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Isabela P. Gomes Talita L. Santos Amanda N. de Souza Lúcio O. Nunes Gabriele A. Cardoso Carolina O. Matos Lívia M.F. Costa Luciano M. Lião Jarbas M. Resende Rodrigo M. Verly 《生物化学与生物物理学报:生物膜》2021,1863(1):183449
Studies have suggested that antimicrobial peptides act by different mechanisms, such as micellisation, self-assembly of nanostructures and pore formation on the membrane surface. This work presents an extensive investigation of the membrane interactions of the 14 amino-acid antimicrobial peptide hylaseptin P1-NH2 (HSP1-NH2), derived from the tree-frog Hyla punctata, which has stronger antifungal than antibacterial potential. Biophysical and structural analyses were performed and the correlated results were used to describe in detail the interactions of HSP1-NH2 with zwitterionic and anionic detergent micelles and phospholipid vesicles. HSP1-NH2 presents similar well-defined helical conformations in both zwitterionic and anionic micelles, although NMR spectroscopy revealed important structural differences in the peptide N-terminus. 2H exchange experiments of HSP1-NH2 indicated the insertion of the most N-terminal residues (1–3) in the DPC-d38 micelles. A higher enthalpic contribution was verified for the interaction of the peptide with anionic vesicles in comparison with zwitterionic vesicles. The pore formation ability of HSP1-NH2 (examined by dye release assays) and its effect on the size and surface charge as well as on the lipid acyl chain ordering (evaluated by Fourier-transform infrared spectroscopy) of anionic phospholipid vesicles showed membrane disruption even at low peptide-to-phospholipid ratios, and the effect increases proportionately to the peptide concentration. On the other hand, these biophysical investigations showed that a critical peptide-to-phospholipid ratio around 0.6 is essential for promoting disruption of zwitterionic membranes. In conclusion, this study demonstrates that the binding process of the antimicrobial HSP1-NH2 peptide depends on the membrane composition and peptide concentration. 相似文献
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BACKGROUNDTubulins, building blocks of microtubules, are modified substrates of diverse post-translational modifications including phosphorylation, polyglycylation and polyglutamylation. Polyglutamylation of microtubules, catalyzed by enzymes from the tubulin tyrosine ligase-like (TTLL) family, can regulate interactions with molecular motors and other proteins. Due to the diversity and functional importance of microtubule modifications, strict control of the TTLL enzymes has been suggested.AIMTo characterize the interaction between never in mitosis gene A-related kinase 5 (NEK5) and TTLL4 proteins and the effects of TTLL4 phosphorylation.METHODSThe interaction between NEK5 and TTLL4 was identified by yeast two-hybrid screening using the C-terminus of NEK5 (a.a. 260–708) as bait and confirmed by immunoprecipitation. The phosphorylation sites of TTLL4 were identified by mass spectrometry and point mutations were introduced.RESULTSHere, we show that NEK5 interacts with TTLL4 and regulates its polyglutamylation activity. We further show that NEK5 can also interact with TTLL5 and TTLL7. The silencing of NEK5 increases the levels of polyglutamylation of proteins by increasing the activity of TTLL4. The same effects were observed after the expression of the catalytically inactive form of NEK5. This regulation of TTLL4 activity involves its phosphorylation at Y815 and S1136 amino acid residues.CONCLUSIONOur results demonstrate, for the first time, the regulation of TTLL activity through phosphorylation, pointing to NEK5 as a potential effector kinase. We also suggest a general control of tubulin polyglutamylation through NEK family members in human cells. 相似文献
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Trichoderma aureoviride URM 5158 and Trichoderma hamatum URM 6656 are Biocontrol Agents that act against Cassava Root rot through different Mechanisms 下载免费PDF全文
José Aldo Teixeira da Silva Erika Valente de Medeiros Jéssica Morais da Silva Dyana de A. Tenório Keila Aparecida Moreira Talita Camila Evaristo da Silva Nascimento Cristina Souza‐Motta 《Journal of Phytopathology》2016,164(11-12):1003-1011
Trichoderma has been used to manage a large number of pathogens, but there is a gap in the mechanisms used by these biocontrol agents regarding the physiological response of cassava plants (Manihot esculenta) when it is subjected to cassava root rot. The aims of this study were to investigate the antagonist activity of ten Trichoderma isolates against Fusarium solani on potato dextrose Agar (PDA), to quantify the chitinase production, to select and test in vivo the best isolate from each experiment and to assess the physiological response of cassava to the production of oxidative enzyme complex production (ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase). All Trichoderma isolates have shown competitive capability against F. solani, and Trichoderma hamatum URM 6656 showed the highest inhibition of pathogen growth (88.91%). All isolates have shown chitinase activity, but Trichoderma aureoviride URM 5158 produced the highest amount of chitinase. T. hamatum URM 6656 and T. aureoviride URM 5158 were selected to be applied in vivo. The two Trichoderma strains reduced 64 and 60% of the disease severity in the shoot and 82 and 84% in the root. Cassava plants infected with Trichoderma have shown the highest peroxidase and ascorbate peroxidase production. Our results have indicated that T. aureoviride URM 5158 is an effective biocontrol agent against cassava root rot caused by F. solani, because it presented competitive antagonist capability in vitro, the highest chitinase production, and reduced the cassava root rot severity. The application of T. aureoviride has led to the maximum enzyme activity of reactive oxygen species group in cassava plants. 相似文献
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Hutz MH Callegari-Jacques SM Almeida SE Armborst T Salzano FM 《Human biology; an international record of research》2002,74(6):791-806
Data related to 15 short tandem repeat polymorphisms (STRPs) are reported for five Brazilian Indian populations, and a set of them compared with results previously reported for Asian, neo-Brazilian, North American, Iberian, and African populations. The low variability observed for these markers among the Suruí Indians is confirmed, but the other populations show variability levels that are similar to those found elsewhere. Previous suggestions of population bottlenecks in the prehistorical colonization of the New World were not confirmed. On the other hand, STRPs again showed to be good markers for the establishment of population relationships. 相似文献
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Elevation as a barrier: genetic structure for an Atlantic rain forest tree (Bathysa australis) in the Serra do Mar mountain range,SE Brazil 下载免费PDF全文
Talita Soares Reis Maísa Ciampi‐Guillardi Miklos Maximiliano Bajay Anete Pereira de Souza Flavio Antonio Maës dos Santos 《Ecology and evolution》2015,5(9):1919-1931
Distance and discrete geographic barriers play a role in isolating populations, as seed and pollen dispersal become limited. Nearby populations without any geographic barrier between them may also suffer from ecological isolation driven by habitat heterogeneity, which may promote divergence by local adaptation and drift. Likewise, elevation gradients may influence the genetic structure and diversity of populations, particularly those marginally distributed. Bathysa australis (Rubiaceae) is a widespread tree along the elevation gradient of the Serra do Mar, SE Brazil. This self‐compatible species is pollinated by bees and wasps and has autochoric seeds, suggesting restricted gene dispersal. We investigated the distribution of genetic diversity in six B. australis populations at two extreme sites along an elevation gradient: a lowland site (80–216 m) and an upland site (1010–1100 m.a.s.l.). Nine microsatellite loci were used to test for genetic structure and to verify differences in genetic diversity between sites. We found a marked genetic structure on a scale as small as 6 km (FST = 0.21), and two distinct clusters were identified, each corresponding to a site. Although B. australis is continuously distributed along the elevation gradient, we have not observed a gene flow between the extreme populations. This might be related to B. australis biological features and creates a potential scenario for adaptation to the different conditions imposed by the elevation gradient. We failed to find an isolation‐by‐distance pattern; although on the fine scale, all populations showed spatial autocorrelation until ~10‐20 m. Elevation difference was a relevant factor though, but we need further sampling effort to check its correlation with genetic distance. The lowland populations had a higher allelic richness and showed higher rare allele counts than the upland ones. The upland site may be more selective, eliminating rare alleles, as we did not find any evidence for bottleneck. 相似文献
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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
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Piccinini Alexandre Oliveira Mariana Pacheco Silva Mariella Reinol Bett Gabriela Souza Becker Isabel Borges Mendes Talita Farias Salla Daniéle Hendler Silva Larissa Espindola Vilela Thais Ceresér Moraes Fernanda Mendes Moterle Diego Damiani Adriani Paganini Dagostin Lígia Salvan Tietbohl Lariani Tamires Bittencourt João Vitor Silvano Biehl Erica Denicol Tais Luise Bonfante Sandra Regina Andrade Vanessa Moraes Silveira Paulo Cesar Lock Prophiro Josiane Somariva Ferreira Gabriela Kozuchovski Petronilho Fabricia Kanis Luiz Alberto Rezin Gislaine Tezza 《Neurochemical research》2022,47(7):1888-1903
Neurochemical Research - This study aimed to evaluate the effect of Cynara cardunculus leaf ethanol extract on inflammatory and oxidative stress parameters in the hypothalamus, prefrontal cortex,... 相似文献
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Talita A. Sampaio e Silva Adriana Knob Célia R. Tremacoldi Marcia R. Brochetto-Braga Eleonora Cano Carmona 《World journal of microbiology & biotechnology》2011,27(11):2491-2497
Acid proteases represent an important group of enzymes, widely used in food, beverage and pharmaceutical industries. For most
of these applications the enzymatic preparation must be at least partially purified and free of substances that could change
the characteristics of the product or the process. Fungal proteases have replaced other sources because they are easily obtained
mainly from Mucor, Rhizopus, Penicillium
and
Aspergillus species. A strain of Aspergillus
clavatus was selected by producing high level of acid protease activity. An extracellular aspartatic protease from this strain was
purified 37.2 times with 37% recovery using (NH4)2SO4 fractionation and ion-exchange chromatography. The enzyme was found to be monomeric having a molecular mass of 30.4 kDa.
The purified enzyme is an acid protease with optimum pH of 5.5 and temperature for optimum activity of 50 °C. Its high pH
stability was verified in the range of 3.5–6.5. The acid protease was strongly inhibited by Hg+2 and partially inhibited by Cu+2, Zn+2 and Mn+2. The enzyme was sensitive to denaturing agent SDS and activated by thiol-containing reducing agent dithiotreitol (DTT). The
protease activity was not influenced by iodoacetic acid, E-64 and PMSF, while it was lightly actived by EDTA and totally inhibited
by pepstatin, with a Ki of 7.8 μM, indicating that is an aspartic protease. A.
clavatus acid protease presents interesting characteristics for biotechnological process, such as cheese and flavor manufacture and
dietary supplements, in which activity and stability in acid pH are required. 相似文献