• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.182-186
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• 2012

human tyrosinase (hTyr) catalyzes first and the rate limiting step in the synthesis of polymerized pigment, melanin which determines skin, hair and eye colors. Mutation of hTyr often brings about decrease of melanin production and further albinism. Meanwhile, a number of cosmetic companies providing skincare products for woman in Asia-Pacific region have tried to develop inhibitors to bright skin color for several decades. In this study, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from bacillus megaterium as a template to serve structural information of hTyr. According to our model and sequence analysis of type 3 copper protein family proteins, two copper atoms of active site located deep inside are coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Cavity which accommodates substrates was like funnel shape of which entrance was wide and expose to solvent. In addition, protein-substrate and protein-inhibitor complex were modeled with the guide of van der waals surface generated by in house software. Our model suggested that only phenol group or its analogs can fill the binding site near nuclear copper center because inside of binding site has narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogensis agents.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.490-493
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• 2011

Purpose: Basosquamous carcinoma is a rare malignancy, with features of both basal cell carcinoma and squamous cell carcinoma. It is considered as aggressive tumor with a high risk of recurrence and metastases. Authors report a case of basosquamous cell carcinoma. Methods: A 72 year-old man, who had an erythematous ulcer on his left auricle, described a slow growing lesion, starting at the posterior surface of the superior helix with a steady increase in size during the past 10 years. At operation, auricular cartilage was grossly invaded by the tumor and was, therefore, amputated with tumor-free margins. Results: Histopathologic examination was revealed a basosquamous cell carcinoma. On positron emission tomography/computed tomography (PET/CT) and neck CT were negative for signs of further nodal involvement or metastases to other organs. At follow-up 6 months later, his wounds were noted to be well healed, with no evidence of local recurrence or identifiable metastases. Conclusion: Because basosquamous cell carcinoma has a significant potential to recur and metastasize, surgical excision for this type of carcinoma should be more extensive than that performed for conventional basal cell carcinoma or squamous cell carcinoma. In addition, regional lymph nodes should be monitored and close follow-up should be carried out.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.2
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• pp.74-92
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• 2005

The high resolution solution structure of MCP-3 was determined using multinuclear, multidimensional NMR spectroscopy with an expressed and $^{13}C-\;and\;^{15}N-labeled$ protein. The MCP-3 has a typical chemokine fold including 3 anti-parallel $\beta-sheets$, and a C-terminal helix, but it exists as a monomer in solution under the conditions where the structure was determined (2 mM, pH 5.1 at $30^{\circ}C$). Based on the structure and the amino acid sequence compared to other chemokines we propose that Ile20 and Leu25 in MCP-3 play key roles in the formation of N-loop (residues between the $2^{nd}$ cysteine and the I sheet) which has been implicated as a determinant of chemokine specificity. Additional receptor binding surface is supplied by the 40s loop (residues between the 2 and the 3 sheet) and the binding interface of the acidic N-terminal region of chemokine receptor to MCP-3 would resemble the dimerization interface of CC type dimer.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.36-43
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• 2020

A marine turning gear is the main auxiliary machine that enables the disassembly of and maintenance on the main engines. In this study, a marine turning gear based on a helical planetary reducer was developed through analysis of a marine turning gear based on a spur planetary reducer. Nonlinear numerical analysis was performed to determine the ideal contact ratio between the sun gear and the idle gear. Based on this, the surface durability, tooth bending strength, and contact ratio were calculated. In addition, the helix direction was selected to utilize the existing bearings. Gears were manufactured based on the helical gear design values, and the turning gear was evaluated using the FTA standards of MAN Co. Ltd. As a result, a lifetime of 3,000 to 5,000 hours was verified, the maximum torque measured was 105kNm, and the efficiency was measured to be 87.4%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1668-1675
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• 2004

The effect of pH on surface hydrophobicity, sulfhydryl group, infrared spectrum, SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) pattern and enthalpy was investigated in recovered protein from mackerel and frozen blackspotted croaker by alkaline processing. Hydrophobic residue in myofibrillar protein exposed to the surface of protein, and hydrophobic interaction were the highest around 6$0^{\circ}C$. The surface hydrophobicity was different between myofibrillar protein and myofibrillar protein including sarcoplasmic protein (recovered protein). The peak at 1636 c $m^{-l}$ was increased with pH, and the recovered protein was unfolded in alkali pH. Difference of surface and total sulfhydryl group at pH 7.0 and 10 was comparative high, and decrease of surface sulfhydryl group indicated formation of S-S bonds. Mackerel and frozen blackspotted croaker in alkaline pH showed bands of polymerized myosin heavy chain on SDS-PAGE pattern. The transition temperatures of recovered protein were 33.1, 44.3 and 65.5$^{\circ}C$. Gelation of recovered protein from alkali processing was estimated by increase of $\beta$-sheet structure by pH treatment, S-S bonds by oxidation of surface sulfhydryl group in heating, polymerization of myosin heavy chain in order.r.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.79-89
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• 1987

This study was executed to examine helical structure and other feature, of Taxus cuspidata S. et Z. and Larix gmelinii var. principis-ruprechtii Pilger through photomicroscopic and scanning electron microscopic observation, and the obtained result, were summarized as follows: 1. Tracheid transition from springwood to summerwood was abrupt, mel slightly gradual in Taxus cuspidata S. et Z. and summerwood width of Larix gmelinii var. principis-ruprechtii Pilger was wider than that of Taxus cuspidata S. et Z. 2. Normal vertical and horizontal resin canals and surrounding thick epithelial cells were present in Larix gmelinii var. principis-ruprechtii Pilger but not present in Taxus cuspidata S. et Z. 3. Instead of helical thickening, helical chicks were observed only in summerwood trachieds of Larix gmelinii var. principis-ruprechtii Pilger. However, helical thickenings forming S, Z., and horizontal helix perpendicular to long axis of tracheid were observed in springood and summerwood tracheids of Taxus cuspidata S. et Z. and these helical thickenings were considered as analogous to the innermost layer of secondary wall. 4. Uniseriate and fusiform rays were appeared on tangential surface of Larix gmelinii var. principis-ruprechtii Pilger but oly uniserate ray was observed on tangential surface ot Taxus cuspidata S. et Z. The fusiform rays of Larix gmelinii var. principis-ruprechtii Pilger usually contained one horizontal resin canal bot occasionally two horizontal resin canals were contained in a fusiform ray. 5. Trabeculae and crassulae were observed in the tracheids of Larix gmelimii var. principis-ruprechtii Pilger but not observed in the tracheids of Taxus cuspidata S. et Z.

• Research in Plant Disease
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• v.13 no.1
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• pp.61-65
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• 2007

English ivy (Hedera helix) in Araliaceae family is an evergreen climbing vine. A severe bacterial disease of English ivy was observed and investigated in January 2005. Initial symptoms on the leaves appeared as small water-soaked lesions on the lower surface. As the spots enlarged, the center became brown to brownish black and greenish-brown water-soaked, irregular margins surrounded the center, The spots developed into large irregular blotches, sometimes 5$\sim$10 mm in diameter, then coalesced. Finally, the water-soaked margins raised, dried out, became corky and broke in the center. A bacterial organism, isolated from the advancing margins of the lesions, was tested for its pathogenicity according to the Koch's postulates and biochemical and physiological tests identified the isolated bacterium as a Xanthomonas. The representative Xanthomonas strains (SL4821 and SL4822) isolated from English ivy were compared with a reference strain X. hortorum pv. hederae for fatty acid profiles, metabolic fingerprints and 16s rDNA sequences, showing that all outcomes were indistinguishable between the representative and reference strains. This is the first report of bacterial leaf spot of English ivy in Korea.

• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.18-18
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• 2003

Thioredoxin (Trx) is a small redox protein that is ubiquitously distributed from achaes to human. In diverse organisms, the protein is involved in various physiological roles by acting as electron donor and regulators of transcription and apoptosis as well as antioxidants. Sequences of Trx within various species are 27～69% identical to that of E. coli and all Trx proteins have the same overall fold, which consists of central five β strands surrounded by four α helices. The N-terminal cysteine in WCGPC motif of Trx is redox sensitive and the motif is highly conserved. Compared with general cysteine, the N-terminal cysteine has low pKa value. The result leads to increased reduction activity of protein. Recently, novel thio.edoxin-related protein (TRP14) was found from rat brain. TRP14 acts as disulfide reductase like Trx1, and its redox potential and pKa are similar to those of Trx1. However, TRP14 takes up electrons from cytosolic thioredoxin reductase (TrxR1), not from the mitochondrial thioredoxin reductase (TrxR2). Biological roles of TES14 were reported to be involved in regulating TNF-α induced signaling pathways in different manner with Trx1. In depletion experiments, depletion of TRP14 increased TNF-α induced phosphorylation and degradation of IκBα more than the depletion Trx1 did. It also facilitated activation of JNK and p38 MAP kinase induced by TNF-α. Unlike Trx1, TRP14 shows neither interaction nor interference with ASK1. Here, we determined three-dimensional crystal structure of TRP14 by MAD method at 1.8Å. The structure reveals that the conserved cis-Pro (Pro90) and active site-W-C-X-X-C motif, which may be involved in substrate recognition similar to Trx1 , are located at the beginning position of strand β4 and helix α2, respectively. The TRP14 structure also shows that surface of TRP14 in the vicinity of the active site, which is surrounded by an extended flexible loop and an additional short a helix, is different from that of Trx1. In addition, the structure exhibits that TRP14 interact with a distinct target proteins compared with Trx1 and the binding may depend mainly on hydrophobic and charge interactions. Consequently, the structure supports biological data that the TRP14 is involved in regulating TNF-α induced signaling pathways in different manner with Trx1.

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.162-165
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• 2012

The synchondrosis between the sixth and seventh costal cartilage is usually used for the base frame in autogenous ear reconstruction. If the synchondrosis is loose, a variety of modifications can be devised. This report introduces new methods for these problems. In cases of incomplete synchondrosis, only the surface of the base block margin was smoothly tapered without carving for the removal of the conchal deepening. The secure fixation of the two segments (helix and antihelix) to the base block using fine wire sutures gave stability to the unstable basal frame. After confirming that all the segments were assembled in one stable piece, the remaining conchal deepening of the basal framework was removed, and the outer lower portion of the basal cartilage was trimmed along its whole length. A total of 10 consecutive patients with microtia, ranging from 8 to 13 years old, were treated from 2008 to 2009. The follow-up period was 6 months to 2 years. Despite incomplete synchondrosis, the stable frameworks were constructed using the authors' method and aesthetically acceptable results were achieved. The proposed method can provide an easy way to make a stable cartilage framework regardless of the variable conditions of synchondrosis.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1261-1271
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• 2020

Cytochrome c_L (Cytc_L) is an essential protein in the process of methanol oxidation in methylotrophs. It receives an electron from the pyrroloquinoline quinone (PQQ) cofactor of methanol dehydrogenase (MDH) to produce formaldehyde. The direct electron transfer mechanism between Cytc_L and MDH remains unknown due to the lack of structural information. To help gain a better understanding of the mechanism, we determined the first crystal structure of heme c containing Cytc_L from the aquatic methylotrophic bacterium Methylophaga aminisulfidivorans MP^T at 2.13 Å resolution. The crystal structure of Ma-Cytc_L revealed its unique features compared to those of the terrestrial homologues. Apart from Fe in heme, three additional metal ion binding sites for Na⁺, Ca⁺, and Fe²⁺ were found, wherein the ions mostly formed coordination bonds with the amino acid residues on the loop (G93-Y111) that interacts with heme. Therefore, these ions seemed to enhance the stability of heme insertion by increasing the loop's steadiness. The basic N-terminal end, together with helix α4 and loop (G126 to Y136), contributed positive charge to the region. In contrast, the acidic C-terminal end provided a negatively charged surface, yielding several electrostatic contact points with partner proteins for electron transfer. These exceptional features of Ma-Cytc_L, along with the structural information of MDH, led us to hypothesize the need for an adapter protein bridging MDH to Cytc_L within appropriate proximity for electron transfer. With this knowledge in mind, the methanol oxidation complex reconstitution in vitro could be utilized to produce metabolic intermediates at the industry level.