• Journal of the Korean Magnetic Resonance Society
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• v.2 no.2
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• pp.85-105
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• 1998

Prions cause neurodegenerative diseases in animals and humans. The scrapie prion protein (PrPSc) is the major-possibly only-component of the infectious prion and is generated from the cellular isoform (PrPC) by a conformational change. Limited proteolysis of PrPSc produces an polypeptide comprised primarily of residues 90 to 231, which retains infectivity. The three-dimensional structure of rPrP(90-231), a recombinant protein resembling PrPC with the Syrian hamster (SHa) sequence, was solved using multidimensional NMR. Low-resolution structures of rPrP(90-231), synthetic peptides up to 56 residues, a longer (29-231, full-length) protein with SHa sequence, and a short here further structure refinement of rPrP(90-231) and dynamic features of the protein. Consideration of these features in the context of published data suggests regions of conformational heterogeneity, structural elements involved in the PrPC\longrightarrowPrPSc transformation, and possible structural features related to a species barrier to transmission of prion diseases.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.591-600
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• 1998

We have examined 24 human aortas aged $46{\sim}90$ years obtained from autopsies. Most exhibited gross lesions of some degree on the lumenal surface. Using hot alkaline treatment (0.1 N NaOH) at $70{\sim}75^{\circ}C$ for 5 hours, we extracted and quantitated elastin portions from the aortic wall in 3 different segments (UTA=upper thoracic aorta, LTA=lower thoracic aorta, AA=abdominal aorta). We have found UTA had $70.6%{\pm}1.39$ (SE), LTA $61.6%{\pm}1.94$ (SE), AA $49.2%{\pm}1.84$ (SE) elastin respectively based on wet weight. The differences between segments are statistically significant (p＜0.05, 0.025). However, there is no significant correlation between the age of the patients and the relative amounts of elastin in each segment. We have also observed the structure of elastin in the internal elastic lamina (IEL) and tunica media (TM) with SEM (scanning electron microscopy), and discovered that the IEL shows various forms of elastolysis- broken sheets, discontinuity, various sizes of lumps, vesicles, and possible newly formed elastin in the aortic lesions (Song and Roach submitted to YMJ). From these studies we conclude that elastin in the aortic wall remains well balanced quantitatively with age in spite of evidence suggesting vigorous degeneration and regeneration in the atherosclerotic lesions.

• YAKHAK HOEJI
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• v.56 no.2
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• pp.108-115
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• 2012

The hyperpolarization-activated current ($I_h$) is an inward cation current activated by hyperpolarization of the membrane potential and plays a role as an important modulator of action potential firing frequency in many excitable cells. In the present study we investigated the effects of extracellular divalent cations on $I_h$ in dorsal root ganglion (DRG) neurons using whole-cell voltage clamp technique. $I_h$ was slightly increased in $Ca^{2+}$-free bath solution. BAPTA-AM did not change the amplitudes of $I_h$. Amplitudes of $I_h$ were decreased by $Ca^{2+}$, $Mg^{2+}$ and $Ba^{2+}$ dose-dependently and voltage-independently. Inhibition magnitudes of $I_h$ by external divalent cations were partly reversed by the concomitant increase of extracellular $K^+$ concentration. Reversal potential of $I_h$ was significantly shifted by $Ba^{2+}$ and $V_{1/2}$ was significantly affected by the changes of extracellular $Ca^{2+}$ concentrations. These results suggest that $I_h$ is inhibited by extracellular divalent cations ($Ca^{2+}$, $Mg^{2+}$ and $Ba^{2+}$) by interfering ion influxes in cultured rat DRG neurons.

• Journal of Acupuncture Research
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• v.19 no.6
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• pp.171-183
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• 2002

Objective : To research the trends of study related to myofascial pain syndrome(MPS) and acupuncture in PubMed, and to establish the hereafter direction of myofascial pain syndrome(MPS) with acupuncture. Methods : We searched in PubMed, with myofascial pain syndrome and acupuncture, trigger point and acupuncture limitted by abstract. Results : 1. The pattern of the study was as follows : Review article(11), Clinical(11) rondomized controlled trials(21). We further estimated 24 articles. 2. Many of these studies provide equivocal results because of designs, sample size and the other, affirmative view is 10 articles, contradictive view is 6 articles, and somewhat reservative regards are 8 articles for therapeutic effect of myofascial pain syndrome with acupuncture. 3. Suggestions on further endolphin related research, neurophysiology, biophysics and phamacology are made. 4. More clinical data would be needed to prove effects of myofascial pain syndrome with acupuncture.

• BMB Reports
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• v.39 no.5
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• pp.578-585
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• 2006

The cDNA of a firefly luciferase from lantern mRNA of Lampyroidea maculata has been cloned, sequenced and functionally expressed. The cDNA has an open reading frame of 1647 bp and codes for a 548-residue-long polypeptide. Noteworthy, sequence comparison as well as homology modeling showed the highest degree of similarity with H. unmunsana and L. mingrelica luciferases, suggesting a close phylogenetic relationship despite the geographical distance separation. The deduced amino acid sequence of the luciferase gene of firefly L. maculata showed 93% identity to H. unmunsana. Superposition of the three-dimensional model of L. maculata luciferase (generated by homology modeling) and three dimensional structure of Photinus pyralis luciferase revealed that the spatial arrangements of Luciferin and ATP-binding residues are very similar. Putative signature of AMP-binding domain among the various firefly species and Lampyroidea maculata was compared and a striking similarity was found. Different motifs and sites have been identified in Lampyroidea maculata by sequence analysis. Expression and purification of luciferase from Lampyroidea maculata was carried out using Ni-NTA Sepharose. Bioluminescence emission spectrum was similar to Photinus pyralis luciferase.

• BMB Reports
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• v.45 no.12
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• pp.748-753
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• 2012

A sequence of 10 amino acids at the C-terminus region of methylglyoxal synthase from Escherichia coli (EMGS) provides an arginine, which plays a crucial role in forming a salt bridge with a proximal aspartate residue in the neighboring subunit, consequently transferring the allosteric signal between subunits. In order to verify the role of arginine, the gene encoding MGS from a thermophile species, Thermus sp. GH5 (TMGS) lacking this arginine was cloned with an additional 30 bp sequence at the 3'-end and then expressed in form of a fusion TMGS with a 10 residual segment at the C-terminus ($TMGS^+$). The resulting recombinant enzyme showed a significant increase in cooperativity towards phosphate, reflected by a change in the Hill coefficient (nH) from 1.5 to 1.99. Experiments including site directed mutagenesis for Asp-10 in TMGS and $TMGS^+$, two dimentional structural survey, fluorescence and irreversible thermoinactivation were carried out to confirm this pathway.

• Journal of Life Science
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• v.2 no.2
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• pp.97-107
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• 1992

Strichartz and Richie have suggested that the mechanism of sodium donductance block of local anesthetics involves their interaction with a specific binding site within the sodium channel. However, there is evidence that local anesthetics can interact electrostatically with membrane proteins as well as membrane lipids. Whether or not all actions of local anesthetics are mediated by common site remains unclear. Thus, it can not be ruled out that local anesthetics concurrently interact with neuronal membrane lipids since sodium channels were found to be tightly associated with membrane lipids through covalent or noncovalent bonds. In summary, it is strongly postulated that local anesthetics, in addition to their direct interaction with sodium channels, concurrently interact with membrane lipids, fluidize the membrane, and thus induce conformational changes of sodium channels, which are known to be tightly associated with membrane lipids.

• Animal cells and systems
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• v.8 no.1
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• pp.49-55
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• 2004

In vertebrates, multisubunit cofactors regulate gene expression through interacting with cell-type- and gene-specific DNA-binding proteins in a chromatin-selective manner. ADD1/SREBP1c regulates fatty acid metabolism and insulin-dependent gene expression through binding to SRE and E-box motif with dual DNA binding specificity. Although its transcriptional and post-translational regulation has been extensively studied, its regulation by interacting proteins is not well understood. To identify cellular proteins that associate with nuclear form of ADD1/SEBP1c, we employed the GST pull-down system with Hela cell nuclei extract. In this study, we demonstrated that Ku proteins interact specifically with ADD1/SREP1c protein. GST pull-down combined with peptide sequencing analysis revealed that Ku80 binds to ADD1/SREBP1c in vitro. Additionally, western blot analysis showed that Ku70, a heterodimerizing partner of Ku80, also associates with ADD1/SREBP1c. Furthermore, co-transfection of Ku70/Ku80 with ADD1/SREBP1c enhanced the transcriptional activity of ADD1/SREBP1c. Taken together, these results suggest that the Ku proteins might be involved in the lipogenic and/or adipogenic gene expression through interacting with ADD1/SREBP1c.

• Animal cells and systems
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• v.16 no.5
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• pp.351-356
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• 2012

Food is important to any animal, and a large part of the behavioral repertoire is concerned with ensuring adequate nutrition. Two main nutritional sensations, hunger and satiety, produce opposite behaviors. Hungry animals seek food, increase exploratory behavior and continue feeding once they encounter food. Satiated animals decrease exploratory behavior, take rest, and stop feeding. The signals of hunger or satiety and their effects on physiology and behavior will depend not only on the animal's current nutritional status, but also on its experience and the environment in which the animal evolved. In our novel, nutritionally rich environment, improper control of appetite contributes to diseases from anorexia to the current epidemic of obesity. Despite extraordinary recent advances, genetic contribution to appetite control is still poorly understood partly due to lack of simple genetic model systems. In this review, we will discuss current understanding of molecular and cellular mechanisms by which animals regulate food intake depending on their nutritional status. Then, focusing on relatively less known muscarinic and cGMP signals, we will discuss how the molecular and behavioral aspects of hunger and satiety are conserved in a simple invertebrate model system, Caenorhabditis elegans so as for us to use it to understand the genetics of appetite control.

• The Plant Pathology Journal
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• v.19 no.4
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• pp.217-220
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• 2003

Zucchini squash (Cucurbita pepo cv. Black Beauty) plants infected with A strain of Zucchini yellow mosaic virus (ZYMV-A) isolated from a hollyhock plant showed systemically severe mosaic symptom, similar to previously established Cu strain of ZYMV. However, initial symptom of squash infected by ZYMV-A strain was generally more severe than those infected by ZYMV-Cu. Using leaf-detachment assay, examination of kinetics of accumulation of the coat protein (CP) in systemic loaves of squash plants showed that CPs of ZYMV-A appeared earlier than those of ZYMV-Cu. However, both ZYMV-A and ZYMV-Cu showed similar kinetics of CP accumulation 7 days post-inoculation. These results indicate that different rates and initial severity of systemic symptom development were due to differences in the rate of movement rather than vims replication.