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101.
Lee WS Lee DW Baek YI An S An SJ Cho KH Choi YK Kim HC Park HY Bae KH Jeong TS 《Bioorganic & medicinal chemistry letters》2004,14(12):3109-3112
The sesquineolignan, saucerneol B (1), and dineolignans, manassantin A (2), and manassantin B (3), were isolated from the methanol extracts of Saururus chinensis root and elucidated by their spectroscopic data analysis. Compounds 1-3 inhibited hACAT-1 and hACAT-2 with IC(50) values of 43.0 and 124.0 microM for 1, of 39.0 and 8.0 microM for 2, of 82.0 microM and only 32% inhibition at 1mM for 3, respectively. The EtOAc-soluble fraction, which contained compounds 1-3, of methanol extracts of S. chinensis exhibited strong cholesterol-lowering effect in high cholesterol-fed mice. 相似文献
102.
Chawla-Sarkar M Bae SI Reu FJ Jacobs BS Lindner DJ Borden EC 《Cell death and differentiation》2004,11(8):915-923
Melanoma cells are relatively resistant to Apo2L/TRAIL (TNF-related apoptosis-inducing ligand). We postulated that resistance might result from higher expression of inhibitors of apoptosis including Bcl-2, FLIP (FLICE-like inhibitory protein) or IAPs such as XIAP (X-linked inhibitor of apoptosis) or survivin. Compared to scrambled or mismatch controls, targeting individual inhibitors with siRNA (si-Bcl-2, si-XIAP, si-FLIP or si-Surv), followed by Apo2L/TRAIL resulted in marked increase in apoptosis in melanoma cells. Compared to Bcl-2 or FLIP, siRNAs against XIAP and survivin were most potent in sensitizing melanoma cells. A similar substantial increase in apoptosis was seen in renal carcinoma cells (SKRC-45, Caki-2), following the inhibition of either XIAP or survivin by siRNAs. Apo2L/TRAIL treatment in IAP-targeted cells resulted in cleavage of Bid, activation of caspase-9 and cleavage of PARP (poly ADP-ribose polymerase). Thus, Apo2L/TRAIL resistance can be overcome by interfering with expression of inhibitors of apoptosis regulating both extrinsic (death receptor) or intrinsic (mitochondrial) pathways of apoptosis in melanoma cells. 相似文献
103.
Bae TJ Kim MS Kim JW Kim BW Choo HJ Lee JW Kim KB Lee CS Kim JH Chang SY Kang CY Lee SW Lee SW Ko YG 《Proteomics》2004,4(11):3536-3548
Since detergent-resistant lipid rafts are involved in pathogen invasion, cholesterol homeostasis, angiogenesis, neurodegenerative diseases and signal transduction, protein identification in the rafts could provide important information to study their function. Here, we analyzed detergent-resistant raft proteins isolated from rat liver by capillary liquid chromatography-tandem mass spectrometry. Out of 196 proteins identified, 32% belonged to the raft or plasma membrane, 24% to mitochondrial, 20% to microsomal, 7% to miscellaneous, and 17% are unknown proteins. For example, membrane-bound receptors, trimeric GTP-binding proteins, ATP-binding cassette transporters, and glycosylphosphatidylinositol-anchored proteins were identified in this analysis. Unexpectedly, there were many mitochondrial proteins, raising a new issue for the presence of mitochondrial rafts or the localization of mitochondrial proteins into plasma membrane rafts. We confirmed that ATP synthase alpha and beta were expressed on the surface of the plasma membrane in HepG2 hepatocytes by immunofluorescence, cell surface biotinylation, and cellular fractionation. They had two distinct biochemical properties, detergent insolubility and low density, suggesting that the ATP synthase complex might be located in plasma membrane rafts as well as in the mitochondria. 相似文献
104.
Budisa N Pal PP Alefelder S Birle P Krywcun T Rubini M Wenger W Bae JH Steiner T 《Biological chemistry》2004,385(2):191-202
The expanded genetic code in combination with site-directed mutagenesis was used to probe spectroscopic and structural roles of tryptophan (Trp) residues in Aequorea victoria green fluorescent proteins (avGFPs). Nine different halogen-, chalcogen-, and methyl-containing Trp isosteric analogues and surrogates were incorporated into avGFPs containing indole moieties in, and outside of, the chromophore, by the use of the selective pressure incorporation method. Such isosteric replacements introduced minimal local geometry changes in indole moieties, often to the level of single atomic exchange ('atomic mutation') and do not affect three-dimensional structures of avGFPs but induce changes in spectral properties. Our approach offers a new platform to re-evaluate issues like resonance transfer, mechanisms of chromophore formation and maturation, as well as the importance of local geometry and weak sulphur-aromatic interactions for avGFP spectral properties and structural stability. The library of novel tailor-made avGFP mutants and variants generated in this work has demonstrated not only the potentials of the expanded genetic code to study spectroscopic functions, but also a new approach to generate tailor-made proteins with interesting and useful spectral properties. 相似文献
105.
Activated platelets rapidly up-regulate CD40L expression and can effectively mature and activate autologous ex vivo differentiated DC 总被引:2,自引:0,他引:2
Background DC are a promising immunotherapeutic for treatment of infectious/malignant disease. For clinical trials, immature DC generated from precursor cells such as monocytes, using serum-free media containing GM-CSF and IL-4, can be matured with specific cytokines/factors. CD40 ligand (CD40L) plays an important role in DC activation/maturation but is not available for clinical applications. These studies evaluated the feasibility of using activated platelets with elevated CD40L surface expression to stimulate autologous DC maturation. Methods Pilot and clinical scale studies were executed using magnetic/centrifugal separation. Monocyte precursors were differentiated to immature DC with GM-CSF and IL-4 and the ability of activated autologous platelets to mature these cells was evaluated on the basis of phenotype and function. Results In small-scale studies, DC cultures stimulated with activated autologous platelets (CD40L-AP), tumor necrosis factor-alpha (TNF-alpha) or soluble CD40L (sCD40L) up-regulated expression of phenotype markers indicative of activation and maturation. CD86 expression was significantly enhanced (P<0.05) by stimulation with either CD40L-AP (75.5+/-14.5%) or sCD40L (80.5%+/-5.3%) compared with immature DC (55.2+/-14.8%), as were CD80 and CD83. Similarly, in large-scale studies using Isolex 300I to enrich for monocytes and platelets for DC generation/maturation on a clinical scale, stimulation with CD40L-AP increased CD86 and CD80 expression as well as the ability to stimulate allogeneic lymphocytes compared with control cultures. Discussion These results demonstrate that thrombin-activated platelets express CD40L and are effective at inducing matured DC with potent immunogenic activity. Furthermore, these studies demonstrate the feasibility of this approach for clinical immunotherapeutic interventions. 相似文献
106.
107.
Bae JH Rubini M Jung G Wiegand G Seifert MH Azim MK Kim JS Zumbusch A Holak TA Moroder L Huber R Budisa N 《Journal of molecular biology》2003,328(5):1071-1081
Much effort has been dedicated to the design of significantly red shifted variants of the green fluorescent protein (GFP) from Aequoria victora (av). These approaches have been based on classical engineering with the 20 canonical amino acids. We report here an expansion of these efforts by incorporation of an amino substituted variant of tryptophan into the "cyan" GFP mutant, which turned it into a "gold" variant. This variant possesses a red shift in emission unprecedented for any avFP, similar to "red" FPs, but with enhanced stability and a very low aggregation tendency. An increasing number of non-natural amino acids are available for chromophore redesign (by engineering of the genetic code) and enable new general strategies to generate novel classes of tailor-made GFP proteins. 相似文献
108.
A bacterial strain capable of degrading medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was isolated from a soil sample.
This organism, which was identified as Streptomyces sp. KJ-72, secreted MCL-PHA depolymerase into the culture fluid only when it was cultivated on MCL-PHAs. The extracellular
MCL-PHA depolymerase of the organism was purified to electrophoretic homogeneity by ion exchange column chromatography and
gel filtration. The enzyme consisted of a monomeric subunit having a molecular mass of 27.1 kDa and isoelectric point of 4.7.
The maximum activity was observed at pH 8.7 and 50 °C. The enzyme was sensitive to N-bromosuccinimide and acetic anhydride, indicating the presence of tryptophan and lysine residues in the catalytic domain.
The enzyme was able to hydrolyze various chain-length p-nitrophenyl esters of fatty acids and polycaprolactone as well as various types of MCL-PHAs. However, lipase activity of
the enzyme was not detected. The main hydrolysis product of poly(3-hydroxyheptanoate) was identified to be the dimer of 3-hydroxyheptanoate.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
109.
Anti-angiogenic and anti-tumor invasive activities of tissue inhibitor of metalloproteinase-3 from shark,Scyliorhinus torazame 总被引:1,自引:0,他引:1
Kang JA Kim JT Song HS Bae MK Yi EY Kim KW Kim YJ 《Biochimica et biophysica acta》2003,1620(1-3):59-64
In order to investigate the anti-angiogenic activity of shark TIMP-3 (sTIMP-3) in endothelial cells, angiogenic assays including in vitro invasion assay, migration assay, zymogram assay and tube formation assay were performed. We observed that the overexpression of sTIMP-3 decreased the invasive capacity by about 70%, the migratory activity by about 50% and the production of gelatinase A in bovine aortic endothelial cells (BAECs). In addition, the overexpression of sTIMP-3 interfered with the formation of capillary-like network in endothelial cells. We also examined whether sTIMP-3 shows the anti-invasive activity in cancer cells. We found that the overexpression of sTIMP-3 diminished the invasive ability of the human fibrosarcoma HT1080 cells by about 40%. Also, the production of specific gelatinases was suppressed in the cancer cells. Therefore, we propose that sTIMP-3 acts as the inhibitor of angiogenesis in endothelial cells and the suppressor of tumor invasion in human fibrosarcoma HT1080 cells. 相似文献
110.
Bae SW Kim HS Cha YN Park YS Jo SA Jo I 《Biochemical and biophysical research communications》2003,306(4):981-987
Bradykinin (BK) acutely increases endothelial nitric oxide (NO) production by activating endothelial NO synthase (eNOS), and this increase is in part correlated with enhanced phosphorylation/dephosphorylation of eNOS by several protein kinases and phosphatases. However, the signaling mechanisms producing this increase are still controversial. In an attempt to delineate the acute effect of BK on endothelial NO production, confluent bovine aortic endothelial cells were incubated with BK, and NO production was measured by NO-specific chemiluminescence. Significant increase in NO levels was detected as early as 1 min after BK treatment, with concomitant increase in the phosphorylation of Ser(1179) (bovine sequence) site of eNOS (eNOS-Ser(1179)). This acute effect of BK on both increases was blocked only by treatment of protein kinase A inhibitor H-89, but not by the inhibitors of calmodulin-dependent kinase II and protein kinase B, suggesting that the rapid increase in NO production by BK is mediated by the PKA-dependent phosphorylation of eNOS-Ser(1179). 相似文献