• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1827-1834
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• 2015

The SMG1 lipase from Malassezia globosa is a newly found mono- and diacylglycerol (DAG) lipase that has a unique lid in the loop conformation that differs from the common alpha-helix lid. In the present study, we characterized the contribution of three residues, L103 and F104 in the lid and F278 in the rim of the binding site groove, on the function of SMG1 lipase. Site-directed mutagenesis was conducted at these sites, and each of the mutants was expressed in the yeast Pichia pastoris, purified, and characterized for their activity toward DAG and p-nitrophenol (pNP) ester. Compared with wild-type SMG1, F278A retained approximately 78% of its activity toward DAG, but only 11% activity toward pNP octanoate (pNP-C8). L103G increased its activity on pNP-C8 by approximately 2-fold, whereas F104G showed an approximate 40% decrease in pNP-C8 activity, and they both showed decreased activity on the DAG emulsion. The deletion of 103-104 retained approximately 30% of its activity toward the DAG emulsion, with an almost complete loss of pNP-C8 activity. The deletion of 103-104 showed a weaker penetration ability to a soybean phosphocholine monolayer than wild-type SMG1. Based on the modulation of the specificity and activity observed, a pNP-C8 binding model for the ester (pNP-C8, N102, and F278 form a flexible bridge) and a specific lipid-anchoring mechanism for DAG (L103 and F104 serve as "anchors" to the lipid interface) were proposed.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.579-584
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• 2000

To explore the effect of substituents' on phenyl motif on sulfonyl function of novel anticancer 4-phenyl-1-benzenesulfonylimidazolidinones (1), electron donating or withdrawing sub-stituents were introduced at 3 or 4-position and the analogs were tested against human lung (A549) and colon (HCT-15) cancer cell lines. Quantitative structure activity relation-ship of the 4-substituted series shows that only STERIMOL L values are well correlated. The increment of substituent's volume enhances the activity against both cell lines. The small substituent at 3-position additionally increases the activity. However naphthyl group in place of phenyl reduces the activity, Therefore the phenyl motif with sterically large substituent at 4-position and small substituent at 3-position may be important for their activity. Integration of these substituents' effects into the structural design led to discover the more potent analog, 4-phenyl-1-(N-acetylindoline-5-sulfonyl) imidazolidinone (1n).

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.369-372
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• 2009

In the present study, the effect of chemical treatment on graphite nanofibers (GNFs) supports with various concentrated nitric acids was investigated for methanol oxidation. To optimize the electrocatalytic activity, PtRu catalysts were deposited on GNF supports by impregnation method. The surface and structural properties of the GNF supports were characterized by X-ray photoelectron spectroscopy (XPS), element analyzer (EA), and X-ray diffraction (XRD). The morphology of the catalysts was observed by means of transmission electron microscopy (TEM). The electrocatalytic activity of PtRu/GNF catalysts was investigated by cyclic voltammetry measurement. As a result, the oxygen functional groups were introduced on the GNF supports and were gradually increased with increasing of concentrated nitric acid, causing the smaller particle size and higher loading level. And the electrocatalytic activity of the catalysts for methanol oxidation was gradually improved. Consequently, it was found that chemical treatments could influence on surface properties of the carbon supports, resulting in enhancing the electrocatalytic activity of the catalysts for DMFCs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.137-145
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• 2016

This study screened the biological activity of an acidified gill extract of the Manila clam Ruditapes philippinarum including antimicrobial, hemolytic, membrane permeabilization, and DNA-binding activity, and purified the antimicrobial material. The acidified gill extract showed potent antimicrobial activity against Bacillus subtilis and Escherichia coli without significant hemolytic activity, but showed no membrane permeabilization or DNA-binding ability. An antimicrobial material was purified from the acidified gill extract using C₁₈ reversed-phase and cation-exchange high-performance liquid chromatography (HPLC). Treatment of the purified material with trypsin completely abolished all of the antibacterial activity against Bacillus subtilis, suggesting that the purified material is a proteinaceous antibiotic. The molecular weight of the purified material was 2571.9 Da, but no primary structural information was obtained due to N-terminal blocking. A future study should confirm the primary structure. Our results suggest that the Manila clam gill contains proteinaceous antibiotics that have a role in first-line defense. This information could be used to better understand the Manila clam innate immune system.

• BMB Reports
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• v.39 no.5
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• pp.546-555
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• 2006

An acidic polysaccharide fraction that had high anti-complementary activity was isolated from the stems of Grey Mangrove in 0.15% yield. The final fractions was designated HAM-3-IIb-II. The polysaccharide fraction appeared to be homogenous by high performance size exclusion chromatography with an estimated molecular weight of 105 kDa. The isolated polysaccharide is more effective than polysaccharide K (PSK) in its anti-complementary activity at 58 ${\mu}g/ml$ of PSK and 23 ${\mu}g/ml$ of HAM-3-IIb-II that inhibit 50% of complement activity in the complement fixation assay. Structural studies indicated that HAM-3-IIb-II was rich in galacturonic acid along with arabinose, galactose and rhamnose, characterizing a pectin-type polysaccharide, which was also confirmed by FT-IR spectrum. The presence of rich neutral sugar side chains of arabinogalactans may have contributed to the expression of high activity. Traditionally, this mangrove plant is used for medicinal purposes and it appears to have some scientific applications.

• International Commerce and Information Review
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• v.7 no.1
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• pp.121-144
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• 2005

This paper describes a theoretical model for investigating the relationship commitment of trade portal site 6C's. This research is the first to empirical test the causal relationships in Trade portal site. The relationship commitment for e-Trade portal site are tested here using data from 195 samples. Research methodology used in this study was mainly survey and questionnaire. Structural equation model is used in the hypotheses test. the results support all hypotheses involving hypothesis 1 and 6. The major finding of this paper would be summarized as followed: 1) Perceived relationship commitment of e-Trade site 6C's is positively related to contents, community, communication, customization in e-trade activity level and activity range of trade practical 2) Perceived commerce of electronic trade site is negatively related to the relationship commitment of trade companies. 3) Perceived e-trade site in electronic trade connection is positively related to the re-activity intention. In examining the relationships commitment of the factors, e-trade potal 6C's show in significantly by Contents, Community, Communication, Customization, Re-activity intention, but that show in not significantly by Commerce factor.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.49-57
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• 2005

Enterococcus faecium MJ-14, having strong antilisterial activity, was isolated from Korean fermented food, Meju. MJ-14 showed the same phenotypic characteristics, but different sugar utilization, as reference strain, E. faecium KCCM12118. It could utilize D-xylose, amygdaline, and gluconate, whereas E. faecium KCCM12118 could not. Optimal condition for bacteriocin production by E. faecium MJ-14 was at $37^{\circ}C$ and pH 7.0. Bacteriocin activity appeared in mid exponential phase and increased rapidly up to stationary phase. Activity was significantly promoted in MRS broth containing 3.0% glucose, 1.5% lactose, 2.0% peptone, or 1.5% tryptone. Bacteriocins effectively inhibited Enterococcus faecalis and Listeria spp. of Gram-positive bacteria, and Helicobacter pylori of Gram-negative bacteria, but did not inhibit yeasts and molds. They were stable against heat (for 30 min at $100^{\circ}C$), pH (3.0-9.0), long-term storage (for 60 days at 4 or $-20^{\circ}C$), and enzymatic digestion by catalase, proteinase K, papain, lysozyme, trypsin, chymotrypsin, and lipase, etc. Bacteriocin activity was completely inhibited by protease and pepsin, and 50% by ${\alpha}$-amylase. Studies on PCR detection of enterocin structural genes revealed bacteriocins are identical to enterocins A and B.

• YAKHAK HOEJI
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• v.55 no.2
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• pp.98-105
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• 2011

To search the minimum structural requirement of tricyclic isoxazole analogues (1~30) as new class potent antidepressant, thee-dimensional quanti- tative-structure relationship (3D-QSAR) models between substituents ($R_1{\sim}R_5$) of tricyclic isoxazoles and their antidepressant activity against medetomidine-induced loss of righting were performed and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indies analysis (CoMSIA) methods. The correlativity and predictability ($r^2$=0.484 and $q^2$=0.947) of CoMSIA-2 model were higher than those of the rest models. The inhibitory activity against medetomidine-induced loss of righting was dependent on electrostatic field (43.4%), hydrophobic field (35.3%), and steric field (21.2%) of tricyclic isoxazoles. From the CoMSIA-2 contour maps, it is predicted that the antidepressant activity of potent antidepressants against medetomidine-induced loss of righting will be able to increase by the substituents ($R_1{\sim}R_5$) which were in accord with CoMSIA field.

• Korean Journal of Childcare and Education
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• v.13 no.2
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• pp.149-164
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• 2017

Objective: This study aimed to examine the mediation effects of parenting style and daily activity on the relationships between cumulative parental stress and cognitive and language development of children. Methods: The participants of this study were 1,154 mothers, their five-year-old children, and teachers enrolled in the population-based study of the Panel Study of Korea Children (PSKC) conducted by the Korea Institute of Childcare and Education from 2008 to 2013. In order to analyze the data, descriptive analysis, Pearson correlation analysis, and structural equation modeling were used. Results: The results revealed that warm parenting style as well as daily activity had dual mediating effects between cumulative parental stress and child development (cognitive and language development). However, warm parenting style did not have any direct effects on child development in this model. Conclusion/Implications: Given that actual mother-child daily activity had an important role in affecting child development, support programs for parenting should include activities that include specific materials and activities which parents can do with their children in everyday life.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.246-247
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• 1996

In the previous reports (Park et al., 1991, and 1993), we described the synthesis and analgesic effects of various homovanillic amides as analogs of capsaicin. In the study, we tried to enhance the analgesic actvity of capsaicin by structural modification. Our study has been performed in three directions. First, the amide bond of capsaicin was transposed. Second, a phenyl ring was introduced to replace a double bond of capsaicin. Finally, aminoethylation was performed on 4-hydroxy group of capsaicin to improve oral bioavailability. These studies have led to N-(3-phenylpropyl)homovanillic amide 2 which has high analgesic activity. Our continuing efforts in this area have focused on the introduction of various substituents on the phenyl ring of 2 as well as their pharmacological studies. We report herein the synthesis of homovanillic amide derivatives and their analgesic activity.