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61.
Zhao Wei Fan Aili Tarcz Sylwia Zhou Kang Yin Wen-Bing Liu Xiao-Qing Li Shu-Ming 《Applied microbiology and biotechnology》2017,101(5):1989-1998
Applied Microbiology and Biotechnology - The fungal cyclic dipeptide prenyltransferase FtmPT1 from Aspergillus fumigatus catalyzes a regular C2-prenylation of brevianamide F (cyclo-l-Trp-l-Pro) and... 相似文献
62.
Rodziewicz-Motowidło S Czaplewska P Sikorska E Spodzieja M Kołodziejczyk AS 《Journal of structural biology》2008,164(2):199-209
The beta-amyloid (Abeta) is the major peptide constituent of neuritic plaques in Alzheimer's disease, and its aggregation is believed to play a central role in the pathogenesis of the disease. Naturally occurring mutations resulting in changes in the Abeta sequence (pos. 21-23) are associated with familial Alzheimer's-like diseases with extensive cerebrovascular pathology. It has been demonstrated that such mutations alter the aggregation ability of Abeta and its neurotoxicity. Among the five mutations at positions 21-23 there is one with distinct clinical characteristics and a potentially distinct pathogenic mechanism-the Arctic (E22G) mutation. We have examined the structures of fragment 11-28 of the native peptide and its E22G variant. This fragment was chosen because it has been shown to be a good model for conformational and aggregation studies as it contains the hydrophobic core responsible for aggregation and the residues critical to alpha-secretase cleavage of APP. The detailed structure of the two peptides was determined using CD, 2D NMR and molecular dynamics techniques under water-SDS micelle conditions. Our studies indicated the existence of partially alpha- and 3(10)-helical conformations in the native and mutated peptide, respectively. 相似文献
63.
The conformations of four BK antagonists, [D-Arg 0, Hyp3, Thi5, D-Phe7, Acc8]BK (1), Aaa[D-Arg 0, Hyp3, Thi5, D-Phe7, Acc8]BK (2), [D-Arg 0, Hyp3, Thi5, 8, Apc7]BK (3), and Aaa[D-Arg(0), Hyp(3), Thi(5, 8), Apc7]BK (4) were studied by using 2D NMR spectroscopy and MD simulations with time-averaged (TAV) restraints. According to the results of the NMR measurements, the BK antagonists contain 7-30% of minor conformation resulting from cis/trans isomerization of the peptide bonds preceding either Pro or Hyp residues. The major conformation of each peptide possesses all peptide bonds in trans configuration. Peptides modified with the Apc residue at position 7 (peptides 3 and 4) possess a higher percentage of minor isomer.Peptide 1 exhibits the strongest vasodepressor potency among the analogs studied and as a single one forms the betaII-turn in the 2-5 fragment, which is believed to be crucial for antagonistic activity. This peptide is also the most compact. The radius of gyration (Rg) amounts to 6.9 A and is by ca 1.5 A lower than that of the remaining analogs. With peptide 4, the ST-turn of type I within the Ser6-Thi8 fragment was found. 相似文献
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65.
Wanda Małek Sylwia Wdowiak-Wróbel Michał Bartosik Grażyna Konopa Magdalena Narajczyk 《Current microbiology》2009,59(2):187-192
Three lytic phages (ΦRP1, ΦRP2, and ΦRP3) specific for Robinia pseudoacacia rhizobia were isolated from the soil under black locust. They were characterized by their morphology, host range, and some
other properties including DNA molecular weights. Studied phages have been found to belong to Siphoviridae family that comprises viruses with long, and noncontractile tails. They had broad host ranges and effectively lysed not only
Robinia pseudoacacia microsymbionts but also different Mesorhizobium species. The phages were homogenous in latent periods (300 min) but heterogeneous in burst sizes (100–200 phage particles
per one infected cell) and rise periods (90–120 min). They showed a distinct adsorption rate to Robinia pseudoacacia rhizobia (70.4–93.94%). The molecular weights of phage DNAs estimated from restriction enzyme digests were in the range from
ca. 82 kb to ca. 105 kb. 相似文献
66.
Sylwia Krzymiska Joanna Mokracka Ryszard Koczura & Adam Kaznowski 《FEMS immunology and medical microbiology》2009,56(3):248-252
We examined 55 Enterobacter cloacae isolates from clinical specimens for the production of cytotonic and cytotoxic toxins and the presence of the type III secretion system (TTSS). Twelve isolates (22%) revealed cytotoxic activity that caused destruction of Vero cells, whereas 28 (51%) strains induced lysis of the murine macrophage J774 cell line. TTSS genes were present in 27% of the isolates. The results indicated that these bacteria may destroy phagocytes and epithelial cells, which may lead to spread within the host. 相似文献
67.
This research aims to examine the effect of phenolics on pea aphid (Acyrthosiphon pisum) (Homoptera: Aphididae) development and feeding behaviour, on leaves of selected low-saponin lines of Radius alfalfa (Medicago sativa). There was a slight, negative correlation (Spearman rank correlation r
s = −0.80) between concentrations of saponins and phenols. Lines with higher concentrations of saponins had less phenolics.
Levels of phenolics in low-saponin lines of alfalfa cv. Radius were related to their acceptance by the pea aphid. Our data
revealed an inverse relationship between level of phenolics and the aphid abundance and its biology on studied alfalfa lines.
Larval development of the pea aphid was longer, reproduction period was shorter, and the fecundity was lower on low-saponin
lines with higher level of phenolics. There were observed some tendencies in the pea aphid feeding behaviour on these lines:
prolonging the probing of the peripheral tissues (epidermis and mesophyll) and shortening the period of phloem sap ingestion.
The better hosts for the pea aphid were low-saponin lines with low levels of phenolic compounds. 相似文献
68.
Sylwia Flis Agnieszka Gnyszka Irena Misiewicz-Krzemińska Jacek Spławiński 《Cancer cell international》2009,9(1):10-10
Background
DNA methylation is an epigenetic phenomenon known to play an important role in the development of cancers, including colorectal cancer (CRC). Aberrant methylation of promoter regions of genes is potentially reversible, and if methylation is important for cancer survival, demethylation should do the opposite. To test this we have addressed the hypothesis that DNA methyltransferase inhibitors (DNMTi), decytabine and zebularine, potentiate inhibitory effects of classical anti-CRC cytostatics, oxaliplatin and 5-fluorouracil (5-FU), on survival of CRC cells in vitro. 相似文献69.
70.
Jezierska Sylwia Van Bogaert Inge N. A. 《Journal of industrial microbiology & biotechnology》2017,44(4-5):721-733
Journal of Industrial Microbiology & Biotechnology - How small molecules cross cellular membranes is an often overlooked issue in an industrial microbiology and biotechnology context. This is... 相似文献