• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.246-248
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• 1993

We investigated the responses of six types of lipid-coated AT-cut quartz crystal resonators to chemical vapour sensors. The responses of quartz crystal at 9 MHz coated with phosphatidylglycerol (PG), phosphatidylinositol(PI), phosphatidylethanolamine(PE), phosphatidylserine(PS), and lipid A(LA) were obtained for amyl acetate, acetoin, menthane and other organic gases which showed different affinities for each lipid. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the normalized resonant frequency shift pattern.

• Journal of Plant Biology
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• 제36권1호
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• pp.97-104
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• 1993

The lipid composition of thylakoid membranes was compared between mesophyll and bundle sheath chloroplasts of maize. According to mild-denaturing gel electrophoresis, mesophyll thylakoids contained both PS I complex and PS II light-harvesting chlorophyll-protein complex(LHCP), while those of bundle sheath cells contained mainly PS I complex. The amount of lipids per mg chlorophyll was higher in bundle sheath thylakoids than in mesophyll. The major polar lipid classes were monogalactosyldiacylglycerol(MGDG), digalactosyldiacylglycreol, sulfolipid and phosphatidylglycerol (PG) in both tissues. Linolenic acid(18 : 3), linoleic acid(18 : 2) and palmitic acid(16 : 0) were the main fatty acyl components, with higher ratio of unsaturated to saturated fatty acids in bundle sheath thylakoids, suggesting these membranes are more fluid. The most striking difference in lipid composition between the two kinds of tissues was the practical absence of trans- 3-hexadecenoic acid(16 : 1t) in PG of bundle sheath thylakoids. This fatty acid is known to be involved in the association of LHCP as oligomeric form. More than 80% of MGDG molecular species was 18 : 3, 18 : 3, demonstrating that maize is a typical 18 : 3 plant. Therefore, the possibility of the functional relationships between the lamella structure, and thus the distribution of photosystems, and MGDG molecular species was excluded.

• 대한화학회지
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• 제54권2호
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• pp.183-191
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• 2010

1-Palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$)로 이루어진 지질 이중막에 항균성 펩타이드 magainin 2와 aurein 3.3이 작용했을 때 일어나는 상변화를 중수소 고체 핵자기 공명 스펙트럼을 관측하여 탐구하였다. 측정된 중수소 고체 핵자기 공명 스펙트럼의 선모양을 이론적 모델 구조를 통하여 모사함으로써, 펩타이드-지질 혼합상태의 기하학적 구조상수 및 동력학적 표면 확산 계수 등을 구하였다. 펩타이드의 혼합 이후 5일 이내의 짧은 작용시간에는 지질 이중막의 정렬이 파괴되는 현상이 나타났으나, 100일 이후에는 magainin 2에 의해서는 타원형 원환체 기공 (elliptic toroidal pore)이, aurein 3.3에 의해서는 6각형 단면 막대구조 상(hexagonal phase)이 관측되었다. 지질 이중막 표면의 전하밀도가 항균성 펩타이드의 작용에 미치는 효과를 보기 위해 산성 지질인 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG)를 함유한 POPC_$d_{31}$/POPG 지질 이중막에 대해서도 동일한 실험을 수행하였다. 동일한 ${\alpha}$-나선형 구조를 가지는 두 펩타이드가 두 종류의 지질 이중막에 작용하는 과정의 차이를 확인할 수 있었다.

• The Plant Pathology Journal
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• 제31권3호
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• pp.316-321
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• 2015

A small cationic peptide (JH8944) was tested for activity against a number of pathogens of agricultural crops. JH8944 inhibited conidium growth in most of the tested plant pathogens with a dose of $50{\mu}g/ml$, although one isolate of Fusarium oxysporum was inhibited at $5{\mu}g/ml$ of JH8944. Most conidia of Fusarium graminearum were killed within 6 hours of treatment with $50{\mu}g/ml$ of JH8944. Germinating F. graminearum conidia required $238{\mu}g/ml$ of JH8944 for 90% growth inhibition. The peptide did not cause any damage to tissues surrounding maize leaf punctures when tested at a higher concentration of $250{\mu}g/ml$ even after 3 days. Liposomes consisting of phosphatidylglycerol were susceptible to leakage after treatment with 25 and $50{\mu}g/ml$ of JH8944. These experiments suggest this peptide destroys fungal membrane integrity and could be utilized for control of crop fungal pathogens.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.372-378
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• 2010

Membrane disruption by an antimicrobial peptide, protegrin-1 (PG-1), was investigated by measuring the $^2H$ solid-state nuclear magnetic resonance (SSNMR) spectra of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) in the mixture of PG-1 and POPC_$d_{31}$ lipids deposited on thin cover-glass plates. The experimental line shapes of anisotropic $^2H$ SSNMR spectra measured at various peptide-to-lipid (P/L) ratios were simulated reasonably by assuming the mosaic spread of bilayers containing pore structures or the coexistence of the mosaic spread of bilayers and a fast-tumbling isotropic phase. Within a few days of incubation in the hydration chamber, the pores were formed by the peptide in the POPC_$d_{31}$ and POPC_$d_{31}$/cholesterol membranes. However, the formation of the pores was not clear in the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) membrane. Over a hundred days after hydration, a rapidly rotating isotropic phase increased in the POPC_$d_{31}$ and the POPC_$d_{31}$/cholesterol membranes with the higher P/L ratios, but no isotropic phase appeared in the POPC_$d_{31}$/POPG membrane. Cholesterol added in the POPC bilayer acted as a stabilizer of the pore structure and suppressed the formation of a fast-tumbling isotropic phase.

• Biomolecules & Therapeutics
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• 제5권3호
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• pp.253-259
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• 1997

The effect of corticosteroid on the diabetic pregnant rats and their fetuses was investigated. Streptozotocin (STB) was injected into the pregnant rats on the fifth day of pregnancy. Dexamethasone (DXM) was injected into the pregnant rats on the 17th, 18th, 19th and 20th days of pregnancy In prenatal rats, the body weight, an abortion rate, number of fetus, the ratio of lecithin/sphingomyelin (L/S) and the levels of blood glucose and phosphatidylglycerol (PG) were determined. In the postnatal rats, the body weight, the levels of blood glucose, fetal number, stillbirth rate, an organ weight and the levels of hepatic glycogen, protein and triglyceride were determined. The body weight of fetuses was lower in the DXM group and higher in the STZ group than the those of control group. Blood glucose of fetuses produced hypoglycemia in the STZ group compared with the control group. A significant increase in the abortion and stillbirth rates was observed in STZ group. The levels of glycogen, protein and triglyceride in fetus liver and the weight of pancreas were significantly increased in the 572 and STZ+DXM groups compared with the control group. The L/S ratio and the level of PG in the amniotic (quid were significantly decreased in STZ group compared with the control group, whereas those of the STZ+DXM group were similar to the control group. It has been observed that corticosteroid administration on the STZ-induced diabetic rats during final stage of pregnancy can prevent the respiratory depression syndrome of neonatal rats.

• 한국환경보건학회지
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• 제23권3호
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• pp.91-101
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• 1997

Cycloheximide와 nalidixic acid를 처리한 배지에 Chlorella ellipsoidea를 배양하였을 때 mitochondria의 인지질 생합성과 그의 지방산 조성에 어떤 영향을 미치는 가를 분석하였다. 생장율과 total lipid 함량은 항생제 처리구에서는 대조구보다 낮게 나타났다. PC와 PI의 합성은 nalidixic acid 처리구에서는 억제되었고, PC, PE, PG 그리고 PI의 함량은 cycloheximide 처리구에서 억제되었다. 항생제 처리구에서 여러가지 인지질 형성에 이용된 주요 지방산은 배양 말기에 stearic acid, myristic acid, palmitic acid, oleic acid, linoleic acid 및 linolenic acid들 인것이 분석되었다.

• 한국식품조리과학회지
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• 제23권2호통권98호
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• pp.180-186
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• 2007

In this study, we examined the effects of different water activities (Aw: 0.3, 0.5, and 0.8) on the lipid composition and oxidation of wheat flour after 28 days of storage in the dark at $60^{\circ}$C. The lipid content of the flour was 2.7%, and had decreased significantly (p<0.05) at the end of the storage period. Decrease in monoacylglycerol and increase in free fatty acids were observed, however, phosphatidic acid, phosphatidylglycerol, and phosphatidylinositiol were not detected after storage. Phosphatidylehtanolamine was more stable than phosphatidylcholine during the dark storage of flour. The flour lipids consisted of palmitic (18%), stearic (1%), oleic (14%), linoleic (63%), and linolenic (4%) acids, and the relative content of linolenic acid decreased after 28 days of storage. The conjugated dienoic acid content of the flour lipid had increased due to lipid oxidation during dark storage. Hydrolysis of neutral lipids and glycolipids, and lipid oxidation, were higher in the flour stored at Aw 0.8 than in the flour stored at Aw 0.3 or 0.5.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1300-1305
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• 2017

A rod shaped, aerobic, Gram-stain-negative, and motile bacterium, strain $AR2^T$, was isolated from a water sample of Yeongsan river, Republic of Korea. Strain $AR2^T$ clustered closely with the members of the genus Chitinimonas and showed the highest 16S rRNA gene sequence similarity with Chitinimonas prasina $LY03^T$ (96.4%), Chitinimonas viridis $HMD2169^T$ (96.4%), Chitinimonas taiwanensis $cf^T$ (96.2%), and Chitinimonas koreensis $R2A43-10^T$ (94.2%). The predominant fatty acids of strain $AR2^T$ were identified to be summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$), $C_{16:0}$, and $C_{10:0}3-OH$. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were found to be the major polar lipids. The genomic DNA G+C content was 60.4 mol%. Based on the polyphasic characterization, the isolated strain $AR2^T$ is described as a representative of a novel species in the genus Chitinimonas, for which the name Chitinimonas naiadis sp. nov. (type strain =$AR2^T$ =KCTC $42755^T$ =JCM $31504^T$) is proposed.

• Journal of Photoscience
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• 제7권2호
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• pp.39-44
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• 2000

To examine the chilling tolerance lipids, we compared the chilling susceptibility of photosystem II of wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids by being tansformed with cDNA for glycerol-3-phosphate acyltransferase from squash. For the purpose of studying on the functional integrity of photosystem II during low-temperature photoinhibition, the photochemical efficiency was measured as the ration of the maximun fluorescence of chlorophyll (Fv/Fm) of photosystem II. In parallel with an investigation on the transgenic plants, susceptibility of chilling-resistant species, such as spinah and pea, and of chilling-sensitive ones, such as squash and sweet potato, to low-temperature photoinhibition was also compared in terms of room temperature-induced chlorophyll fluorescence from photosystem II. When leaf disks from the two genotypes of tobacco plants were exposed to light at 5$^{\circ}C$, the transgenic plants showed more rapid decline in photochemical activity of photosysytme II than wild-type plants. When they were pretreated with lincomycin, an inhibitor of chloroplast-encoded protein synthesis, the extent of photoinhibition was even more accelerated. More impottantly, they showed a comparable extent of photoinhibition in the presence of lincomycin, making a clear contrast to the discrepancy observed in the discrepancy observed in the absence of lincomycin. Restoration of Fv/Fm during recovery from low-temperature photoinhibition occurred more slowly in the transgenic tobacco plants than the wild-type. These findings are discussed in relation to fatty acid unsaturation of membrane phosphatidylglycerol. It appears that the ability of plants to rapidly regenerate the active photosystem II complex from might explain, in part, why chilling-resistant plants can toleratlow-temperature photoinhibition.