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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Clonagem, expressão heteróloga, modelagem e interações intermoleculares da proteína corismato sintase de Paracoccidioides brasiliensis / Cloning, heterologous expression, modeling and intermolecular interactions of the chorismate synthase protein from Paracoccidioides brasiliensis

Santana, Andrea Leite Camargo 29 March 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-24T13:45:43Z No. of bitstreams: 2 Dissertação - Andrea Leite Camargo Santana - 2017.pdf: 3114758 bytes, checksum: 4fa4c3e9a2e7062f2940b053f1250619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-24T13:46:06Z (GMT) No. of bitstreams: 2 Dissertação - Andrea Leite Camargo Santana - 2017.pdf: 3114758 bytes, checksum: 4fa4c3e9a2e7062f2940b053f1250619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-24T13:46:06Z (GMT). No. of bitstreams: 2 Dissertação - Andrea Leite Camargo Santana - 2017.pdf: 3114758 bytes, checksum: 4fa4c3e9a2e7062f2940b053f1250619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Paracoccidioides fungi are the causative agents of paracoccidioidomycosis, an endemic disease in Latin America with great socioeconomic importance. Inhalation of spores, the infectious particles of the fungus, is a common way to get the infection. Its treatment is slow and generates long-term side effects making it necessary to study new metabolic pathways that can be potential targets for antifungal development. In this context, stands out the chiquimate pathway in Paracoccidioides spp., related to the production of chorismate and production of aromatic amino acids, and the chorismate synthase involved in the last stage of this pathway. The chorismate synthase from Pb18 was cloned into pGEX-4T3 vector, expressed in pLysS cells and purified on a glutathione-sepharose column. Antibodies were produced from the immunization of mice with the recombinant protein obtained and used in Western blot assay to confirm protein expression. For characterization of the enzyme, its modeling was carried out. Pull-down-GST assay was performed to identify interactions between the chorismate synthase and soluble proteins present in total protein extract of Pb18. The interactions found included proteins of different functional categories related to protein synthesis, related with metabolism of common intermediates such as folate and quinolinate or related with the availability of ATP, phosphoenolpyruvate and erythrose-4-phosphate required in the chiquimate pathway. Unexpected interactions with proteins of the cell cycle and also with regulating proteins of the cell division process were observed. / Fungos do gênero Paracoccidioides são os agentes causadores da paracoccidioidomicose, uma doença endêmica na América Latina de grande importância socioeconômica. A inalação de esporos, partículas infecciosas do fungo, é uma forma comum de adquirir a infecção. O seu tratamento é lento e gera efeitos colaterais tornando necessário o estudo de novas vias metabólicas que sejam potenciais alvos para o desenvolvimento de antifúngicos. Nesse contexto, destaca-se a via do chiquimato em Paracoccidioides spp., relacionada à obtenção de corismato e produção de aminoácidos aromáticos, sendo corismato sintase a enzima envolvida na última etapa dessa via. A corismato sintase proveniente de Pb18 foi clonada em vetor pGEX-4T3, expressa em células pLysS e purificada em coluna de glutationa-sefarose. Anticorpos foram produzidos a partir da imunização de camundongos com a proteína recombinante obtida e utilizados em ensaio de Western blot a fim de confirmar a expressão proteica. A modelagem da corismato sintase foi realizada e os aminoácidos envolvidos no sítio ativo foram identificados. Ensaios de pull-down-GST foram realizados a fim de identificar os complexos de interações entre a corismato sintase e proteínas solúveis presentes em extrato proteico total de Pb18. As interações encontradas incluíram proteínas de diferentes categorias funcionais relacionadas à síntese proteica, ao metabolismo de intermediários comuns como folato e quinolinato ou ainda com a disponibilidade de ATP, fosfoenolpiruvato e eritrose-4-fosfato necessários na via do chiquimato. Interações inesperadas com proteínas do ciclo celular e também com proteínas reguladoras do processo de divisão celular foram observadas.
22

Síntese, caracterização e estrutura cristalina de polímeros de coordenação envolvendo metais de transição (Mn+2, Co+2, Cu+2 e Zn+2), ligantes nitrogenados multidentados e policarboxilatos

Corrêa, Charlane Cimini 04 March 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-08T17:51:58Z No. of bitstreams: 1 charlaneciminicorrea.pdf: 11668631 bytes, checksum: a7ab701003fdf688b49377e542ceb430 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T14:03:22Z (GMT) No. of bitstreams: 1 charlaneciminicorrea.pdf: 11668631 bytes, checksum: a7ab701003fdf688b49377e542ceb430 (MD5) / Made available in DSpace on 2017-05-17T14:03:22Z (GMT). No. of bitstreams: 1 charlaneciminicorrea.pdf: 11668631 bytes, checksum: a7ab701003fdf688b49377e542ceb430 (MD5) Previous issue date: 2011-03-04 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho de tese de doutorado consistiu na síntese e caracterização de arranjos supramoleculares com os metais Mn2+, Co2+, Cu2+ e Zn2+ da primeira série de transição contendo ligantes nitrogenados 1,3-bis(4-piridil)propano (BPP), sulfeto de di(4-piridila) (DPS) e dissulfeto de di(4-piridila) (DPSS) e policarboxilatos 1,2,4,5-benzenotetracarboxilato (BT), p-sulfobenzoato (SF) e 1,3,5-benzenotricarboxilato (BTC). Foram obtidos vinte e seis compostos que foram caracterizados por técnicas analíticas e espectroscópicas, tais como, análise elementar (CHN), análise térmica (TG/DTA) e espectroscopia vibracional (infravermelho e Raman). Dentre esses, vinte e dois compostos foram obtidos na forma de monocristais e tiveram suas estruturas determinadas por difração de raios X de monocristal. A análise térmica mostrou que todos os compostos apresentam-se hidratados, com moléculas de água de coordenação e/ou de cristalização. A espectroscopia vibracional foi importante para inferir sobre os modos de coordenação dos grupos carboxilatos através do cálculo do ∆ν (νassimCOO-νsimCOO). Nos compostos contendo o ligante BT, o grupo carboxilato atuou sempre de modo monodentado. Para os compostos com o ligante SF foram observados os modos monodentado e quelato e para o ligante BTC os modos monodentado, quelato e em ponte syn-syn e syn-anti. Foram descritas a síntese e caracterização dos compostos envolvendo o carboxilato BT e os ligantes nitrogenados BPP, DPS e DPSS que originaram onze complexos inéditos nomeados como: MnBTBPP, CoBTBPP, CuBTBPP, ZnBTBPP, MnBTDPS, CoBTDPS, CuBTDPS, ZnBTDPS, MnBTDPSS, CoBTDPSS e ZnBTDPSS. O ligante BT está presente em todos estes compostos e, com exceção do CoBTDPSS, apresentaram o ligante nitrogenado coordenado em ponte. Todos os compostos exceto o ZnBTBPP tiveram suas estruturas determinadas por difração de raios X de monocristal. Em especial, MnBTDPS e CoBTDPS são isoestruturais e os compostos ZnBTDPS e ZnBTDPSS apresentam estruturas semelhantes inclusive com a mesma topologia de rede. Realizou-se o estudo da síntese e caracterização de nove compostos utilizando o carboxilato SF e os ligantes nitrogenados BPP, DPS e DPSS nomeados, MnSFBPP, CoSFBPP, CuSFBPP, ZnSFBPP, CoSFDPS, CuSFDPS, ZnSFDPS, CoSFDPSS e ZnSFDPSS. Todos os compostos com exceção do CoSFDPSS tiveram suas estruturas determinadas por difração de raios X de monocristal. Em todas as estruturas analisadas os ligantes nitrogenados se coordenaram aos centros metálicos em ponte. No composto MnSFBPP o ligante SF não estava presente. Nos compostos CoSFBPP e CoSFDPS este ligante permaneceu na rede agindo como ânion estabilizando estas estruturas. Os arranjos bidimensional e tridimensional dos compostos foram observados pela presença de ligações de hidrogênio clássicas e não-clássicas, mostrando a importância das interações não covalentes na formação do arranjo supramolecular, bem como da estabilização das estruturas. Por fim, através das sínteses envolvendo o carboxilato BTC com os ligantes nitrogenados BPP, DPS e DPSS, seis complexos foram descritos como MnBTCBPP, CoBTCBPP, ZnBTCBPP, MnBTCDPS, ZnBTCDPS e ZnBTCDPSS. Os complexos CoBTCBPP, MnBTCDPS e ZnBTCDPS não apresentaram o ligante nitrogenado na estrutura, sendo que em todos eles pôde-se observar a presença do ligante BTC. Os complexos MnBTCBPP, CoBTCBPP, ZnBTCBPP e ZnBTCDPSS foram obtidos na forma de monocristais e tiveram suas estruturas cristalinas determinadas por difração de raios X de monocristal. Confirmaram-se então diversos modos de coordenação do ligante BTC nestes complexos tais como monodentado, quelato e em ponte syn-syn e syn-anti. / This work presents the synthesis and characterization of supramolecular arrays with Mn2+, Co2+, Cu2+ and Zn2+ first row transition metal ions, polydentate nitrogen ligands 1,3-bis(4-pyridyl) propane (BPP); di(4-pyridyl)sulfide (DPS) and di(4-pyridyl)disulfide (DPSS) and polycarboxylates 1,2,4,5-benzenotetracarboxylate (BT), p-sulfobenzoate (SF) and 1,3,5-benzenotricarboxylate (BTC). Twenty six compounds were synthesized and characterized of elemental analysis (CHN), thermal analysis (TG/DTA) and vibrational spectroscopy (infrared and Raman). Among these, twenty two compounds were isolated as single crystals and had their structures determined by single crystal X-ray diffraction analysis. Thermal analysis showed that all compounds are hydrated with coordination and/or lattice water molecules. Vibrational spectroscopy was very important to inform about the carboxylate groups coordination mode through ∆ν (νasymCOO - νsymCOO) value. In compounds containing BT ligand, the carboxylate group always acted in monodentate mode. For compounds containing SF ligands, monodentate and bidentatechelate modes were observed and for BTC ligand, monodentate, bidentate-chelate and syn-syn and syn-anti bridging modes were noted. The synthesis and characterization of compounds involving the BT carboxylate ligand and BPP, DPS and DPSS nitrogen ligands gives rise to eleven complexes described as MnBTBPP, CoBTBPP, CuBTBPP, ZnBTBPP, MnBTDPS, CoBTDPS, CuBTDPS, ZnBTDPS, MnBTDPSS, CoBTDPSS and ZnBTDPSS. BT ligand is present in all compounds and, except CoBTDPSS, they showed the nitrogen ligand in bridging coordination mode. All compounds, except ZnBTBPP, had their structures determined by single crystal X-ray diffraction analysis. In particular, MnBTDPS and CoBTDPS are isostructural and ZnBTDPS and ZnBTDPSS present similar structures with the same network topology. Studies of the synthesis and characterization of nine compounds using SF carboxylate and BPP, DPS and DPSS nitrogen ligands were realized, appointed as MnSFBPP, CoSFBPP, CuSFBPP, ZnSFBPP, CoSFDPS, CuSFDPS, ZnSFDPS, CoSFDPSS and ZnSFDPSS. All compounds, except CoSFDPSS, had their structures determined by single crystal X-ray diffraction analysis. In all structures the nitrogenated ligands coordinate to the metal centers in the bridging mode. For MnSFBPP the absence of ligand SF was noted. In CoSFBPP and CoSFDPS, this ligand remained uncoordinated, acting as a counter anion stabilizing these structures. The two- and three-dimensional arrays of the compounds were observed by the presence of classic and non-classic hydrogen bondings showing the importance of non-covalent interactions in the supramolecular arrangement, as well as in the structure stabilization. Finally, through the syntheses involving the BTC carboxylate with nitrogenated ligands BPP, DPS and DPSS, six complexes are described as MnBTCBPP, CoBTCBPP, ZnBTCBPP, MnBTCDPS, ZnBTCDPS and ZnBTCDPSS. CoBTCBPP, MnBTCDPS and ZnBTCDPS do not present nitrogen ligands in their structures and in all of them the presence of BTC ligand is observed. MnBTCBPP, CoBTCBPP, ZnBTCBPP and ZnBTCDPSS were obtained as single crystals and had their crystal structures determined by X-ray diffraction analysis. Great diversity of BTC ligand coordination modes as monodentate, chelate and syn-syn, syn-anti bridging modes were confirmed.

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