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81.
Carlos E.M. Gomes Aulus E.A.D. Barbosa Leonardo L.P. Macedo Joelma C.M. Pitanga Fabiano T. Moura Adeliana S. Oliveira Raniere M. Moura Alexandre F.S. Queiroz Francisco P. Macedo Lúcia B.S. Andrade Mrcia S. Vidal Mauricio P. Sales 《Plant Physiology and Biochemistry》2005,43(12):1095-1102
A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulfate precipitation, affinity chromatography on immobilized trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named CpaTI, had M(r) of 32.5 kDa as determined by SDS-PAGE and was composed of two subunits with 27.7 and 5.6 kDa linked by disulfide bridges. CpaTI was stable at 50 degrees C and lost 40% of activity at 100 degrees C. CpaTI was also stable from pH 2 to 12 at 37 degrees C. CpaTI weakly inhibited chymotrypsin and elastase and its inhibition of papain, a cysteine proteinase, were indicative of its bi-functionality. CpaTI inhibited, in different degrees, digestive enzymes from Spodoptera frugiperda, Alabama argillacea, Plodiainterpunctella, Anthonomus grandis and Zabrotes subfasciatus guts. In vitro and in vivo susceptibility of Callosobruchus maculatus and Ceratitis capitata to CpaTI was evaluated. C. maculatus and C. capitata enzymes were strongly susceptible, 74.4+/-15.8% and 100.0+/-7.3%, respectively, to CpaTI. When CpaTI was added to artificial diets and offered to both insect larvae, the results showed that C. maculatus was more susceptible to CpaTI with an LD(50) of 3.0 and ED(50) of 2.17%. C. capitata larvae were more resistant to CpaTI, in disagreement with the in vitro effects. The larvae were more affected at lower concentrations, causing 27% mortality and 44.4% mass decrease. The action was constant at 2-4% (w/w) with 15% mortality and 38% mass decrease. 相似文献
82.
Yadvinder Malhi Timothy R. Baker Oliver L. Phillips Samuel Almeida Esteban Alvarez Luzmilla Arroyo Jerome Chave Claudia I. Czimczik Anthony Di Fiore Niro Higuchi Timothy J. Killeen Susan G. Laurance William F. Laurance Simon L. Lewis Lina María Mercado Montoya Abel Monteagudo David A. Neill Percy Núez Vargas Sandra Patio Nigel C.A. Pitman Carlos Alberto Quesada Rafael Salomo Jos Natalino Macedo Silva Armando Torres Lezama Rodolfo Vsquez Martínez John Terborgh Barbara Vinceti Jon Lloyd 《Global Change Biology》2004,10(5):563-591
The net primary production of tropical forests and its partitioning between long‐lived carbon pools (wood) and shorter‐lived pools (leaves, fine roots) are of considerable importance in the global carbon cycle. However, these terms have only been studied at a handful of field sites, and with no consistent calculation methodology. Here we calculate above‐ground coarse wood carbon productivity for 104 forest plots in lowland New World humid tropical forests, using a consistent calculation methodology that incorporates corrections for spatial variations in tree‐size distributions and wood density, and for census interval length. Mean wood density is found to be lower in more productive forests. We estimate that above‐ground coarse wood productivity varies by more than a factor of three (between 1.5 and 5.5 Mg C ha?1 a?1) across the Neotropical plots, with a mean value of 3.1 Mg C ha?1 a?1. There appear to be no obvious relationships between wood productivity and rainfall, dry season length or sunshine, but there is some hint of increased productivity at lower temperatures. There is, however, also strong evidence for a positive relationship between wood productivity and soil fertility. Fertile soils tend to become more common towards the Andes and at slightly higher than average elevations, so the apparent temperature/productivity relationship is probably not a direct one. Coarse wood productivity accounts for only a fraction of overall tropical forest net primary productivity, but the available data indicate that it is approximately proportional to total above‐ground productivity. We speculate that the large variation in wood productivity is unlikely to directly imply an equivalent variation in gross primary production. Instead a shifting balance in carbon allocation between respiration, wood carbon and fine root production seems the more likely explanation. 相似文献
83.
Egg characteristics are unreliable in determining maternity in communal clutches of guira cuckoos Guira guira 总被引:1,自引:0,他引:1
Mariana O. Cariello Marcos R. Lima Hubert G. Schwabl Regina H. Macedo 《Journal of avian biology》2004,35(2):117-124
Egg characteristics have been used to determine egg maternity for birds in situations where two or more females lay eggs in a single nest (as in communal breeders and intraspecific parasites). We assessed the applicability of egg morphometry and eggshell appearance in ascribing egg ownership in communal clutches of guira cuckoos Guira guira , a species where up to seven females may lay eggs in a joint nest. We used both combined variables (including egg mass, length, width, shape and two eggshell variables), and a shape index to test whether eggs laid by each female were similar but different from eggs laid by other females. Also, we conducted discriminant function analyses to verify if eggs could be correctly classified to their mothers based on their characteristics. The correct maternity was determined by yolk protein electrophoresis of freshly-laid eggs. Individual female chutches were separated through egg characteristics or shape alone in 29% and 41% of the groups tested, respectively. Differences were mostly due to a single female that differed from her nest-mates in a unique egg variable. On average, 55% of the eggs analyzed were not assigned to the correct mother using egg dimensions and eggshell speckling pattern. In conclusion, the egg characteristics used do not reliably indicate maternity in guira cuckoo communal clutches. We therefore recommend a protein-based verification of egg appearance characteristics for assigning maternity in other species in which multiple female laying occurs. 相似文献
84.
Shams-Eldin H de Macedo CS Niehus S Dorn C Kimmel J Azzouz N Schwarz RT 《Biochemical and biophysical research communications》2008,370(3):388-393
Dolichol phosphate mannose synthase (DPM) catalyzes the reaction between dolichol phosphate (Dol-P) and guanosine diphosphate mannose (GDP-Man) to form dolichol-phosphate-mannose (Dol-P-Man). This molecule acts as mannose donor for N-glycosylation and glycosylphosphatidylinositol (GPI) biosynthesis. The Plasmodium falciparum DPM1 (Pfdpm1) possesses a single predicted transmembrane region near the N-, but not the C-terminus. Here we show that the cloned Pfdpm1 gene failed to complement a Saccharomyces cerevisiae mutant indicating that the parasite gene does not belong to the baker’s yeast group, as was previously assumed. Furthermore, Pfdpm1 was unable to complement a mouse mutant deficient in DPM but efficiently complements the Schizosaccharomyces pombe fission yeast mutant, indicating a difference between fission yeast and mammalian DPM genes. Therefore, we reanalyzed the hydrophobicity scales of all known DPMs and consequently reclassify the DPM clade into six major novel subgroups. Furthermore, we show that Pfdpm1 represents a unique enzyme among these subgroups. 相似文献
85.
S. Casal B. Macedo M. B. P. P. Oliveira 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2001,763(1-2)
A method is described for evaluation of fat-soluble vitamin in human adipose tissue with the aim to obtain, accurately and within the shortest analysis time, a time-integrated measure of exposure to vitamins from the diet. Fat tissue was deproteinized with ethanol and extracted with n-hexane. Normal-phase HPLC was performed in a Lichrosorb Si60 column with a gradient of n-hexane–2-propanol at 1 ml/min. Detection was accomplished using a diode-array system (for retinol and β-carotene) in series with a fluorescence detector (α-tocopherol). The method was validated and applied to human adipose tissue in a total of 140 subjects. The mean contents found were 0.43, 0.84, 240.3 μg/g for retinol, β-carotene and α-tocopherol, respectively. The method is sensitive enough for detecting the compounds in 1.6 mg of adipose tissue considering the lowest concentration found. 相似文献
86.
87.
Claudiane V. Almeida Caio F.R. de Oliveira Edson L. dos Santos Helder F. dos Santos Edson C. Júnior Reinaldo Marchetto Leticia A. da Cruz Alda Maria T. Ferreira Valdirene M. Gomes Gabriel B. Taveira Bruna O. Costa Octávio L. Franco Marlon H. Cardoso Maria Lígia R. Macedo 《Biochimica et Biophysica Acta (BBA)/General Subjects》2021,1865(9):129937
BackgroundAntimicrobial peptides (AMPs) are molecules with potential application for the treatment of microorganism infections. We, herein, describe the structure, activity, and mechanism of action of RQ18, an α-helical AMP that displays antimicrobial activity against Gram-positive and Gram-negative bacteria, and yeasts from the Candida genus.MethodsA physicochemical-guided design assisted by computer tools was used to obtain our lead peptide candidate, named RQ18. This peptide was assayed against Gram-positive and Gram-negative bacteria, yeasts, and mammalian cells to determine its selectivity index. The secondary structure and the mechanism of action of RQ18 were investigated using circular dichroism, large unilamellar vesicles, and molecular dynamic simulations.ResultsRQ18 was not cytotoxic to human lung fibroblasts, peripheral blood mononuclear cells, red blood cells, or Vero cells at MIC values, exhibiting a high selectivity index. Circular dichroism analysis and molecular dynamic simulations revealed that RQ18 presents varying structural profiles in aqueous solution, TFE/water mixtures, SDS micelles, and lipid bilayers. The peptide was virtually unable to release carboxyfluorescein from large unilamellar vesicles composed of POPC/cholesterol, model that mimics the eukaryotic membrane, indicating that vesicles' net charges and the presence of cholesterol may be related with RQ18 selectivity for bacterial and fungal cell surfaces.ConclusionsRQ18 was characterized as a membrane-active peptide with dual antibacterial and antifungal activities, without compromising mammalian cells viability, thus reinforcing its therapeutic application.General significanceThese results provide further insight into the complex process of AMPs interaction with biological membranes, in special with systems that mimic prokaryotic and eukaryotic cell surfaces. 相似文献
88.
Timmers LF Ducati RG Sánchez-Quitian ZA Basso LA Santos DS de Azevedo WF 《Journal of molecular modeling》2012,18(2):467-479
Cytidine Deaminase (CD) is an evolutionarily conserved enzyme that participates in the pyrimidine salvage pathway recycling cytidine and deoxycytidine
into uridine and deoxyuridine, respectively. Here, our goal is to apply computational techniques in the pursuit of potential
inhibitors of Mycobacterium tuberculosis CD (MtCDA) enzyme activity. Molecular docking simulation was applied to find the possible hit compounds. Molecular dynamics simulations
were also carried out to investigate the physically relevant motions involved in the protein-ligand recognition process, aiming
at providing estimates for free energy of binding. The proposed approach was capable of identifying a potential inhibitor,
which was experimentally confirmed by IC50 evaluation. Our findings open up the possibility to extend this protocol to different databases in order to find new potential
inhibitors for promising targets based on a rational drug design process. 相似文献
89.
Roney Fontes Guimarães Luciana Rodrigues Camillo Aurizangela Oliveira Sousa Luana Pereira Gonçalves Jamilly Costa Cardoso Macedo Giovano Sousa Siqueira Antônia Marlene Magalhães Barbosa Fátima Cerqueira Alvim Marcio Gilberto Cardoso Costa Carlos Priminho Pirovani 《Tree Genetics & Genomes》2018,14(6):90
Here, we report for the first time the genome-wide identification and expression analysis of the molecular chaperone BiP genes in Citrus. Six genes encoding the conserved protein domain family GPR78/BiP/KAR2 were identified in the genome of Citrus sinensis and C. clementina. Two of them, named here as CsBiP1 and CsBiP2, were classified as true BiPs based on their deduced amino acid sequences. Alignment of the deduced amino acid sequences of CsBiP1 and CsBiP2 with BiP homologs from soybean and Arabidopsis showed that they contain all the conserved functional motifs of BiPs. Analysis of the promoter region of CsBiPs revealed the existence of cis-acting regulatory sequences involved in abiotic, heat-shock, and endoplasmic reticulum (ER) stress responses. Publicly available RNA-seq data indicated that CsBiP1 is abundantly expressed in leaf, flower, fruit, and callus, whereas CsBiP2 expression is rarely detected in any tissues under normal conditions. Comparative quantitative real-time PCR (qPCR) analysis of expression of these genes between C. sinensis grafted on the drought-tolerant “Rangpur” lime (C. limonia) and -sensitive “Flying Dragon” trifoliate orange (Poncirus trifoliata) rootstocks showed that CsBiP1 was upregulated by drought stress on the former but downregulated on the latter, whereas the CsBiP2 mRNA levels were downregulated on drought-stressed “Flying Dragon,” but remained constant on “Rangpur.” CsBiP2 upregulation was only observed in C. sinensis seedlings subjected to osmotic and cold treatments. Taken together, these results indicate the existence of two highly conserved BiP genes in Citrus that are differentially regulated in the different tissues and in response to abiotic stresses. 相似文献