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71.
Bacillus licheniformis bacitracin-resistance ABC transporter: relationship to mammalian multidrug resistance 总被引:4,自引:2,他引:2
Zdravko Podlesek Aleksandra Comino Blagajana Herzog-Velikonja Darja gur-Bertok Radovan Komel Miklav Grabnar 《Molecular microbiology》1995,16(5):969-976
The nucleotide sequence of the Bacillus licheniformis bacitracin-resistance locus was determined. The presence of three open reading frames, bcrA, bcrB and bcrC, was revealed. The BcrA protein shares a high degree of homology with the hydrophilic ATP-binding components of the ABC family of transport proteins. The bcrB and bcrC genes were found to encode hydro-phobic proteins, which may function as membrane components of the permease. Apart from Bacillus subtilis, these genes also confer resistance upon the Gram-negative Escherichia coli. The presumed function of the Bcr transporter is to remove the bacitracin molecule from its membrane target. In addition to the homology of the nucleotide-binding sites, BcrA protein and mammalian multidrug transporter or P-glycoprotein share collateral detergent sensitivity of resistant cells and possibly the mode of Bcr transport activity within the membrane. The advantage of the resistance phenotype of the Bcr transporter was used to construct deletions within the nucleotide-binding protein to determine the Importance of various regions in transport. 相似文献
72.
Lefèvre Isabelle Vogel-Mikuš Katarina Arčon Iztok Lutts Stanley 《Plant and Soil》2016,399(1-2):193-208
Plant and Soil - Zygophyllum fabago is a perennial species tolerating high concentrations of Cd and Zn through protection of photosynthetically active leaves and regulation of Cd and Zn... 相似文献
73.
Jerneja Kladnik Ana Dolinar Jakob Kljun David Perea Judith Grau-Expsito Meritxell Genesc Marko Novinec Maria J. Buzon Iztok Turel 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):2158
Zinc pyrithione (1a), together with its analogues 1b–h and ruthenium pyrithione complex 2a, were synthesised and evaluated for the stability in biologically relevant media and anti-SARS-CoV-2 activity. Zinc pyrithione revealed potent in vitro inhibition of cathepsin L (IC50=1.88 ± 0.49 µM) and PLPro (IC50=0.50 ± 0.07 µM), enzymes involved in SARS-CoV-2 entry and replication, respectively, as well as antiviral entry and replication properties in an ex vivo system derived from primary human lung tissue. Zinc complexes 1b–h expressed comparable in vitro inhibition. On the contrary, ruthenium complex 2a and the ligand pyrithione a itself expressed poor inhibition in mentioned assays, indicating the importance of the selection of metal core and structure of metal complex for antiviral activity. Safe, effective, and preferably oral at-home therapeutics for COVID-19 are needed and as such zinc pyrithione, which is also commercially available, could be considered as a potential therapeutic agent against SARS-CoV-2. 相似文献
74.
Rumen bacteriophage-lyzed bacterial strains of the genusPrevotella were isolated and preliminarily characterized. The strain TC1-1 the speciesP. bryantii was the only prevotella strain successfully infected with filter sterilized rumen fluid from a black-and-white Holstein cow.
Two types of plaques were observed, both rather small and turbid. Preliminary electron microscopy observation showed that
several morphologically different bacteriophages were present in these plaques. The plaque eluates were further used for the
infection of other prevotella strains. The plaques produced by the bacteriophages were observed with two strains,i.e. P. bryantii B14 andP. brevis GA33. The bacteriophages from both strains were examined by transmission electron microscopy and several morphologically
different bacteriophages were observed, among others also a large virion with an icosahedral head with the diameter of approximately
120 nm. The bacteriophage was identified in plaques of bacterial cells of the strain GA33 and has an approximately 800 nm
long helical tail, which places it among the largest ruminal bacteriophages described to date. Other bacteriophages from the
same indicator strain as well as fromP. bryantii B14 strain were smaller and tail structures were not observed in all of them. 相似文献
75.
Laznik Žiga Košir Iztok Jože Košmelj Katarina Murovec Jana Jagodič Anamarija Trdan Stanislav Ačko Darja Kocjan Flajšman Marko 《Plant and Soil》2020,455(1-2):367-379
Plant and Soil - Soils represent the natural habitat of entomopathogenic nematodes (EPNs). When moving in soil, EPNs are oriented to follow a chemical signal (chemotaxis). Cannabis sativa L. is... 相似文献
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78.
Drevensek P Zupancic T Pihlar B Jerala R Kolitsch U Plaper A Turel I 《Journal of inorganic biochemistry》2005,99(2):432-442
A new quinolone-metal complex was prepared by a hydrothermal reaction in the presence of L-histidine that served as a reducing agent for a metal. The title compound [Cu(II)(cfH)(2)(Cu(I)Cl(2))(2)] (1) is a mixed-valence Cu(II)-Cu(I) complex, which contains two ciprofloxacin (cfH) molecules bonded to the central copper(II) atom and two almost planar [Cu(I)Cl(2)](-) moieties. Both metal centers are connected through two bridging atoms (chloride and quinolone oxygen). The electrochemical methods (differential-pulse polarography and cyclovoltammetric measurements) confirmed the presence of various copper-ciprofloxacin complex species in aqueous solution at low concentrations used in biological activity tests and also indicated that the equilibria in this system are very complex. The biological properties of the title compound and some previously isolated copper-ciprofloxacin complexes ([Cu(cfH)(2)Cl(2)].6H(2)O (2) and [CuCl(cfH)(phen)]Cl.2H(2)O (3)) (phen=1, 10-phenantroline) were determined and compared. The DNA gyrase inhibition tests and antibacterial activity tests have shown that the effect of copper complexes is comparable to that of free quinolone. Additionally, an interesting DNA cleavage activity of the title compound was also discovered. 相似文献
79.
Locatelli I Kmetec V Mrhar A Grabnar I 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,818(2):191-198
An assay comprising two simple, selective and isocratic HPLC methods with UV detection was developed and validated for measuring warfarin enantiomers and all five warfarin monohydroxylated metabolites in patient blood plasma. Following liquid/liquid extraction from 1 ml of blood plasma a baseline separation of analytes was achieved on chiral (alpha(1) acid glycoprotein - AGP) and achiral (C(18)) column. Both methods were consistent (R.S.D.<6.9% for warfarin enantiomers and<8.9% for monohydroxylated metabolites) and linear (r>0.998). The limits of detection were 25 ng/ml for warfarin enantiomers, 25 ng/ml for 4'-, 10-, 6- and 7-hydroxywarfarin, 35 ng/ml for 8-hydroxywarfarin and 50 ng/ml for racemic warfarin. In a clinical study in 204 patients, it was confirmed that the assay is appropriate for evaluation of influences of genetic polymorphisms, demographic factors and concomitant drug treatment on warfarin metabolism. 相似文献
80.
The bacitracin resistance of Bacillus licheniformis, a producer of bacitracin, is mediated by the ABC transporter Bcr. Bacillus subtilis cells carrying bcr genes on high-copy number plasmids developed collateral detergent sensitivity, as did human cells with overexpressed multidrug resistance P-glycoprotein. Resistance against bacitracin and sensitivity of resistant cells to detergents were shown to be inseparable phenomena associated with the membrane part of Bcr transporter, namely protein BcrC. A fused protein, consisting of ATP-binding protein BcrA and membrane component BcrC was constructed. It resembled a half molecule of P-glycoprotein and was capable of providing a significant degree of antibiotic resistance and detergent sensitivity. 相似文献