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The role of mevalonate pathway intermediates in erythropoietin receptor signal transduction and surface expression studies in hematopoietic and nonhematopoietic cancers /Hamadmad, Sumaya Nizar. January 2006 (has links)
Thesis (Ph.D.)--University of Iowa, 2006. / Supervisor: Raymond J. Hohl. Includes bibliographical references (leaves 114-129).
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Desymmetrisation of prochiral dialdehydesBuckley, Shirley Louise Jane January 2000 (has links)
No description available.
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Protocols, pathways, peptides and the aorta : relationship to atherosclerosisWalsh, Marilyn L. 03 May 2001 (has links)
The vascular system transports components essential to the survival of the
individual and acts as a barrier to substances that may injure the organism.
Atherosclerosis is a dynamic, lesion producing disease of the arterial system that
compromises the functioning of the organ by occlusive and thrombogenic
processes. This investigation was undertaken to elucidate some of the normal
biochemical processes related to the development of atherosclerosis. A significant
part of the investigation was directed toward developing and combining methods
and protocols to obtain the data in a concerted manner.
A postmitochondnal supernatant of bovine aorta, using mevalonate-2-�����C as
the substrate, was employed in the investigation. Methods included paper, thin
layer, and silica gel chromatography; gel filtration, high performance liquid
chromatography (HPLC), and mass spectrometry.
This current research demonstrated direct incorporation of mevalonate-2-
�����C into the trans-methyiglutaconic shunt intermediates. The aorta also contains
alcohol dehydrogenase activity, which converts dimethylallyl alcohol and
isopentenol to dimethylacrylic acid, a constituent of the trans-methylgiutaconate
Small, radioactive peptides, named Nketewa as a group, were biosynthesized
using mevalonate-2-�����C as the substrate. They were shown to pass through a 1000 D
membrane. Acid hydrolysis and dabsyl-HPLC analysis defined the composition of the
Nketewa peptides. One such peptide, Nketewa 1, had a molecular weight of 1038 and a
sequence of his-gly-val-cys-phe-ala-ser-met (HGVCFASM), with a farnesyl group linked
via thioether linkage to the cysteine residue.
Methods were developed for the concerted investigation of the trans-methylglutaconate
shunt, the isolation of mevalonate-2-�����C labeled peptides, and
characteristics of neutral and acidic metabolites of mevalonate. The question as to
whether or not mevalonate was the direct precursor was answered in the affirmative.
These results contribute to the understanding of the biochemistry of the vessel wall and
the associated atherogenic processes. Mevalonate-derived volatile and acidic compounds
may represent an alternate metabolic pathway. The prenylated Nicetewa peptide may be,
as are other prenylated peptides, participants in the intracellular signaling process, release
of cytokines, expansion of extracellular matrix, and calcium release. / Graduation date: 2001
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Genotyping Candida species and molecular analysis of C. albicans gene encoding mevalonate pyrophosphate decarboxylase /Dassanayake, Ranil Samantha. January 2000 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 203-238).
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Genotyping Candida species and molecular analysis of C. albicans gene encoding mevalonate pyrophosphate decarboxylaseDassanayake, Ranil Samantha. January 2000 (has links)
published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy
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Obtenção e propriedades de toruleno da levedura Rhodotorula glutinis / Obtaining and properties of torulene from Rhodotorula glutinis yeastSentanin, Michelle Andriati 19 August 2018 (has links)
Orientador: Delia Rodriguez-Amaya / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T01:25:42Z (GMT). No. of bitstreams: 1
Sentanin_MichelleAndriati_D.pdf: 945275 bytes, checksum: 8006d9bfad9ddd336494867a2761a66f (MD5)
Previous issue date: 2011 / Resumo: Os carotenóides são corantes naturais, alguns dos quais são precursores de vitamina A. Desde a década passada, tem sido atribuído a estes compostos um importante papel na diminuição do risco de várias doenças degenerativas. Com estas funções vitais, a procura por fontes intensificou-se mundialmente. A produção biotecnológica de carotenóides específicos, utilizando bactérias, fungos e leveduras, vem despertando crescente interesse. O presente trabalho teve como objetivos otimizar a extração dos carotenóides de Rhodotorula glutinis, estimular a produção de carotenóides pela adição de ácido mevalônico, substituir o meio de cultivo por substrato de baixo custo e avaliar a estabilidade e degradação de toruleno. O capítulo 1 apresenta uma revisão bibliográfica sobre a biossíntese de carotenóides e a produção biotecnológica desses pigmentos nos últimos dez anos, destacando a produção por bactérias, algas e fungos. O segundo capítulo visa otimizar a extração dos carotenóides da levedura Rhodotorula glutinis e avaliar o efeito de diferentes concentrações de ácido mevalônico na produção de carotenóides. Por ser um precursor chave no caminho biossintético dos carotenóides em leveduras, este composto influenciou de modo significativo a produção dos pigmentos. Apesar da quantidade de biomassa não ter sido afetada, a produção de carotenóides totais aumentou em até 114% e o rendimento de toruleno e de b-caroteno aumentou 157% e 168%, respectivamente. O Capítulo 3 tem o intuito de baixar o custo de produção de carotenóides pela levedura em estudo, através da substituição do meio de cultura usual YM por um residuo da industria da mandioca, a manipueira, substrato rico em nutrientes. Para otimizar a producao dos pigmentos, realizou-se um planejamento fatorial completo de quatro variaveis, a saber pH, temperatura, agitacao e volume de inoculo. A condicao que melhor favoreceu o rendimento de carotenoides foi 26°C, 250 rpm de agitacao, pH 7,0 e 10% de volume de inoculo. Nessa condicao, a producao de carotenoides totais foi de 2068 ?g/L de meio de cultura. O tradicional meio YM proporcionou a producao de apenas 899 ?g/L de meio de cultura de carotenoides totais. O quarto capitulo tem por objetivo avaliar a estabilidade do carotenoide toruleno produzido por Rhodotorula, em comparacao com os carotenoides bem conhecidos licopeno e ?-caroteno. Para isso, foram montados sistemas modelos de baixa umidade, utilizando como matriz celulose microcristalina, que ficaram expostos durante 15 dias a luz ou ao abrigo da mesma. O carotenoide que mais sofreu degradacao foi o licopeno, seguido de ?-caroteno e toruleno. O Capitulo 5 visa investigar a degradacao oxidativa do toruleno e os compostos volateis produzidos durante esse processo. Para atingir esse objetivo, foram montados sistemas modelo de baixa umidade, com matriz de celulose microcristalina, em frascos de vidro, com injecao de fluxo de oxigenio. Houve a formacao de diversos compostos de degradacao, dos quais os que mais se destacaram, quantitativamente, foram metacroleina, prenal, 2,6- dimetil-hepta-2,4-dieno, 6-metil-hept-5-en-2-ona, 2-etil-hexanol, 2-etenil- 1,3,3-trimetil-ciclohexeno e 3,3-dimetil-acetaldeido-ciclohexilideno / Abstract: Carotenoids are natural colorants, some of which are precursors of vitamin A. Since the past decade, an important role in reducing the risk of various degenerative diseases was attributed to these compounds. With these vital functions, the search for sources has intensified worldwide. The biotechnological production of specific carotenoids, using bacteria, fungi and yeasts, have attracted increasing interest. This study had the objective of optimizing the extraction of carotenoids from Rhodotorula glutinis, stimulating the production of carotenoids with mevalonic acid, substituting the medium with low-cost substrate and evaluating the stability and degradation of torulene. Chapter 1 presents a review of the biosynthesis of carotenoids and biotechnological production of these pigments in the last ten years, highlighting the production by bacteria, algae and fungi. The second chapter aims to optimize the extraction of carotenoids from the yeast Rhodotorula glutinis and assessing the effect of different concentrations of mevalonic acid on the production of carotenoids. Being a key precursor in the biosynthetic pathway of carotenoids in yeasts, it significantly influenced the production of pigments. Although the amount of biomass was not affected, the production of total carotenoid increased by 114% and the yield of torulene and ?-carotene increased by 157% and 168%, respectively. Chapter 3 is intended to lower the cost of production of carotenoids by the yeast under investigation, by replacing the usual culture medium YM with a sub-product of the cassava industry, the nutrient-rich substrate manipueira. To optimize the production of pigments, a full factorial design was used with four variables: pH, temperature, agitation and inoculum volume. The condition that favored yield of carotenoids was: 26°C, 250 rpm agitation, pH 7.0 and 10% volume of inoculum. In this condition, the production of carotenoids was 2068 mg/L of culture medium. The traditional YM provided the production of only 899 mg/L of culture medium of carotenoids. The fourth chapter aims to evaluate the stability of torulene produced by Rhodotorula, compared with well-known carotenoids, lycopene and b-carotene. For this purpose, model systems of low moisture were mounted, using microcrystalline cellulose as the matrix, which were kept in the dark or exposed to light for 15 days. The carotenoid that suffered the most degradation was lycopene, followed by b-carotene and torulene. Chapter 5 investigates the oxidative degradation of torulene and the volatile compounds produced during this process. To achieve this goal, model systems of low moisture were mounted, with microcrystalline cellulose matrix, in glass bottle, with injection of oxygen flow. Several degradation compounds were formed, of which the following compounds stood out quantitatively: methacrolein, prenal, 2,6-dimethyl-hepta-2,4-diene, 6-methyl-hept-5-en-2- one, 2-ethylhexanol, 2-ethenyl-1,3,3-trimethyl-cyclohexene and 3,3-dimethylciclohexilideno acetaldehyde / Doutorado / Ciência de Alimentos / Doutor em Ciência de Alimentos
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