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51.
We measured the nucleotide turnover rate of myosin in tarantula leg muscle fibers by observing single turnovers of the fluorescent nucleotide analog 2′-/3′-O-(N′-methylanthraniloyl)adenosine-5′-O-triphosphate, as monitored by the decrease in fluorescence when 2′-/3′-O-(N′-methylanthraniloyl)adenosine-5′-O-triphosphate (mantATP) is replaced by ATP in a chase experiment. We find a multiexponential process with approximately two-thirds of the myosin showing a very slow nucleotide turnover time constant (∼ 30 min). This slow-turnover state is termed the super-relaxed state (SRX). If fibers are incubated in 2′-/3′-O-(N′-methylanthraniloyl)adenosine-5′-O-diphosphate and chased with ADP, the SRX is not seen, indicating that trinucleotide-relaxed myosins are responsible for the SRX. Phosphorylation of the myosin regulatory light chain eliminates the fraction of myosin with a very long lifetime. The data imply that the very long-lived SRX in tarantula fibers is a highly novel adaptation for energy conservation in an animal that spends extremely long periods of time in a quiescent state employing a lie-in-wait hunting strategy. The presence of the SRX measured here correlates well with the binding of myosin heads to the core of the thick filament in a structure known as the “interacting-heads motif,” observed previously by electron microscopy. Both the structural array and the long-lived SRX require relaxed filaments or relaxed fibers, both are lost upon myosin phosphorylation, and both appear to be more stable in tarantula than in vertebrate skeletal or vertebrate cardiac preparations. 相似文献
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Discovery of a New Class of Inhibitors of Vaccinia Virus Based on (−)‐Borneol from Abies sibirica and (+)‐Camphor 下载免费PDF全文
Anastasiya S. Sokolova Olga I. Yarovaya Nikolay I. Bormotov Larisa N. Shishkina Nariman F. Salakhutdinov 《化学与生物多样性》2018,15(9)
A series of the bornyl ester/amide derivatives with N‐containing heterocycles were designed and synthesized as vaccinia virus (VV) inhibitors. Bioassay results showed that among the designed compounds, derivatives 6 , 13 , 14 , 34 , 36 and 37 showed the best inhibitory activity against VV with the IC50 values of 12.9, 17.9, 3.4, 2.5, 12.5 and 7.5 μm , respectively, and good cytotoxicity. The primary structure–activity relationship (SAR) study suggested that the combination of a saturated N‐heterocycle, such as morpholine or 4‐methylpiperidine, and a 1,7,7‐trimethylbicyclo[2.2.1]heptane scaffold was favorable for antiviral activity. 相似文献
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Aleksei Menzorov Inna Pristyazhnyuk Helen Kizilova Anastasia Yunusova Nariman Battulin Antonina Zhelezova Aleftina Golubitsa Oleg Serov 《Cytotechnology》2016,68(1):61-71
Mouse embryonic stem (ES) cells are widely used in early development studies and for transgenic animal production; however, a stable karyotype is a prerequisite for their use. We derived 32 ES cell lines of outbred mice (129 × BALB (1B), C57BL × 1B, and DD × 1B F1 hybrids). Pluripotency was assessed by utilizing stem-cell-marker gene expression, teratoma formation assays and the formation of chimeras. It was shown that only 21 of the 32 ES cell lines had a diploid modal number of chromosomes of 40. In these lines, the percentage of diploid cells varied from 30.3 to 78.9 %, and trisomy of chromosomes 1, 8 and 11 was observed in some cells in 16.7, 36.7 and 20.0 % of the diploid ES cell lines, respectively. Some cells had trisomy of chromosomes 6, 9, 12, 14, 18 and 19. In situ hybridization with an X chromosome paint probe revealed that 7 of the 11 XX-cell lines had X chromosome rearrangements in some cells. Analysis of the methylation status of the Dlk1-Dio3 locus showed that imprinting was altered in 4 of the 18 ES cell lines. Thus, mouse ES cell lines are prone to chromosome abnormalities even at early passages. Therefore, routine cytogenetic and imprinting analyses are necessary for ES cell characterization. 相似文献
54.
Ghoneum M Badr El-Din NK Noaman E Tolentino L 《Cancer immunology, immunotherapy : CII》2008,57(4):581-592
This study was undertaken to evaluate the effectiveness and mechanisms of anti-tumor activity of Baker’s yeast, Saccharomyces cerevisiae, in immunocompetent mice. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich Ascites Carcinoma
(EAC) cells. At day 8, mice bearing Solid Ehrlich Carcinoma tumor (SEC) were intratumorally (IT) injected with killed S. cerevisiae (10 × 106 and 20 × 106 cells) for 35 days. Histopathology of yeast-treated mice showed extensive tumor degeneration, apoptosis, and ischemic (coagulative)
and liquefactive necrosis. These changes are associated with a tumor growth curve that demonstrates a significant antitumor
response that peaked at 35 days. Yeast treatment (20 × 106 cells) three times a week resulted in a significant decrease in tumor volume (TV) (67.1%, P < 0.01) as compared to PBS-treated mice. The effect was determined to be dependent on dose and frequency. Yeast administered
three and two times per week induced significant decrease in TV as early as 9 and 25 days post-treatment, respectively. Administration
of yeast significantly enhanced the recruitment of leukocytes, including macrophages, into the tumors and triggered apoptosis
in SEC cells as determined by flow cytometry (78.6%, P < 0.01) at 20 × 106 cells, as compared to PBS-treated mice (42.6%). In addition, yeast treatment elevated TNF-α and IFN-γ plasma levels and lowered
the elevated IL-10 levels. No adverse side effects from the yeast treatment were observed, including feeding/drinking cycle
and life activity patterns. Indeed, yeast-treated mice showed significant final body weight gain (+21.5%, P < 0.01) at day 35. These data may have clinical implications for the treatment of solid cancer with yeast, which is known
to be safe for human consumption. 相似文献
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Oleg I. Artyushin Elena V. Sharova Natalya M. Vinogradova Galina K. Genkina Aleksandra A. Moiseeva Zinaida S. Klemenkova Iana R. Orshanskaya Anna A. Shtro Renata A. Kadyrova Vladimir V. Zarubaev Olga I. Yarovaya Nariman F. Salakhutdinov Valery K. Brel 《Bioorganic & medicinal chemistry letters》2017,27(10):2181-2184
A series of seventeen tetrazole derivatives of 1,7,7-trimethyl-[2.2.1]bicycloheptane were synthesized using click chemistry methodology and characterized by spectral data. Studies of cytotoxicity and in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells of the compounds obtained were performed. The structure-activity relationship analysis suggests that to possess virus-inhibiting activity, the compounds of this group should bear oxygen atom with a short linker (C2-C4), either as a hydroxyl group (18, 19, 29), keto-group (21) or as a part of a heterocycle (24). These compounds demonstrated low cytotoxicity along with high anti-viral activity. 相似文献
56.
Tatyana M. Khomenko Vladimir V. Zarubaev Iana R. Orshanskaya Renata A. Kadyrova Victoria A. Sannikova Dina V. Korchagina Konstantin P. Volcho Nariman F. Salakhutdinov 《Bioorganic & medicinal chemistry letters》2017,27(13):2920-2925
Compounds simultaneously carrying the monoterpene and coumarin moieties have been tested for cytotoxicity and inhibition of activity against influenza virus A/California/07/09 (H1N1)pdm09. The structure of substituents in the coumarin framework, as well as the structure and the absolute configuration of the monoterpenoid moiety, are shown to significantly influence the anti-influenza activity and cytotoxicity of the compounds under study. The compounds with a bicyclic pinane framework exhibit the highest selectivity indices (the ratios between the cytotoxicity and the active dose). The derivative of (?)-myrtenol 15c, which is characterized by promising activity, low cytotoxicity, and synthetic accessibility, has the greatest potential among this group of compounds. It exhibited the highest activity when added to the infected cell culture at early stages of viral reproduction. 相似文献
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Anti-Helicobacter pylori activities of six Iranian plants 总被引:1,自引:0,他引:1
BACKGROUND: Helicobacter pylori is the major worldwide cause of bacterial gastrointestinal infections in adults and children. Antibiotic therapy and a combination of two or three drugs have been widely used to eradicate these infections. However, development of drug resistance in bacteria calls for new sources of drugs, and plants seem to be a logical source of new antibacterial compounds. METHODS: The anti-H. pylori activities of six native Iranian plants (Glycyrrhiza aspera, Juglans regia, Ligustrum vulgare, Thymus kotschyanus, Trachyspermum copticum and Xanthium brasilicum) and seven antibiotics were determined against 70 clinical isolates from children using the disk susceptibility assay. Minimum inhibitory concentrations were also measured for the biologically active extracts. One extract with the best anti-H. pylori activity was fractionated by silica gel and thin layer chromatography and the active compounds were identified by hydrogen nuclear magnetic resonance ((1)HNMR) spectroscopy. RESULTS: All plant extracts showed anti-H. pylori activity by the disk sensitivity method, but the most active extracts were those from X. brasilicum and T. copticum. In fact, the anti-H. pylori activities of the two extracts were superior to the disk antibiotic susceptibility profile. Minimum inhibitory concentrations were within the range of 31.25-250 micro g/ml. Fractionation and chemical identification of the extract from X. brasilicum showed the presence of two substances, a flavonoid and a xanthanolide. CONCLUSIONS: Due to the rise in antibiotic resistance, new sources of anti-H. pylori drugs are needed. The use of medicinal plants and/or their chemical components may have potential benefit in eradicating such problems. 相似文献
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Dmitriy N. Sokolov Vladimir V. Zarubaev Anna A. Shtro Marina P. Polovinka Olga A. Luzina Nina I. Komarova Nariman F. Salakhutdinov Oleg I. Kiselev 《Bioorganic & medicinal chemistry letters》2012,22(23):7060-7064
Influenza is a widespread respiratory infection. Every year it causes epidemics, quickly spreading from country to country, or even pandemics, involving a significant part of the human population of the earth. Being a highly variable infection, influenza easy accumulates the resistance mutations to many antivirals.Usnic acid, a dibenzofuran originally isolated from lichens belongs to the secondary metabolites and has a broad spectrum of biological activity. In humans, it can act as an anti-inflammatory, antimitotic, antineoplasic, antibacterial, and antimycotic agent. In this work we studied for the first time the antiviral activity of usnic acid and its derivatives against the pandemic influenza virus A(H1N1)pdm09. A total of 26 compounds representing (+) and (?) isomers of usnic acid and their derivates were tested for cytotoxicity and anti-viral activity in MDCK cells by microtetrazolium test and virus yield assay, respectively. Based on the results obtained, 50% cytotoxic dose (CTD50) and 50% effective dose (ED50) and selectivity index (SI) were calculated for each compound. Eleven of them were found to have SI higher than 10 (highest value 37.3). Absolute configuration was shown to have critical significance for the anti-viral activity. With minor exceptions, in the pair of enantiomers, (?)-usnic acid was more active comparing to (+)-isomer, but its biological activity was reversed after the usnic acid was chemically modified. Based on the obtained results, derivatives of usnic acid should be considered as prospective compounds for further optimization as anti-influenza substances. 相似文献
59.
Goodarzi Golnoosh Setayesh Leila Fadaei Reza Khamseh Mohammad Ebrahim Aliakbari Fereshteh Hosseini Jalil Moradi Nariman 《Molecular biology reports》2021,48(7):5443-5450
Molecular Biology Reports - Adipokines play an important role in the development of type 2 diabetes mellitus (T2DM) and its complications like nephropathy. Asprosin is a newly discovered adipokine... 相似文献
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