Navegando por Assunto "Enzimas"

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Acesso aberto (Open Access)
Análise da atividade enzimática de quitotriosidase como um marcador para a malária vivax: abordagens bioquímicas e moleculares
(Universidade Federal do Pará, 2010) CRUZ, Cleber Monteiro; SILVA, Luiz Carlos Santana da; http://lattes.cnpq.br/6161491684526382
Chitotriosidase was the first described chitinase and its physiologic role is not entirely clear, although many studies have been showed its participation as a component of human immune response. A 24pb duplication on exon 10 of chit1 gene results on RNAm frameshift, leading to a 87 nucleotides deletion. This alteration generates a protein with no catalytic activity at all. This condition is called chitotriosidase deficiency and presents a frequency close to 6% of homozygosis duplication in different ethnical groups. Malaria is an amazon endemic parasitosis caused by protozoaries of genus Plasmodium and causes symptoms as fever, headache and vomit, which leads to a characteristic immune response. The objective of this study was to evaluate the chitotriosidase enzyme behavior in patients suffering of malaria in Pará state and to determine the frequency of 24pb duplication on chitotriosidase gene in a representative sample. Chitotriosidase measurement was made in 100 healthy individual and in 47 malarial patients. The molecular analysis of the 24pb duplication was realized in 100 volunteers trough a protocol which included DNA extraction techniques, PCR and 2,5% agarose gel visualization to verify normal fragments (normal homozygote: 195pb) and the 24pb duplication (mutant homozygote: 219pb; heterozygote: 219pb e 195pb). This study described at first time on scientific literature the chitotriosidase plasmatic levels increasing in patients suffering of malaria vivax compared to healthy individual. No association was observed between parasitemia and plasmatic chitotriosidase levels in malarial patients. Molecular analysis showed a frequency of 72% normal homozygotes, 24% heterozygotes and 4% mutant homozygotes to 24pb duplication. Allelic frequencies were around 84% to wild allele and 16% to mutant allele. No correlation was found between genotype and biochemical phenotype (represented by chitotriosidase levels) on control group.
Acesso aberto (Open Access)
Avaliação da influência da temperatura e do tratamento enzimático no comportamento reológico do suco de abacaxi pérola (Ananas Comosus L. merr.)
(2013-03) BRAGA, Adriano Cesar Calandrini; RODRIGUES, Antonio Manoel da Cruz; SILVA, Luiza Helena Meller da; ARAÚJO, Lícia Amazonas de
The objective this study was determinate the rheological behavior of pineapple juice natural and treated with pectinolytic enzymes. Tests for optimization of enzyme activity used in treatment were realized using a complete factorial planning 2k, with three repetitions of center point and two independent variables (temperature and time of treatment). In evaluation of rheological behavior of pineapple juice, were utilized two samples submitted to sieving (N and D), analyzed in four different temperatures (10, 25, 50 e 65 °C). The rheological analyses were realized using a Brookfield concentric cylinders viscometer and the relationship in the temperature and apparent viscosity was described by an equation type Arrhenius. The experimental data were adjusted by the Mizrahi-Berk model. The optimization tests indicated by ANOVA and response surface methodology that the variables temperature and time of treatment have statistically significant effect (p<0,05) on concentration of pectin present in the samples. The enzymatic treatment was carried with an enzyme concentration of 150 mg.L-1, temperature at 50 °C and treatment time of 80 minutes. The model used was adequate to describe the rheological behavior of the juices according to the parameters R2, χ2 e Bf. The reduced values of the behavior index (0.61-0.83 for natural juice and 0.57-0.72 for despectinized juice) indicated the pseudoplastic behavior (n<1). The temperature influenced the yield stress and apparent viscosity of the juices analyzed, where the minors values were observed in samples treated at 65 °C, 2.4 mPa.s and 1.4 mPa.s, respectively, for the natural and despectinized samples. The equation of Arrhenius described satisfactorily the effect of temperature in the apparent viscosity. The activation energy values (Eat) was of 4.54 Kcal.g.mol-1and 4.89 Kcal.g.mol-1, respectively, for the natural and despectinized samples of pineapple juice, increasing with enzymatic treatment. The enzymatic treatment decreased the values of rheological behavior parameters for samples of pineapple juice, and the apparent viscosity for all temperatures used, where the largest percentage reduction was observed at 65 °C (41.66%).
Acesso aberto (Open Access)
Estudo de misturas de enzimas (complexo celulásico, complexo enzimático, xilanase, β-glucanase e xilanase, β-glucosidase e Glucoamilase) na bioconversão do bagaço da cana-de-açúcar em etanol
(Universidade Federal do Pará, 2015) MOREIRA, Rosiane Fernandes; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
This work, it was proposed to evaluate mixtures of commercial enzymes by supplier Novozymes A / S. The enzymes used in this work were: celulase complex, xylanase, β-glucosidase, enzymático complex, xylanase and β-glucanase and glucoamylase in the glucose production from sugarcane bagasse subjected to treatment with alkali hydroxide solution sodium at room temperature, 70 ° C, 90 ° C and 120 ° C. The BCA yield on a dry basis after treatment with NaOH solution 6 (w / v) were 30.64% ± 1.395 (PACTA), 44.00% ± 1.787 (PAC70), 65.91% ± 1.096 (PAC90), and 95.25% ± 1.461 (CAP 120), respectively. The ash content for the BCA were 2.05% ± 0.027 (PACTA), 0.62% ± 0.013 (PAC70), 0.48% ± 0.007 (PAC90) and 0.18% ± 0.008 (PAC120). The lignin contents were 20.67 ± 0.603 (PACTA), 13.03 ± 0.711 (PAC70), 6.05 ± 0.196 (PAC90) and 5.49 ± 0.151 (PAC120). The results suggest that the conversion rates of cellulosic waste into glucose are strongly dependent on temperature in the alkaline pulping process. The kinetic parameters obtained in kinetic adjustments enzymatic hydrolysis of the BCA for PACTA, PAC70, PAC90 and PAC120 were: Vmax (g/h) equal to 7.20; 5.12; 4.54 and 0.87 respectively; Km (g) equal to 3.6; 2.56; 2.27 and 2.56 respectively; Kcat (h) equal to 1.44; 1.02; 0.91 and 0.17 respectively; Km/Vmax equal to 0.5 for all samples and Kcat/Km of 0.4 for all samples.
Acesso aberto (Open Access)
Hidrólise da quitosana: obtenção de um extrato enzimático e caracterização do produto hidrolisado
(Universidade Federal do Pará, 2022-08-09) GONÇALVES, Cleidiane Gonçalves e; FERREIRA, Nelson Rosa; http://lattes.cnpq.br/3482762086356570; https://orcid.org/0000-0001-6821-6199; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Chitin, extensively found in crustaceans exoskeletons, insects, and microorganisms, has limited usage due to its low solubility in aqueous solution, requiring its partial deacetylation to obtain chitosan. Chitosan's depolymerization has attracted considerable attention, as its oligomers have high water solubility, biocompatibility, and non-toxicity, as well as beneficial properties such as antimicrobial, antioxidant, and antitumor properties. For this reason, in this research, a review article was produced (Chapter I) based on the main methods of chitosan hydrolysis, besides analyzing the parameters that influence the acquisition, and characteristics of hydrolysis results, effectively and at a lower cost. Among the approaches studied, enzymatic hydrolysis excels due to its control ease and performance under milder conditions, making it possible to use low-cost enzymes belonging to the glycoside hydrolases group. Thus, enzymatic hydrolysis was defined as a technique for various sizes of chitosan acquisition (Chapter II) through the production of an enzymatic extract (integral enzymatic extract - IEE) from a filamentous fungus strain. The enzyme identification present in the IEE showed exo-chitinases, endo-chitinase, and cellobiohydrolase. Considering the same reaction conditions, the IEE showed greater efficiency than the commercial enzyme (Celluclast 1.5 L®), which was used as a parameter because it is an enzyme capable of cleaving the β-1,4-glycosidic bond of chitosan - similar to chitosanase, besides presenting a lower cost. The IEE reduced the molecular weight of chitosan by 47.80; 75.24 and 93.26% at 2.0; 5.0, and 24 h, respectively. Through the FTIR analysis, a lower absorbance of the spectral signals of chitosan oligomers was detected, and the crystallinity reduced after 3.0 h of hydrolysis. Based on this study, we can infer that enzymatic hydrolysis, under established conditions, is effective at obtaining lower molecular weight chitosan using unpurified crude extract.
Acesso aberto (Open Access)
Preparação de suportes micro e mesoporosos para imobilização de lipase e aplicação na esterificação do ácido oléico
(Universidade Federal do Pará, 2015-09-29) QUARESMA, Francisco Lucio Barbosa; NASCIMENTO, Luis Adriano Santos do; http://lattes.cnpq.br/3720461233595226
This study aimed to prepare and characterize heterogeneous catalysts using immobilized enzymes in MCM-41 supports and metakaolin. The supports were functionalized with APTES (an amine) for application to the oleic acid esterification reaction with methanol to produce ester. The characterization of the catalyst was made by XRD, FT-IR, physisorption of N2 and spectrometry of UV. The results show that MCM-41 has been effectively functionalized and immobilized enzymes were, however, there was a partial loss of the hexagonal array of such support, while for metakaolin, both functionalization as immobilization did not occur satisfactorily. Using UV spectrometry, it was found that around 80% of the enzymes were effectively immobilized on MCM-41. This biocatalyst (heterogeneous) was tested in the esterification of oleic acid (molar ratio to oleic acid / methanol was 1:15), at a temperature of 30 °C (100 rpm) for 12h. The obtained conversion was 52% of acid mass to ester, indicating that there viability on the use of MCM-41 amine functionalized for the immobilization of lipase, since catalytic activity of the enzyme was preserved. As for metakaolin, the results showed that, despite having been initially some connection enzymes to metakaolin functionalized, UV spectrometry showed that the anchoring enzyme was not effective in the course of 4 hours, however, new methodological approaches to this material may be applied to ensure the efficient functionalization and immobilization.
Acesso aberto (Open Access)
The development of an enzyme-linked immunosorbent assay for Trypanosoma vivax antibodies and its use in epidemiological surveys
(Universidade Federal do Pará, 2006-11) MADRUGA, Cláudio Roberto; ARAÚJO, Flábio Ribeiro de; CAVALCANTE, Gustavo Góes; MARTINS, Charles Ferreira; BARBOSA, Imke Barbara Pfeifer; RIBEIRO, Laura Rios; KESSLER, Raul Henrique; SOARES, Cleber Oliveira; MIGUITA, Midori; MELO, Elaine Silva de Pádua; ALMEIDA, Robson Ferreira Cavalcante de; LIMA JUNIOR, Manoel Sebastião da Costa
There are data indicating that the distribution of Trypanosoma vivax in the Brazilian territory is expanding with potential to reach other areas, where the vectors are present. The detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. For this reason, an enzyme-linked immunosorbent assay (Tv-ELISA-Ab) with crude antigen from one Brazilian isolate of T. vivax was developed and evaluated. The sensitivity and specificity were respectively 97.6 and 96.9%. In the evaluation of cross-reactions, three calves inoculated with T. evansi trypimastigotes blood forms showed optical densities (OD) under the cut-off during the whole experimental period, except one at 45 days post-inoculation. With relation to Babesia bovis, B. bigemina, and Anaplasma marginale, which are endemic hemoparasites in the studied area, the cross-reactions were shown to be 5.7, 5.3, and 1.1%, respectively. The first serological survey of Pantanal and state of Pará showed that T. vivax is widespread, although regions within both areas had significantly different prevalences. Therefore, this Tv-ELISA-Ab may be a more appropriate test for epidemiological studies in developing countries because the diagnostic laboratories in most countries may be able to perform an ELISA, which is not true for polymerase chain reaction.
Acesso aberto (Open Access)
Uso de processo enzimático usando a obtenção de carotenoides da torta residual de dendê
(Universidade Federal do Pará, 2017-02-22) MESQUITA, Eric César Mano; CORRÊA, Nádia Cristina Fernandes; http://lattes.cnpq.br/5763999772352165
The residual fibers from the production of palm oil are a potential source of carotenoids of great economic importance, particularly β-carotene, due to its biological characteristics in human health and its pro-vitamin A. The enzymes cellulite have been shown to be a strong alternative to increase the yield in the oil extraction process, used particularly for the pretreatment of the constituent material of the plants, as it favors the release of the oil inside the plant cell, contributing to the increase of the amount of oil to be extracted and still reducing the extraction time, thus providing the efficiency of the extraction processes of compounds of industrial interest. In the pressed mesocarp pie (TMD), a pre-treatment with the enzymes cellulase (CELLUCLAST) and pectinase (PECTINEX) at the times of 3.6, 12, 24, 48 and 60 h was carried out to evaluate the highest volume yield carotenoid degradation. Then, the effect of the addition of the lipase enzyme was evaluated through a rotational central composite experimental design 2³, on the quality of the oil, in terms of β-carotenes (μg /gTMD48). The results for the pre-treated TMD indicate that 6 hours would be enough to reach this goal, obtaining 55% mass of carotenoids. For the results with addition of lipase, it was observed that in the highest concentration there was a decrease in acidity and an increase in the content of carotenoids. In the present study it was observed that hydrolysis did not occur as a function of the amount of water in the reaction medium favoring the opposite reaction, the esterification of the free fatty acids.