Donat A Chapeaurouge

Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil

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Publications (6)16.19 Total impact

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    ABSTRACT: Thiol groups of cysteine residues represent redox centers involved in multiple biological functions. It has been postulated that changes in the redox status of mammalian epididymal spermatozoa contribute to the sperm maturation process. The present work shows the thiol-disulfide protein profile of stallion epididymal spermatozoa achieved by two-dimension electrophoresis and MALDI-TOF/TOF mass spectrometry of proteins labeled with a thiol-reactive fluorescent tag, monobromobimane. Our results have shown the formation of disulfide bonds in several sperm protein fractions during the epididymal maturation process. The magnitude of the thiol oxidation differs between proteins, and is more drastic in polypeptides with molecular weights of up to 33 kDa. The majority of the oxidized thiol sperm proteins identified correspond to structural molecules of the flagellum (as the outer dense fiber -1,2 proteins), followed by glycolytic enzymes (as glyceraldehyde-3-phosphate dehydrogenase spermatogenic), antioxidant protectors (as glutathione S-transferase and phospholipid hydroperoxide glutathione peroxidase - PHGPx). Disulfide bonds formation was drastic in the 32-kDa and 22-kDa samples, identified as ODF-1 and PHGPx. A kinase anchor protein, a voltage-dependent anion channel protein and a zona pellucida-binding protein were also found in the polypeptide samples that contained oxidized - SH groups. These proteins may be modified or controlled by the mechanisms involved in the cysteine-redox changes, corroborating the belief that a correct degree of protein oxidation is required for the stabilization of sperm structure, protection against oxidative damage, induction of progressive sperm motility and fertilization.
    Animal reproduction science 01/2013; · 1.56 Impact Factor
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    ABSTRACT: Prevotella intermedia is a rod-shaped, Gram-negative anaerobic bacterium found in human indigenous microbiota that plays an important role in opportunistic infections. The successful colonization depends on the ability of anaerobes to respond to oxidative stress (OS) in oxygenated tissues as well as to resist oxidative events from the host immune system until anaerobic conditions are present at the infection site. As knowledge of the mechanisms of protection against OS in Prevotella is limited, studies are needed to clarify aspects of molecular biology, physiology and ecology of this bacterium. The aim of this study was to access the proteins differentially regulated in P. intermedia after exposure to molecular oxygen by using two-dimensional gel electrophoresis (2DE) associated with the approach of MALDI-TOF/TOF Tandem Mass Spectrometry. The identity of the protein was evaluated by database search for homologous genomic sequences of P. intermedia strain 17 (TIGR). Twenty five out of 72 proteins found were identified as up-regulated (17) or down-regulated (9). These proteins were related to a variety of metabolic process, some of which could be associated to antioxidant and redox regulatory roles. Our data indicate that OS may stimulate an adaptive response in P. intermedia whose effect on its biology may be evidenced by the increase in aerotolerance and changes in protein abundance in the oxygen adapted cells.
    Anaerobe 12/2011; 18(1):76-82. · 2.02 Impact Factor
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    ABSTRACT: The PA1 strain of Pseudomonas aeruginosa isolated from oil waste produces rhamnolipid, a biodegradable surfactant with applications in several industrial and environmental fields. The metabolic pathway and genetic regulation of rhamnolipid production in P. aeruginosa are poorly understood. Herein, several proteins directly or indirectly related to rhamnolipid production and their genetic regulations were identified by comparative proteomic. We compared the proteome of P. aeruginosa PA1 after fermentation in two different conditions of carbon and nitrogen sources: condition A allowed rhamnolipid production and condition B prevented it. Protein extracts from cellular pellets were compared using 2D-PAGE stained with colloidal Coomassie followed by MALDI-TOF/TOF mass spectrometry. We identified 21 differentially expressed proteins, including those involved in secretion, quorum sensing, oxidative response and metabolism.
    Process Biochemistry 09/2010; · 2.44 Impact Factor
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    ABSTRACT: We investigated the presence and inducibility of CYP1A in suckermouth catfish (Hypostomus affinis and Hypostomus auroguttatus, Loricariidae), tilapia (Oreochromis niloticus, Cichlidae) and mice (Mus musculus, Muridae). Alkoxyresorufin-O-dealkylases (EROD, MROD, PROD and BROD) were detected and proved to be inducible (beta-naphthoflavone, BNF or dimethylbenz[a]anthracene, DMBA, 50 mg/kg bw ip) in liver microsomes from tilapia and mice. In loricariids, alkoxyresorufin-O-dealkylases were either undetectable (MROD/EROD) or very low (PROD/BROD), and so they remained after treatment with BNF or DMBA. Ethoxycoumarin-O-deethylase (ECOD) was recorded in all species and proved not to be inducible by BNF or DMBA. In loricariids and tilapia, ECOD was not depressed by a concentration of alpha-naphthoflavone (CYP1A-inhibitor) that markedly depressed EROD in tilapia. A CYP1A-like protein was detected by a monoclonal antibody in rats, mice and tilapia, but not in loricariids. A polyclonal antibody, however, detected a CYP1A-like protein in liver microsomes of loricariids. Suckermouth catfish, rats, mice and tilapia express a protein reactive with a polyclonal antibody against trout CYP3A. Loricariids and tilapia exhibited marked genotoxic responses (enhanced incidence of micronucleated erythrocytes) following treatment DMBA (50 mg/kg bw ip), a promutagen activated by CYP1A/1B. Therefore, although not exhibiting EROD, a CYP1A-mediated activity, loricariids converted DMBA into its genotoxic metabolites. Our findings suggest that the CYP1A-like protein of locariid catfish recognizes DMBA, but not ethoxyresorufin, as a substrate.
    Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 06/2009; 150(2):252-60. · 2.71 Impact Factor
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    ABSTRACT: Viral hemorrhagic fever is a clinical syndrome that poses serious global health threat. Among the causative agents, dengue virus (DV) has the highest incidence rate and its infection is the major cause of viral hemorrhagic fever in the world. Although the pathophysiological mechanisms of DV-induced diseases are not yet understood, it is well accepted that liver is a site of viral replication. In this study, we used proteomics to analyze infection of a hepatic cell lineage, HepG2, with DV, focusing on the secreted proteins. 1D-electrophoresis and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) were used, allowing the identification of a total of 107 proteins, among which 35 were found only in control secretome and 24 only in infected cells secretome. To validate these data, we performed 2D-eletrophoresis followed by MALDI-TOF/TOF, resulting in the identification of 20 proteins, 8 of them confirming LC-MS/MS results. We discuss the results obtained taking into account the proteins previously described in the secretome of HepG2 cells, proteins present in human plasma and proteins of interest for dengue pathogenesis. Altogether the data presented here provide clues for the progress in the understanding of the role of liver secretion in the progression of the disease.
    Biochimica et Biophysica Acta 11/2008; 1784(11):1607-16. · 4.66 Impact Factor
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    ABSTRACT: For a better comprehension of the parasite-host interaction, proteins expressed by the cardiac and pericardial tissues were compared between susceptible (Cabo Frio) and resistant (Taim) Biomphalaria tenagophila populations, challenged (c) and non-challenged (nc) with Schistosoma mansoni. Proteins were separated by two-dimensional gel electrophoresis (2DE) and stained with Coomassie blue. A total of 146 and 135 spots were observed in Cabo Frio (CFnc) and in Taim (Tnc) non-challenged populations, respectively, whereas 153 spots were detected in both Cabo Frio (CFc) and Taim (Tc) challenged populations. Regarding comparisons between CFnc and CFc, the numbers of exclusive spots obtained were one and nine, respectively, whereas Tnc yielded 17 and Tc eight exclusive spots. By comparing the total of spots in CF (nc+c) with T (nc+c) populations, we obtained: four exclusive spots for CFc; zero for CFnc; four for Tc and; one for Tnc. A quantitative comparison (reason>2.5) of the total spots of CF (nc+c) with T (nc+c) populations allowed us to distinguish five more intense spots for Tc, 14 for Tnc, 15 for CFnc and 11 for CFc. In the CFnc population, two proteins were identified: actin and ATP synthase alpha chain; in the CFc population, four proteins: actin, calmodulin, HSP70, and dehydrogenase; in the Tnc population, five proteins: matrilin, HSP70, actin, ATP synthase alpha chain and intermediate filament of the protein; and in the Tc population, three proteins: actin, alpha-S1 casein and ATP synthase alpha chain. Out of a total of 79 spots, only nine proteins were identified due to the low number of available nucleotide sequences in the GenBank. Nevertheless, knowing proteins regarded as differentially expressed is indispensable for hitherto unidentified genes implicated in B. tenagophila resistance and or susceptibility to S. mansoni infection.
    Acta Tropica 03/2008; 105(3):229-34. · 2.79 Impact Factor