30 research outputs found

    Nonlinear changes in the activity of the oxygen-dependent demethylase system in Rhodococcus erythropolis cells in the presence of low and very low doses of formaldehyde

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    The effect of exogenous, highly diluted formaldehyde on the rate of demethylation/re-methylation of veratric acid by the bacteria Rhodococcus erythropolis was studied using electrophoretic and microscopic techniques. The activity of 4-O-demethylase, responsible for accumulation of vanillic acid, and the levels of veratric and vanillic acids were determined using capillary electrophoresis. Formaldehyde was serially diluted at 1:100 ratios, and the total number of iterations was 20. After incubation of the successive dilutions of formaldehyde with the bacteria, demethylase activity oscillated in a sinusoidal manner. It was established using capillary electrophoresis that methylation of vanillic acid to veratric acid occurred at a double rate, as shown by the doubled fluctuation in the concentration of veratrate. There were also changes in the NADH oxidase activity, which is associated with methylation processes. Microscopic observations revealed the presence of numerous enlarged vacuoles in bacterial cells during the accumulation of large amounts of vanillic acid, and their disappearance together with a decrease in 4-O-demethylase activity. The presented results give evidence for the ability of living cells to detect the presence of submolecular concentrations of biological effectors in their environment and provide a basis for a scientific explanation of the law of hormesis and the therapeutic effect of homeopathic dilutions

    Influence of very low doses of mediators on fungal laccase activity - nonlinearity beyond imagination

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    Laccase, an enzyme responsible for aerobic transformations of natural phenolics, in industrial applications requires the presence of low-molecular substances known as mediators, which accelerate oxidation processes. However, the use of mediators is limited by their toxicity and the high costs of exploitation. The activation of extracellular laccase in growing fungal culture with highly diluted mediators, ABTS and HBT is described. Two high laccase-producing fungal strains, Trametes versicolor and Cerrena unicolor, were used in this study as a source of enzyme. Selected dilutions of the mediators significantly increased the activity of extracellular laccase during 14 days of cultivation what was distinctly visible in PAGE technique and in colorimetric tests. The same mediator dilutions increased demethylation properties of laccase, which was demonstrated during incubation of enzyme with veratric acid. It was established that the activation effect was assigned to specific dilutions of mediators. Our dose-response dilution process smoothly passes into the range of action of homeopathic dilutions and is of interest for homeopaths

    Quantitative Analysis of Histone Modifications: Formaldehyde Is a Source of Pathological N6-Formyllysine That Is Refractory to Histone Deacetylases

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    Aberrant protein modifications play an important role in the pathophysiology of many human diseases, in terms of both dysfunction of physiological modifications and the formation of pathological modifications by reaction of proteins with endogenous electrophiles. Recent studies have identified a chemical homolog of lysine acetylation, N[superscript 6]-formyllysine, as an abundant modification of histone and chromatin proteins, one possible source of which is the reaction of lysine with 3′-formylphosphate residues from DNA oxidation. Using a new liquid chromatography-coupled to tandem mass spectrometry method to quantify all N[superscript 6]-methyl-, -acetyl- and -formyl-lysine modifications, we now report that endogenous formaldehyde is a major source of N[superscript 6]-formyllysine and that this adduct is widespread among cellular proteins in all compartments. N[superscript 6]-formyllysine was evenly distributed among different classes of histone proteins from human TK6 cells at 1–4 modifications per 10[superscript 4] lysines, which contrasted strongly with lysine acetylation and mono-, di-, and tri-methylation levels of 1.5-380, 5-870, 0-1400, and 0-390 per 10[superscript 4] lysines, respectively. While isotope labeling studies revealed that lysine demethylation is not a source of N[superscript 6]-formyllysine in histones, formaldehyde exposure was observed to cause a dose-dependent increase in N[superscript 6]-formyllysine, with use of [[superscript 13]C,[superscript 2]H[subscript 2]]-formaldehyde revealing unchanged levels of adducts derived from endogenous sources. Inhibitors of class I and class II histone deacetylases did not affect the levels of N[superscript 6]-formyllysine in TK6 cells, and the class III histone deacetylase, SIRT1, had minimal activity (<10%) with a peptide substrate containing the formyl adduct. These data suggest that N[superscript 6]-formyllysine is refractory to removal by histone deacetylases, which supports the idea that this abundant protein modification could interfere with normal regulation of gene expression if it arises at conserved sites of physiological protein secondary modification

    New terpenoids in cultivated and wild chamomile (in vivo and in vitro)

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    The effect of Chamomilla recutita (L.) Rauschert is made up by several groups of active substances, among which terpenoids in the inflorescences are of greatest importance. Among cultivated species, the Hungarian BK-2 contains more chamazulene in its essential oil than the German Degumil type, which is mainly cultivated for its (-)-alpha-bisabolol. Both components have important antiinflammatory activities. Among wild chamomile populations in Hungary, a population was found in the area of Szabadkigyos containing significant amounts-on average 48%-of (-)-alpha-bisabolol in its inflorescence oil. In vitro cultures were made from this population to obtain propagation material containing a high number of active substances. The intact roots contained no (-)-alpha-bisabolol but the sesquiterpene alcohol beta-eudesmol as new compound was identified by our group. Sterile plantlets, cultured in vitro, were multiplied for phytochernical investigations. Pharmacologically important compounds of the essential oils were followed in great detail. The amount of in vitro cultured terpenoids and polyin compounds was compared with that of in vivo plants. These volatile compounds were identified by comparing their retention times with those of authentic standards, essential oils of known composition and peak enrichment. The confirmation of identity was done by comparison of their mass spectra with those reported in the literature and reference compounds. The percentage evaluation of each component was made by area normalisation. Gas chromatography (GC) and mass spectrometry (MS) showed that sterile chamomile cultures generated the most important terpenoid and polyin compounds characteristic of the parent plant. We identified germacrene-D, berkheyaradulene, 4-(2', 4, 4'-trimethyl-bicyclo[4.1.0]hept-2'-en-3'-yl)-3-buten-2-one, geranyl-isovalerate and cedrol as new components in these sterile cultures. (C) 2003 Elsevier B.V. All rights reserved
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