• BMB Reports
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• 제50권7호
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• pp.367-372
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• 2017

Monoacylglycerol acyltransferase 1 (MGAT) is a microsomal enzyme that catalyzes the synthesis of diacylglycerol (DAG) and triacylglycerol (TAG). However, the subcellular localization and catalytic function domain of this enzyme is poorly understood. In this report, we identified that murine MGAT1 localizes to the endoplasmic reticulum (ER) under normal conditions, whereas MGAT1 co-localize to the lipid droplets (LD) under conditions of enriching fatty acids, contributing to TAG synthesis and LD expansion. For the enzyme activity, both the N-terminal transmembrane domain and catalytic HPHG motif are required. We also show that the transmembrane domain of MGAT1 consists of two hydrophobic regions in the N-terminus, and the consensus sequence FLXLXXXn, a putative neutral lipid-binding domain, exists in the first transmembrane domain. Finally, MGAT1 interacts with DGAT2, which serves to synergistically increase the TAG biosynthesis and LD expansion, leading to enhancement of lipid accumulation in the liver and fat.

• BMB Reports
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• 제29권4호
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• pp.343-352
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• 1996

The biosynthesis of phospholipid and the composition of fatty acid were analyzed in mitochondria isolated from Chlorella ellipsoidea treated with carbon sources (glucose, sucrose, raffinose) during the culture. The growth of Chlorella and total lipid contents in mitochondria treated with various carbon sources was increased to compare with the control. When Chlorella mitochondria was treated with various carbon sources, four kinds of phospholipid were increased predominantly. The major fatty acids utilized for the biosynthesis of the phospholipid were analyzed linoleic acid (average 25.18%) and stearic acid (average 10.52%) in the control. But, it was shown that the major fatty acids in Chlorella mitochondria treated with glucose were stearic acid (average 30.93%), palmitic acid (average 17.47%) and stearic acid (average 20.31%), linoleic acid (average 16.68%) in sucrose treatment and oleic acid (average 17.17%), palmitic acid (average 15.64%) in raffinose treatment.

• Animal cells and systems
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• 제2권3호
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• pp.341-349
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• 1998

To analyze the effects of surfactants on the biosynthesis of galactolipid and the composition of fatty acids, the chloroplast envelope and thylakoid membrane were cultivated in medium treated with anionic surfactants, such as linear alkylbenzene sulfonate (0.002%, LAS), a-olefin sulfonate (O.01%, AOS), and sodium lauryl ether sulfate (0.08%, SLES), respectively. During the cultivation, the chloroplast envelope and thylakoid membrane were isolated from the cells collected at the early and middle phase of the culture and the contents of their fatty acid composition were compared with the control. When treated with surfactants, the contents of total lipid MDGD methylesters, and DGDG methylesters decreased significantly when compared with the control. It was also confirmed that more unsaturated fatty acids were involved in the biosynthesis of galactolipid. The fatty acids utilized in the biosynthesis of MGDG were in the chloroplast envelope and in the control, and linoleic acid in LAS, linolenic acid and oleic acid in AOS, and linolenic acid and oleic acid in SLES. The fatty acids in the biosynthesis of DGDG were linolenic acid and oleic acid in the control linolenic acid and stearic acid in LAS, oleic acid and linolenic acid in AOS, oleic acid and linolenic acid in SLES. In the thylakoid membrane, the major fatty acids in the biosynthesis of MGDG were linolenic acid and oleic acid in the control, oleic acid and linolenic acid in LAS, linolenic acid and linoleic acid in AOS, linolenic acid and palmitoleic acid in SLES. The fatty acids in the biosynthesis of DGDG were linolenic acid and oleic acid in the control, oleic acid and linolenic acid in LAS, linolenic acid and linoleic acid in AOS, palmitoleic acid and oleic acid in SLES.

• ALGAE
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• 제26권1호
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• pp.3-20
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• 2011

The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has been studied for several decades. Early D. salina research focused on its remarkable salinity tolerance and ability, upon exposure to various abiotic stresses, to accumulate high concentrations of $\beta$-carotene and other carotenoid pigments valued highly as nutraceuticals. The simple life cycle and growth requirements of D. salina make this organism one of the large-scale commercially exploited microalgae for natural carotenoids. Recent advances in genomics and proteomics now allow investigation of abiotic stress responses at the molecular level. Detailed knowledge of isoprenoid biosynthesis mechanisms and the development of molecular tools and techniques for D. salina will allow the improvement of physiological characteristics of algal strains and the use of transgenic algae in bioreactors. Here we review D. salina isoprenoid and carotenoid biosynthesis regulation, and also the biotechnological and genetic transformation procedures developed for this alga that set the stage for its future use as a production system.

• 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.

• 한국식품과학회지
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• 제10권3호
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• pp.313-319
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• 1978

무지방사료(無脂肪飼料) 및 여기에 17:0, 18:0 혹은 18:2을 첨가(添加)한 사료(飼料)를 병아리에 급여(給與)해서 간장(肝臟) 및 혈장(血漿)의 각지질분획(各脂質分劃)의 지방산조성(脂肪酸組成)에 미치는 급여지방산(給與脂肪酸)의 영향(影響)을 조사(調査)하였다. 그 결과(結果) 간장중(肝臟中)의 총지질함량(總脂質含量) 및 각지질분획(各脂質分劃)의 함량(含量)은 급여지방산(給與脂肪酸)에 의해서 영향(影響)받지 않았다. 그러나 17:0을 급여(給與)하면 간장(肝臟) 및 혈장(血漿)의 각지질분획(各脂質分劃)에 17:0 및 17:1 출현(出現)하고, 혈장(血漿)트리그리세라이드에서는 17:0이 또한 혈장(血漿)콜레스테롤에스텔에서는 17:1이 다른 분획(分劃)보다도 유의(有意)하게 높았다. 더욱이 간장(肝臟)에서는 각분획(各分劃)사이에 양지방산(兩脂肪酸)의 분포치(分布値)에 큰 차이(差異)가 없었다. 18:2의 급여(給與)도 17:0을 급여(給與)한때와 같이 간장(肝臟) 및 혈장(血漿)의 각지질분획(各脂質分劃)에 18:2이 출현(出現)하고, 특(特)히 간장인지질분획(肝臟燐脂質分劃)에서 18:2의 분포치(分布値)는 다른분획(分劃)보다도 유의(有意)하게 높았다. 그러나 18:0을 급여(給與)해도 이것이 간장(肝臟) 및 혈장중(血漿中)에 특별적(特別的)으로 증가(增加)하지는 않았다. 또한 17:0 및 18:2과 같은 외인성지방산(外因性脂肪酸)의 급여(給與)에 의하여 내인적(內因的)으로 합성(合成)되는 16:1 및 18:1의 분포치(分布値)는 간장(肝臟)에서 감소(減少)하는 경향(傾向)을 나타내었다.

• 한국환경보건학회지
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• 제23권2호
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• pp.12-23
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• 1997

Potassium dichromate(PD, 500 ppm, 500 ppm), potassium chromate(PC, 500 ppm, 500 ppm), cobalt chloride(CC, 100 ppm, 10 ppm), methylmercuric chloride(MC, 100 ppm, 10 ppm)을 처리한 배지에 E. coli와 B.subtilis를 배양하는 동안에 당지질과 galactose의 생합성 및 지방산 조성을 대조구와 비교 분석하였다. 금속화합물 처리구에서의 생장과 MGDG, DGDG의 함량 및 total lipid는 대조구에 비해 감소하였다. 또한 당지질 형성에 이용된 galatose의 함량은 억제되었다. E. coli와 B. subtilis에서 MGDG와 DGDG 합성에 이용된 주요 지방산은 다양한 변화를 나타내었다.

• Journal of Plant Biology
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• 제35권1호
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• pp.25-36
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• 1992

Chlorella 엽록체에서 인지질 생합성과 그의 지방산 조성에 미치는 amphotericin B($150\;\mu\textrm{g}/ml$)와 cycloheximide($10\;\mu\textrm{g}/ml$)의 영향을 분석하였다. Total lipid와 인지질 함량(PC, PE, PI)은 항생제 처리구가 대조구에 비하여 낮았다. Whole cell system에서의 주요 지방산은 대조구에서는 palmitic acid(31.96%)와 linoleic acid(16.96%)로 나타났으나 amphotericin B 처리구에서는 palmitic acid(36.15%)와 linolenic acid(16.71%)로 분석되었다. 또한 cycloheximide 처리구에서는 palmitic acid(31.90%)와 stearic acid(15.32%)가 인지질 형성에 이용되었다. 분리한 엽록체의 대조구(33.75%, 18.90)와 amphotericin B 처리(36.75%, 9.46%)에서 분리한 엽록체에서 인지질 형성에 이용되는 주요 지방산은 palmitic acid와 linolenic aicd였으나 cycloheximide 처리구에서는 palmitic acid(28.01%)와 oleic acid(19.27%)가 인지질생합성에 도입된 것으로 분석되었다.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.990-999
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• 2012

The microbial biosynthesis of fatty acid of lipid metabolism, which can be used as precursors for the production of fuels of chemicals from renewable carbon sources, has attracted significant attention in recent years. The regulation of fatty acid biosynthesis pathways has been mainly studied in a model prokaryote, Escherichia coli. During the recent period, global regulation of fatty acid metabolic pathways has been demonstrated in another model prokaryote, Bacillus subtilis, as well as in Streptococcus pneumonia. The goal of this study was to increase the production of long-chain fatty acids by developing recombinant E. coli strains that were improved by an elongation cycle of fatty acid synthesis (FAS). The fabB, fabG, fabZ, and fabI genes, all homologous of E. coli, were induced to improve the enzymatic activities for the purpose of overexpressing components of the elongation cycle in the FAS pathway through metabolic engineering. The ${\beta}$-oxoacyl-ACP synthase enzyme catalyzed the addition of acyl-ACP to malonyl-ACP to generate ${\beta}$-oxoacyl-ACP. The enzyme encoded by the fabG gene converted ${\beta}$-oxoacyl-ACP to ${\beta}$-hydroxyacyl-ACP, the fabZ catalyzed the dehydration of ${\beta}$-3-hydroxyacyl-ACP to trans-2-acyl-ACP, and the fabI gene converted trans-2-acyl-ACP to acyl-ACP for long-chain fatty acids. In vivo productivity of total lipids and fatty acids was analyzed to confirm the changes and effects of the inserted genes in E. coli. As a result, lipid was increased 2.16-fold higher and hexadecanoic acid was produced 2.77-fold higher in E. coli JES1030, one of the developed recombinants through this study, than those from the wild-type E. coli.

• Journal of Nutrition and Health
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• 제20권1호
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• pp.46-53
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• 1987

The effect of bile deprivation on serum lipid and gastrin contents was investigat\ulcornered after choledocho-urinary cystostomy in Sprague-Dawley rats. Bile deprivated rats were compared with sham operated control group. Gastrin levels in serum and antral tissue were measured and serum lipid concentrations were also measured. Gastrin levels of serum and tissue after bile deprivation were increased significantly compared with those of the controL At the end of 1st and 2nd week after bile deprivation, serum cholesterol and triglyceride contents were significantly lower han those of the control. By 4th week, there was no significant difference between two groups. Increases in serum and antral gastrin levels temporarily coincided well with decreases in serum lipid contents after bile deprivation. These results suggest that there is increase in biosynthesis and release of gastrin and decrease in fat absorption at early stage of bile deprivation.