The microbial biofilms are ubiquitous in nature and represent important biological entities that affect various aspects of human life. As such, they attracted considerable attention during last decades, with the factors affecting the biofilm development being among the frequently studied topics. In our work, the biofilm was cultivated on the surface of polypropylene fibers in a nutrient medium inoculated by the suspension of two unsterile soils. The effects of ionic strength and valence of salt on the amount of the produced biofilm and on composition of biofilm microbial communities were investigated. The effect of valence was significant in some OTUs: Arthrobacter/Pseudarthrobacter/Paenarthrobacter and Bacillus with positive response to monovalent salt (KCl) and Streptomyces, Lysinibacillus, Pseudomonas, and Ensifer with positive response to divalent salt (MgSO4). The significant preference for a certain concentration of salts was observed in the case of OTUs Agrobacterium, Bacillus (both 100 mM), and Brevundimonas (30 mM). A new quantification method based on measuring of oxidizable organic carbon in biofilm biomass, based on dichromate oxidation, was used. We compared the results obtained using this method with results of crystal violet destaining and measuring of extracted DNA concentration as proxies of the biofilm biomass. The dichromate oxidation is simple, inexpensive, and fast, and our results show that it may be more sensitive than crystal violet destaining. The highest biomass values tended to associate with high concentrations of the divalent salt. This trend was not observed in treatments where the monovalent salt was added. Our data confirm the importance of inorganic ions for biofilm composition and biomass accumulation.
- MeSH
- Bacteria klasifikace účinky léků genetika izolace a purifikace MeSH
- bakteriologické techniky MeSH
- biofilmy účinky léků růst a vývoj MeSH
- biomasa MeSH
- kultivační média chemie MeSH
- mikrobiota účinky léků MeSH
- minerály analýza farmakologie MeSH
- polypropyleny MeSH
- půdní mikrobiologie MeSH
- soli analýza farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Aggregation of neuronal protein α-synuclein leads to the formation of amyloid fibrils, which are associated with the development of Parkinson's disease. The mechanism of α-synuclein pathology is not fully understood and is a subject of active research in the field. To tackle this problem, the fusions of fluorescent proteins to α-synuclein C-terminus are often used in cellular and animal studies. The effects induced by such α-synuclein sequence extension on α-synuclein aggregation propensity are, however, not systematically examined despite the evidence that the negatively charged C-terminus plays a critical role in the regulation of α-synuclein aggregation. In this work, we investigated how the charge and length variations of the C-terminus affect the aggregation propensity of α-synuclein. To address these questions, we prepared mutants of α-synuclein carrying additional moieties of different charge and length at the protein C-terminus. We determined the rates of two different aggregation stages (primary nucleation and elongation) based on a thioflavin T kinetic assay. We observed that all mutants bearing neutrally charged moieties of different length fibrilized slower than wild-type α-synuclein. The primary nucleation and elongation rates strongly decreased with increase of the C-terminal extension length. Meanwhile, charge variation of the C-terminus significantly changed the rate of α-synuclein nucleation, but did not markedly affect the rate of fibril elongation. Our data demonstrate that both the charge and length of the C-terminus play an important role at the stage of initial fibril formation, but the stage of fibril elongation is affected mainly by the length of C-terminal extension. In addition, our results suggest that there are at least two steps of incorporation of α-synuclein monomers into the amyloid fibril: namely, the initial monomer binding to the fibril end (charge-dependent, relatively fast), and the subsequent conformational change of the protein (charge-independent, relatively slow, and thus the rate-limiting step).
A study of the effects of salt conditions on the association and dissociation of wild type p53 with different ~3 kbp long plasmid DNA substrates (supercoiled, relaxed circular and linear, containing or lacking a specific p53 binding site, p53CON) using immunoprecipitation at magnetic beads is presented. Salt concentrations above 200 mM strongly affected association of the p53 protein to any plasmid DNA substrate. Strikingly different behavior was observed when dissociation of pre-formed p53-DNA complexes in increased salt concentrations was studied. While contribution from the p53CON to the stability of the p53-DNA complexes was detected between 100 and 170 mM KCl, p53 complexes with circular DNAs (but not linear) exhibited considerable resistance towards salt treatment for KCl concentrations as high as 2 M provided that the p53 basic C-terminal DNA binding site (CTDBS) was available for DNA binding. On the contrary, when the CTDBS was blocked by antibody used for immunoprecipitation, all p53-DNA complexes were completely dissociated from the p53 protein in KCl concentrations≥200 mM under the same conditions. These observations suggest: (a) different ways for association and dissociation of the p53-DNA complexes in the presence of the CTDBS; and (b) a critical role for a sliding mechanism, mediated by the C-terminal domain, in the dissociation process.
Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions. Abiotic stress treatments induced PLAT1 expression and caused expansion of its expression domain. The ABF/ABRE transcription factors, which are positive mediators of abscisic acid signalling, activate PLAT1 promoter activity in transactivation assays and directly bind to the ABRE elements located in this promoter in electrophoretic mobility shift assays. This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway. Thus, we showed that PLAT1 critically functions as positive regulator of abiotic stress tolerance, but also is involved in regulating plant growth, and thereby assigned a function to this previously uncharacterised PLAT domain protein. The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.
- MeSH
- aktivace transkripce MeSH
- Arabidopsis klasifikace růst a vývoj metabolismus MeSH
- fylogeneze MeSH
- fyziologický stres * MeSH
- kyselina abscisová farmakologie MeSH
- nízká teplota MeSH
- období sucha MeSH
- promotorové oblasti (genetika) MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin účinky léků MeSH
- retardační test MeSH
- signální transdukce účinky léků MeSH
- soli chemie farmakologie MeSH
- stres endoplazmatického retikula účinky léků MeSH
- transkripční faktory bZIP genetika metabolismus MeSH
- tunikamycin toxicita MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The paper reviews preparation of pharmaceutically active substances intercalated in layered double hydroxides (LDH). A number of such reports have been published mainly in the last decade. The intercalation of various pharmaceuticals, e.g. nonsteroidal anti-inflammatory drugs, antihypertensives, antibiotics, or anticancer drugs in LDH hosts is described. The hybrid materials containing bioactive compounds such as amino acids, vitamins, enzymes, or DNA fragments intercalated in LDH are also mentioned. The active substances are intercalated mostly as water-soluble carboxylate salts. The host LDH particles are nontoxic and biocompatible, and the intercalated substances are more stable to chemical, thermal and light degradation. Intercalated LDH are prospective drug carriers and drug delivery systems with controlled release of active substances.
- MeSH
- aminokyseliny farmakologie chemie MeSH
- antibakteriální látky farmakologie chemie MeSH
- enzymy farmakologie chemie MeSH
- farmaceutický průmysl metody trendy MeSH
- financování organizované MeSH
- fragmentace DNA účinky léků MeSH
- hydroxid hlinitý farmakologie chemie MeSH
- hydroxid hořečnatý farmakologie chemie MeSH
- hydroxidy farmakologie chemie MeSH
- indikátory a reagencie chemie MeSH
- léčivé přípravky chemie MeSH
- lékové formy MeSH
- lidé MeSH
- methotrexát farmakologie chemie MeSH
- nosiče léků farmakologie chemie MeSH
- oligopeptidy farmakologie chemie MeSH
- poruchy fotosenzitivity farmakoterapie MeSH
- soli farmakologie chemie MeSH
- vitaminy farmakologie chemie MeSH
- Check Tag
- lidé MeSH
Pharmaceutical cocrystals are H-bonded multicomponent mixtures formed from a molecular or ionic substance and a cocrystal former, which are solids under ambient conditions. The cocrystals are the latest material investigated to enhance drug properties such as solubility, dissolution rate, stability, powder flow, and hygroscopicity. Very close to cocrystals are salts which can be distinguished by the localization of proton between an acid and base. Crystal engineering of cocrystals is based on the concept of supramolecular synthons. The major experimental techniques in cocrystal screening are cocrystallization in solution, solvent evaporation, melt crystallisation, dry cogrinding, solvent-assisted grinding and cryogrinding.
- MeSH
- butyráty farmakologie chemie MeSH
- chemické jevy MeSH
- chemie farmaceutická metody trendy MeSH
- farmaceutická technologie metody trendy MeSH
- farmaceutický průmysl metody trendy MeSH
- financování organizované MeSH
- itrakonazol MeSH
- karbamazepin chemie MeSH
- kofein farmakologie chemie MeSH
- krystalizace metody trendy využití MeSH
- kyseliny dikarboxylové farmakologie chemická syntéza chemie MeSH
- kyseliny mandlové farmakologie chemie MeSH
- lékové formy MeSH
- objevování léků MeSH
- paracetamol farmakologie chemie MeSH
- rozpouštědla farmakologie chemie MeSH
- sacharin farmakologie chemie MeSH
- soli farmakologie chemie MeSH
- Klíčová slova
- Olynth,
- MeSH
- antibakteriální látky aplikace a dávkování farmakologie terapeutické užití MeSH
- antihistaminika aplikace a dávkování farmakologie terapeutické užití MeSH
- antiinfekční látky aplikace a dávkování farmakologie terapeutické užití MeSH
- antitusika aplikace a dávkování farmakologie terapeutické užití MeSH
- bolest krku etiologie farmakoterapie terapie MeSH
- expektorancia aplikace a dávkování farmakologie terapeutické užití MeSH
- farmakoterapie metody využití MeSH
- horečka etiologie farmakoterapie terapie MeSH
- kašel etiologie farmakoterapie terapie MeSH
- lidé MeSH
- nemoci dýchací soustavy farmakoterapie klasifikace terapie MeSH
- neopioidní analgetika aplikace a dávkování farmakologie terapeutické užití MeSH
- nosní sliznice imunologie účinky léků MeSH
- rinitida etiologie farmakoterapie terapie MeSH
- rizikové faktory MeSH
- soli aplikace a dávkování farmakologie terapeutické užití MeSH
- sympatomimetika aplikace a dávkování farmakologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
Antimicrobial properties of oxidized cellulose and its salts in linters (-L) and microsphere (-M) form (OKCEL H-L, OKCEL Zn-M, OKCEL ZnNa-L, OKCEL ZnNa-M and OKCEL Ag-L) were tested by a dilution method against a spectrum of microbial strains: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Bacillus licheniformis, Aspergillus niger, Penicillium chrysogenum, Rhizopus oryzae, Scopulariopsis brevicaulis, Candida albicans and Candida tropicalis. OKCEL Ag-L exhibited antimicrobial activity in the range 0.1-3.5% w/v against all the bacteria and fungi involved in this study. Strong inhibition by OKCEL ZnNa-M was observed for Staphylococcus epidermidis, Bacillus licheniformis, Rhizopus oryzae, Candida albicans and Candida tropicalis in the range 0.5-2.0% w/v. Antimicrobial effects of oxidized cellulose and its salts in textile form were investigated by a diffusion and dilution method against the spectrum of above-cited microbial strains extended by Clostridium perfringens. Generally, OKCEL Ag-T, OKCEL Zn-T and OKCEL H-T showed high antimicrobial activity against populations of Pseudomonas aeruginosa, Bacillus licheniformis and Staphylococcus epidermidis. OKCEL Zn-T was the only sample suppressing the growth of species.
The family of Nha antiporters mediating the efflux of alkali metal cations in exchange for protons across the plasma membrane is conserved in all yeast species. Yarrowia lipolytica is a dimorphic yeast, phylogenetically very distant from the model yeast Saccharomyces cerevisiae. A search in its sequenced genome revealed two genes (designated as YlNHA1 and YlNHA2) with homology to the S. cerevisiae NHA1 gene, which encodes a plasma membrane alkali metal cation/H+ antiporter. Upon heterologous expression of both YlNHA genes in S. cerevisiae, we showed that Y. lipolytica antiporters differ not only in length and sequence, but also in their affinity for individual substrates. While the YlNha1 protein mainly increased cell tolerance to potassium, YlNha2p displayed a remarkable transport capacity for sodium. Thus, Y. lipolytica is the first example of a yeast species with two plasma membrane alkali metal cation/H+ antiporters differing in their putative functions in cell physiology; cell detoxification vs. the maintenance of stable intracellular pH, potassium content and cell volume.
- MeSH
- antiportéry metabolismus MeSH
- buněčná membrána metabolismus MeSH
- časové faktory MeSH
- draslík metabolismus MeSH
- exprese genu MeSH
- financování organizované MeSH
- fungální proteiny metabolismus MeSH
- rekombinantní fúzní proteiny metabolismus MeSH
- Saccharomyces cerevisiae cytologie MeSH
- sekvenční analýza proteinů MeSH
- sodík metabolismus MeSH
- soli farmakologie MeSH
- transport proteinů MeSH
- Yarrowia fyziologie metabolismus účinky léků MeSH
We have used CD spectroscopy, polyacrylamide gel electrophoresis, and UV absorption spectroscopy to study conformational properties of DNA fragments containing (CCA)n and (TGG)n repeats, which are the most length-polymorphic microsatellite sequences of the human genome. The (CCA)n fragments are random single strands at neutral and alkaline pH but they fold into intramolecular intercalated cytosine tetraplexes at mildly acid pH values. More acid values stabilize intermolecular tetraplex formation. The behavior of (TGG)n repeats is more complex. They form hairpins or antiparallel homoduplexes in low salt solutions which, however, are transformed into parallel-stranded guanine tetraplexes at physiological KCl concentrations. Their molecularity depends on the repeat number: (TGG)4 associates into an octameric complex, (TGG)8 forms tetramolecular complexes. (TGG)n with odd repeat numbers (5, 7, and 9) generate bimolecular and tetramolecular tetraplexes. The only (TGG)7 folds into an intramolecular tetraplex at low KCl concentrations, which is antiparallel-stranded. Moreover, the (TGG)(n) fragments provide various mutually slipped conformers whose population increases with salt concentration and with the increasing repeat number. However, the self-structures of both strands disappear in the presence of the complementary strand because both (TGG)n and (CCA)n prefer to associate into the classical heteroduplex. We suppose that the extreme conformational variability of the DNA strands stands behind the length polymorphism which the (CCA)n/(TGG)n repeats exhibit in the human genome.
- MeSH
- chlorid draselný farmakologie MeSH
- cirkulární dichroismus MeSH
- cytosin chemie MeSH
- denaturace nukleových kyselin MeSH
- DNA chemie MeSH
- EDTA chemie MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- financování organizované MeSH
- genom lidský MeSH
- koncentrace vodíkových iontů MeSH
- konformace nukleové kyseliny MeSH
- konformace proteinů MeSH
- lidé MeSH
- mikrosatelitní repetice MeSH
- oligonukleotidy MeSH
- polymorfismus genetický MeSH
- soli farmakologie MeSH
- spektrofotometrie MeSH
- teplota MeSH
- trinukleotidové repetice MeSH
- ultrafialové záření MeSH
- Check Tag
- lidé MeSH
