103 resultados para Enrichment and characterization
Resumo:
Snake venom C-type lectin-like proteins (CLPs) are ubiquitously found in Viperidae snake venoms and differ from the C-type lectins as they display different biological activities but no carbohydrate-binding activity. Previous analysis of the transcriptome obtained from the Bothrops insularis venom gland showed the presence of two clusters homologous to bothrojaracin (BJC) chains a and P. In an effort to identify a new BJC-like molecule, we used an approach associated with proteomic technologies to identify the presence of the expressed protein and then to purify and characterize a new thrombin inhibitor from B. insularis venom. We also constructed homology models of this protein and BJC, which were compared with other C-type lectin-like family members and revealed several conserved features of this intriguing snake venom toxin family. (C)0 2007 Elsevier Ltd. All rights reserved.
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Anopheles albertoi Unti and Anopheles arthuri Unti are revived from the synonymy with Anopheles strodei Root, and a distinct morphological form (designated in this study as Anopheles CP Form) from the Strodei Complex of Anopheles (Nyssorhynchus) is characterized. The male genitalia of An. arthuri and An. albertoi are described and illustrated for the first time. An. strodei, An. arthuri, and An. albertoi were first distinguished based on scanning electron microphotos of the eggs, and then each egg type was associated with diagnostic characters of the male genitalia. Identification of Anopheles CP Form was based on morphological characters of the male genitalia, characterized and illustrated in this study. Molecular phylogenetic analysis was most clear when an outgroup was not included, in which case using the nuclear white gene, or the white gene in combination with the mitochondrial cytochrome c oxidase subunit I (COI) gene, clearly separated these four taxa. When Anopheles quadrimaculatus Say and Anopheles stephensi Liston were included as an outgroup, combined white and COI data resolved An. strodei and An. albertoi, whereas An. arthuri was not well resolved. The single sequence of Anopheles CP Form was recovered well separated from other groups in all analyses.
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Sodium channel toxins from sea anemones are employed as tools for dissecting the biophysical properties of inactivation in voltage-gated sodium channels. Cangitoxin (CGTX) is a peptide containing 48 amino acid residues and was formerly purified from Bunodosoma cangicum. Nevertheless, previous works reporting, the isolation procedures for such peptide from B. cangicum secretions are controversial and may lead to incorrect information. In this paper, we report a simple and rapid procedure, consisting of two chromatographic steps, in order to obtain a CGTX analog directly from sea anemone venom. We also report a substitution of N16D in this peptide sample and the co-elution of an inseparable minor isoform presenting the R14H substitution. Peptides are named as CGTX-II and CGTX-III, and their effects over Nav1.1 channels in patch clamp experiments are demonstrated. (c) 2008 Elsevier Ltd. All rights reserved.
Resumo:
White-lipped peccaries, Tayassu pecari, are neotropical ungulates whose populations have been declining in numerous locations within their geographical distribution. Here we describe 16 microsatellite loci isolated from T. pecari and their cross-amplification in collared peccaries, Pecari tajacu. In 30 individuals of T. pecari, a total of 32 alleles were found in ten polymorphic loci, ranging from 2 to 8 alleles per locus with a mean of 3.2. The expected and observed heterozygosity ranged from 0.143 to 0.802 and from 0 to 0.704, respectively. Two loci deviated from Hardy-Weinberg equilibrium. In P. tajacu, nine loci were polymorphic with a mean of 3.2 alleles per locus. These molecular markers will be useful to study the genetic status of peccary populations and, consequently, to help their conservation.
Resumo:
The destruction of Brazilian natural habitats has reduced bee populations and negative impacts of native flora pollination have been noticed. This work describes the isolation and characterization of microsatellite loci and evaluates them as molecular markers to study genetic variability of the stingless bee Plebeia remota. A microsatellite enriched genomic library was constructed and 15 primer pairs were designed for this species. The survey was conducted by analyzing 21 unrelated individuals. Genetic diversity indexes were calculated. The mean allelic richness was 6.3, the observed heterozygosity was 0.568, and the percentage of polymorphic loci was 93.33%. Also the primers were tested in cross-species amplification and showed promising results for P. droryana, P. emerina, P. lucii, P. meridionalis, P. pugnax, and P. saiqui. The microsatellite loci described here will be useful to evaluate genetic variability of stingless bees, and certainly will improve our knowledge about population dynamics especially in threatened environments.
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The present study seeks to develop nuclear markers for the kelp gull (Larus dominicanus). We hereby report the characterization of 12 independent nuclear introns, where 104 single nucleotide polymorphisms (SNPs) in 8138 sequenced base pairs were observed. These SNP markers are the first to be designed for genotyping a gull species. The markers will provide useful tools for understanding which processes act or acted upon kelp gulls to cause their low genetic variability in mitochondrial DNA. In addition, these markers open a new opportunity for population genetic and evolutionary studies in the Laridae group.
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Epidendrum fulgens has a patchy distribution along the Atlantic Rainforest in the Brazilian coast, due to the destruction of its native habitat. Here, we report on both the development of nine new microsatellite markers isolated from this species and the characterization of their allele variability in two distant and unrelated populations. The number of alleles observed for each locus ranged from 2 to 17 with an average of 6.4 alleles per locus. These microsatellites should be valuable tools for studying the effect of habitat fragmentation on the genetic structure of E. fulgens populations.
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Epidendrum puniceoluteum is an endemic orchid of Atlantic Rainforest, restricted to few populations only due to the destruction and fragmentation of its native habitat. Here, we report on the development of 10 microsatellite markers isolated from this orchid species. Genetic variability was characterized in two distant populations from Brazil coast. The number of alleles observed for each locus ranged from two to 12 and with an average of 6.4 alleles per locus. These microsatellites should be valuable tools for studying both fine-scale genetic structure of scattered E. puniceoluteum population and patterns will be useful genetic markers for other closely related taxa.
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The Maracaibo false coral snake Erythrolamprus pseudocorallus, previously known only from Venezuela, is recorded from five departments in Colombia. These new data include the westernmost and the southernmost records presently known for the species. Two specimens previously identified as E. aesculapii, from the localities of El Valle, Distrito Federal, Venezuela, and Yarumal, Antioquia, Colombia, are now attributed to E. pseudocorallus, the first one representing the northeasternmost record of the species. Morphological characterization of E. pseudocorallus is expanded based on the new specimens.
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When carrying out experiments on the production of the edible mushroom Pleurotus sajor-caju in the Laboratory of Edible Mushrooms, Universidade Federal de Lavras, Lavras, Brazil, in the second half of 2007, the presence of beetles later identified as belonging to the species Mycotretus apicalis was verified. This is the first recorded instance of this insect in cultures of P. sajor-caju in Brazil. The larvae and adults of this insect feed on the fruiting bodies of commercial harvests, resulting in reduction in mushroom quality. To provide evaluation of the injuries caused by these insects, substrates colonized by P. sajor-caju were infested with 4, 8, 16, 32 and 64 insects per block of substrate being the qualitative and quantitative losses then noted. Despite the lack of an observed decrease in biological efficiency, the injuries caused by these insects affected the commercial quality of the mushrooms, which may result in economic losses. The results showed that infestations of 32 insects per 0.8 kg of substrate led to a depreciation in the prices of mushrooms meant to be sold.
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Chen LM, Zhao J, Musa-Aziz R, Pelletier MF, Drummond IA, Boron WF. Cloning and characterization of a zebrafish homologue of human AQP1: a bifunctional water and gas channel. Am J Physiol Regul Integr Comp Physiol 299: R1163-R1174, 2010. First published August 25, 2010; doi:10.1152/ajpregu.00319.2010.-The mammalian aquaporins AQP1, AQP4, and AQP5 have been shown to function not only as water channels but also as gas channels. Zebrafish have two genes encoding an AQP1 homologue, aqp1a and aqp1b. In the present study, we cloned the cDNA that encodes the zebrafish protein Aqp1a from the 72-h postfertilization (hpf) embryo of Danio rerio, as well as from the swim bladder of the adult. The deduced amino-acid sequence of aqp1a consists of 260 amino acids and is 59% identical to human AQP1. By analyzing the genomic DNA sequence, we identified four exons in the aqp1a gene. By in situ hybridization, aqp1a is expressed transiently in the developing vasculature and in erythrocytes from 16 to 48 h of development. Later, at 72 hpf, aqp1a is expressed in dermal ionocytes and in the swim bladder. Western blot analysis of adult tissues reveals that Aqp1a is most highly expressed in the eye and swim bladder. Xenopus oocytes expressing aqp1a have a channel-dependent (*) osmotic water permeability (P(f)*) that is indistinguishable from that of human AQP1. On the basis of the magnitude of the transient change in surface pH (Delta pHS) that were recorded as the oocytes were exposed to either CO(2) or NH(3), we conclude that zebrafish Aqp1a is permeable to both CO(2) and NH(3). The ratio (Delta pHS*)CO2/P(f)* is about half that of human AQP1, and the ratio (Delta pHS*)NH3/P(f)* is about one-quarter that of human AQP1. Thus, compared with human AQP1, zebrafish Aqp1a has about twice the selectivity for CO(2) over NH(3).
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Poly(3-hydroxybutyrate) was produced in fed-batch cultures of Ralstonia eutropha DSM 428 and Alcaligenes latus ATCC 29712 on a mineral medium with different carbon sources such as sucrose, sodium lactate, lactic acid, soybean oil and fatty acid. The bacteria converted the different carbon sources supplied into P3HB. The best results were obtained when lactate or soybean oil were supplied as the sole carbon source. The range of number average molar mass (Mn) for the polymers, analyzed by Gel Permeation Chromatography was 1.65 to 0.79 x 10(5) g mol(-1). FTIR spectroscopy revealed a characteristic absorbance associated with polyester structures. The crystallinity degree, determinate from X-ray diffractograms, was about 69% in all synthesized polymers. The thermal properties associated to semicrystalline polymers indicated a glass transition at 0.1 degrees C and a melting point at about 175 degrees C and enthalpy of 63-89 J g(-1). The (1)H-NMR and (13)C-NMR spectra of the polymers were in agreement with the calculated chemical shifts associated with P3HB structures.
Resumo:
Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM), a systemic mycosis presenting clinical manifestations ranging from mild to severe forms. A P. brasiliensis cDNA expression library was produced and screened with pooled sera from PCM patients adsorbed against antigens derived from in vitro-grown P. brasiliensis yeast cells. Sequencing DNA inserts from clones reactive with PCM patients sera indicated 35 open reading frames presenting homology to genes involved in metabolic pathways, transport, among other predicted functions. The complete cDNAs encoding aromatic-L-amino-acid decarboxylase (Pbddc), lumazine synthase (Pbls) and a homologue of the high affinity copper transporter (Pbctr3) were obtained. Recombinant proteins PbDDC and PbLS were obtained; a peptide was synthesized for PbCTR3. The proteins and the synthetic peptide were recognized by sera of patients with confirmed PCM and not by sera of healthy patients. Using the in vivo-induced antigen technology (IVIAT), we identified immunogenic proteins expressed at high levels during infection. Quantitative real time RTPCR demonstrated high transcript levels of Pbddc, Pbls and Pbctr3 in yeast cells infecting macrophages. Transcripts in yeast cells derived from spleen and liver of infected mice were also measured by qRT-PCR. Our results suggest a putative role for the immunogenic proteins in the infectious process of P. brasiliensis. (C) 2009 Elsevier Masson SAS. All rights reserved.
Resumo:
Here, we described the expression and characterization of the recombinant toxin LTx2, which was previously isolated from the venomous cDNA library of a Brazilian spider, Lasiodora sp. (Mygalomorphae, Theraphosidae). The recombinant toxin found in the soluble and insoluble fractions was purified by reverse phase high-performance liquid chromatography (HPLC). Ca2+ imaging analysis revealed that the recombinant LTx2 acts on calcium channels of BC3H1 cells, blocking L-type calcium channels. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
Nanoparticles of NiMn(2)O(4) were successfully obtained by mixing gelatin and inorganic salts NiCl(2) center dot 6H(2)O and MnCl(2) center dot 4H(2)O in aqueous solution. The mixture has been synthesized at different temperatures and resulted in NiMn(2)O(4) nanoparticles with crystallites size in the range of 14-44 nm, as inferred from X-ray powder diffraction (XRPD) data. We have also observed that both the average crystallite size and the unit cell parameters increase with increasing synthesis temperature. Magnetic measurements confirmed the presence of a magnetic transition near 110K. (C) 2008 Published by Elsevier B.V.