Processamento de Proteína Pós-Traducional , Proteínas/química , Proteoma , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodosRESUMO
The revised legislation on medicinal cannabis has triggered a surge of research studies in this space. Yet, cannabis proteomics is lagging. In a previous study, we optimised the protein extraction of mature buds for bottom-up proteomics. In this follow-up study, we developed a top-down mass spectrometry (MS) proteomics strategy to identify intact denatured protein from cannabis apical buds. After testing different source-induced dissociation (SID), collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and electron transfer dissociation (ETD) parameters on infused known protein standards, we devised three LC-MS/MS methods for top-down sequencing of cannabis proteins. Different MS/MS modes produced distinct spectra, albeit greatly overlapping between SID, CID, and HCD. The number of fragments increased with the energy applied; however, this did not necessarily translate into greater sequence coverage. Some precursors were more amenable to fragmentation than others. Sequence coverage decreased as the mass of the protein increased. Combining all MS/MS data maximised amino acid (AA) sequence coverage, achieving 73% for myoglobin. In this experiment, most cannabis proteins were smaller than 30 kD. A total of 46 cannabis proteins were identified with 136 proteoforms bearing different post-translational modifications (PTMs), including the excision of N-terminal M, the N-terminal acetylation, methylation, and acetylation of K resides, and phosphorylation. Most identified proteins are involved in photosynthesis, translation, and ATP production. Only one protein belongs to the phytocannabinoid biosynthesis, olivetolic acid cyclase.
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BACKGROUND: Candida albicans is present as part of the normal gut flora and detected in the oral cavities and GI tracts of around fifty percent of adults. Benign colonization can turn pathogenic causing a variety of mild to severe infections. In a pathogen, the cell wall and cell surface proteins are major antigenic determinants and drug targets as they are the primary structures that contact the host. Cell surface proteins perform a variety of functions necessary for virulence such as adhesion, host degradation, resistance to oxidative stress, and drug resistance. We have previously characterized Hwp2, a C. albicans cell wall adhesin shown to play a major role in the cell wall architecture and function as hwp2 mutants were deficient in chitin deposition, filamentation, adhesion and invasive growth, virulence, and resistance to oxidative stress. OBJECTIVE/METHOD: Here, we utilized tandem mass spectrometry coupled with a bioinformatics approach to differentially profile the cell wall proteome of a wild-type strain compared to an hwp2 null mutant to determine key differentially expressed proteins. RESULT: Many proteins identified exclusively in the wild-type go a long way in explaining the abovementioned phenotypes. These include virulence factors such as members of the SAP family including Sap4, Sap5, and Sap10, as well as several lipases involved in host degradation. We also identified members of the PGA family of proteins Pga28, Pga32, Pga41 and Pga50, which function in adhesion, Cht2 a chitinase involved in chitin remodeling, and several proteins that function in promoting filamentation such as Phr1, Mts1, and Rbr1.
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Candida albicans/metabolismo , Parede Celular/metabolismo , Proteínas Fúngicas/metabolismo , Mutação/genética , Proteoma/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Candida albicans/crescimento & desenvolvimento , Proteínas Fúngicas/químicaRESUMO
BACKGROUND: Zinc transporter (tzn-1) of Neurospora crassa plays a crucial role in conidiation pathway, as its removal results in aconidiation which was reported in our earlier studies. OBJECTIVES: The main objective of this study was to analyze the role of tzn-1 in conidiation process, by comparing knockout (KO) mutants zinc transporter KO (Δtzn-1) and aconidiating gene KO (Δacon-3) with wild oak ridge (OR) 74 'A' strain by 'Proteo-genomic' approach. METHODS: To identify the commonly expressed protein spots in knockout (KO) mutants zinc transporter KO (Δtzn-1) and aconidiating gene KO (Δacon-3) by comparing with wild oak ridge (OR) 74 'A' strain. Two sets (Δtzn-1 to wild and Δacon-3 to wild) were analyzed by combining 2- Dimensional gel electrophoresis (2DE) with Matrix Associated Laser Desortion/Ionization mass spectrometry -Peptide Mass Fingerprint (MALDI-PMF). Then, the peptide sequences which were obtained by MASCOT (database software) were identified by FGSC BLASTp search analysis. Finally, to evaluate the expression of the KO mutants zinc transporter KO (Δtzn-1) and aconidiating gene KO (Δacon-3) in comparison to wild (OR) 74 'A' type was analyzed by Quantitative Real Time Polymerase Chain Reaction (qRT-PCR) studies. RESULTS: 2DE and MALDI-PMF has shown the nine commonly overexpressed protein spots from the two sets (Δtzn-1 to wild and Δacon-3 to wild). Peptide sequences were obtained by MASCOT (database software) analysis and peptide sequences were identified by FGSC BLASTp search. Eight sequences have shown the similarities with the genes involved during the early stages of conidial and sexual development. Our qRT-PCR analysis has shown that tzn-1 gene was upregulated in contrast to acon-3 gene in absence of iron concentration and down regulated with increase in iron concentrations in wild samples. With increase in zinc supplements, the tzn-1 gene is normally regulated and shown contrasting feature in absence of zinc and acon-3 gene is normally regulated both in presence and absence of zinc. At regular time intervals, declined growth rate was observed after 18hours of induction. CONCLUSION: Thus, we conclude that tzn-1 and acon-3 genes were actively participating in early stages of conidial process and metal ions play some crucial role in the development of the organism.