952 resultados para polysaccharide-protein complex


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Introducción: Las vacunas clásicamente han representado un método económico y eficaz para el control y prevención de múltiples enfermedades infecciosas. En los últimos años se han introducido nuevas vacunas contra neumococo a precios elevados, y los diferentes análisis económicos a nivel mundial de estas vacunas no muestran tendencias. El objetivo de este trabajo era resumir la evidencia existente a través de los diferentes estudios económicos evaluando las dos vacunas de segunda generación contra neumococo en la población a riesgo. Metodología: En este trabajo se realizo una revisión sistemática de la literatura en 8 bases de datos localizadas en diferentes partes del mundo y también que tuvieran literatura gris. Los artículos fueron inicialmente evaluados acorde a su titulo y resumen, posteriormente los elegidos se analizaron en su totalidad. Resultados: Se encontraron 404 artículos, de los cuales 20 fueron incluidos en el análisis final. Se encontró que la mayoría de los estudios se realizaron en áreas donde la enfermedad tiene una carga baja, como es Norte América y Europa, mientras que en los lugares del mundo donde la carga es mas alta, se realizaron pocos estudios. De igual manera se observo que la mayoría de los estudios mostraron por los menos ser costo efectivos respecto a la no vacunación, y en su totalidad las dos vacunas de segunda generación mostraron costo efectividad respecto a la vacunación con PCV-7. Los resultados de los estudios son muy heterogéneos, hasta dentro del mismo país, señalando la necesidad de guías para la conducción de este tipo de estudios. De igual manera, la mayoría de los estudios fueron financiados por farmacéuticas, mientras en un numero muy reducido por entes gubernamentales. Conclusiones: La mayoría de los estudios económicos sobre las vacunas de segunda generación contra neumococo han sido realizados en países con un alto índice de desarrollo económico y patrocinados por farmacéuticas. Dado que la mayoría de la carga de la enfermedad se encuentran en regiones con un menor nivel de desarrollo económico se deberían realizar mas en estas zonas. De igual manera, al ser la vacunación un asunto de salud publica y con un importante impacto económico los gobiernos deberían estar mas involucrados en los mismos.

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The regulation of phosphoinositide (PI) 3-kinase activities has been linked to many normal and disease-related processes, including cell survival, cell growth and proliferation, cell differentiation, cell motility, and intracellular vesicle trafficking. However, as the family of enzymes has now grown to include eight true members, in three functional classes, plus several related protein kinases that are also inhibited by the widely used PI 3-kinase selective inhibitors, wortmannin and LY294002, extended methodologies are required to identify which type of kinase is involved in a particular cellular process, or protein complex, under study. A robust in vitro PI 3-kinase assay, suitable for use with immunoprecipitates, or purified proteins, is described here together with a series of modifications of substrate and assay conditions that will aid researchers in the identification of the particular class and isoform of PI 3-kinase that is involved in a signaling process under investigation.

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Four different beta-galactosidases (previously named BbgI, BbgII, BbgIII and BbgIV) from Bifidobacterium bifidum NCIMB41171 were overexpressed in Escherichia coli, purified to homogeneity and their biochemical properties and substrate preferences comparatively analysed. BbgI was forming a hexameric protein complex of 875 kDa, whereas BbgII, BbgIII and BbgIV were dimers with native molecular masses of 178, 351 and 248 kDa, respectively. BbgII was the only enzyme that preferred acidic conditions for optimal activity (pH 5.4-5.8), whereas the other three exhibited optima in more neutral pH ranges (pH 6.4-6.8). Na+ and/or K+ ions were prerequisite for BbgI and BbgIV activity in Bis-Tris-buffered solutions, whereas Mg++ was strongly activating them in phosphate-buffered solutions. BbgII and BbgIII were slightly influenced from the presence or absence of cations, with Mg++, Mn++ and Ca++ ions exerting the most positive effect. Determination of the specificity constants (k(cat)/K-m) clearly indicated that BbgI (6.11 x 10(4) s(-1) M-1), BbgIII (2.36 x 10(4) s(-1) M-1) and especially BbgIV (4.01 x 10(5) s(-1) M-1) are highly specialised in the hydrolysis of lactose, whereas BbgII is more specific for beta-D-(1 -> 6) galactobiose (5.59 x 10(4) s(-1) M-1) than lactose (1.48 x 10(3) s(-1) M-1). Activity measurements towards other substrates (e. g. beta-D-(1 -> 6) galactobiose, beta-D-(1 -> 4) galactobiose, beta-D-(1 -> 4) galactosyllactose, N-acetyllactosamine, etc.) indicated that the beta-galactosidases were complementary to each other by hydrolysing different substrates and thus contributing in a different way to the bacterial physiology.

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The interaction between pentagalloyl glucose (PGG) and two globular proteins, bovine serum albumin (BSA) and ribulose-1,5-bisphosphate carboxylase oxygenase (rubisco), was investigated by isothermal titration calorimetry (ITC). ITC data fit to a binding model consisting of two sets of multiple binding sites, which reveal similarities in the mode of binding of PGG to BSA and rubisco. In both cases, the interaction is characterized by a high number of binding sites, which suggests that binding occurs by a surface adsorption mechanism that leads to coating of the protein surface, which promotes aggregation and precipitation of the PGG-protein complex. This model was confirmed by turbidimetry analysis of the PGG-BSA interaction. Analysis of tryptophan fluorescence quenching during the interaction of PGG with BSA suggests that binding of PGG leads to some conformational changes that are energetically closer to the unfolded state of the BSA structure, because small red shifts in the resulting emission spectra were observed.

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Duchenne muscular dystrophy is a severe X-linked inherited muscle wasting disorder caused by mutations in the dystrophin gene. Adeno-associated virus (AAV) vectors have been extensively used to deliver genes efficiently for dystrophin expression in skeletal muscles. To overcome limited packaging capacity of AAV vectors (<5 kb), truncated recombinant microdystrophin genes with deletions of most of rod and carboxyl-terminal (CT) domains of dystrophin have been developed. We have previously shown the efficiency of mRNA sequence–optimized microdystrophin (ΔR4-23/ΔCT, called MD1) with deletion of spectrin-like repeat domain 4 to 23 and CT domain in ameliorating the pathology of dystrophic mdx mice. However, the CT domain of dystrophin is thought to recruit part of the dystrophin-associated protein complex, which acts as a mediator of signalling between extracellular matrix and cytoskeleton in muscle fibers. In this study, we extended the ΔR4-23/ΔCT microdystrophin by incorporating helix 1 of the coiled-coil motif in the CT domain of dystrophin (MD2), which contains the α1-syntrophin and α-dystrobrevin binding sites. Intramuscular injection of AAV2/9 expressing CT domain–extended microdystrophin showed efficient dystrophin expression in tibialis anterior muscles of mdx mice. The presence of the CT domain of dystrophin in MD2 increased the recruitment of α1-syntrophin and α-dystrobrevin at the sarcolemma and significantly improved the muscle resistance to lengthening contraction–induced muscle damage in the mdx mice compared with MD1. These results suggest that the incorporation of helix 1 of the coiled-coil motif in the CT domain of dystrophin to the microdystrophins will substantially improve their efficiency in restoring muscle function in patients with Duchenne muscular dystrophy.

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Muscle coenzyme Q(10) (CoQ(10) or ubiquinone) deficiency has been identified in more than 20 patients with presumed autosomal-recessive ataxia. However, mutations in genes required for CoQ(10) biosynthetic pathway have been identified only in patients with infantile-onset multisystemic diseases or isolated nephropathy. Our SNP-based genome-wide scan in a large consanguineous family revealed a locus for autosomal-recessive ataxia at chromosome 1q41. The causative mutation is a homozygous splice-site mutation in the aarF-domain-containing kinase 3 gene (ADCK3). Five additional mutations in ADCK3 were found in three patients with sporadic ataxia, including one known to have CoQ(10) deficiency in muscle. All of the patients have childhood-onset cerebellar ataxia with slow progression, and three of six have mildly elevated lactate levels. ADCK3 is a mitochondrial protein homologous to the yeast COQ8 and the bacterial UbiB proteins, which are required for CoQ biosynthesis. Three out of four patients tested showed a low endogenous pool of CoQ(10) in their fibroblasts or lymphoblasts, and two out of three patients showed impaired ubiquinone synthesis, strongly suggesting that ADCK3 is also involved in CoQ(10) biosynthesis. The deleterious nature of the three identified missense changes was confirmed by the introduction of them at the corresponding positions of the yeast COQ8 gene. Finally, a phylogenetic analysis shows that ADCK3 belongs to the family of atypical kinases, which includes phosphomositide and choline kinases, suggesting that ADCK3 plays an indirect regulatory role in ubiquinone biosynthesis possibly as part of a feedback loop that regulates ATP production.

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Cysteine metabolism exhibits atypical features in Leishmania parasites. The nucleotide sequence annotated as LmjF32.2640 encodes a cysteine desulfhydrase, which specifically catalyzes the breakdown of cysteine into pyruvate, NH(3) and H(2)S. Like in other pathogens, this capacity might be associated with regulatory mechanisms to control the intracellular level of cysteine, a highly toxic albeit essential amino acid, in addition to generate pyruvate for energy production. Besides, our results provide the first insight into the biochemical properties of Leishmania major serine acetyltransferase (SAT), which is likely involved in the two routes for de novo synthesis of cysteine in this pathogen. When compared with other members of SAT family, the N-terminal region of L. major homologue is uniquely extended, and seems to be essential for proper protein folding. Furthermore, unlike plant and bacterial enzymes, the carboxy-terminal-C(10) sequence stretch of L major SAT appears not to be implicated in forming a tight bi-enzyme complex with cysteine synthase. (C) 2010 Elsevier B.V. All rights reserved.

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Vanillin was found to be efficient as a deactivator of ferrylmyoglobin with a second-order rate constant of k(2) = S7 +/- 1 L mol(-1) s(-1) for reduction to metmyoglobin with Delta H(double dagger) = 58.3 +/- 0.3 kJ mol(-1) and Delta S(double dagger) = -14 +/- 1 J mol(-1) K(-1) in aqueous pH 7.4 solution at 25 degrees C. Binding to beta-lactoglobulin (AG) was found to affect the reactivity of vanillin at 25 degrees C only slightly to k(2) = 48 +/- 2 L mol(-1) s(-1) (Delta H(double dagger) = 68.4 +/- 0.4 kJ mol(-1) and Delta S(double dagger) = 17 +/- 1 J mol(-1) K(-1)) for deactivation of ferrylmyoglobin. Binding of vanillin to beta LG was found to have a binding stoichiometry vanillin/beta LG > 10 with K(A) = 6 x 10(2) L mol(-1) and an apparent total Delta H degrees of approximately -38 kJ mol(-1) and Delta S degrees = -S5.4 +/- 4J mol(-1) K(-1) at 25 degrees C and Delta C(p), (obs) = -1.02 kJ mol(-1) K(-1) indicative of increasing ordering in the complex, as determined by isothermal titration microcalorimetry. From tryptophan fluorescence quenching for beta LG by vanillin, approximately one vanillin was found to bind to each beta LG far stronger with K(A) = 5 x 10(4) L, mol(-1) and a Delta H degrees = 10.2 kJ mol(-1) and Delta S degrees = 55J mol(-1) K(-1) at 25 degrees C. The kinetic entropy/enthalpy compensation effect seen for vanillin reactivity by binding to beta LG is concluded to relate to the weakly bound vanillin oriented through hydrogen bonds on the beta LG surface with the phenolic group pointing toward the solvent, in effect making both Delta H(double dagger) and Delta S(double dagger) more positive. The more strongly bound vanillin capable of tryptophan quenching in the fiLG calyx seems less or nonreactive.

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Fungal polysaccharides have received a great deal of attention due to itsbecause of their potential use in a wide rangegreat variety fromof industries. Some studies have demonstrated that polysaccharides extracted offrom basidiomycetes they have presented significant properties as anti-inflammatory, antimicrobial, antioxidant and anti-tumoral properties. In spite of thisDespite these potential properties, these mushrooms have not been insufficiently investigated, and the great number of antibiotics number produced forby these organisms suggests that they canmay be a new source of bioactives composites source. In tThe present work, reports onlated the chemical composition, potential antioxidant, antiinflammatory and citotoxycity of extracted polymers extracted offrom the fruits bodies of the fungiius Geastrum saccatum and Polyporus dermoporus, native mushrooms of the Atlantic forest inof the state of the Rio Grande do Norte, Brazil. The Cchemical analyses had revealed ademonstrated text of total sugar rates of 65% and 49%, and proteins of 7.0% for in extracts of G. saccatum and P. dermoporus extracts, respectively. The analyses ofNMR spectroscopy of RMN had demonstrated that these extracts are composites forof a complex involving β- glucans and- proteins complex. The inhibition of the formation of superoxide radicals formation was of 88.4% in G. saccatum and 83.3% in P. dermoporus, and 75 and 100% for inhibition of hydroxyls radicals inhibition. TopicalThe topic application of extracts the 10, 30 and 50 mg/kg extract in BALBc mice with cutaneous inflammation induced byfor croton oil demonstrated to inhibitedion of ear edema of ear and cells polimorfonuclears cells atin the inflamed siteplace, being this reply more effective in lower concentrations being more effective. The evaluation of the glucans of G. saccatum and P. dermoporus glucans under induced pleurisy for carrageenan-induced pleurisya of showed the antiinflammatory action of these composites., being analyzed tThe frame number in the pleural exudates and thedosage of nitric oxide dosage was also analyzed. The cytotoxic action of these polymers was analyzed throughthrough the mitochondrial function (MTT). The incubation of the glucans with mononuclear cells of the peripheral blood demonstrated that the extracted glucans extracted fromof G. saccatum havepossess a moderate cytotoxic action. These results suggest that these mushrooms possess polymers formed byfor a complex glucana-protein complex, with antiinflammatory and antioxidant actions

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The crystal structure of dimeric Lys49-phospholipase A2 myotoxin-II from Bothrops moojeni (MjTX-II) co-crystallized with stearic acid (C18H36O2) has been determined at a resolution of 1.8 angstrom. The electron density maps permitted the unambiguous inclusion of six stearic acid molecules in the refinement. Two stearic acid molecules could be located in the substrate-binding cleft of each monomer in positions, which favor the interaction of their carboxyl groups with active site residues. The way of binding of stearic acids to this Lys49-PLA(2)s is analogous to phospholipids and transition state analogues to catalytically active PLA(2)s. Two additional stearic acid molecules were located at the dimer interface region, defining a hitherto unidentified acyl-binding site on the protein surface. The strictly conserved Lys122 for Lys49-PLA(2)s may play a fundamental role for stabilization of legend-protein complex. The comparison of MjTX-II/satiric acid complex with other Lys-PLA(2)s structures whose putative fatty acids were located at their active site is also analysed. Molecular details of the stearic acid/protein interactions provide insights to binding in croup I/II PLA(2)s and to the possible interactions of Lys49-PLA(2)s with target membranes. (c) 2004 Elsevier SAS. All rights reserved.

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A bacterium isolated from soil contaminated by hydrocarbon was studied and, by biochemical tests and analysis of PCR, the presence of Bacillus pumilus was identified. The production of biosurfactant was optimized, test of oil degradation and antimicrobial activity determination. The results showed that pH 5.0 and 7.0, 72 h of fermentation, sucrose and sugar cane juice (2%) had best yields. The bacterium is able to degrade crude oil and displays bacteriostatic and fungistatic activity. From the analysis of proximate composition of biosurfactant found the presence of biopolymer formed by a lipopolysaccharide-protein complex.

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Ganoderma lucidum is an edible medicinal mushroom with immunomodulatory and antitumor properties, which are mainly attributed to polysaccharides and triterpenes that can be isolated from mycelia, fruiting bodies and spores. G. lucidum has been us d in a powdered form, as a medicinal beverage and a nutraceutical food (usually dried). In the present review we report some historical facts and the experimental evidence that polysaccharides and triterpenes obtained from this mushroom present potential antitumor activity. Direct effects on tumor cells include induction of apoptosis and interference in the cell cycle, whereas indirect effects are based on the modulation of immune response, usually impaired by cancer cells. Data indicate that G. lucidum can be used as a complementary tool for treatment of cancer patients. © by São Paulo State University.

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Zara, F.J., Gaeta, H.H., Costa, T.M., Toyama, M.H. and Caetano, F.H. 2011. The ovarian cycle histochemistry and its relationship with hepatopancreas weight in the blue crab Callinectes danae (Crustacea: Portunidae). -Acta Zoologica (Stockholm) 00:1-13. Several studies use macroscopic patterns of the ovarian development in crustaceans. Here, we examined the relationship between ovary histochemistry, changes in gonadosomatic and hepatosomatic indices against the macroscopic pattern of the ovarian development in Callinectes danae. Animals were collected in the south coast of São Paulo State, Brazil. Ovaries were macroscopically classified as juvenile, rudimentary, developing, intermediary, mature, and rudimentary ovigerous. Samples were fixed in 4% paraformaldehyde, processed for historesin, and stained with HE, protein, and neutral and acid polysaccharides detection. The juvenile oocytes are not enclosed by follicular cells and have fewer yolk nuclei being less intense in PAS reactivity than rudimentary oocytes. Developing oocytes show yolk granules and thick follicular cells. Yolk granules were positive for proteins and neutral polysaccharides. The intermediary stage is marked by a qualitative increase in yolk granules and the onset of chorion formation. In mature oocytes, cytoplasm is completely filled by yolk granules and the chorion is completely formed. Ovigerous ovaries have several atretic follicles and large quantities of hemocytes in the process of tissue reorganization. In C. danae, the changes in cell, goandosomatic and hepatosomatic indices coinciding with macroscopic observations and any combination of different macroscopic stages in a single pattern should be avoided. © 2011 The Royal Swedish Academy of Sciences.

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This study presents the ovarian morphology and the dynamics of the vitellogenesis process in the oocytes of the diplopod Leptodesmus dentellus. The oocytes are arranged in clusters called ovisacs which are distributed in pairs along the midline of the body forming the ovary. Regions similar to the germarium appear paired in the anterior region of the ovary; however, the development of the oocytes of this species does not follow a regionalisation in the reproductive organ. Cells in three developmental stages are found throughout the length of the ovary. Calcium, proteins, lipids and neutral polysaccharides were detected in the oocytes of L. dentellus. The polysaccharides and the proteins found in the oocytes have a double origin: endogenous, with the participation of the germinative vesicle, and exogenous, from follicular epithelium. The origin of the lipids is exogenous, i.e., they are incorporated into the oocytes, probably derived from the perivisceral fat body, which are highly developed in this region. The deposition of calcium is pre-vitellogenic and probably functions as a reserve during the juvenile stages. © 2012 Koninklijke Brill NV, Leiden.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)