• Proceedings of the EASDL Conference
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• 2005.04a
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• pp.21-34
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• 2005

Increase in daily protein consumption per capita from 1975(85.1 g) to 2001(88.4 g) was 3.3 g. This trend was relatively slower than the case of Japan where daily protein consumption was 84.7 g in 1975 and 90.3 g in 2001. Animal-related protein in 2003 was 45.7 g in which 61% was originated from meat, milk and egg whereas 39% was composed of fish and its relevance. The trend of protein consumption fairly come up with the ideal ratio of 5:5 between animal-originated protein and plant-originated protein, following the base case of Japan. The effect of animal protein on human health can vary depending on one's viewpoint and its controversy is still a subject of debate. For reason, two faces of positive and negative effects on human health coexists. However, there is no doubt that positive effect is far more than negative one. It is not important whether or not animal protein is more beneficial for human health. However, it is more important how human balance between two proteins.

• Proceedings of the PSK Conference
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• 2005.11a
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• pp.231-232
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• 2005

Bacteria of Shigella spp. are responsible for shigellosis in humans, a disease characterized by destruction of the colonic epithelium that is induced by the inflammatory response elicited by invasive bacteria. They use a type III secretion system injecting effector proteins into host cells to induce their entry into epithelial cells and triggers apoptosis in macrophages. We present evidence that the effector OspG is a protein kinase that binds various ubiquitinylated ubiquitin-conjugating enzymes (E2s) and blocks degradation of phospho-$I{\kappa}B{\alpha}$ induced upon entry of bacteria into epithelial cells. Transfection experiments confirmed that OspG interferes with the $NF-{\kappa}B$ activation patway by preventing phospho-$I{\kappa}B{\alpha}$ degradation, suggesting that OspG inactivates a component of the $SCF^{{\beta}-TrCP}$ ubiquitin ligase complex (E3) involved in phospho-$I{\kappa}B{\alpha}$ ubiquitination. Upon infection of ileal loops in rabbits, the ospG mutant induced a stronger inflammatory response compared with the wild-type strain, indicating that OspG down-regulates the host innate response induced by invasive bacteria.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.122-129
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• 2008

The purpose of this work was to investigate the synergically bactericidal effects and cellular responses of green tea polyphenols (TPPs) and nalidixic acid (NA) on nalidixic acid-resistant (NAR) Salmonella typhimurium. The bactericidal activities of $>3,500{\mu}g/ml$ TPPs and $<256{\mu}g/ml$ NA were investigated for S. typhimurium of which initial cell number was approximately adjusted to 107 cell/ml. Complete elimination of NAS-S. typhimurium was achieved within 6 hr of incubation at the concentrations of $3,500{\mu}g/ml$ TPP or $256{\mu}g/ml$ NA, whereas only partial bactericidal effect was achieved under the same conditions. However, the combinations of $3,000{\mu}g/ml$ TPPs and $32{\mu}g/ml$ NA against NAS-S. typhimurium and $3,500{\mu}g/ml$ TPPs and $64{\mu}g/ml$ nalidixic acid against NAR-S. typhimurium showed complete removal within 5 hr of incubation. The stress shock proteins (SSPs) were induced at different concentrations of TPP o rNA used as stressors against cell culture of S. typhimurium. The proteins were identified as 70-kDa DnaK and 60-kDa GroEL by SDS-PAGE and Western blot. SSPs induced by the stressors were found to increase in proportion to the TPPs or NA. Scanning electron microscopy analyses revealed the presence of perforations and irregular rod shape with wrinkled surfaces for cells treated with TPPs or NA.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.131-133
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• 2002

In 'Nature', Dixon et al. reported the first cloned mammalian G-protein coupled receptor sequence (1). The DNA sequence from a hamster encodes the $\beta$$_2$-aderenergic receptor. In the same year, 1986, Kubo et al. published the muscarinic acetylcholine receptor sequence (M$_1$) from a rat in the same journal (2). Both groups purified the receptor proteins and identified the DNA sequences (1, 2). (omitted)

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.36-36
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• 1996

The activities of Maxi-K channels were recorded using inside-out patches. The application of 30 nM of non-specific G protein activator, GTP $\gamma$S, to the intracellular side of the channels increases the channel activities about 3-fold, indicating that there exist some G proteins within the patch membranes to regulate the channel activities. (omitted)

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.17-19
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• 2000

Heterotrimeric G Proteins transduce ligand binding to a wide variety of seven transmembrane cell surface receptors into intracellular signals. The currently accepted model for the activation of G protein suggests that ligand-activated receptor accelerates GDP-GTP exchange reactions on the ${\alpha}$ subunit of the heterotrimeric G protein. At least seventeen distinct isoforms of the G${\alpha}$ subunit protein have been identified in mammalian organisms. Among them, the G${\alpha}$q family consists of five members whose ${\alpha}$ subunits show different expression patterns. G${\alpha}$q and G${\alpha}$11 seem to be almost ubiquitously expressed, whereas G${\alpha}$14 is predominantly expressed in spleen, lung, kidney and testis. G${\alpha}$16 and its murine counterpart G${\alpha}$15 are expressed in hematopoietic cells and has been shown to couple a wide variety of receptors to phosphoinositide-specific phospholipase C activity. Beta-isoforms of phospholipase C were shown to be activated by all members of G${\alpha}$q family, i.e., G${\alpha}$q, G${\alpha}$11, G${\alpha}$l4 and G${\alpha}$16 subunits either in reconstitution system. or in experiments using cDNA transfection with intact Cos-7 cells.

• BMB Reports
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• v.41 no.7
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• pp.555-560
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• 2008

The interaction of the rod GTP binding protein, Transducin ($G_t$), with bleached Rhodopsin ($R^*$) was investigated by measuring radiolabeled guanine nucleotide binding to and release from soluble and/or membrane-bound Gt by reconstituting $G_t$ containing bound GDP ($G_t$-GDP) or the hydrolysis-resistant GTP analog guanylyl imidodiphosphate ($G_t$-p[NH]ppG) with $R^*$ under physiological conditions. Release of GDP and p[NH]ppG from $G_t$ occurred to the same extent and with the same light sensitivity both in the presence and absence of added GTP. Significant amounts of $G_t$ without bound nucleotide ($G_{t^-}$) were generated. When ROS containing bleached rhodopsin ($R^*$) were centrifuged in low ionic strength buffer, $G_{t^-}$ remained associated with the membrane fraction, whereas $G_t$-GDP remained in the soluble fraction. These results suggest that $G_t$-GDP and $G_t$-p[NH]ppG have similar affinities for $R^*$. The results also suggest that $G_{t^-}$, rather than $G_t$-GDP, is the moiety which exhibits tight, "light-induced" binding to rhodopsin.

• Journal of Life Science
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• v.21 no.9
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• pp.1346-1353
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• 2011

Sophora tonkinensis Gapnep has been used as a traditional herbal medicine in oriental regions since ancient times. In this study, the effect and mechanism of the MeOH extract of Sophora tonkinensis Gapnep (STME) on adipocite differentiation and adipogenesis in 3T3-L1 preadipocites were investigated. Treatment with STME in the concentration range of 0-200 ${\mu}g$/ml significantly inhibited the differentiation of 3T3-L1 preadipocites in a dose-dependent manner, as determined by a decrease in intracellular lipid droplets and lipid contents measured by Oil Red O staining. In association with the inhibitory effect of lipid accumulation, the expressions of the proteins concerned with adipogenesis in 3T3-L1 preadipocites were also investigated. Treatment with STME reduced the expressions of peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ and ${\beta}$ (C/EBP${\alpha}$ and C/EBP${\beta}$) and sterol regulatory element binding protein (SREBP), which are adipocyte specific markers. In flow cytometry analysis, the inhibitory effect of differentiation was caused by G1 arrest and following mitotic clonal expansion cease. Therefore, we also investigated the alteration of G1 phase arrest-related proteins. As a result, the expression of p21 protein was significantly increased, while the expressions of Cdk2, E2F-1 and phospho-Rb were reduced in a dose-dependent manner in STME treated 3T3-L1 cells. According to these results, STME might inhibit differentiation through G1 arrest in 3T3-L1 preadipocytes adipogenesis, and further studies, which are in progress, have to be completed to identify the active compounds.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.624-629
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• 2009

It is the most important step to screen soluble and insoluble proteins when we attempt to improve the solubility of recombinant proteins through directed evolution approach. Here we show that the solubility of a recombinant protein in vivo can be examined by expressing the recombinant protein with beta-lactamase as a fusion partner. First we constructed an expression system which can produc a fusion protein with the C-terminal of beta-lactamase. Two soluble proteins, i.e. adenine deaminase and aspartate aminotransferase, and insoluble GlcNAc-2-epimerase were cloned into the developed expression vector, respectively. We investigated the effect of the expression of the three recombinant fusion proteins on the growth of E. coli, and confirmed that the solubilities of the recombinant proteins correlated with cell growth rates.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.912-918
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• 2008

This study was conducted to identify the differences in proteomic characteristics of 'Agakong', recombinant inbred line, and its parental genotypes 'Eunhakong' (Glycine max) and 'KLG10084' (G. soja). The isoflavone content of 'Agakong' was 3 times higher than that of its parental lines. A combined high-throughput proteomic approach was employed to determine the expression profile and identity of proteins using 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The overall distribution patterns of proteins are quite similar, but lots of protein spot intensities varied among the genotypes. A total of 41 proteins, representing significant difference in the quantities of protein among the lines, were successfully identified. Among them, more than 50% of the proteins identified were subunits of glycinin and $\beta$-conglycinin, 2 major storage proteins. This study showed that the proteomic analysis could help to define specific changes in protein level and composition, which can occur in the generation of new soybean varieties.