• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 1997년도 추계정기총회 및 학술발표대회
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• pp.52-52
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• 1997

• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 2001년도 제10차 추계학술대회
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• pp.44-45
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• 2001

• Journal of Microbiology
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• 제40권1호
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• pp.43-50
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• 2002

A cluster of genes encoding the pyruvate dehydrogenase complex (PDC) of Streptomyces seoulensis, a Gram-positive bacterium, was cloned and sequenced. The genes of S. seoulensis consist of four open reading frames. The first gene, lpd, which encodes a lipoamide dehydrogenase, is followed by pdhB encoding a dihydrolipoamide acetyltransferase (E2p), pdhR, a regulatory gene, and pdhA encoding a pyruvate dehydrogenase component (Elp). Elp had an unusual homodimeric subunit, which has been known only in Gram-negative bacteria S. seoulensis E2p contains two lipoyl domains like those of humans and Streptomyces faecalis. The pdhR gene appears to be clustered with the structural genes of S. seoulensis PDC. The PdhR-overexpressed S. seoulensis howed growth retardation and the decrease of Elp, indicating that PdhR regulates the function of PDC by repressing the expression of Elp. A strain of Streptomyces licidans overexpressing S. seoulensis PdhR showed a significant decreasein the level of actinorhodin, implying a regulatory role for Streptomyces PDC in antibiotic biosynthesis.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.48-48
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• 2001

Gene expression and protein levels of serotonin N-acetyltransferase (AA-NAT, EC2.3.1.87) directly control the diurnal production of the melatonin and correlate with enzyme activity. Effects of protein phosphorylation on the AA-NAT activity were investigated in rat pineal glands and COS-7 cells transiently transfected with AA-NAT cDNA.(omitted)

• 약학회지
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• 제47권2호
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• pp.69-77
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• 2003

Arachidonic acid (AA), which is stored in membrane glycerophospholipids, is liberated by phospholipase $A_2$ (PLA$_2$) enzymes and is sequentially converted to cyclooxygenases (COXs) and lipoxygenases (LOXs) then to various bioactive PGs, and LTs. In order to find the specific inhibitors of AA metabolism especially PLA$_2$, COX-2, 5-LO and lyso PAF acetyltransferase, 120 Korean residential plants extracts were evaluated for their inhibitory activity on PGD$_2$, LTC$_4$ production from cytokine-induced mouse bone marrow-derived mast cells (BMMC) and arachidonic acid released from phospholipid and PAF production from lyso PAF. From this screening procedure, methanol extract of ten indigenous plant such as Salix gracilistyla, Sedum kamtschaticum, Cirsium chanroenicum, Hypericum ascyron, Astilbe chinensis, Agrimonia pilosa, Aristolochia manshuriensis, Vodia daniellii, Pyrola japonica, Styrax obassia were found to inhibit production of inflammatory mediators in vitro assay system.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.857-864
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• 2017

Objective: The purpose of this study was to investigate the influence of AMP-activated protein kinase (AMPK) activation on protein acetylation and glycolysis in postmortem muscle to better understand the mechanism by which AMPK regulates postmortem glycolysis and meat quality. Methods: A total of 32 mice were randomly assigned to four groups and intraperitoneally injected with 5-Aminoimidazole-4-carboxamide1-${\beta}$-D-ribofuranoside (AICAR, a specific activator of AMPK), AICAR and histone acetyltransferase inhibitor II, or AICAR, Trichostatin A (TSA, an inhibitor of histone deacetylase I and II) and Nicotinamide (NAM, an inhibitor of the Sirt family deacetylases). After mice were euthanized, the Longissimus dorsi muscle was collected at 0 h, 45 min, and 24 h postmortem. AMPK activity, protein acetylation and glycolysis in postmortem muscle were measured. Results: Activation of AMPK by AICAR significantly increased glycolysis in postmortem muscle. At the same time, it increased the total acetylated proteins in muscle 45 min postmortem. Inhibition of protein acetylation by histone acetyltransferase inhibitors reduced AMPK activation induced increase in the total acetylated proteins and glycolytic rate in muscle early postmortem, while histone deacetylase inhibitors further promoted protein acetylation and glycolysis. Several bands of proteins were detected to be differentially acetylated in muscle with different glycolytic rates. Conclusion: Protein acetylation plays an important regulatory role in postmortem glycolysis. As AMPK mediates the effects of pre-slaughter stress on postmortem glycolysis, protein acetylation is likely a mechanism by which antemortem stress influenced postmortem metabolism and meat quality though the exact mechanism is to be elucidated.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1203-1210
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• 2011

Function-driven metagenomic analysis is a powerful approach to screening for novel biocatalysts. In this study, we investigated lipolytic enzymes selected from an alluvial soil metagenomic library, and identified two novel esterases, EstDL26 and EstDL136. EstDL26 and EstDL136 reactivated chloramphenicol from its acetyl derivates by counteracting the chloramphenicol acetyltransferase (CAT) activity in Escherichia coli. These two enzymes showed only 27% identity in amino acid sequence to each other; however both preferentially hydrolyzed short-chain p-nitrophenyl esters (${\leq}C_5$) and showed mesophilic properties. In vitro, EstDL136 catalyzed the deacetylation of 1- and 3-acetyl and 1,3-diacetyl derivates; in contrast, EstDL26 was not capable of the deacetylation at $C_1$, indicating a potential regioselectivity. EstDL26 and EstDL136 were similar to microbial hormone-sensitive lipase (HSL), and since chloramphenicol acetate esterase (CAE) activity was detected from two other soil esterases in the HSL family, this suggests a distribution of CAE among the soil microorganisms. The isolation and characterization of EstDL26 and EstDL136 in this study may be helpful in understanding the diversity of CAE enzymes and their potential role in releasing active chloramphenicol in the producing bacteria.

• Biomolecules & Therapeutics
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• 제10권3호
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• pp.193-199
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• 2002

The arylamine N-acetyltransferases (NATs) are a family of enzymes that N-acetylate mylhydrazines and arylamines through transfer of an acetyl group from acetyl coenzyme A. This activity was found to vary among individuals as a Mendalian trait and the basis of the genetic differences in human NAT activity is one of the best of the genetic studied examples of pharmacogenetic variation. The classical N-acetylation polymorphism is regulated at the NAT2 locus, which segregates individuals into rapid, intermediate, and slow acetylator phenotypes. In this study, the relationship between NAT2 activity phenotype using HPLC:UV assay for the determination of dapsone and monoacetyldapsone in plasma and NAT2 genotype by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) was investigated in the F2 hybrid (Fischer 344 vs Wistar-Kyoto) rats. Three Common mutant alleles at the NAT2 gene locus have been identified in the F2 generation progeny of Fischer 344 rats as raid acetylator and Wistar-Kyoto rats as slow acetylator segregated into three modes (low, intermediates, and high) with simple Mendelian inheritance. The metabolic activity of NAT2 of the intermediate and rapid acetylators is significant1y greater than slow acetylator, but the metabolic activity of rapid acetylator is not significantly different from Intermediate type. Therefore, we could observe that complete trimodal NAT2 genotypic alleles and incomplete trimodal NAT2 metabolic phenotypic distribution in tile F2 hybrid rats. These observations suggest that the relationships between NAT2 genotype and metabolic phenotype exists and F2 hybrid (Fischer 344: Wistar-Kyoto) animal models about NAT2 polymorphism might be applied in the toxicity and pharmacogenetic studies of arylamine drugs and carcinogens.

• 미생물학회지
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• 제31권4호
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• pp.274-278
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• 1993

단백질이 어떻게 비수용성이 되는지를 알기위해, 클로람페니콜 아세틸전이효소와 베타-락타메이즈를 과잉생산하여 그들의 수용성과 활성을 측정하였다. 클로람페니콜 아세틸전이효소는 총단백질의 9에서 45%를 차지하였으며, inclusion body 형성없이 완전히 수용성이었으며, 효소활성은 만들어진 양과 비례하였다. 또한 30℃에서 T7 발현체계에 의해 생성된 베타-락타메이즈는 수용성의 숙성체였으나, 37℃에서는 비수용성이 되었다. 세포질에 있는 대부분의 베타-락타메이즈는 비수용성이었고. 페리플라즘 공간에서는 대부분이 수용성이었다. 단백질의 올바른 폴딩을 도와주는 chaperone의 일종인 GroEL 단백질은 본 실험조선에서는 베타-락타베이즈의 수용성을 별로 높이지는 못했다. 세포 내에서 inclusion body의 형성은 단백질의 높은 종도보다는 각각 단밸질 자체의 특성과 관련된 듯하다.

• 한국식품위생안전성학회지
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• 제18권3호
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• pp.146-152
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• 2003

당 대사에 관여하는 Pyruvate dehydrogenase phosphatase (PDP)는 해당과정에서의 대사 산물인 pyruvate 를 acetyl CoA로 만들어 구연산 회로로 진입시켜주는 효소인 Pyruvate dehydrogenase complex(PDP)의 활성을 조절하는 중요한 효소이다. PDP의 catalytic subunit는 PDP의 dihydrolipoamide acetyltransferase(E2), PDP regulatory subunit (PDPr), 그리고 칼슘 결합 도메인 등으로 구성되어 있는 것으로 추측되어지고 있다. 본 연구에서는 PDP 단백질을 분리정제하고 결정화 하고자하였다. PDP는 catalytic subunit(PDPc, Mr 52,600 Da)과, regulatory subunit (PDPr, 95,600 Da)으로 구성되어 있으며 칼슘 존재하에 PDPc는 dihydrolipoamide acetyltransferase(E2) component와 결합하여 기질인 인산 E1 component의 탈인산화율을 증가시킨다. PDPc는 intrinsic 칼슘 결합부위를 가지며 두 번째 칼슘 부위는 E2 존재 하에 형성된다. 이러한 특이한 상호반응을 이용한 GSH-Sepharose-GST-L2 matrix를 이용하여 약 1000 U/mg의 specific activity를 갖는 순수 PDPc를 약 80%의 yield로 얻어 결정화에 사용하였다.