published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

Typescript (Photocopy). / Digitized by Kansas Correctional Industries

Orientador: Luiz Shiguero Matsubara / Resumo: A hemoglobina, o componente principal do citoplasma eritrocitário, está sujeita à oxidação, fisiologicamente ou por agentes externos, seja através da formação de Metahemoglobina, ou pela oxidação da cisteína β93 por agentes tiois. Impossibilitado de sintetizar proteína, o eritrócito depende primordialmente da via glicolítica, que, além de fornecer ATP, através da integração da formação de NADH e da Via da Hexose Monofosfato, mantém o potencial redutor extremamente eficiente. A presente investigação teve como finalidade avaliar o sistema de óxido-redução eritrocitário, à partir da oxidação da hemoglobina pelas seguintes drogas: a) Nitrito de Sódio, indutora da formação de Metahemoglobina; b) Azul de Metileno, utilizado terapeuticamente e em testes laboratoriais na redução de Metahemoglobina; c) Cistamina, agente tiol, que induz à formação do complexo Hemoglobina-Etilamina, através da oxidação da cisteína β93. Doadores de sangue da Divisão Hemocentro foram convidados a participar do trabalho e tiverem seu sangue coletado após consentimento - 96 - verbal e por escrito. Todos os indivíduos eram do sexo masculino, não anêmicos e sem deficiência de G6PD. Foram utilizados, para os testes, glóbulos lavados, ressuspensos em PBS, pH 7.45, com hemoglobina ajustada entre 11 e 13 g/dl, na presença de glicose e incubados a 37o C com as drogas testadas, nos momentos 10. 90 e 180 minutos de incubação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hemoglobin, the essential component of erythrocyte cytoplasm, is physiologically prone to oxidation by external agents, through the formation of Methemoglobin or the oxidation of β93 cysteine by thiol agents. Unable to protein synthesis, the erythrocyte depends essentially on glycolysis, which, besides producing ATP, maintains the highly efficient reduction potential through the integration of NADH production and the Hexose Monophosphate Shunt. The present investigation's purpose was to evaluate the erythrocyte antioxidant system by studying hemoglobin oxidation by the following substances: a) Sodium Nitrite (SN), a well known Methemoglobin-forming agent; b) Methylene Blue (MB), a Methemoglobin reductant reagent, available for therapeutic and laboratory tests; c) the thiol reagent Cystamine (CI), that reacts with hemoglobin through the β93 cysteine oxidation, forming the Hemoglobin-Ethylamine complex. After informed... (Complete abstract click electronic access below) / Doutor

Thesis (Ph. D.)--University of Hong Kong, 1987.

The organization and structure of the leghemoglobin (Lb) genes in soybean have been investigated. Using molecular cloning techniques, a Lb-cDNA recombinant molecule, pLb1, was prepared and characterized. Hybridization of this clone of genomic DNA revealed the presence of at least seven Lb genes in the soybean genome. The arrangement of these genes appeared to be the same in DNA isolated from infected or uninfected tissues. The plasmid pLb1 was also used to isolate three Lb sequences from a genomic library constructed in (lamda) Charon4 vector. Nucleotide sequence analysis showed that one Lb gene, present on an 11.5 kilobases (kb) Eco RI genomic fragment, spans about 1 200 nucleotides and appears to code for Lbc(,3). Its coding sequence is interrupted at amino acid positions 32 to 33, 68 to 69 and 103 to 104. The intervening sequences, as well as the 5' and 3' flanking regions of this gene, contain some consensus sequences found in other eukaryotic genes. The length of the 5'-untranslated region is 49 bases as determined by nuclease S1 mapping. R-loop analysis of the recombinant phage containing the 11.5 kb Eco RI fragment showed that another Lb gene is located 2.5 kb away. The nucleotide sequences of the second gene showed that this gene is incomplete, containing only two exons. The deduced amino acid sequence of this gene, although showing 78% homology with the corresponding region of the other Lb gene, is not represented in any of the known Lb proteins. Both genes are oriented in the same direction with respect to the coding strand. Analysis of the sequence present in a second genomic clone containing a 4.2 kb Eco RI fragment revealed a truncated Lb gene showing homology with the last exon and the non-coding region at the 3' end of the two other Lb genes. A very high homology is found among the nucleotide sequence of the Lbc(,3), Lba and Lbc(,1) genes. Comparison of the intervening sequences of these genes indicated that they diverged mainly through the creatio

Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 124-138) / Microfiche. / xiii, 138 leaves, bound ill. 29 cm

Thesis (Ph. D.)--Montana State University--Bozeman, 2004. / Typescript. Chairperson, Graduate Committee: David J. Singel. Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 89-92). Also available via the Internet.

Thesis (Ph. D.)--University of California, Berkeley, 1984. / Includes bibliographical references (leaves 178-188).

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