• Journal of Pharmaceutical Investigation
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• 제22권2호
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• pp.115-124
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• 1992

The characteristics and stabilities of phosphatidylcholine liposomes covalently coupled with immunoglobulin fragments prepared by the REV method were investigated by the dynamic light scattering, absorbance and calcein release. Using a sulfhydryl-reactive phospholipid derivative of N-[4$({\rho}-maleimido-phenyl)$ butyl] phosphatidylethanolamine (MPB-PE), Fab' antibody fragments were covalently combined with preformed large unilamellar vesicles (LUV), Coupling ratio was $250\;{\mu}g$ of $Fab'/{\mu}mol$ of phospholipid in vesicles, From dynamic light scattering, it was found that the size of the vesicles increases as the ratio of cholesterol to lipid increases, but that apparently, the size of liposomes was not sensitive to the existence of Fab' fragments. Regardless of inserting Fab' fragments, the absorbance of liposomes decreased as the amounts of bile salt (BS) added. At very low BS concentrations, BS/lipid aggregates would be formed in the outer vesicles monolayer, while, at the high BS concentrations, mixed micelles would be preferred. The vesicles incorporated with Fab' fragments, however, are more resistant to the bile salts than the MPB-PE vesicle are. The absorbance of vacant liposomes and calcein release resulted in that the Fab' vesicles and MPB-PE vesicles by the REV method are very stable, but that those by the sonication method sufferred the significant change of turbidities.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1536-1541
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• 2018

A yellowish, flexirubin-pigment-producing strain $I3-3^T$ was isolated from river water in Iksan, the Republic of Korea. The strain was gram-negative, aerobic, non-motile, showed catalase and oxidase activities, and could grow at a temperature range of $10-35^{\circ}C$, pH 5.0-10 and 0-2.0% (w/v) of NaCl. The major fatty acids were iso-$C_{15:0}$, iso-$C_{17:0}$ 3-OH and summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$). The isolate contained phosphatidylethanolamine, one aminolipid, and two unidentified lipids as the major polar lipids. Menaquinone-6 (MK6) was the major respiratory quinone. The G+C content of the genomic DNA of strain $I3-3^T$ was 35.6%. Comparison of the 16S rRNA gene sequence with the sequences of the closely related type strains showed highest sequence similarity of 96.95% and 96.93% to Flavobacterium nitrogenifigens $NXU-44^T$ and Flavobacterium compostarboris $15C3^T$, respectively. Based on phenotypic and phylogenetic distinctiveness, strain $I3-3^T$ is considered as a member of novel species within the genus Flavobacterium, for which Flavobacterium amnigenum sp. nov. is proposed. The type strain is $I3-3^T$ (=KCTC $52884^T$ =NBRC $112871^T$).

• 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.

• Parasites, Hosts and Diseases
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• 제49권2호
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• pp.103-108
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• 2011

Autophagy is a catabolic process involved in the degradation of a cell's own components for cell growth, development, homeostasis, and the recycling of cellular products. Autophagosome is an essential component in the protozoan parasite during differentiation and encystation. The present study identified and characterized autophagy-related protein (Atg) 3, a member of Atg8 conjugation system, in Acanthamoeba castellanii (AcAtg3). AcAtg3 encoding a 304 amino acid protein showed high similarity with the catalytic cysteine site of other E2 like enzymes of ubiquitin system. Predicted 3D structure of AcAtg3 revealed a hammer-like shape, which is the characteristic structure of E2-like enzymes. The expression level of AcAtg3 did not increase during encystation. However, the formation of mature cysts was significantly reduced in Atg3-siRNA transfected cells in which the production of Atg8-phosphatidylethanolamine conjugate was inhibited. Fluorescent microscopic analysis revealed that dispersed AcAtg3-EGFP fusion protein gathered around autophagosomal membranes during encystation. These results provide important information for understanding autophagic machinery through the lipidation reaction mediated by Atg3 in Acanthamoeba.

• 한국식생활문화학회지
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• 제35권3호
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• pp.302-310
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• 2020

Although the age-standardized incidence of gastric cancer has decreased in Korea, it remains the second most common type of cancer. The purpose of this study was to analyze the phospholipid fatty acid compositions of gastric mucosa in gastric cancer. Cancerous mucosa and noncancerous mucosa adjacent to cancerous tissues were obtained from 29 patients who had undergone gastrectomy for gastric adenocarcinoma. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) were separated from phospholipids by thin-layer chromatography, and fatty acids were analyzed by gas chromatography. In cancerous mucosa, saturated fatty acids of total phospholipids and stearic acid of PE and PC contents as well as total phospholipids were significantly more abundant than in noncancerous tissues. The ratios of ω6 fatty acid products to linoleic acid of PC, PE, PI, and PS contents as well as total phospholipids were significantly higher in cancerous mucosa than in noncancerous mucosa. Arachidonic acid levels of PE and PI were significantly higher, but the PC level was lower in cancerous mucosa. These results suggest that the characteristic differences in fatty acid compositions of phospholipids and their subfractions shown in gastric cancerous mucosa may be affected by changes in lipid metabolism in gastric carcinogenesis. Further studies on structural and functional changes in phospholipids related to gastric carcinogenesis will be needed.

• 대한화학회지
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• 제44권5호
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• pp.448-452
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• 2000

포스포리파제 D(PLD)는 인지질의 말단염기를 가수분해하여 phosphatidic acid(PA)와 염기로 분리시키는 효소이다. 본 연구는 쥐의 뇌에서 분리한 미토콘드리아 분획에서 PLD를 활성에 미치는 spermine의 영향을 조사하였다. 올레산 존재하에서 spermine이 PLD를 활성화시켰으며 $Ca^{2+}$, $Mg^{2+}$ 그리고 $Ba^{2+}$는 spermine의 영향을 더욱 강화시켜주는 것으로 나타났다. 다른 아민들은 별 효과가 없었으나 histamine경우 높은 농도에서 PLD를 활성화시켰다. Polylysine들도 PLD를 활성화시켰으며 그 길이가 길수옥 더욱 효과적으로 작용하였다. 기질 특이성에 있어서는 phosphatidylcholine(PC)과 phosphatidylethanolamine(PE) 사이에 큰 차이를 보이지는 않았다. 이 기질 특이성은 쥐 소장 미토콘드리아 PLD의 PE 특이성과 상이한 것으로 나타났다.

• 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.

• 한국동물학회지
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• 제37권1호
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• pp.76-87
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• 1994

High density lipophorin-L (HDLP-L) was purified from the hemolymph of Bombyx modi using KBr density gradient ultracentrifugation and gel permeation chromatographv (Sephadex G-2001. Lipophorin has native molecular weight of 730 Nd and consists of Apo-Lp I and Apo-Lp II with molecular weights of 250 Kd and 90 Kd, respectively. Lp contains large amounts of glutamine & glutamic acid, threonine, leucine but small amounts of cysteic acid & oxidized cystine, tyrosine, methionine. Lp also contains diacylglycerol, cholesterol, phosphatidylcholine, and phosphatidylethanolamine. Anti-lipophorin showed positive reaction with fat body and ovarial extracts and also revealed immunological identity with lipophorin of Fall webworm, Hyphantria cunea. Lipophorin maintains constant level during larval and pupal stapes but greatlv increases during adult stage in both male and female. Apo-Lp III was purified from adult hemolymph. Hemolymph was subjected to KBr ultracentrifusation and Lp-free fraction was submitted to cation exchange chromatosraphy after ammonium sulfate precipitation. Apo-Lp III has molecular weight of 17 Kd, and similar amino acid composition ar those of other species Lp but contains high amounts of tryptophan which other are tacking in.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.373-377
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• 2007

No phosphatidylcholine (PC) was detected in the membrane of Rhodobacter sphaeroides pmtA mutant (PmtAl) lacking phosphatidylethanolamine (PE) N-methyltransferase, whereas PE in the mutant was increased up to the mole % comparable to the combined level of PE and PC of wild type. Neither the fatty acid composition nor the fluidity of membrane was altered by pmtA mutation. Consistently, aerobic and photoheterotrophic growth of PmtAl were not different from wild type. However, PmtAl showed an extended lag phase (15 h) after the growth transition from aerobic to photoheterotrophic conditions, indicating the PC requirement for the efficient formation of intracytoplasmic membrane (ICM). Interestingly, the B800-850 complex of PmtAl was decreased more than twofold in comparison with wild type, whereas the level of the B875 complex comprising the fixed photosynthetic unit was not changed. Since puc expression is not affected by pmtA mutation, PC appears to be required for the proper formation of the B800-850 complex in the ICM of R. sphaeroides.

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.194-201
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• 2017

Lysophosphatidylethanolamine (LPE), a lyso-type metabolite of phosphatidylethanolamine, has been reported to be an intercellular signaling molecule. LPE mobilizes intracellular $Ca^{2+}$ through G-protein-coupled receptor (GPCR) in some cells types. However, GPCRs for lysophosphatidic acid (LPA) were not implicated in the LPE-mediated activities in LPA GPCR overexpression systems or in SK-OV3 ovarian cancer cells. In the present study, in human SH-SY5Y neuroblastoma cells, experiments with $LPA_1$ antagonists showed LPE induced intracellular $Ca^{2+}$ increases in an $LPA_1$ GPCR-dependent manner. Furthermore, LPE increased intracellular $Ca^{2+}$ through pertussis-sensitive G proteins, edelfosine-sensitive-phospholipase C, 2-APB-sensitive $IP_3$ receptors, $Ca^{2+}$ release from intracellular $Ca^{2+}$ stores, and subsequent $Ca^{2+}$ influx across plasma membranes, and LPA acted on $LPA_1$ and $LPA_2$ receptors to induce $Ca^{2+}$ response in a 2-APB-sensitive and insensitive manner. These findings suggest novel involvements for LPE and LPA in calcium signaling in human SH-SY5Y neuroblastoma cells.