Thesis(M.I.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.161-162).

Thesis (Ph. D.)--Psychology, Georgia Institute of Technology, 2006. / Corso, Gregory, Committee Member ; Fisk, Arthur, Committee Member ; Rogers, Wendy, Committee Chair ; Folds, Dennis, Committee Member ; Spieler, Daniel, Committee Member. Includes bibliographical references.

Thesis (M.A.) in Psychology--University of Maine, 2004. / Includes vita. Includes bibliographical references (leaves 54-65).

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

No description available.

Orientador: Anita Jocelyne Marsaioli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T11:17:14Z (GMT). No. of bitstreams: 1 Pinheiro_Lucimar_D.pdf: 3524874 bytes, checksum: 8abbae35ad9ff5f54218f4dac80a18bf (MD5) Previous issue date: 2006 / Resumo: A utilização de enzimas para a transformação de compostos orgânicos é cada vez mais utilizada como alternativa à síntese clássica. As enzimas são utilizadas como biocatalisadores para as sínteses in vitro de compostos assimétricos uma vez que elas são intrinsicamente quirais e apresentam alta eficiência catalítica. Diante da biodiversidade de microrganismos existentes na natureza e da necessidade de descobrir novos biocatalisadores para as sínteses de blocos de construções quirais e de produtos químicos de alto valor agregado, esta tese teve como objetivos a avaliação enzimática de células microbianas íntegras, o isolamento e a identificação de compostos enantiomericamente puros obtidos através da ação enzimática de oxidorredutases. Inicialmente, a avaliação da presença de Baeyer-Villiger monooxigenases em 12 espécies de fungos através de biocatálise convencional levou a produção de (R)-(+)-5-metil-e-caprolactona (1b), produzida pelos fungos Aspergillus oryzae CCT 0975 e Geotricum candidum CCT 1205 em excelentes conversões (ambas 98%) e excessos enantioméricos (96% e 91%), respectivamente. Na etapa seguinte foi desenvolvida uma metodologia alternativa a biocatálise convencional, denominada "multibiorreações", objetivando uma triagem mais rápida e eficiente. A metodologia foi aplicada na detecção de atividade de monooxigenase permitindo um aumento no conhecimento do perfil de seletividade dos substratos analisados. A ação enzimática das células íntegras de Trichosporum cutaneum CCT 1903 resultou na redução de metilcicloexanonas orto- e para-substituídas (1 e 6) e na oxidação da cis-jasmona (8). Posteriormente realizou-se o isolamento, identificação, determinação dos excessos enantioméricos, determinação das configurações relativas e absolutas dos produtos obtidos a partir da oxidação da cis-jasmona (8): (7S,8R)-epoxijasmona, 12 (92% e.e.), 7,8-diidróxijasmona, 13 (53% e.e.) e (4S)-hidroxijasmona (86% e.e.). Nesta etapa, a determinação do perfil de seletividade de T. cutaneum CCT 1903 foi avaliado frente a 14 substratos contendo ligações duplas olefínicas (24-37). A atividade de monooxigenase foi verificada sobre os seguintes monoterpenos monocíclicos: (R)-(-)-carvona (25), a- e b- iononas (26 e 27) e (R)-(+)-limoneno (32). As biotransformações destes compostos de fragrâncias levaram às sínteses de: (1S,2R,4R)-neoisodiidrocarveol (41), (6R)-isoprenil- (3R)-metil-2-oxo-oxepanona (42), ácido-(3R)-isopropenil-6-oxo-heptanóico (43), 2,3-epóxi-(5R)-isopropenil-2-metilcicloexanol (44), 4-oxo-7,8-diidro-b-ionona (50), a-homociclogeraniol (51), limoneno-1,2-diol (54) e (+)-(4R)-p-1-menteno-8,9-diol (55), os quais foram identificados espectroscopicamente (RMN de H e C, H e H gCOSY, H e C HSQC, H e C gHMBC). Finalmente, foi realizado um estudo das atividades enzimáticas para os fungos CCT 5632, Rhyzopus oryzae CCT 1022 e a levedura AMA 7, utilizando a metodologia de multibiorreações e reações de biotransformações convencionais (substratos 8, 25-27 e 32). Uma atividade oxidorredutase foi detectada em AMA7 e R. oryzae CCT 1022. A levedura AMA7 produziu a: 7,8-epoxijasmona (12), 7,8-diidroxijasmona (13), 4- hidroxijasmona (14) e a diidrocarvona (45), enquanto que R. oryzae CCT 1022 produziu o composto 14 e o neoisodiidrocarveol (41). O fungo 5632 também apresentou atividade monooxigenase verificada a partir da formação da 4-oxo-7,8-diidro-b-ionona (50) / Abstract: The utilization of enzymes for organic compound transformations is an alternative to classical syntheses. Enzymes are used as biocatalysts for the syntheses in vitro of asymmetric compounds because they are intrinsically chiral and result in high catalytic efficiency. In front of the biodiversity of existing microorganisms in Nature and of the necessity to discover new biocatalysts for the syntheses of blocks of chiral constructions and of chemical products with high added value, this thesis aimed at enzymatic evaluation of oxidoreductase from microbial whole cells and their application of the production of enantiomerically pure compounds. First of all, Baeyer-Villiger monooxygenase (BVMO) activity was monitored using traditional biocatalytic methods. Bioprospection in 14 fungi resulted in the detection of cyclohexanone BVMO in Aspergillus oryzae CCT 0975 and Geotrichium candidum CCT 1205. The lactone (R)-(+)-1b was obtained in high enantiomeric excesses (96% and 91%, respectively) and conversion (98%). Searching for rapid screening method, multibioreaction methodology was implemented and applied to the detection of monooxigenase activity, which increased n times the amount of evaluated microorganisms per unit of time, where n is the number of added substrates. Trichosporum cutaneum CCT 1903 produced outstanding results, reducing the ortho- and para-substituted (1 and 6) methyl-cyclohexanones and oxidizing cis-jasmone (8). After isolation, identification and determination of the enantiomeric excess, the relative and absolute configuration of the cis-jasmone bioproducts were: (7S,8R)-epoxyjasmone, 12 (e.e. 92%), 7,8-dihydroxyjasmone, 13 (e.e. 53%) and (4S)-hydroxyjasmone, 14 (e.e. 86%). The enantioselectivity and substrate specificity of alkene monooxygenase in T. cutaneum CCT 1903 was further investigated using 14 substrates (24-37), applying the multibioreaction approach. Monooxygenase activity was detected in (R)-(-)-carvone, a- and b-ionones and (R)-(+)-limonene. Batch reactions of these fragrance compounds produced: (1S,2R,4R)- neoisodihydrocarveol (41), (6R)-isoprenyl-(3R)-methyl-2-oxo-oxepanone (42), (3R)- isopropenyl-6-oxoheptanoic acid (43), 2,3-epoxy-(5R)-isopropenyl-2-methylcyclohexenol (44), 4-oxo-7,8-dihydro-b-ionone (50), a-homo-cyclogeraniol (51), (R)-(+)-limonene-1,2-diol (54) and uroterpenol (55) as pure samples for spectroscopic identification (H and C NMR, H and H gCOSY, H and C HSQC, H and C gHMBC). Oxidoreductase activity was monitored using multibioreaction methodology and traditional biocatalytic methods with the fungi CCT 5632, Rhyzopus oryzae CCT 1022 and the yeast AMA 7 (substrates 8, 25-27 and 32). Thus AMA7 produced epoxyjasmone (12), 7,8- dihydroxyjasmone (13), hydroxyjasmone (14) and dihydrocarvone (45), while that R. oryzae CCT 1022 produced 14 and neoisodihydrocarveol (41). The fungus 5632 also presented monooxygenase activity confirmed through formation from 4-oxo-7,8-dihydro-b- ionone (50) / Doutorado / Quimica Organica / Doutor em Ciências

Spin dependent electron transport in chiral molecules, the so-called chirality induced spin selectivity (CISS) effect, have attracted much attention over the past few years. Experimentally the spin polarization has been detected, and there is a theoretical consensus on the necessity of both spin-orbit coupling and geometrical helicity in order to get a non-vanishing spin polarization. Several model Hamiltonians has been proposed to describe the CISSS effect, and while they can yield spin polarization agreeing with the experimentally observed magnitudes, they are relying on unrealistic values of the spin orbit interaction parameters. In recent years the importance of electron correlation has been emphasized. Thus, this thesis presents the general theory on how to treat the CISS effect as a many body problem, taking electron correlation into account. The Hamiltonian modelling is described and one approach on how to treat the helical structure of the molecule and the spin-orbit coupling is presented. Building on this thesis, further studies will hopefully lead to a first principle understanding of the CISS effect.

Submitted to the faculty of the University Graduate School in partial fulfillment of the requirements for the degree Master of Science in the School of Informatics, Indiana University December 2005 / The approach of exploiting highly conserved protein folds and structure in understanding protein function and in designing drugs leads to drugs that are less selective due to association with similar proteins. Over the years an open problem for researchers has been to develop drug design models based on non-conserved features to have higher selectivity. Recently a new structural feature, the dehydron, has been demonstrated to vary across proteins with conserved folds. Dehydrons are backbone hydrogen bonds that are not adequately protected from water. The importance of wrapping dehydrons in ligand binding and non-conservation of dehydrons across similar proteins makes them important candidates for markers in drug design. Investigation on a series of proteins – PDB entries: 1IA8, 1NVQ, 1NVS, 1NVR, 1OKZ, and 1PKD – revealed the potential impact of wrapping on binding affinity of the ligands. Unlike in 1NVS, 1NVR, 1OKZ, and 1PKD, inhibitor UCN in 1NVQ wrapped both the dehydrons in active site region of the checkpoint protein kinase, thereby indicating an increased potency and higher selectivity. On detailed analysis of 193 protein kinases, roughly 70% were found to have two or more dehydrons in the neighborhood of the bound ligand. Also, about 70% of proteins had dehydrons within the active site region. Only around 20% of ligands, however, actually wrapped two or more dehydrons. These statistics clearly illustrate the significance of dehydrons and their potential use as markers for drug design to enhance drug efficacy as well as selectivity, and to reduce side effects in the process.

Indiana University-Purdue University Indianapolis (IUPUI) / Calcium/calmodulin (CaM)-dependent protein kinase II (CaMKII) is a multimeric holoenzyme composed of 8–14 subunits from four closely related isoforms (α, β, γ, δ). CaMKII plays a strategic, multifunctional role in coupling the universal second messenger calcium with diverse cellular processes including metabolism, cell cycle control, and synaptic plasticity. CaMKII exhibits broad substrate specificity, targeting numerous substrates with diverse phosphorylation motifs. Binding of the calcium sensor CaM to the autoregulatory domain (ARD) of CaMKII functions to couple kinase activation with calcium signaling. Important sites of autophosphorylation, namely T287 and T306/7 (δ isoform numbering), reside within the ARD and control either CaM dependence or ability to bind to CaMKII respectively, thus determining various activation states of the kinase. Because autophosphorylation is critical to the function of CaMKII in vivo, we sought to determine the relationship between the activation state of the kinase and substrate selectivity. We show that the ARD of activated CaMKII tunes substrate selectivity by competing for substrate binding to the catalytic domain, thus functioning as a selectivity filter. Specifically, in the absence of T287 autophosphorylation, substrate phosphorylation is limited to high-affinity, consensus substrates. T287 autophosphorylation restores maximal kinase activation and broad substrate selectivity by disengaging ARD filtering. The unique multimeric architecture of CaMKII is an ideal sensor which encodes calcium-spike frequency into graded levels of subunit activation/autophosphorylation within the holoenzyme. We find that differential activation states of the holoenzyme produce distinct substrate phosphorylation profiles. Maximal holoenzyme activation/autophosphorylation leads to further broadening of substrate specificity beyond the effect of autophosphorylation alone, which is consistent with multivalent avidity. Thus, the ability of calcium-spike frequency to regulate T287 autophosphorylation and holoenzyme activation permits cellular activity to dictate switch-like behavior in substrate selectivity that is required for diverse cellular responses by CaMKII.

<p> The effects of migration selectivity on the population of the Atlantic region are determined by creating six net migration schedules for six personal variables: age, sex, nativity, education status, mother tongue and marital status. Although the migration schedules were rather complex, selectivity was greatest for young adults and the well educated. The population of the Atlantic region is selective with respect to age and education status. The Atlantic region is losing its young and well educated individuals through the migration process. Furthermore, the Atlantic region had a net inflow of elderly individuals. The effect of the migration selectivity is the loss of young adults, which is interpreted as an important loss of human capital compounding the economic problems of the region. While the increase in elderly population will economically burden the local social and health systems. Using the argument that the migration process is severely hurting the region economically, the Atlantic governments can argue for larger equalization payments to the region.</p> / Thesis / Candidate in Philosophy