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91.
Adriana Farias Silva Erick Leite Bastos Marcelo Der Torossian Torres André Luis Costa‐da‐Silva Rafaella Sayuri Ioshino Margareth Lara Capurro Flávio Lopes Alves Antonio Miranda Renata de Freitas Fischer Vieira Vani Xavier Oliveira Jr. 《Journal of peptide science》2014,20(8):640-648
Angiotensin II (AII) as well as analog peptides shows antimalarial activity against Plasmodium gallinaceum and Plasmodium falciparum, but the exact mechanism of action is still unknown. This work presents the solid‐phase synthesis and characterization of eight peptides corresponding to the alanine scanning series of AII plus the amide‐capped derivative and the evaluation of the antiplasmodial activity of these peptides against mature P. gallinaceum sporozoites. The Ala screening data indicates that the replacement of either the Ile5 or the His6 residues causes minor effects on the in vitro antiplasmodial activity compared with AII, i.e. AII (88%), [Ala6]‐AII (79%), and [Ala5]‐AII (75%). Analogs [Ala3]‐AII, [Ala1]‐AII, and AII‐NH2 showed antiplasmodial activity around 65%, whereas the activity of the [Ala8]‐AII, [Ala7]‐AII, [Ala4]‐AII, and [Ala2]‐AII analogs is lower than 45%. Circular dichroism data suggest that AII and the most active analogs adopt a β‐fold conformation in different solutions. All AII analogs, except [Ala4]‐AII and [Ala8]‐AII, show contractile responses and interact with the AT1 receptor, [Ala5]‐AII and [Ala6]‐AII. In conclusion, this approach is helpful to understand the contribution of each amino acid residue to the bioactivity of AII, opening new perspectives toward the design of new sporozoiticidal compounds. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
92.
Luiza Pinheiro Carla Ivo Brito Valéria Cataneli Pereira Adilson de Oliveira Carlos Henrique Camargo Maria de Lourdes Ribeiro de Souza da Cunha 《Memórias do Instituto Oswaldo Cruz》2014,109(7):871-878
This study aimed to correlate the presence of ica genes, biofilm
formation and antimicrobial resistance in 107 strains of Staphylococcus
epidermidis isolated from blood cultures. The isolates were analysed to
determine their methicillin resistance, staphylococcal cassette chromosome
mec (SCCmec) type, ica genes
and biofilm formation and the vancomycin minimum inhibitory concentration (MIC) was
measured for isolates and subpopulations growing on vancomycin screen agar. The
mecA gene was detected in 81.3% of the S.
epidermidis isolated and 48.2% carried SCCmec type III.
The complete icaADBC operon was observed in 38.3% of the isolates;
of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on
vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates.
Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg
mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with
an MIC of 16 μg mL-1. The presence of the icaADBC operon,
biofilm production and reduced susceptibility to vancomycin were associated with
methicillin resistance. This study reveals a high level of methicillin resistance,
biofilm formation and reduced susceptibility to vancomycin in subpopulations of
S. epidermidis. These findings may explain the selection of
multidrug-resistant isolates in hospital settings and the consequent failure of
antimicrobial treatment. 相似文献
93.
94.
Ozmen Cobanoglu Lou Delval Daniele Ferrari Lucie Deruyter Séverine Heumel Isabelle Wolowczuk Abir Hussein Ayse Nur Menevse David Bernard Philip Beckhove Frauke Alves François Trottein 《Aging cell》2023,22(12):e14007
The age-related decline in immunity reduces the effectiveness of vaccines in older adults. Immunosenescence is associated with chronic, low-grade inflammation, and the accumulation of senescent cells. The latter express Bcl-2 family members (providing resistance to cell death) and exhibit a pro-inflammatory, senescence-associated secretory phenotype (SASP). Preexisting senescent cells cause many aging-related disorders and therapeutic means of eliminating these cells have recently gained attention. The potential consequences of senescent cell removal on vaccine efficacy in older individuals are still ignored. We used the Bcl-2 family inhibitor ABT-263 to investigate the effects of pre-vaccination senolysis on immune responses in old mice. Two different ovalbumin (OVA)-containing vaccines (containing a saponin-based or a CpG oligodeoxynucleotide adjuvant) were tested. ABT-263 depleted senescent cells (apoptosis) and ablated the basal and lipopolysaccharide-induced production of SASP-related factors in old mice. Depletion of senescent cells prior to vaccination (prime/boost) had little effect on OVA-specific antibody and T-cell responses (slightly reduced and augmented, respectively). We then used a preclinical melanoma model to test the antitumor potential of senolysis before vaccination (prime with the vaccine and OVA boost by tumor cells). Surprisingly, ABT-263 treatment abrogated the vaccine's ability to protect against B16 melanoma growth in old animals, an effect associated with reduced antigen-specific T-cell responses. Some, but not all, of the effects were age-specific, which suggests that preexisting senescent cells were partly involved. Hence, depletion of senescent cells modifies immune responses to vaccines in some settings and caution should be taken when incorporating senolytics into vaccine-based cancer therapies. 相似文献
95.
Saulo Alves Aflitos Gabino Sanchez‐Perez Dick de Ridder Paul Fransz Michael E. Schranz Hans de Jong Sander A. Peters 《The Plant journal : for cell and molecular biology》2015,82(1):174-182
Breeding by introgressive hybridization is a pivotal strategy to broaden the genetic basis of crops. Usually, the desired traits are monitored in consecutive crossing generations by marker‐assisted selection, but their analyses fail in chromosome regions where crossover recombinants are rare or not viable. Here, we present the Introgression Browser (iBrowser ), a bioinformatics tool aimed at visualizing introgressions at nucleotide or SNP (Single Nucleotide Polymorphisms) accuracy. The software selects homozygous SNPs from Variant Call Format (VCF) information and filters out heterozygous SNPs, multi‐nucleotide polymorphisms (MNPs) and insertion–deletions (InDels). For data analysis iBrowser makes use of sliding windows, but if needed it can generate any desired fragmentation pattern through General Feature Format (GFF) information. In an example of tomato (Solanum lycopersicum) accessions we visualize SNP patterns and elucidate both position and boundaries of the introgressions. We also show that our tool is capable of identifying alien DNA in a panel of the closely related S. pimpinellifolium by examining phylogenetic relationships of the introgressed segments in tomato. In a third example, we demonstrate the power of the iBrowser in a panel of 597 Arabidopsis accessions, detecting the boundaries of a SNP‐free region around a polymorphic 1.17 Mbp inverted segment on the short arm of chromosome 4. The architecture and functionality of iBrowser makes the software appropriate for a broad set of analyses including SNP mining, genome structure analysis, and pedigree analysis. Its functionality, together with the capability to process large data sets and efficient visualization of sequence variation, makes iBrowser a valuable breeding tool. 相似文献
96.
Ester B. M. Remmerswaal Paul L. Klarenbeek Nuno L. Alves Marieke E. Doorenspleet Barbera D. C. van Schaik Rebecca E. E. Esveldt Mirza M. Idu Ester M. M. van Leeuwen Nelly van der Bom-Baylon Antoine H. C. van Kampen Sven D. Koch Hanspeter Pircher Frederike J. Bemelman Anja ten Brinke Frank Baas Ineke J. M. ten Berge Rene A.W. van Lier Niek de Vries 《Journal of virology》2015,89(1):568-580
97.
Structural analysis of an Echinococcus granulosus actin-fragmenting protein by small-angle x-ray scattering studies and molecular modeling 下载免费PDF全文
Grimm ED Portugal RV de Oliveira Neto M Martins NH Polikarpov I Zaha A Ferreira HB 《Biophysical journal》2006,90(9):3216-3223
The Echinococcus granulosus actin filament-fragmenting protein (EgAFFP) is a three domain member of the gelsolin family of proteins, which is antigenic to human hosts. These proteins, formed by three or six conserved domains, are involved in the dynamic rearrangements of the cytoskeleton, being responsible for severing and capping actin filaments and promoting nucleation of actin monomers. Various structures of six domain gelsolin-related proteins have been investigated, but little information on the structure of three domain members is available. In this work, the solution structure of the three domain EgAFFP has been investigated through small-angle x-ray scattering (SAXS) studies. EgAFFP exhibits an elongated molecular shape. The radius of gyration and the maximum dimension obtained by SAXS were, respectively, 2.52 +/- 0.01 nm and 8.00 +/- 1.00 nm, both in the absence and presence of Ca2+. Two different molecular homology models were built for EgAFFP, but only one was validated through SAXS studies. The predicted structure for EgAFFP consists of three repeats of a central beta-sheet sandwiched between one short and one long alpha-helix. Possible implications of the structure of EgAFFP upon actin binding are discussed. 相似文献
98.
Molecular,genetic and evolutionary analysis of a paracentric inversion in Arabidopsis thaliana 下载免费PDF全文
Paul Fransz Gabriella Linc Cheng‐Ruei Lee Saulo Alves Aflitos Jesse R. Lasky Christopher Toomajian Hoda Ali Janny Peters Peter van Dam Xianwen Ji Mateusz Kuzak Tom Gerats Ingo Schubert Korbinian Schneeberger Vincent Colot Rob Martienssen Maarten Koornneef Magnus Nordborg Thomas E. Juenger Hans de Jong Michael E. Schranz 《The Plant journal : for cell and molecular biology》2016,88(2):159-178
Chromosomal inversions can provide windows onto the cytogenetic, molecular, evolutionary and demographic histories of a species. Here we investigate a paracentric 1.17‐Mb inversion on chromosome 4 of Arabidopsis thaliana with nucleotide precision of its borders. The inversion is created by Vandal transposon activity, splitting an F‐box and relocating a pericentric heterochromatin segment in juxtaposition with euchromatin without affecting the epigenetic landscape. Examination of the RegMap panel and the 1001 Arabidopsis genomes revealed more than 170 inversion accessions in Europe and North America. The SNP patterns revealed historical recombinations from which we infer diverse haplotype patterns, ancient introgression events and phylogenetic relationships. We find a robust association between the inversion and fecundity under drought. We also find linkage disequilibrium between the inverted region and the early flowering Col‐FRIGIDA allele. Finally, SNP analysis elucidates the origin of the inversion to South‐Eastern Europe approximately 5000 years ago and the FRI‐Col allele to North‐West Europe, and reveals the spreading of a single haplotype to North America during the 17th to 19th century. The ‘American haplotype’ was identified from several European localities, potentially due to return migration. 相似文献
99.
Peptidases in the extracellular space might affect the integrity of recombinant proteins expressed in, and secreted from, plant cells. To identify extracellular peptidases, we recovered the leaf intercellular fluid from Nicotiana tabacum plants by an infiltration-centrifugation method. The activity of various peptidases was detected by an in vitro assay in the presence of specific inhibitors, using BSA and human serum gamma-globulin as substrates. Peptidases were detected by 1- and 2-D zymography in a polyacrylamide gel containing gelatin as substrate. Proteolytic activity was observed over a wide range of molecular masses equal to, or higher than, 45 kDa. To identify the peptidases, the extracellular proteins were digested with trypsin and analyzed by LC and MS. Seventeen peptides showing identity or similarity to predicted plant aspartic, cysteine, and serine peptidases have been identified. The extracellular localization of a cysteine peptidase aleurain homolog was also shown. 相似文献
100.
de Aquino TM Liesen AP da Silva RE Lima VT Carvalho CS de Faria AR de Araújo JM de Lima JG Alves AJ de Melo EJ Góes AJ 《Bioorganic & medicinal chemistry》2008,16(1):446-456
In the present communication, a new series of 2-[(phenylmethylene)hydrazono]-4-oxo-3-phenyl-5-thiazolidineacetic acids (2a-p) have been synthesized. Benzaldehyde 4-phenyl-3-thiosemicarbazones substituted (1a-p) were also obtained and used as intermediate to give the title compounds. All synthesized compounds were characterized by IR, (1)H and (13)C NMR. The in vitro anti-Toxoplasma gondii activity of 1a-p and 2a-p was evaluated. The 4-thiazolidinones (2a-p) were screened for their in vitro antimicrobial activity. For anti-Toxoplasma gondii activity, in general, all compounds promoted decreases in the percentage of infected cells leading to parasite elimination. These effects on intracellular parasites also caused a decrease in the mean number of tachyzoites. In addition, most of the 4-thiazolidinones showed more effective toxicity against intracellular parasites, with IC(50) values ranging from 0.05 to 1 mM. According to results of antimicrobial activity, compounds 2f, 2l, and 2p showed best activity against Mycobacterium luteus, 2c was more active against Mycobacterium tuberculosis, and 2g, 2l, and 2n showed same activity as nistatin (standard drug) against Candida sp. (4249). 相似文献