3,5-Dinitrobenzylsulfanyl tetrazoles and 1,3,4-oxadiazoles, previously identified as having high in vitro activities against both replicating and nonreplicating mycobacteria and favorable cytotoxicity and genotoxicity profiles were investigated. First we demonstrated that these compounds act in a deazaflavin-dependent nitroreduction pathway and thus require a nitro group for their activity. Second, we confirmed the necessity of both nitro groups for antimycobacterial activity through extensive structure-activity relationship studies using 32 structural types of analogues, each in a five-membered series. Only the analogues with shifted nitro groups, namely, 2,5-dinitrobenzylsulfanyl oxadiazoles and tetrazoles, maintained high antimycobacterial activity but in this case mainly as a result of DprE1 inhibition. However, these analogues also showed increased toxicity to the mammalian cell line. Thus, both nitro groups in 3,5-dinitrobenzylsulfanyl-containing antimycobacterial agents remain essential for their high efficacy, and further efforts should be directed at finding ways to address the possible toxicity and solubility issues, for example, by targeted delivery.
- MeSH
- antituberkulotika farmakologie chemie MeSH
- mikrobiální testy citlivosti MeSH
- Mycobacterium tuberculosis * MeSH
- nitroreduktasy MeSH
- oxadiazoly farmakologie chemie MeSH
- savci MeSH
- tetrazoly farmakologie chemie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Trichomoniasis, a globally distributed sexually transmitted infection, is caused by the urogenital parasite Trichomonas vaginalis Donné, 1836 affecting both women and men. The treatment of choice is metronidazole (MTZ). In the present study, 15 samples of vaginal discharge and urine were analysed by sequencing nitroreductase genes (ntr4 and ntr6). An in silico model was structured to illustrate the location of point mutations (PM) in the protein. The ntr4 gene presented four PMs: G76C (10/10), C213G (9/10), C318A (5/10) and G424A (1/10), while the ntr6 gene had eight PMs; G593A (13/13) the most frequent, G72T and G627C, both in 8/13. The PM C213G and A438T generated a stop codon causing a truncated nitroreductase 4 and 6 protein. Docking analysis demonstrated that some models had a decrease in binding affinity to MTZ (p < 0.0001). A high frequency of mutations was observed in the samples analysed that could be associated with resistance to MTZ in Chile.
- MeSH
- antiprotozoální látky farmakologie MeSH
- bodová mutace * MeSH
- léková rezistence * MeSH
- lidé MeSH
- metronidazol * farmakologie MeSH
- nitroreduktasy * genetika metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- trichomonádová vaginitida parazitologie MeSH
- Trichomonas vaginalis * genetika účinky léků enzymologie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Chile MeSH
Heterologously expressed and purified azoreductase enzyme from facultative Klebsiella pneumoniae was used to degrade sulphonated azo dye. Methyl orange (MO) was used as the model dye to study the azo dye decolorization potential of the purified enzyme at different conditions. The enzyme had maximum activity at 40 °C and pH 8.0. The enzyme was observed to be thermo-stable as some enzyme activity was retained even at 80 °C. The apparent kinetic parameters, i.e., appKm and appVmax, for azoreductase using MO as a substrate were found to be 17.18 μM and 0.08/min, respectively. The purified enzyme was able to decolorize approximately 83% of MO (20 μM) within 10 min in the presence of NADH. Thus, efficient decolorization of MO was observed by the purified enzyme. The recombinant enzyme was purified approximately 18-fold with 46% yield at the end of four steps of the purification process. Enzyme was present in a tetrameric structure as confirmed by the volume at which protein was eluted in gel filtration chromatography, and the monomeric molecular mass of enzyme was found to be 23 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The dye degradation efficiency of azoreductase cloned from Klebsiella pneumoniae and purified from recombinant Escherichia coli was observed to be much higher as compared with the efficiencies of the reported azoreductases from other bacterial strains. In the present study, we report the purification and characterization of the azoreductase cloned from Klebsiella pneumoniae and expressed in Escherichia coli.
- MeSH
- azosloučeniny metabolismus MeSH
- bakteriální proteiny chemie genetika izolace a purifikace metabolismus MeSH
- barvicí látky metabolismus MeSH
- biodegradace MeSH
- Escherichia coli genetika metabolismus MeSH
- kinetika MeSH
- Klebsiella pneumoniae enzymologie genetika MeSH
- koncentrace vodíkových iontů MeSH
- molekulová hmotnost MeSH
- nitroreduktasy chemie genetika izolace a purifikace metabolismus MeSH
- rekombinantní proteiny chemie genetika izolace a purifikace metabolismus MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
A systematic study on the lack of dissimilatory nitrate reductase (NAR) properties in Halomonas strains had been reported so far. The effects of different factors on Halomonas sp. B01 NAR activity were investigated. The salt tolerance of NAR was characterized. The denitrification process under high salt conditions was reported. Halomonas sp. B01 expressed membrane-bound NAR under induced culture by nitrate. The optimum pH of the enzyme reaction system was 8, and the optimum temperature was 30 °C. The mRNA expression abundance of narH in NAR encoding gene was highest in the 60 g/L NaCl inducing matrix. The NaCl concentration of optimum growth and induction of NAR were both 60 g/L. The ectoine added to the NAR vitro enzyme reaction system could maintain NAR activity under high NaCl concentration. In the range of 0-60 g/L NaCl, the NAR activity was stable at 17.7 (± 0.3) U/mg. The denitrification was performed by Halomonas sp. B01 at 60 g/L NaCl, and the denitrification rate reached 97.1% at 24 h. This study reveals for the first time the NAR properties of Halomonas strains, which provides a theoretical and technical basis for the nitrogen removal of high-salt nitrogenous wastewater using this strain.
- MeSH
- aminokyseliny diaminové metabolismus MeSH
- bakteriální proteiny genetika metabolismus MeSH
- buněčná membrána metabolismus MeSH
- chlorid sodný metabolismus MeSH
- denitrifikace MeSH
- dusičnany metabolismus MeSH
- Halomonas enzymologie genetika růst a vývoj metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- nitrátreduktasa genetika metabolismus MeSH
- regulace genové exprese u bakterií MeSH
- teplota MeSH
- tolerance k soli * MeSH
- Publikační typ
- časopisecké články MeSH
In this year there is the 40th anniversary of the first publication of plant nitric oxide (NO) emission by Lowell Klepper. In the decades since then numerous milestone discoveries have revealed that NO is a multifunctional molecule in plant cells regulating both plant development and stress responses. Apropos of the anniversary, these authors aim to review and discuss the developments of past concepts in plant NO research related to NO metabolism, NO signaling, NO's action in plant growth and in stress responses and NO's interactions with other reactive compounds. Despite the long-lasting research efforts and the accumulating experimental evidences numerous questions are still needed to be answered, thus future challenges and research directions have also been drawn up.
- MeSH
- fyziologie rostlin * MeSH
- nitrátreduktasa fyziologie MeSH
- nitrosativní stres fyziologie MeSH
- oxid dusnatý metabolismus MeSH
- rostliny metabolismus MeSH
- rozmnožování fyziologie MeSH
- signální transdukce fyziologie MeSH
- symbióza fyziologie MeSH
- synthasa oxidu dusnatého fyziologie MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The objective of our concise review is to elaborate an evidence-based integrative medicine model that incorporates functional linkages of key aspects of cortically-driven mind-body training procedures to biochemical and molecular processes driving enhanced cellular bioenergetics and whole-body metabolic advantage. This entails the adoption of a unified biological systems approach to selectively elucidate basic biochemical and molecular events responsible for achieving physiological relaxation of complex cellular structures. We provide accumulated evidence in support of the potential synergy of voluntary breathing exercises in combination with meditation and/or complementary cognitive tasks to promote medically beneficial enhancements in whole-body relaxation, anti-stress mechanisms, and restorative sleep. Accordingly, we propose that the widespread metabolic and physiological advantages emanating from a sustained series of complementary mind-body exercises will ultimately engender enhanced functional integration of cortical and limbic areas controlling voluntary respiratory processes with autonomic brainstem neural pattern generators. Finally, a unified mechanism is proposed that links behaviorally-mediated enhancements of whole-body metabolic advantage to optimization of synchronous regulation of mitochondrial oxygen utilization via recycling of nitrite and nitric oxide by iron-sulfur centers of coupled respiratory complexes and nitrite reductases.
- MeSH
- dechová cvičení metody psychologie MeSH
- dýchání MeSH
- energetický metabolismus fyziologie MeSH
- lidé MeSH
- meditace metody psychologie MeSH
- mitochondrie metabolismus fyziologie MeSH
- nitritreduktasy metabolismus MeSH
- oxid dusnatý metabolismus MeSH
- relaxační terapie metody psychologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Environmental cues modulate the balance of carbon (C) and nitrogen (N) which are essential elements for plant metabolism and growth. In Arabidopsis, photochemical efficiency of PSII, phosphorylation status and localization of many enzymes, and the level of total soluble sugars were affected by an unbalanced C/N ratio. Since differences in C/N affect these parameters, here we checked whether different sources of N have different effects when a high C/N ratio is imposed. NO3- and NH4+ were separately provided in C/N medium. We investigated the effects on photochemical efficiency of PSII, the level of total soluble sugars and nitrate reductase activity under stressful C/N conditions compared with control conditions. We found that treated plants accumulated more total soluble sugars when compared with control. Photochemical efficiency of PSII did not show significant differences between the two sources of nitrogen after 24 h. The actual nitrate reductase activity was the result of a combination of activity, activation state and protein level. This activity constantly decreased starting from time zero in control conditions; in contrast, the actual nitrate reductase activity showed a peak at 2 h after treatment with NO3-, and at 30 min with NH4+. This, according to the level of total soluble sugars, can be explained by the existence of a cross-talk between the sugars in excess and low nitrate in the medium that blocks the activity of nitrate reductase in stressful sugar conditions until the plant is adapted to the stress.
- MeSH
- amoniové sloučeniny metabolismus MeSH
- Arabidopsis enzymologie genetika MeSH
- dusičnany metabolismus MeSH
- dusík metabolismus MeSH
- fosforylace MeSH
- nitrátreduktasa genetika metabolismus MeSH
- proteiny 14-3-3 genetika metabolismus MeSH
- regulace genové exprese u rostlin * MeSH
- uhlík metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
During plant growth and defense, cell cycle activity needs to be coordinated with cell wall integrity. Little is known about how this coordination is achieved. Here, we investigated coordination in Arabidopsis thaliana seedlings by studying the impact of cell wall damage (CWD, caused by cellulose biosynthesis inhibition) on cytokinin homeostasis, cell cycle gene expression and cell shape in root tips. CWD inhibited cell cycle gene expression and increased transition zone cell width in an osmosensitive manner. These results were correlated with CWD-induced, osmosensitive changes in cytokinin homeostasis. Expression of CYTOKININ OXIDASE/DEHYDROGENASE 2 and 3 (CKX2, CKX3), which encode cytokinin-degrading enzymes, was induced by CWD and reduced by osmoticum treatment. In nitrate reductase1 nitrate reductase2 (nia1 nia2) seedlings, CKX2 and CKX3 transcript levels were not increased and cell cycle gene expression was not repressed by CWD. Moreover, established CWD-induced responses, such as jasmonic acid, salicylic acid and lignin production, were also absent, implying a central role of NIA1/2-mediated processes in regulation of CWD responses. These results suggest that CWD enhances cytokinin degradation rates through a NIA1/2-mediated process, leading to attenuation of cell cycle gene expression.
- MeSH
- Arabidopsis cytologie účinky léků genetika MeSH
- benzamidy farmakologie MeSH
- biologické modely MeSH
- buněčná stěna účinky léků metabolismus MeSH
- buněčný cyklus účinky léků genetika MeSH
- cytokininy farmakologie MeSH
- fenotyp MeSH
- homeostáza účinky léků MeSH
- kořeny rostlin cytologie účinky léků růst a vývoj MeSH
- messenger RNA genetika metabolismus MeSH
- nitrátreduktasa metabolismus MeSH
- osmóza MeSH
- proteiny huseníčku metabolismus MeSH
- regulace genové exprese u rostlin * účinky léků MeSH
- semenáček účinky léků genetika MeSH
- sorbitol farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Typical alkaloids expressed by prokaryotic and eukaryotic cells are small heterocyclic compounds containing weakly basic nitrogen groups that are critically important for mediating essential biological activities. The prototype opiate alkaloid morphine represents a low molecular mass heterocyclic compound that has been evolutionarily fashioned from a relatively restricted role as a secreted antimicrobial phytoalexin into a broad spectrum regulatory molecule. As an essential corollary, positive evolutionary pressure has driven the development of a cognate 6-transmembrane helical (TMH) domain μ3 opiate receptor that is exclusively responsive to morphine and related opiate alkaloids. A key aspect of "morphinergic" signaling mediated by μ3 opiate receptor activation is its functional coupling with regulatory pathways utilizing constitutive nitric oxide (NO) as a signaling molecule. Importantly, tonic and phasic intra-mitochondrial NO production exerts profound inhibitory effects on the rate of electron transport, H+ pumping, and O2 consumption. Given the pluripotent role of NO as a selective, temporally-defined chemical regulator of mitochondrial respiration and cellular bioenergetics, the expansion of prokaryotic denitrification systems into mitochondrial NO/nitrite cycling complexes represents a series of evolutionary modifications of existential proportions. Presently, our short review provides selective discussion of evolutionary development of morphine, opiate alkaloids, μ3 opiate receptors, and NO systems, within the perspectives of enhanced mitochondrial function, cellular bioenergetics, and the human microbiome.
- MeSH
- alkaloidy metabolismus MeSH
- biologická evoluce * MeSH
- energetický metabolismus * MeSH
- lidé MeSH
- mikrobiota * MeSH
- nitritreduktasy metabolismus MeSH
- oxid dusnatý metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The effect of Typha latifolia and its litter on density and abundance of three denitrifying genes (nirS, nirK and nosZ) were investigated in six laboratory-scale SSF CW microcosms. Results showed that the copy numbers of nirS, nirK and nosZ in wetland microcosms were ranged between 10(8)-10(9), 10(6)-10(7) and 10(7)-10(8) copies g(-1), respectively. The presence of T. latifolia encouraged the growth of nirK containing bacteria. Addition of cattail litter could greatly stimulate the growth of bacteria containing nirS and nosZ gene. Path analysis illustrated that the presence of plants and litters had no significant direct impact on denitrifying genes, while it affected the denitrifying genes via alteration of dissolved oxygen and carbon sources.
- MeSH
- Bacteria enzymologie genetika MeSH
- bakteriální geny * MeSH
- biologické modely MeSH
- biomasa * MeSH
- denitrifikace genetika MeSH
- mokřady * MeSH
- nitrátreduktasa genetika metabolismus MeSH
- RNA ribozomální 16S genetika MeSH
- rostliny mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
