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101.
Thalita G. Barros Sergio Pinheiro J. S. Williamson Amílcar Tanuri M. Gomes Jr Helena S. Pereira R. M. Brindeiro José B. A. Neto O. A. C. Antunes Estela M. F. Muri 《Amino acids》2010,38(3):701-709
In this paper, we describe the synthesis of a novel class of pseudo-peptides derived from isomannide and several oxazolones as potential inhibitors of serine proteases as well as preliminary pharmacological assays for hepatitis C. Hepatitis C, dengue and West Nile fever are among the most important flaviviruses that share one important serine protease enzyme. Serine proteases belong to the most studied class of proteolytic enzymes and are a primary target in the drug development field. Several pseudo-peptides were obtained in good yields from the reaction of isomannide and oxazolones, and their anti-HCV potential using the HCV replicon-based assay was shown. 相似文献
102.
Janaína A Couto Karina LA Saraiva Cleiton D Barros Daniel P Udrisar Christina A Peixoto Juliany SB César Vieira Maria C Lima Suely L Galdino Ivan R Pitta Maria I Wanderley 《Reproductive biology and endocrinology : RB&E》2010,8(1):13
Background
The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats. 相似文献103.
The host selection for oviposition by Spodoptera frugiperda (J.E. Smith) among corn, millet, cotton and soybean, and its relationship with the biological characteristics were investigated. Free and non-choice tests for oviposition using plots containing five plants each, from each host in plastic greenhouse, resulted in similar oviposition preference among the host plants. In addition, selected biological characteristics of S. frugiperda were determined in the laboratory with larvae feeding on host leaves, and the combination of leaf and cotton boll. Neonate larvae exhibited low success of colonization on cotton boll compared to the leaves of all other hosts. Spodoptera frugiperda fed only on cotton bolls exhibited longer larval and pupal development, and longer adult life span; however with similar egg production. Larvae fed cotton leaves during six days and then transferred to cotton bolls, however, exhibited development and reproduction similar to those reared on corn or only on cotton leaves. Therefore, the variations on immature stages of S. frugiperda were not related with host selection for oviposition which was similar among the studied hosts. Based on our data, the millet as a winter, rotational, and cover crop is a potential host for S. frugiperda, while leaves and cotton bolls were diets of intermediate suitability as compared to corn and soybean leaves. 相似文献
104.
Leila M. Luheshi Wolfgang Hoyer Teresa Pereira de Barros Iris van Dijk H?rd Ann-Christin Brorsson Bertil Macao Cecilia Persson Damian C. Crowther David A. Lomas Stefan St?hl Christopher M. Dobson Torleif H?rd 《PLoS biology》2010,8(3)
Protein aggregation, arising from the failure of the cell to regulate the synthesis or degradation of aggregation-prone proteins, underlies many neurodegenerative disorders. However, the balance between the synthesis, clearance, and assembly of misfolded proteins into neurotoxic aggregates remains poorly understood. Here we study the effects of modulating this balance for the amyloid-beta (Aβ) peptide by using a small engineered binding protein (ZAβ3) that binds with nanomolar affinity to Aβ, completely sequestering the aggregation-prone regions of the peptide and preventing its aggregation. Co-expression of ZAβ3 in the brains of Drosophila melanogaster expressing either Aβ42 or the aggressive familial associated E22G variant of Aβ42 abolishes their neurotoxic effects. Biochemical analysis indicates that monomer Aβ binding results in degradation of the peptide in vivo. Complementary biophysical studies emphasize the dynamic nature of Aβ aggregation and reveal that ZAβ3 not only inhibits the initial association of Aβ monomers into oligomers or fibrils, but also dissociates pre-formed oligomeric aggregates and, although very slowly, amyloid fibrils. Toxic effects of peptide aggregation in vivo can therefore be eliminated by sequestration of hydrophobic regions in monomeric peptides, even when these are extremely aggregation prone. Our studies also underline how a combination of in vivo and in vitro experiments provide mechanistic insight with regard to the relationship between protein aggregation and clearance and show that engineered binding proteins may provide powerful tools with which to address the physiological and pathological consequences of protein aggregation. 相似文献
105.
N. Berois M. J. Arezo C. Chalar M. M. Brauer C. Barros 《Zeitschrift fur angewandte Ichthyologie》2007,23(1):34-39
The organization, time‐course deposition and protein composition of the oocyte envelope in the whitemouth croaker, Micropogonias furnieri, were analyzed at different stages of oocyte maturation. Adult females were sampled in the Uruguayan coast of the Río de la Plata during three annual periods. Morphological organization and temporal deposition were assessed by histology and electron microscopy. Protein composition was analyzed using gel electrophoresis, followed by MALDI‐TOF‐MS. Oocyte envelope deposition starts in lipid‐yolk oocytes, reaching maximum width in fully grown oocytes when it shows a three‐layer organization. In mature oocytes, the envelope becomes narrower than in the previous stage and loses its trilaminar structure. In envelopes from fully grown oocytes, one‐dimensional gel electrophoresis revealed five bands; mature oocytes showed only three bands. Following two‐dimensional gel electrophoresis, 14 major polypeptides were detected in envelopes from fully grown oocytes. Considering that morphological and biochemical results obtained from samples of the three annual periods were remarkably similar, data reported here might provide a useful baseline to assess the future impact of pollutants on the oocyte envelope and reproductive success of whitemouth croakers inhabiting the geographic area. 相似文献
106.
da Silva Júnior EN de Souza MC Pinto AV Pinto Mdo C Goulart MO Barros FW Pessoa C Costa-Lotufo LV Montenegro RC de Moraes MO Ferreira VF 《Bioorganic & medicinal chemistry》2007,15(22):7035-7041
Several arylamino derivatives of nor-beta-lapachone were synthesized in moderate to high yields and found to show very potent cytotoxicity against six neoplastic cancer cells: SF-295 (central nervous system), HCT-8 (colon), MDAMB-435 (breast), HL-60 (leukaemia), PC-3 (prostate), and B-16 (murine melanoma), with IC(50) below 1 microg/mL. Their cytotoxicities were compared to doxorubicin and with their synthetic precursors, beta-lapachone and nor-beta-lapachone. The activity against a normal murine fibroblast L-929 showed that some of the compounds were selective against cancer cells. The absence of hemolytic activity (EC(50)>200 microg/mL), performed with erythrocyte suspensions, suggests that the cytotoxicity of the compounds was not related to membrane damage of mouse erythrocytes. For comparison purposes, one isomeric compound based on nor-alpha-lapachone was also synthesized and showed lower activity than the related ortho-derivative. The modified arylamino quinones appear as interesting new lead compounds in anti-cancer drug development. 相似文献
107.
Talita Lopes Honorato Maria Cristiane Rabelo Luciana Rocha Barros Gonçalves Gustavo Adolfo Saavedra Pinto Sueli Rodrigues 《World journal of microbiology & biotechnology》2007,23(10):1409-1415
The use of agriculture substrates in industrial biotechnological processes has been increasing because of its low cost. Cashew
apples are considered an agriculture low cost product in the Brazilian Northeast because the cashew cultivation is done mainly
to produce cashew nuts. About 90% of the cashew apples production is lost in the field after removing the nut. In this work,
the use of clarified cashew apple juice as substrate for microbial cultivation was investigated. The results showed that cashew
apple juice is a good source of reducing sugars and can be used to grow Leuconostoc mesenteroides to produce high added value products such as dextran, lactic acid, mannitol and oligosaccharides. 相似文献
108.
Batista WL Barros TF Goldman GH Morais FV Puccia R 《Fungal genetics and biology : FG & B》2007,44(5):347-356
The MDJ1/LON locus is conserved among pathogenic dimorphic fungi. We have mapped using DNase I footprinting and mobility shift assays three putative heat shock elements and one AP-1 binding domain (ARE) in the 5' intergenic region shared by PbMDJ1and PbLON (ML) from Paracoccidioides brasiliensis. The region bearing an ARE-like towards PbLON also has an opposite skn-1-like element. We studied genetically and pathogenically distinct isolates Pb18 and Pb3, where ML is polymorphic and the number of elements detected was higher. The functionality of the elements was suggested by the stimulatory response of both genes to heat shock and oxidative stress. Co-regulation occurred upon heat shock from 36 to 42 degrees C and, only in Pb3, also during mycelium to yeast transformation (26-36 degrees C). In Pb18, PbMDJ1 seemed to be preferentially expressed in yeast. Our study might help understand regulation of genes involved in fungal adaptation to the host. 相似文献
109.
Zuanon JA Pezzato AC Ducatti C Barros MM Pezzato LE Passos JR 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,147(3):761-765
The effects of grain-based diets from C3 or C4-cycle plants on muscle delta(13)C change process in Nile tilapia (Oreochromis niloticus) fingerlings were investigated. Two groups of sex reversal males Nile tilapia fingerlings were fed with isoproteic (32.0% DP) and isocaloric (3200 kcal DE/kg) diets, differing from each other by their delta(13)C. Muscle samples were collected and the carbon isotopic composition was measured. For C4 diet, the formula for the muscle delta(13)C change related to the intake time of a new diet was delta(13)C=-14.88-9.21e(-0.0209t) and the half-life (T) of the muscle carbon was 33.2 days. For C3 diet, the formula was delta(13)C=-25.43+8.59e(-0.0533t) with T=13 days. The C3 diet was considered more appropriate based on its palatability and consequent larger food intake than the C4 diet, resulting in an increased muscle delta(13)C change rate. However, for future studies, would be necessary to mix both the C3 and C4 feedstuffs to formulate diets nutritionally appropriated, with contrasting stable isotopes signatures. Tissue delta(13)C change rate is therefore indicated as a promising tool to better understand the biotic and abiotic factors that influence nutrients utilization from the diet and animal growth. 相似文献
110.
Expression of LH receptor mRNA splice variants in bovine granulosa cells: changes with follicle size and regulation by FSH in vitro 总被引:1,自引:0,他引:1
Nogueira MF Buratini J Price CA Castilho AC Pinto MG Barros CM 《Molecular reproduction and development》2007,74(6):680-686
In cattle, most evidence suggests that granulosa cells express LH receptors (LHR) after (or as) the follicle becomes dominant, however there is some suggestion that granulosa cells from smaller pre-dominant follicles may express several LHR mRNA splice variants. The objective of this study was to measure LHR expression in bovine follicles of defined size and steroidogenic ability, and in granulosa cells from small follicles (<6 mm diameter) undergoing differentiation in vitro. Semiquantitative RT-PCR demonstrated that LHR mRNA was undetectable in granulosa cells of follicles <7 mm diameter (nondominant follicles), and increased with follicle diameter in follicles >7 mm diameter. Splice variants with deletions of exon 10 and part of exon 11 were detected as previously described, and we detected a novel splice variant with a deletion of exon 3. Cultured granulosa cells contained LHR mRNA, but with significantly greater amounts of variants with deletions of exon 10 and/or exon 11 compared with cells from dominant follicles. FSH increased the abundance of some but not all LHR mRNA splice variants in cultured granulosa cells. The addition of LH to cultured cells did not increase progesterone secretion, despite the presence of LHR mRNA. Collectively, these data suggest that granulosa cells do not acquire functional LHR until follicle dominance occurs. 相似文献