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1.
It was demonstrated that the nuclear matrix of rat liver possesses the protease activity. The specific activity of nuclear matrix proteases exceeds that of intact nuclei 7-fold. The optimum activity of nuclear matrix proteases is observed at pH 8-9. The protease activity of the nuclear matrix is inhibited by p-chloromercuribenzoate, N-ethylmaleimide, EDTA, phenylmethylsulfonyl fluoride. This suggests that thiol, serine and metalloproteases are associated with the nuclear matrix. 相似文献
2.
mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
相似文献
3.
N. V. Pimenov V. N. Egorov T. A. Kanapatskii T. V. Malakhova Yu. G. Artemov P. A. Sigalevich L. V. Malakhova 《Microbiology》2013,82(5):618-627
The rates of microbial processes of sulfate reduction and of the methane cycle were measured in the bottom sediments of the Sevastopol basin, where seeps of gaseous methane have been previously found. Typically for marine environments, sulfate reduction played the major role in the terminal phase of decomposition of organic matter (OM) in reduced sediments of this area. The rate of this process depended on the amount of available OM. The rate of methanogenesis in the sediments increased with depth, peaking in the subsurface horizons, where decreased sulfate concentration was detected in the pore water. The highest rates of sulfate-dependent anaerobic methane oxidation were found close to the methane-sulfate transition zone as is typical of most investigated marine sediments. The data on the carbon isotopic composition of gaseous methane from the seeps and dissolved CH4 from the bottom sediments, as well as on the rates of microbial methanogenesis and methane oxidation indicate that the activity of the methane seeps results from accumulation of biogenic methane in the cavities of the underlying geological structures with subsequent periodic release of methane bubbles into the water column. 相似文献
4.
Oshkin I. Yu. Danilova O. V. Suleimanov R. Z. Tikhonova E. N. Malakhova T. V. Murashova I. A. Pimenov N. V. Dedysh S. N. 《Microbiology》2021,90(5):588-597
Microbiology - The technology of single-cell protein production from natural gas is based on using thermotolerant methanotrophic bacteria with high growth rates on methane. So far, the spectrum of... 相似文献
5.
Tikhonova E. N. Tarnovetskii I. Yu. Malakhova T. V. Gulin M. B. Merkel A. Yu. Pimenov N. V. 《Microbiology》2020,89(6):740-749
Microbiology - Methane oxidation rates and diversity of methane-oxidizing microorganisms in the upper sediment layers of the Crimean Peninsula coastal regions (Black Sea) were investigated.... 相似文献
6.
Komissarov A. B. Sergeeva M. V. Mozhaeva E. V. Eshchenko N. V. Vasilieva A. D. Vasilyev K. A. Medvedev S. P. Malakhova A. A. Balakhonova E. A. Malanin S. Yu. Grigoryeva T. V. Zhuravlev E. S. Semenov D. V. Richter V. A. Stepanov G. A. 《Russian Journal of Bioorganic Chemistry》2019,45(6):749-757
Russian Journal of Bioorganic Chemistry - Interferon-regulated factors play a central role in the activation of the innate immune response. The interferon-regulatory factor 7 (IRF7) is one of the... 相似文献
7.
Heat-induced formation of reactive oxygen species and 8-oxoguanine, a biomarker of damage to DNA 总被引:5,自引:0,他引:5 下载免费PDF全文
Heat-induced formation of 8-oxoguanine was demonstrated in DNA solutions in 10–3 M phosphate buffer, pH 6.8, by enzyme-linked immunosorbent assays using monoclonal antibodies against 8-oxoguanine. A radiation-chemical yield of 3.7 × 10–2 µmol J–1 for 8-oxoguanine production in DNA upon γ-irradiation was used as an adequate standard for quantitation of 8-oxoguanine in whole DNA. The initial yield of heat-induced 8-oxoguanine exhibits first order kinetics. The rate constants for 8-oxoguanine formation were determined at elevated temperatures; the activation energy was found to be 27 ± 2 kcal/mol. Extrapolation to 37°C gave a value of k37 = 4.7 × 10–10 s–1. Heat-induced 8-oxoguanine formation and depurination of guanine and adenine show similarities of the processes, which implies that heat-mediated generation of reactive oxygen species (ROS) should occur. Heat-induced production of H2O2 in phosphate buffer was shown. The sequence of reactions of thermally mediated ROS formation have been established: activation of dissolved oxygen to the singlet state, generation of superoxide radicals and their dismutation to H2O2. Gas saturation (O2, N2 and Ar), D2O, scavengers of 1O2, O2–• and OH• radicals and metal chelators influenced heat-induced 8-oxoguanine formation as they affected thermal ROS generation. These findings imply that heat acts via ROS attack leading to oxidative damage to DNA. 相似文献
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10.
SUMO fusions and SUMO-specific protease for efficient expression and purification of proteins 总被引:9,自引:0,他引:9
Malakhov MP Mattern MR Malakhova OA Drinker M Weeks SD Butt TR 《Journal of structural and functional genomics》2004,5(1-2):75-86
SUMO (small ubiquitin-related modifier) modulates protein structure and function by covalently binding to the lysine side chains of the target proteins. Yeast cells contain two SUMO proteases, Ulp1 and Ulp2, that cleave sumoylated proteins in the cell. Ulp1 (SUMO protease 1) processes the SUMO precursor to its mature form and also de-conjugates SUMO from side chain lysines of target proteins. Here we demonstrate that attachment of SUMO to the N-terminus of under-expressed proteins dramatically enhances their expression in E. coli. SUMO protease 1 was able to cleave a variety of SUMO fusions robustly and with impeccable specificity. Purified recombinant SUMO-GFPs were efficiently cleaved when any amino acid, except proline, was in the+1 position of the cleavage site. The enzyme was active over a broad range of buffer and temperature conditions. Purification of certain recombinant proteins is accomplished by production of Ub-fusions from which Ub can be subsequently removed by de-ubiquitinating enzymes (DUBs). However, DUBs are unstable enzymes that are difficult to produce and inexpensive DUBs are not available commercially. Our findings demonstrate that SUMO protease 1/SUMO-fusion system may be preferable to DUB/Ub-fusion. Enhanced expression and solubility of proteins fused to SUMO combined with broad specificity and highly efficient cleavage properties of the SUMO protease 1 indicates that SUMO-fusion technology will become a useful tool in purification of proteins and peptides. 相似文献