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101.
Kim SW Jeong EJ Kang HS Tak JI Bang WY Heo JB Jeong JY Yoon GM Kang HY Bahk JD 《Plasmid》2006,55(2):99-113
The plasmid pJB01 (GenBank Accession No. AY425961) isolated from the pathogenic bacterium, Enterococcus faecium JC1, is 2235 base pairs in length and consists of a putative double-strand origin (dso), a single-strand origin, a counter-transcribed RNA, and three open reading frames. A comparison of a few replication factors and motifs, bind and nic regions, for replication initiation on the nucleotide sequence level revealed that it belongs to the pMV158 family among RC-replicating plasmids. A runoff DNA synthesis assay demonstrated that nicking occurred between G525 and A526, which is located on the internal loop of a putative secondary structure in the dso. Unlike all the other plasmids of the pMV158 family having two or three direct repeats, pJB01 has three non-tandem direct repeats of 5'-CAACAAA-3' separated by four nucleotides, as the RepB-binding site in the dso. Moreover, the nick site on the internal loop is located at 77 nucleotides upstream from the RepB-binding region. Irrespective of the structural difference of direct repeats from other members of the pMV158 family, we think, it is still a new member of this plasmid family. The introduction of mutations in conserved regions of RepB confirmed that RepB N-moiety is important for nicking/nick-closing activity. Within N-moiety, especially all of the motif R-III, the Y100 in R-IV and Y116 in R-V residues, played particularly critical roles in this activity, however, for its binding, both of the N- and C-moieties of RepB were needed. 相似文献
102.
Evaluation of formulations of Bacillus licheniformis for the biological control of tomato gray mold caused by Botrytis cinerea 总被引:2,自引:0,他引:2
Jae Pil Lee Seon-Woo Lee Choul Sung Kim Ji Hee Son Ju Hee Song Kwang Youll Lee Hyun Ju Kim Soon Je Jung Byung Ju Moon 《Biological Control》2006,37(3):329-337
Bacillus licheniformis N1, which has previously exhibited potential as a biological control agent, was investigated to develop a biofungicide to control the gray mold of tomato caused by Botrytis cinerea. Various formulations of B. licheniformis N1 were developed using fermentation cultures of the bacteria in Biji medium, and their ability to control gray mold on tomato plants was evaluated. The results of pot experiments led to the selection of the wettable powder formulation N1E, based on corn starch and olive oil, for evaluation of the disease control activity of this bacterium after both artificial infection of the pathogen and natural disease occurrence under production conditions. In plastic-house artificial infection experiments, a 100-fold diluted N1E treatment was found to be the optimum biofungicide spray formulation. This treatment resulted in the significant reduction of symptom development when N1E was applied before Bo. cinerea infection, but not after the infection. Both artificial infection experiments in a plastic house and natural infection experiments under production conditions revealed that the N1E significantly reduced disease severity on tomato plants and flowers. The disease control value of N1E on tomato plants was 90.5% under production conditions, as compared to the 77% conferred by a chemical fungicide, the mixture of carbendazim and diethofencarb (1:1). The prevention of flower infection by N1E resulted in increased numbers of tomato fruits on each plant. N1E treatment also had growth promotion activity, which showed the increased number of tomato fruits compared to fungicide treatment and non-treated control and the increased fruit size compared the non-treated control under production conditions. This study suggests that the corn starch-based formulation of B. licheniformis developed using liquid fermentation will be an effective tool in the biological control of tomato gray mold. 相似文献
103.
Nam SM Kim YN Yoo DY Yi SS Kim W Hwang IK Seong JK Yoon YS 《Neurochemical research》2012,37(2):253-260
In this study, we investigated the differences in calbindin D-28k (CB), calretinin, (CR) and parvalbumin (PV) immunoreactivity
in the hippocampus of Zucker diabetic fatty (ZDF) rats and Zucker lean control (ZLC) rats. In addition, we observed the effects
of hypothyroidism on the levels of immunoreactivity of these proteins in ZDF rats. For this study, 7-week-old ZDF rats were
used, and methimazole treatment was continued for 5 weeks to induce hypothyroidism. The animals were sacrificed at 12 weeks
of age. ZDF rats showed increased blood glucose levels compared to those in ZLC rats. Methimazole intervention significantly
reduced total and free T3 levels, and it ameliorated the increase of blood glucose levels in ZDF rats. In ZLC rats, CB, CR,
and PV immunoreactivity was detected in regions of the hippocampus proper. In vehicle-treated ZDF rats, CB, CR, and PV immunoreactivity
was significantly decreased in the hippocampus. However, in the methimazole-treated rats, CB, CR, and PV immunoreactivity
was significantly increased compared to that in the vehicle-treated rats. These results suggest that hypothyroidism ameliorated
the diabetes-induced reduction of CB, CR, and PV immunoreactivity in the hippocampus. 相似文献
104.
Lee JC Lee EJ Lee JH Jun SH Choi CW Kim SI Kang SS Hyun S 《FEMS microbiology letters》2012,331(1):17-24
Outer membrane vesicles (OMVs) derived from pathogenic Gram-negative bacteria are an important vehicle for delivery of effector molecules to host cells, but the production of OMVs from Klebsiella pneumoniae, an opportunistic pathogen of both nosocomial and community-acquired infections, and their role in bacterial pathogenesis have not yet been determined. In the present study, we examined the production of OMVs from K. pneumoniae and determined the induction of the innate immune response against K. pneumoniae OMVs. Klebsiella pneumoniae ATCC 13883 produced and secreted OMVs during in vitro culture. Proteomic analysis revealed that 159 different proteins were associated with K. pneumoniae OMVs. Klebsiella pneumoniae OMVs did not inhibit cell growth or induce cell death. However, these vesicles induced expression of proinflammatory cytokine genes such as interleukin (IL)-1β and IL-8 in epithelial cells. An intratracheal challenge of K. pneumoniae OMVs in neutropenic mice resulted in severe lung pathology similar to K. pneumoniae infection. In conclusion, K. pneumoniae produces OMVs like other pathogenic Gram-negative bacteria and K. pneumoniae OMVs are a molecular complex that induces the innate immune response. 相似文献
105.
Lipase B from Candida antarctica (CalB) is a versatile biocatalyst for various bioconversions. In this study, the thermostability of CalB was improved through the introduction of a new disulfide bridge. Analysis of the B‐factors of residue pairs in CalB wild type (CalB‐WT) followed by simple flexibility analysis of residues in CalB‐WT and its designated mutants using FIRST server were newly proposed to enhance the selective power of two computational tools (MODIP and DbD v1.20) to predict the possible disulfide bonds in proteins for the enhancement of thermostability. Five residue pairs (A162‐K308, N169‐F304, Q156‐L163, S50‐A273, and S239C‐D252C) were chosen and the respective amino acid residues were mutated to cysteine. In the results, CalB A162C‐K308C showed greatly improved thermostability while maintaining its catalytic efficiency compared to that of CalB‐WT. Remarkably, the temperature at which 50% of its activity remained after 60‐min incubation (T) of CalB A162C_K308C was increased by 8.5°C compared to that of CalB‐WT (55 and 46.5°C, respectively). Additionally, the half‐life at 50°C of CalB A162C‐K308C was 4.5‐fold higher than that of CalB‐WT (220 and 49 min, respectively). The improvement of thermostability of CalB A162C‐K308C was elucidated at the molecular level by molecular dynamics (MD) simulation. Biotechnol. Bioeng. 2012; 109:867–876. © 2011 Wiley Periodicals, Inc. 相似文献
106.
Song SA Yoo KH Ko JY Kim BH Yook YJ Park JH 《Biochemical and biophysical research communications》2012,419(3):459-465
Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disease. ADPKD is characterized by cyst development that leads to abnormal kidney structure. Renal tubules are a fundamental unit of architecture, so controls of tubular growth and formation are important for proper kidney function. The molecular mechanisms of tubulogenesis are being actively studied as the basis of diagnosis and treatment of ADPKD. Mxi1 is a member of the MAD family of proteins that functions in terminal differentiation, inhibition of cell cycle progression and tumor suppression, while the Myc protein, which is antagonized by Mxi1, causes renal cystogenesis. Based on these molecular relationships, the present study implicated Mxi1 with ADPKD be demonstrating that curtailed Mxi1 gene expression caused cyst formation in Mxi1-deficient mice. To ascertain whether Mxi1 affects renal epithelial cell tubulogenesis, three-dimensional cultures (3D culture) of mIMCD-3 cells and stably Mxi1 over-expressed mIMCD-3 cells were established. The results indicated that over-expression of the Mxi1 gene plays a role in the regulation of tubulogenesis by regulating some genes participating in renal epithelial branching tubulogenesis such as matrix metalloproteinase 9 (MMP9), integrins, fibronectin, and E-cadherin. The results support the suggestion that over-expression of Mxi1 can suppress renal epithelial tubulogenesis. In particular, MMP9 is greatly affected by the expression level of Mxi1. It can be concluded that mIMCD-3 cells that stably over-express Mxi1 fail to form renal epithelial tubules because of abnormally reduced expression of MMP9. 相似文献
107.
Zhong‐Ji Qian Kyong‐Hwa Kang BoMi Ryu Se‐Kwon Kim Jae‐Young Je Soo‐Jin Heo Chulhong Oh Do‐Hyung Kang Won Sun Park Il‐Whan Choi 《Journal of phycology》2012,48(2):475-482
Microalgae are major primary producers of organic matter in aquatic environments through their photosynthetic activities. Fermented microalga (Pavlova lutheri Butcher) preparation (FMP) is the product of yeast fermentation by Hansenula polymorpha. It was tested for the antioxidant activities including lipid peroxidation inhibitory activity, free‐radical‐scavenging activity, inhibition of reactive oxygen species (ROS) on mouse macrophages (RAW264.7 cell), and inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60). FMP exhibited the highest antioxidant activity on free‐radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. MTT [3‐(4,5‐dimethyl‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay showed no cytotoxicity in mouse macrophages (RAW264.7 cell), human myeloid cells (HL60), and human fetal lung fibroblast cell line (MRC‐5). Furthermore, the antioxidative mechanism of FMP was evaluated by protein expression levels of antioxidant enzyme (superoxide dismutase [SOD] and glutathione [GSH]) using Western blot. The results obtained in the present study indicated that FMP is a potential source of natural antioxidant. 相似文献
108.
Nagaj J Starosta R Szczepanik W Barys M Młynarz P Jeżowska-Bojczuk M 《Journal of inorganic biochemistry》2012,106(1):23-31
Protonation equilibria and Cu(II) binding processes by an antifungal agent fluconazole, α-(2,4-difluorophenyl)-α-(1H-1,2,4-triazol-1-yl-methyl)-1H-1,2,4-triazole-1-ethanol, were studied using the UV-Vis, EPR and NMR spectroscopic techniques. The protonation constant of fluconazole was determined from NMR titration and attributed to N4′ nitrogen atoms using the DFT methods. The spectroscopic data suggest that at pH as low as 0.4 the first complex is formed, in which one or two Cu(II) ions are bound to one of the nitrogen atoms (N4′) from triazole rings. Above pH 1.5 each Cu(II) ion is surrounded by two nitrogen atoms (also N4′) from two different ligand molecules, forming primary monomeric complexes and above pH = 5, both dimeric or oligomeric species occur, which is well registered by the EPR technique.The mixture of Cu(NO3)2 with fluconazole in a 1:1 molar ratio in a water (pH = 4.5)/ethanol solution gave crystals of [Cu2(H2O){(C6H3-2,4-F2)(CH2N3C2H2)2C-OH}{(C6H3-2,4-F2)(CH2N3C2H2)2C-O}(NO3)](NO3)2·9(H2O). This complex is the first example of a cupric 3D polymeric structure with a fluconazole ligand coordinated via both N2′ and N4′ atoms from the same triazole rings. At higher pH values, we obtained a binuclear complex [Cu2(L)2(H2O)2(NO3)2], in which the copper(II) atoms were bridged by the oxygen atoms of the deprotonated OH group of fluconazole.The hypothetical oxidative properties of this system were also examined, however it failed to generate either reactive oxygen species or DNA scission products. 相似文献
109.
110.
Bong Cho Kim Hyung Chul Lee Je‐Jung Lee Chang‐Min Choi Dong‐Kwan Kim Jae Cheol Lee Young‐Gyu Ko Jae‐Seon Lee 《The EMBO journal》2012,31(22):4289-4303
Premature senescence, a key strategy used to suppress carcinogenesis, can be driven by p53/p21 proteins in response to various stresses. Here, we demonstrate that Wig1 plays a critical role in this process through regulation of p21 mRNA stability. Wig1 controls the association of Argonaute2 (Ago2), a central component of the RNA‐induced silencing complex (RISC), with target p21 mRNA via binding of the stem‐loop structure near the microRNA (miRNA) target site. Depletion of Wig1 prohibited miRNA‐mediated p21 mRNA decay and resulted in premature senescence. Wig1 plays an essential role in cell proliferation, as demonstrated in tumour xenografts in mice, and Wig1 and p21 mRNA levels are inversely correlated in human normal and cancer tissues. Together, our data indicate a novel role of Wig1 in RISC target accessibility, which is a key step in RNA‐mediated gene silencing. In addition, these findings indicate that fine‐tuning of p21 levels by Wig1 is essential for the prevention of cellular senescence. 相似文献