Navegando por Palavras-chave "Pireno"

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    Análise molecular dos genes nid e cyp e avaliação da degradação de pireno por isolados de Mycobacterium sp
    (Universidade Federal de São Paulo, 2017-07-07) Silva, Natalia Maria da [UNIFESP]; Niero, Cristina Viana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Polycyclic aromatic hydrocarbons (PAHs) are compounds found in the environment as a result of incomplete combustion of organic matter or the anthropogenic activity of exploration, refining and petroleum derivatives. They have complex structures with low solubility in water and remain for long periods in the environment being considered pollutants. Mycobacterium vanbaalenii-PYR1 was the first described microorganism with the ability to degrade pyrene, a polycyclic aromatic hydrocarbon. Sequencing of the genome of this strain revealed the presence of a region specialized in the degradation of HPA, called region A, containing genes encoding dioxygenase (nid). In addition, genes dispersed in the genome that encode monooxygenases (cyp150) with involvement in the degradation of these compounds have been described. Thus, this work investigated the presence of the nid and cyp genes in five Mycobacterium sp isolates by PCR and hybridizations with specific probes, besides the degradation of pyrene by phenotypic tests and by gas chromatography coupled to mass spectrometry (GC-MS). In the first stage of the work, the identification of the isolates was performed by the analysis of three essential genes by sequencing and the results obtained allowed to conclude that the isolates of this study are related to M. vanbaalenii and M. austroafricanum species. All isolates analyzed showed the ability to degrade pyrene by phenotypic tests. Gas chromatographic analyzes suggest that the MYC038, MYC040 and MYC211 isolates degrade 69.5%, 60.3% and 50.5% pyrene, respectively, over a period of 14 days. PCR results and hybridizations revealed the presence of only nidA and cyp150 genes in all isolates analyzed. The nidB, nidA3, nidB3 and ferredoxin phtAcAd genes were not identified in any of the isolates analyzed in this study suggesting their absence. Analyzes of the nidB2 gene did not allow to conclude its presence / absence. These data re-inforce the hypothesis of the present work that there is polymorphism in the A region of these isolates, and may also imply the existence of a new pathway for the degradation of aromatic hydrocarbons.
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    Relação de alterações conformacionais da prolil oligopeptidase devido a interação com a α – sinucleína
    (Universidade Federal de São Paulo (UNIFESP), 2019-09-26) Santos, Gabriel Silva [UNIFESP]; Oliveira, Vitor Marcelo Silveira Bueno Brandao De [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Prolyl oligopeptidase (EC 3.4.21.26, POP) is a serine peptidase, involved in the metabolism of neuropeptides and peptide hormones. In vitro and in vivo studies show that POP interacts with alpha synuclein (syn) by accelerating the aggregation of this protein, although when prolyl oligopeptidase is inhibited, syn aggregation is reduced. This mechanism for POP's participation in syn aggregation is totally unknown. The structure of POP does not allow peptides larger than 30 amino acid residues or proteins to reach their active center. Data from the literature show that POP presents an open (catalytic and regulatory domain shift with active center exposure) and a closed (catalytic and regulatory domain approach) conformation. The overall objective of this project was to study this possible "open and close" movement that may occur in POP due to interaction with substrates or inhibitors, and the implication of this conformational change in interaction with alpha synuclein. For this purpose, spectroscopic probes were used, when nearby they have characteristic fluorescence emission, excimer, in order to evaluate the conformational movements of POP and the possible implication of these movements in the interaction with syn. To validate the applied methodology, we used Thimet Oligopeptidase (TOP) a protein widely studied in our research group. The use of TOP provided important data for the use of spectroscopic probes showing that the separation of oligomeric species is fundamental for the analyzes studied here. The proteins with the spectroscopic probes showed activity, indicating that the tertiary structure was not impaired and consequently its function. Probe approximation with increasing guanidine chloride concentration showing probe spacing and excimer disappearance were evaluated. In addition, we evaluated by circular dichroism the POP - syn interaction and the hydrolysis profile of POP in the presence of syn. Interestingly, the high concentration of syn hinders substrate access to the active center, and the interaction between proteins occurs a change in secondary structure