• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1799-1804
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• 2003

Acetolatate synthase(ALS) catalyzes the first common step in the biosynthesis of valine, leucine, isoleucine in plants and microorganisms. ALS is the target of several classes of herbicides, including the sulfonylureas, the imidazolinones, and the triazolopyrimidines. To elucidate the roles of arginine residues in tobacco ALS, chemical modification and site-directed mutagenesis were performed. Recombinant tobacco ALS was expressed in E. coli and purified to homogeneity. The ALS was inactivated by arginine specific reagents, phenylglyoxal and 2,3-butanedione. The rate of inactivation was a function of the concentration of modifier. The inactivation by butanedione was enhanced by borate, and the inactivation was reversible on removal of excess butanedione and borate. The substrate pyruvate and competitive inhibitors fluoropyruvate and phenylpyruvate protected the enzyme against inactivation by both modifiers. The mutation of well-conserved Arg198 of the ALS by Gln abolished the enzymatic activity as well as the binding affinity for cofactor FAD. However, the mutation of R198K did not affect significantly the binding of FAD to the enzyme. Taken together, the results imply that Arg198 is essential for the catalytic activity of the ALS and involved in the binding of FAD, and that the positive charge of the Arg is crucial for the interaction with negatively charged FAD.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.642-645
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• 2001

Enterococcus faecalis was cultivated under oxidative conditions established by adding some oxidants. FAD and lipoic acid either stimulate the biosynthesis of benzoylformate reductase or stabilize the enzyme, while $MV^{2+}$ enhance the biosynthesis of the oxidoreductase but destabilize it. Since $MV^{2+}$ destabilize the benzoylformate reductase, substituting FAD for $MV^{2+}$ as a redox mediator would be desirable. Production of (R)-(-)-mandelic acid by a coupled reaction between the enzymatic reaction using benzoylformate reductase and the electrocatalytic reduction under the conditions of 1.5 U LiDH $ml^{-1}$, 0.2 mM FAD, and 0.3 mM $NAD^+$ is now performing.

• Applied Biological Chemistry
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• 제2권
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• pp.29-35
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• 1961

The daily variation in the total quantity of flavin compounds (FAD, FMN, FR) in greenbean during its germination were measured by Yagi's methods. The results obtained were as follow. 1. The total quantity of flavin compounds of the greenbean sprouts was increased with growth of sprouts until the 8th days. After this period its contents were decreased slightly. 2. The flavin compounds of greenbean sprouts were comfirmed to be synthesized as free riboflavin during its germination. 3. FAD was the major pat of total flavin compounds in cotyledon but there was significant variation in the contents of FAD, FMN and FR in hypocotyl.

• Applied Biological Chemistry
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• 제1권
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• pp.62-67
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• 1960

1) The variations of flavin adenine dinucleotide(FAD), flavin monomucleotide(FMN) and free riboflavin in control and 600r X-ray irradiated soybean sprout were estimated by the paper chromatographic method. 2) It was found that the formation of riboflavin in soybean sprout was mainly in FAD. 3) There were no great variation of FMN and free riboflavin in soybean sprout during the germination. 4) The moderate amount (600r) of X-ray irradiation accerelated the formation of FAD in soybean sprout during the germination.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.413-413
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• 2005

• 한국식품위생안전성학회지
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• 제2권1호
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• pp.9-14
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• 1987

식품의 상품화에 따라 식품 첨가물의 사용이 증가되고 있다. 식품 첨가물로서 색소는 고유의 색소를 보존하기 어려운 식품에 따라 사용되며 tar 색소, 식물성 색소 및 광물성 색소로 나눌 수 있는데 tar 색소는 독성이 강한 것이 많으므로 현재 15종만이 법적으로 허용되어 있다. 이중 azo 화합물인 amaranth, tartrazine, sunset yellow, allura red에 대하여 흰 주위 hepatic azo reductase의 활성을 측정 비교하였고 이에 대한 flavin의 효과를 보았다. 1. Amaranth를 기질로 사용하여 kinetic constants $Km=645\;\mu\textrm{M}$, Vmax=50 n mol/min/mg protein의 값을 얻었다. 2. Amaranth의 농도를 일정하게 하고 FAD의 농도를 증가시켰을 때 hepatic azo reductase의 활성은 현저히 증가하였으나 NADPH-generating system에 의한 환원은 작은 증가를 나타냈다. 3. 기타 식용 azo 색소 tartrazine, sunset yellow, allura red를 기지로 azo reductase activity를 측정한 결과 sunset yellow는 amaranth와 비슷한 환원활성은 나타냈고, tartrazine은 보다 낮은 환원활성을 allura red는 보다 높은 환원활성을 나타냈으며, $300\;\mu\textrm{M}-FAD$에 의해 기질 모두에서 환원활성이 증가함을 알 수 있었다.

• 수산해양기술연구
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• 제57권3호
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• pp.194-204
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• 2021

The research was analyzed the catch data of the five years (2016-2020) for six joint venture company tuna purse seiners in the Atlantic Ocean, with the aim of suggesting improvement measures for responsible and sustainable fishing according to changes of recommendation by International Commission for the Conservation of Atlantic Tuna (ICCAT) on the tropical tunas. In the last five years, the average catch of six tuna purse seiner gradually increased to 7,745 tons, 8,364 tons and 9,053 tons from 2016 to 2018, but decreased to 7,761 tons in 2019 and 6,214 tons in 2020. The reason for the decrease in fishing volume in 2019 and 2020 was the fluctuation of the formation of the cold water zone (22-23℃), and the total ICCAT convention area of FAD closure in January and February due to the expansion of the FAD closure area and poor free school catching during two months period, respectively. The analysis on fishing area showed that the percentage of fishing in the high sea was about 85% although the FAD closure area included the EEZ zone in coastal countries; the rise of the fishing license in coastal countries is also believed to be a factor. In order to overcome such situations and improve catching volume, it will be possible if excellent manpower is secured, school fishing is expanded, and the production of high value-added catch (purse seine special: PS).

• Clinical Nutrition Research
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• 제11권3호
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• pp.159-170
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• 2022

Ischemic stroke and Alzheimer's disease (AD) are representative geriatric diseases with a rapidly increasing prevalence worldwide. Recent studies have reported an association between ischemic stroke neuropathology and AD neuropathology. Ischemic stroke shares some similar characteristics with AD, such as glia activation-induced neuroinflammation, amyloid beta accumulation, and neuronal cell loss, as well as some common risk factors with AD progression. Although there are considerable similarities in neuropathology between ischemic stroke and AD, no studies have ever compared specific genetic changes of brain cortex between ischemic stroke and AD. Therefore, in this study, I compared the cerebral cortex transcriptome profile of 5xFAD mice, an AD mouse model, with those of middle cerebral artery occlusion (MCAO) mice, an ischemic stroke mouse model. The data showed that the expression of many genes with important functional implications in MCAO mouse brain cortex were related to synaptic dysfunction and neuronal cell death in 5xFAD mouse model. In addition, changes in various protein-coding RNAs involved in synaptic plasticity, amyloid beta accumulation, neurogenesis, neuronal differentiation, glial activation, inflammation and neurite outgrowth were observed. The findings could serve as an important basis for further studies to elucidate the pathophysiology of AD in patients with ischemic stroke.

• 한국균학회지
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• 제17권3호
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• pp.161-168
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• 1989

표고버섯(L. edodes) 중의 mitochondria는 설탕밀도단계기울기법에 따라 분리정제 하였다. 앞서 보고한 바와 같이, 각 파장별 빛조사(400-700nm)에 따른 mitochondrial ATPase와 ATP synthase의 활성도는 680nm와 470nm에서 각각 활성화되었다. 본 연구에서, 400nm 이하의 파장별 빛조사에 따른 mitochondrial ATPase 및 ATP synthase의 활성도는 380nm와 330nm에서 각각 활성화되었으며, 330nm 및 350에서 각각 억제되었다. FAD의 존재하에서, mitochondrial ATP synthase는 활성화 파장 및 억제 파장의 조사에 의하여 활성도가 각각 증가된 반면, mitochondrial ATPase의 활성도는 감소되었다. 그러나, NADH의 존재하에서, 이들 파장의 조사에 의한 효소의 활성도는 변화가 없었다. 또한, 두 효소는 각각의 활성화 파장 및 억제 파장이 조사됨에 따라 $FADH_2$를 FAD로 산화시키는 spectrum을 보였다. 이로써, 이 두 효소는 빛 조사에 의하여 생체내의 산화 환원반응의 산화제로 작용하였으며, 특히 mitochondrial ATP synthase의 활성화에 따른 광유발물질은 mitochondria 중에 존재하는 flavin 또는 flavoprotein으로 추정된다.

• Journal of Applied Biological Chemistry
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• 제42권3호
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• pp.113-118
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• 1999

The transgenic plant of Citrus species (Citrus aurantium L.) was constructed with a fatty acid desaturase gene using microprojectile bombardment transformation system. The DNA of a fatty acid desaturase gene, fad7, constructed in pBI121 was coated onto tungsten particles ($1.1{\mu}m$) and introduced into callus cells by bombarding with 1100 psi of helium pressure, 1/4 in of gap distance, 7.0 cm of target distance and 27 in Hg of chamber vacuum. The bombarded cells were selected on the medium containing kanamycin. The selected cells were successfully regenerated into plantlets via somatic embryogenesis on the media containing plant growth regulators. The results of polymerase chain reaction analysis of genomic DNAs from the putative transformants showed that the introduced DNAs of fad7 were present in both the selected callus cells and the regenerated plantlets.