The knowledge of the human genome sequence, as revealed in the HUGO project, has created exciting new possibilities for biomedical research. The Swedish Human Proteome Resource (HPR) program aims to make use of this information to gain further insight into the human proteome. Recombinant proteins are generated from coding sequences identified from the human genome sequence and used to produce specific antibodies to target proteins. Antibodies are subsequently utilized for functional analysis of the corresponding proteins using tissue micro arrays. The aim of my project was to investigate the possibility of distinguishing characteristic distribution patterns of intracellular proteins in the resolution capacity offered by light microscopy. A map of representative distribution patterns was created using immunohistological staining with commercially available antibodies toward well-characterised proteins in the cell. Such a map could then aid in interpreting the results of immunohistological staining of intracellular proteins using antibodies produced within the Human Proteome Resource program. Proteins manifested in nucleus, nuclear membrane and plasma membrane were clearly visible at the expected location. Proteins manifested in different organelles in the cytoplasm however, showed all a similar staining pattern, making determination of exact protein location uncertain. A possible explanation is the resolution of the light microscope not being sufficient to visualize certain proteins specific to organelles in the cytoplasm. Results may also have been influenced by the choice of secondary antibody, where the strenghtened signal generated by an enzyme labelled polymer may have a negative effect on depiction of details in the image generated.

Therapeutic monoclonal antibodies (MAb) are produced as secreted complex glycoproteins from mammalian cell systems and represent one of the most important classes of therapeutic medicines for the treatment of a variety of human diseases. Their benefit in health care and high economic impact provide the driving force for the development of improved production levels with the focus of optimizing clinical efficacy. One important issue is the optimization of monoclonal antibody production. A frequent approach used to address this challenge is the engineering of mammalian cell lines to increase antibody production levels through genetic manipulation. Valuable information can then be obtained by monitoring the effects of genetic changes on the biochemistry of the cell associated with MAb production. Global protein expression profiling of mammalian cells used for the production of biopharmaceuticals may reveal key biochemical characteristics associated with MAb-producing cell lines. A better understanding of these characteristics can in turn lead to more rational strategies for cell line and process development. The proposed research relates to a larger NSERC Strategic Network (MAbNet) Grant to develop and establish a novel platform for the large-scale manufacture of specific glycoforms of therapeutic monoclonal antibodies. The efficacy of these recombinant MAbs will be enhanced by the control of their glycosylation profiles. The work presented in this thesis will assist MAbNet in meeting their objectives. Specifically, we use 2D-Differential In-Gel Electrophoresis (2D-DIGE) to quantify protein expression differences between EG2-hFc1-producing Chinese Hamster Ovary cells (CHO-1A7) with its parental cell line (CHO-BRI). Here, we identified 34 unique differentially expressed proteins associated with EG2-hFc1 production that relate to various biological processes including protein processing, carbohydrate metabolism, amino acid metabolism, energy metabolism, apoptosis, and cell proliferation pathways. The majority of identified significant protein expression changes and their associated metabolic processes seem to prioritize energy production in CHO-1A7 cells. Due to the metabolic load of recombinant antibody production, the CHO-1A7 cell line attempts to meet the energy requirements needed for recombinant protein biosynthesis while maintaining cell viability and efficient protein folding mechanisms. A 2-D proteome reference map was also constructed for the CHO-BRI host cell line containing 131 identified protein spots. The map provides information that will further expand our understanding of this particular cell line. It will be a useful tool for studies investigating physiological responses and protein expression patterns of CHO-BRI to genetic and environmental perturbations. The set of identified differentially expressed proteins provides data on the downstream changes in protein expression due to genetic manipulation, and furthermore can provide targets for cell-line specific optimization of antibody production. The work described in this thesis furthers our understanding of antibody production in a specific CHO cell line.

Listeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. The infectious process depends upon survival in high bile salt conditions encountered throughout the gastrointestinal tract, including the gallbladder. However, it is not clear how bile salt resistance mechanisms are induced, especially under physiologically relevant conditions. This study sought to determine how L. monocytogenes responds to bile salts under anaerobic conditions. The study found resistance to be strain specific and not dependent upon virulence. Changes in the expressed proteome were analyzed using multidimensional protein identification technology coupled with electrospray ionization tandem mass spectrometry. A general response among virulent and avirulent strains found significant alterations in intensity of cell wall associated proteins, DNA repair proteins, protein folding chaperones and oxidative response proteins. Strain viability was correlated with an initial osmotic stress response followed by strain specific proteins associated with biofilm formation in EGDe and a transmembrane efflux pump in F2365.

Il existe un certain nombre de situations au cours desquelles l’intégrité du génome cellulaire est mise en danger. Ceci se produit notamment lors de mouvements de gènes (translocation, éléments mobiles), lors d’infections virales parfois intégratives (AAV, HBV, HPV) ou lors d’infections rétrovirales. En effet, le cycle de réplication des rétrovirus nécessite une étape d’intégration du génome viral dans l’ADN génomique de la cellule infectée. Malgré les nombreuses études menées sur les infections par le VIH, les cancers viro-induits ou non et les thérapies géniques basées sur les rétrovirus, aucune donnée n’est actuellement disponible sur les modifications cellulaires induites par de telles perturbations chromosomiques. L’objectif du projet était d’identifier des mécanismes cellulaires induits par des atteintes à l’intégrité du génome, plus précisément par l’insertion de molécules d’ADN non cellulaire dans les chromosomes. L’intégration de matériel génétique additionnel a été induite par des vecteurs lentiviraux dérivés du VIH-1. Les modifications cellulaires uniquement dues à l’intégration ont été isolées par comparaison de vecteurs intégratif et non intégratif. Des cellules primaires du derme humain ont été sélectionnées pour l’étude. Les temps post infection et les doses virales les plus adéquates ont été sélectionnés grâce à des expériences de cinétiques d’intégration couplées à une quantification des ADN viraux intégrés. L’analyse des modifications cellulaires induites par l’intégration de l’ADN étranger a portée sur l’ensemble du transcriptome et sur l’ensemble du protéome cellulaire. Dans le but d’effectuer une analyse transcriptomique, des puces à ADN, représentant le génome humain complet, ont été utilisées. Cette étude a démontré une forte répression transcriptionnelle induite par l’intégration. De plus, toutes les fonctions cellulaires sont perturbées par le processus. Finalement, une classification par interactions et fonctions biologiques a mis en évidence cinq processus cellulaires majoritairement affectés par l’intégration de l’ADN étranger, qui correspondent au cycle et à la mort cellulaire, au remodelage et à la réparation de la chromatine et à la réponse immunitaire ou au stress. Dans le but de compléter cette analyse transcriptomique, une étude protéomique a été réalisée. Les protéines cellulaires ont été séparées sur des gels bi-dimensionnels. Parmi les neuf protéines identifiées en spectrométrie de masse, certaines appartiennent au cytosquelette et d’autres aux mécanismes de réponse au stress. L’intégration d’un ADN étranger au sein du génome provoque donc bien des perturbations cellulaires. L’intégration de matériel génétique additionnel ne concernant pas seulement les rétrovirus, les données obtenues lors de cette étude pourront permettre (i) de développer des stratégies de défenses contre les rétrovirus ou contre les autres maladies caractérisées par des atteintes à l’intégrité du génome, (ii) d’évaluer les risques encourus par l’intégration d’un vecteur thérapeutique dans le génome cellulaire lors des thérapies géniques ou des expériences de transfert de gènes / In numerous situations, cell genome integrity could be in danger. This is the case during gene movements (translocations, mobiles elements), during viral infections that could be sometimes integrative (AAV, HBV, HPV) or during retroviral infections. Indeed, the replication cycle of retroviruses requires a viral genome integration step. In spite of the studies on HIV infections, viral or non viral cancers and retrovirus-based gene therapy, no data are available concerning the cellular modifications induced by such chromosomal disruptions. The aim of work was to identify cellular mechanisms induced by the insertion of a non cellular DNA into the chromosomes. The integration of additional DNA was provoked by HIV-1-based lentiviral vectors. Cellular modifications only due to the integration step were isolated by comparison of integrative and non integrative vectors. Primary human dermal fibroblasts cells were selected for the study. Optimal times post infection and viral quantities were defined using kinetic integration experiments and integrated viral DNA quantifications. The study of cellular modifications induced by the integration of the foreign DNA was applied on the cellular global transcriptome and proteome. In order to perform a transcriptomic analyses, DNA microarray corresponding to the whole human genome, were used. This study revealed a strong transcriptional repression induced by the integration. Moreover, every cellular function are disturbed by the process. Finally, a network based on molecular interactions and biological functions underlined five cellular processes mostly affected by the foreign DNA integration and corresponding to the cell cycle and death, the remodelling and repair of chromatin and the immunity or stress responses. To complete this transcriptomic analyses, a proteomic study was realized. Cellular proteins were separated on 2D gels. Among the nine proteins identified by mass spectrometry, some are linked to the cytoskeleton and other to the cellular stress. Thus, integration of a foreign DNA into the genome provoked cellular perturbations. As additional DNA integration do not only concern retroviruses, data obtained during this study could allow (i) the development of defensive strategies against retroviruses or other diseases implicating the genome integrity and (ii) the evaluation of risks linked to the integration of a therapeutic vector into the genome during gene therapy and gene transfer experiments

Naegleria fowleri are free-living ameboflagellates found in soil and freshwater habitats throughout the world that cause a fatal disease in humans called Primary Amoebic Meningoencephalitis (PAM). Mechanisms of host resistance or susceptibility to infection have not been fully elucidated, and possible treatment methods are still sub optimal. The disease is diagnosed using specific laboratory tests available in only a few laboratories in the United States. Because of the rarity of infection and difficulty in initial detection, more than often PAM is misdiagnosed. Therefore, it is very important to find causative marker for early detection of an infection. The purpose of this study is to create a proteomic signature map using two-dimensional gel electrophoresis (2-D gel) and recommend a subset of proteins that may be directly linked to the pathogenic state of N. fowleri. Replicates of 2-D Gels were created for both strains of N. fowleri and the proteomic templates from these gels were compared with each other. Scatter Plots were generated measuring the density of protein spots from 2-D gels being analyzed for each study. For each strains of N. fowleri, the 2-D gels from each study were compared within and compared between the two studies for reproducibility in data. The resulting correlation values for all of the Scatter Plots were greater or equal to 0.90. Finally, the representative proteomic template for axenically grown N. fowleri and mouse passaged N. fowleri were compared and the correlation value of 0.60 was observed. This confirmed our theory that these two strains or states of N. fowleri have very different protein expressions, and we were able to identify a subset of proteins, both over expressed and newly synthesized, that may be linked to the highly pathogenic state of N. fowleri.

DYRK1A is a protein kinase encoded by a gene implicated in Down syndrome pathogenesis. Loss of DYRK1A could promote oncogenic transformation. However, the regulation and substrates of DYRK1A are not fully understood. MudPIT proteomic analysis revealed novel DYRK1A interacting proteins with poorly characterized or even unknown functions. Therefore, the aim of this thesis was to understand the function of DYRK1A through the characterization of its interacting proteins. To achieve this aim, we established stable cell lines expressing these proteins and confirmed the interactions between DYRK1A and seven candidate binding partners. Furthermore, we found that all novel DYRK1A-interacting proteins also bind DCAF7, a previously reported DYRK1A-binding scaffold protein that binds to the N-terminus of DYRK1A. Using cyto-nuclear fractionation and immunostaining we found that DYRK1A-interacting proteins were present in different cellular compartments, suggesting that DYRK1A could play distinct roles in the cell depending on its localization. DYRK1A has been shown to regulate cell proliferation and actin cytoskeleton therefore we used cell proliferation assays and actin staining to determine the role of DYRK1A-interacting proteins in these processes. Here we report functional characterization of the interacting partners of DYRK1A and present cell-based models that will help to understand the function and regulation of this important protein kinase.

The increase of multi-resistant bacteria highlights that the golden era of antibiotics is ending and that alternative treatmentsare urgently needed. Phages have been historically used to treat bacterial infections prior to the discovery of antibiotics and have gained renewed interest in the past decade. Despite the advantages of phage therapy over traditional antibiotic usage, a number of concerns persist over their clinical application centring on their efficacy and safety. This thesis presents four papers that focus on the isolation and characterization of phages that target reference strains and drug-resistant strains of E. coli as well as their infection dynamics and kinetics. In Paper I, six of thirty isolated phages were selected to be characterized for their growth parameters and host range using two commonly used methods. The study showed that the host range (an important selection criteria for phages) of the phages can change based on the assessment method and that the lysis efficiency of phages is host-dependent. The study suggests that standardised methods to assess the host range and lytic activity of phages are required to reduce result variability between research groups. Paper II investigated a rare phage with C3 morphotype from the Podoviridae family and characterised it via genomic, proteomic, morphologic and phylogenetic analysis. The study revealed previously unseen aspects including the formation of a honeycomb structure comprised of phage head during DNA packaging, the possible contractile nature of the tail and the 280 million year co-evolution between the major head protein and the scaffolding protein. Paper III highlights the need to take the immune system into consideration when designing phage therapeutics. In the study, four purified structurally distinct phages (selected from the three main phage families) were exposed to human cells (HT-29 and Caco-2 immortalised intestinal epithelial cell lines and donor-derived peripheral blood mononuclear cells) and the immunogenicity of the phages determined. Phage immunogenicity was shown to vary in a concentration and phage dependent manner with SU63 (a Myoviridae) being the most immunogenic phage and SU32 (a Siphoviridae) the least immunogenic. In the presence of human cells and a suitable host, phages were shown to maintain their killing efficacy as well as the ability to proliferate. Paper IV studies the infection dynamics of an experimental two-phage cocktail against a single bacterial host in vitro and in silico. However, in silico analysis and in vitro analysis produced conflicting results, in which mathematical modelling predicted the complete clearance of bacteria for all treatment scenarios whereas experimental results showed a 1-3log10 reduction in bacterial content. Practical experiments also showed increased anti-bacterial activity when the time between the additions of each phage was varied. This discrepancy suggests that the current mathematical model is unsuitable due to the inability to account for discrete variables such as interference. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p><p> </p>

As cascavéis são classificadas como grupo monofilético contendo dois gêneros descritos ao grupo: Crotalus ssp. e Sistrurus ssp., os quais surgiram no México a aproximadamente 20 milhões de anos, colonizando então, praticamente todo o continente americano. Fatores como dieta, dimorfismo sexual, ontogenia, mutações e distribuição geográfica podem influenciar na composição dos venenos e consequentemente no envenenamento. O presente trabalho tem como objetivo caracterizar o perfil proteico, bem como as propriedades enzimáticas e imunológicas dos venenos de algumas espécies e subespécies de Crotalus ssp. (C. atrox, C. scutulatus scutulatus, C. viridis viridis, C. vegrandis, C. durissus cascavella, C. d. collilineatus e C. d. terrificus). Os resultados indicaram pouca variabilidade entre os perfis eletroforéticos dos venenos, contudo as diferenças foram na concentração relativa das proteínas. A análises proteômica identificou alguns componentes dos venenos e serinopeptidases, metalopeptidases e fosfolipases A2 foram as mais abundantes. Além disso, por zimografia, observou-se que todos os venenos analisados apresentaram atividade proteolítica e que os venenos norte-americanos em todos os zimogramas foram mais hidrolíticos. Em caseína, a atividade enzimática dos venenos foi menos intensa comparado aos outros substratos. Em relação às gelatinases das amostras estudadas, pôde ser observado inibição da atividade enzimática induzida por alguns componentes utilizando EDTA, principalmente nos venenos de C. atrox e C. vegrandis. Em relação à inibição das serinopeptidases, foi observado que todas as gelatinases dos venenos crotálicos apresentaram inibição total ou parcial da atividade hidrolítica. Houve variabilidade entre as hialuronidases encontradas dos venenos crotálicos, tanto em relação à massa das enzimas e intensidade da degradação, quanto em diferentes pHs. Nos ensaios enzimáticos quantitativos (azocaseinolítico fosfolipásico e peptidásico) os venenos Norte Americanos demonstraram conter mais proteases em relação aos venenos Sul Americanos. Por Western Blotting, as amostras reagiram com os anticorpos presentes nos soros anti-crotálico e anti-botrópico, apresentando reatividade antigênica cruzada entre as amostras homólogas e heterólogas. Além disso, houve imunoreatividade entre o soro anti-jararagina e alguns componentes de todos os venenos crotálicos norte-americanos. / The rattlesnakes are classified as a monophyletic group containing two genera referring to the group: Crotalus ssp. and Sistrurus ssp., which arose in Mexico 20 millions of years ago, colonizing then, practically all the American continent. Some scientific works indicate that factors such as diet, sexual dimorphism, ontogeny, mutations and distribution may influence the composition of the venoms and consequently the poisoning. The present work aims to characterize the enzymatic and immunological properties of the venoms of some species and subspecies of Crotalus ssp. (C. atrox, C. scutulatus scutulatus, C. viridis viridis, C. vegrandis, C. durissus cascavella, C. collilineatus and C. d. terrificus). The results indicated few variability among the electrophoretic profiles of the venoms, however the differences were in the relative concentration of the proteins. The proteomic analysis identified serinopeptidases, metallopeptidases and phospholipases A2, which were the most abundant components of the venoms. In addition, zymography assays indicate that the all the venoms showed proteolytic activity, furthermore, the North American venoms, presented more hydrolysis in all zimograms. The caseinolytic activity was less intense compared with other substrates. Regarding the gelatinolytic activity of the samples, inhibition of the enzymatic activity of some components could be observed using EDTA, mainly in the C. atrox and C. vegrandis venoms. Partial or total inhibition was observed of the serinopeptidases activity of the crotalic gelatinases. Among the hyaluronidases, variations between crotalic venoms, in relation to the enzymes mass and degradation intensity were identified. In addition, when incubated at different pHs, the hyaluronidase profile presented different patterns in the activity. In the quantitative enzymatic assays (azocaseinolytic phospholipasic, peptidasic) the North American venoms displayed higher activity in relation to the South American venoms. In the Western Blotting assays, the samples reacted with antibodies present in the Brazilian anti-crotalic and bothropic sera, indicating cross-reactive antigenicity between the homologous and heterologous samples. Besides that, there was immunoreactivity between the anti-jararrhagin serum and some components of all North American crotalic venoms.

Thesis advisor: Eranthie Weerapana / A chemical-proteomic platform to monitor cysteine sensitivity to transnitrosation Yani Zhou Dissertation advisor: Dr. Eranthie Weerapana Abstract S-nitrosation has emerged as a ubiquitous endogenous protein posttranslational modification that significantly impacts cellular protein function through a variety of mechanisms. Despite the advent of chemical and proteomic methods to study S-nitrosation, the subset of cellular cysteine residues that show uniquely high reactivity to endogenous transnitrosation donors is poorly characterized. To further these existing global studies, a cysteine-reactivity profiling strategy was applied herein to rank ~600 cysteine residues by sensitivity to S-nitrosoglutathione. These proteomic studies revealed several previously uncharacterized sites of S-nitrosation, including Cys58 in HADH2. Further characterization revealed that HADH2 catalytic activity is allosterically regulated by S-nitrosation, and this modification occurs in cells at (patho)physiological levels of nitrosative stress. Functional role of Cys58 and its regulation by S-nitrosation facilitated the identification of RB-21-CA as a potential covalent Cys58 inhibitor. Global analysis of GSNO, S-nitroso-Coenzyme A and Thioredoxin-C73-SNO transnitrosation identified 756 cysteines with different sensitivity to each of three SNO donors. Systematic evaluation on transnitrosation selectivity revealed that specific interaction of transnitrosation donor with its protein target is a key component governing the selective transnitrosation of a specific cysteine residue. Together, these studies illustrated the potential of cysteine-reactivity profiling strategy for evaluating the substrate specificity of transnitrosation donors and enable the identification of previously uncharacterized, functionally relevant sites of S-nitrosation. Another cysteine oxoform, S-glutathionylation, is the disulfide formation of a protein cysteine residue with glutathione. Although glucose starvation is known to induce redox-disturbance, global and individual protein S-glutathionylation in response to glucose metabolism or mitochondrial activity remains largely unknown. By using a clickable glutathione approach, which forms clickable glutathione by the use of a mutant of glutathione synthetase, we found that protein S-glutathionylation is readily induced in response to glucose starvation when mitochondrial reactive oxygen species are elevated in cells, and glucose is the major determinant for inducing reversible glutathionylation. Application of a proteomic mass spectrometry platform identified over 1,300 S-glutathionylated. Confirmation of S-glutathionylation for selected proteins by in gel analysis further validated the mass spectrometry results, and highlights the dynamic change of S-glutathionylation on an individual protein level. In order to expand on the understanding of the functional role of the cysteine residues in biological systems, we evaluated a panel of 1,3,5-triazine- and 4-aminopiperidine-based cysteine-reactive small-molecules on two proteins, apoptosis signal-regulating kinase 1 (ASK1) and peroxiredoxin 1 (Prdx1), between which a intermolecular disulfide forms and results in the activation of mitogen-activated protein kinase pathway. In-gel fluorescence revealed that RB-11-CA and SMC-1, both of which contain an n-octyl group as a diversity element, showed greatest selectivity and potency to ASK1 and Prdx1, respectively. Further mass spectrometry analysis identified cysteine 225 of ASK1 and cysteine 173 of Prdx1 are the sites of covalent probe modification. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

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No. of bitstreams: 2 Dissertação - Paulo Henrique Rosa Martins - 2014.pdf: 1886835 bytes, checksum: cf3cb1538605c45883b5362030c74911 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-03-20 / Paracoccidioides spp. are pathogens of Paracoccidioidomycosis a systemic mycosis that affects about 10 million people in endemic regions. The incidence of the disease is restricted to Latin America and most cases are found in Brazil. The disease is characterized by chronic granulomatous inflammation, and patients may present with a wide spectrum of clinical manifestations. After inhalation of conidia, the installation of fungus in the lungs, which subsequently through hematogenous route may cause an infection spreads. Hematogenous fungal infections represent a serious health problem, involving hospitalized patients with predisposing conditions that lead to a high mortality rate. Fungemia corresponds to isolation of fungi in the bloodstream and occurs mainly in immunocompromised patients. Yeasts have been increasingly present as etiological agents fungemia including Candida albicans and other species such as Candida non- albicans. In this study, Paracoccidioides spp. was isolated from a case of fungemia. So far this is the first molecular study of a case of fungemia caused by this fungus. In order to identify the molecular factors associated with this specific phenotype, a comparative proteomic analysis was performed. The samples were analyzed by nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoUPLC - EPM), where the soluble proteins of fungemia were compared with strain Pb01 -like proteins. 206 proteins regulated positively and negatively regulated 183 were identified. Among the positively regulated protein, 22 % were related to cellular metabolism, 15 % related to protein synthesis and 12% energy. Of phenotypic characterization tests, which showed a better adaptation of isolated Pb9840 blood were also conducted. With this work we propose that the isolated Pb9840 developed mechanisms to better installing the bloodstream and causing the fungemia. The study of the proteomic profile of this isolate may elucidate the virulence mechanisms used by this fungus during fungemia and / or hematogenous spread. / Paracoccidioides spp. são agentes etiológicos da Paracoccidioidomicose uma micose sistêmica que afeta cerca de 10 milhões de pessoas nas regiões endêmicas. A incidência da doença é restrita à América Latina e a maioria dos casos são encontrados no Brasil. A doença é caracterizada por uma inflamação granulomatosa crônica, e os pacientes podem apresentar um amplo espectro de manifestações clínicas. Após a inalação de conídios, ocorre a instalação do fungo nos pulmões, que posteriormente através de rota hematogenica pode causar uma infecção disseminada. Infecções fúngicas hematogênicas representam um grave problema de saúde, envolvendo pacientes hospitalizados com condições predisponentes que levam a uma alta taxa de mortalidade. Fungemia corresponde ao isolamento de fungos na corrente sanguínea e ocorre principalmente em pacientes imunossuprimidos. As leveduras têm sido cada vez mais presente como agentes etiológicos de fungemia, incluindo Candida albicans e outras espécies, como Candida não-albicans. No presente estudo, Paracoccidioides spp. foi isolado de um caso de fungemia. Até o momento esse é o primeiro estudo molecular de um caso de fungemia causado por este fungo. A fim de identificar os fatores moleculares associados a este fenótipo específico, uma análise proteômica comparativa foi realizada. As amostras foram analisadas por cromatografia líquida de nanoescala acoplada a espectrometria de massa em tandem (nanoUPLC - EPM), onde as proteínas solúveis da estirpe fungemia foram comparadas com proteínas do Pb01. Foram identificadas 206 proteinas reguladas positivamente e 183 reguladas negativamente. Dentre as proteínas reguladas positivamente 22% estavam relacionadas com o metabolismo celular, 15% relacionadas com síntese proteica e 12% produção de energia. Foram realizados também testes de caracterização fenotípica, que demonstraram uma melhor adaptação do isolado Pb9840 ao sangue. Com o presente trabalho podemos propor que o isolado Pb9840 desenvolveu mecanismos para melhor de instalar na corrente sanguínea e assim causar o quadro de fungemia. O estudo do perfil proteômico deste isolado poderá elucidar os mecanismos de virulência utilizados por este fungo durante fungemia e / ou disseminação hematogênica.