• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.108-109
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• 2013

Mitochondria play key roles in the production of cell's energy. Their dominant function is the synthesis of adenosine 5'-triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi) through the oxidative phosphorylation. Evaluation of drug-induced mitochondrial toxicity has become increasingly important since mitochondrial dysfunction has recently been implicated in numerous diseases including cancer and diabetes mellitus. Mitochondrial functions have been monitored via oxygen consumption, mitochondrial membrane potential, and more importantly via ATP synthesis since ATP synthesis is the most essential function of mitochondria. Various analytical methods have been employed to investigate ATP synthesis in mitochondria, including high performance liquid chromatography (HPLC), bioluminescence technique, and pH measurement. However, most of these methods are based on destructive analysis or indirect monitoring through the enzymatic reaction. Infrared absorption spectroscopy (IRAS) is one of the useful techniques for real-time, label-free, and direct monitoring of biological reactions [1,2]. However, the strong water absorption requires very short path length in the order of several micrometers. Transmission measurements with thin path length are not suitable for mitochondrial assays because solution handlings necessary for evaluating mitochondrial toxicity, such as rapid mixing of drugs and oxygen supply, are difficult in such a narrow space. On the other hand, IRAS in the multiple internal reflection (MIR) geometry provides an ideal optical configuration to combine solution handling and aqueous-phase measurement. We have recently reportedon a real-time monitoring of drug-induced necrotic and apoptotic cell death using MIR-IRAS [3,4]. Clear discrimination between viable and damaged cells has been demonstrated, showing a promise as a label-free and real-time detection for cell-based assays. In the present study, we have applied our MIR-IRAS system to mitochondria-based assays by monitoring ATP synthesis in isolated mitochondria from rat livers. Mitochondrial ATP synthesis and hydrolysis were in situ monitored with MIR-IRAS, while dissolved oxygen level and solution pH were simultaneously monitored with O2 and pH electrodes, respectively. It is demonstrated that ATP synthesis and hydrolysis can be monitored by the IR spectral changes in phosphate groups in adenine nucleotides and MIR-IRAS is useful for evaluating time-dependent drug effects of mitochondrial toxicants.

• 한국식품과학회지
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• 제31권1호
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• pp.13-19
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• 1999

신선한 개불 U. unicinctus의 맛 성분 조성을 구명하기 위하여 1988년 4월 어시장에서 살아있는 시료를 구입하여 체중에 따라 중형과 대형으로 나누고 가식부의 엑스분질소, 유리아미노산, oligopeptide류, 핵산관련물질, betaine류, TMAO, TMA, creatine 및 creatinine 등 함 질소 엑스성분을 분석하였다. 엑스분질소는 $601{\sim}610\;mg100g$이었고, 유리아미노산은 32종이 검출되었으며 총량은 $2,437{\sim}2,609mg/100g$이었다. 함량이 많고 중요한 유리아미노산으로는 glycine, alanine, taurine, serine 등이었다. Oligopeptide에서 유래한 아미노산은 유리아미노산 총량의 $28.6{\sim}30.4%$ 수준이었다. 핵산관련물질로서 ATP 관련물질 총량은 $3.04{\sim}3.12\;{\mu}mol/g$이었으며 그 중 AMP가 $87.2{\sim}89.4%$로서 대부분을 차지하였다. 개불 중에는 adenine nucleotides 이외에도 GTP, UTP, CTP 관련물질 등 11종의 핵산성분이 검출되었으며 그 총량도 ATP 관련물질에 버금가는 량이 존재하는 것으로 확인되었다. Betaine류로서는 Homarine과 trigonelline이 미량검출되었다. 그리고, TMAO, TMA, creatine도 함량이 낮았다. 개불 엑스분 중의 질소분포 특징은 glycine함량이 $1,075{\sim}1,171\;mg$에 달하여 단일 성분으로 유리아미노산 총량의 $50.6{\sim}51.6%$, 그리고 엑스분질소의 $33.4{\sim}35.9%$를 차지하여 단맛의 중요한 성분으로 판단되었다. 분석된 성분에 의한 엑스분질소의 회수율은 $92.3{\sim}96.4%$ 범위였다. 체중에 따른 맛 성분의 차이는 발견 할 수 없었다.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.219-228
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• 2015

Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, $1{\mu}g/ml$)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of $gp91^{phox}$, which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways.

• 한국산림과학회지
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• 제80권1호
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• pp.1-8
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• 1991

Nodule 배양(培養) 방법(方法)을 이용(利用)하여 잡종(雜種) 포플러 양황철62-9와 이태리포플러 1호 Eco 28의 보다 진보(進步)된 재분화(再分化) 방법(方法)과 체세포(體細胞) 배(胚) 발생(發生) 방법(方法)을 얻었다. 칼루스는 2,4-D가 0.5, 2.0mg/l씩 첨가(添加)된 배지상(培地上)에 잎 조직(組織)을 치상(置床)하여 얻었고, 발달(發達)한 칼루스 조직(組織)을 액체(液體) 배지(培地)로 옮겨 세포(細胞) 현탁 배양으로 세포를 증식(增殖)했다. 현탁세포로 부터 적당한 생장(生長) 조절물질(調節物質)을 첨가(添加)하여 nodule을 생산(生産)했다. 액체 배지에서 직접(直接) 줄기를 재분화(再分化)하는 시도(試圖)는 양황철에서만 가능(可能)했다. Agar 배지(培地)에 재분화용(再分化用) 생장조절(生長調節) 물질(物質)을 첨가(添加)한 경우 상당히 많은 수(數)의 줄기 분화(分化)가 분화 되었고, 몇몇 배지에서는 체세포(體細胞) 배(胚)로 분화 했다. 이러한 nodule 배양 방법은 묘목(苗木)의 생산(生産), 체세포(體細胞) 변이(變異)의 이용(利用), 이차(二次) 산물(産物)의 생산(生産) 그리고 그밖의 생물공학적 응용을 위한 조직 배양 재료로서 그 이용성에 대하여 고찰(考察)했다.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1519-1526
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• 2010

The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

• 한국동물학회지
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• 제31권3호
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• pp.191-206
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• 1988

계배 대뇌의 발생에 미치는 malathion의 영향을 형태,세포화학으로 비교분석하기 위하여, 수정란 부란 2일, 4일 및 6일째에 0.1mg의 malathion을 단독으로 처리하거나,NAM 5.0mg을 복합처리하여 부란 9일째 조사하였던 바, 다음과 같은 결과를 얻었다. 1.malathion은 대뇌피질내 신경세포들의 분화를 억제하여, 처리군의 핵의 불규칙상,핵막이중층의 분리, 리보솜의 분포감소, 혹은 소포체 팽창에 의한 액포형성과 같은 미세구조상의 특징이 나타났다. 2.신경세포내에서 AchE 활성은 핵막과 소포체에서 주로 나타나고, malathion에 의하여 이 효소의 활성은 크게 억제되었으며, 이러한 효소활성 억제현상은 정량분석 결과와 거의 일치하였다. 3.대뇌의 LDH 활성은 malathion에 의하여 오히려 증가되었다. 4.malathion은 계배 NAD를 크게 감소 시켰고, NAM복합처리에 의하여 NAD함량과 형태적 변화가 회복되었고, 대뇌의 Ach 및 LDH 활성 변화를 다소 완화시키는 것으로 나타났다. 이상의 결과들을 종합해보면 유기적 화합물의 하나인 malathion은 분화중인 계배 대뇌의 신경세포들의 미세구조를 변화시키고, 대뇌의 LDH활성은 증가시켰으나 AChE 활성을 크게 억제하였으며, 계배의 NAD 함량을 감소시켰다. 또한 NAD 함량의 감소와 형태적인 변화사이에는 다소간의 연관성이 나타났고, malathion의 저해작용은 처리량과 처리시기에 의존한는 것으로 나타났다.

• Journal of Ginseng Research
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• 제41권1호
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• pp.23-30
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• 2017

Background: Ginsenoside Rg1 is a class of steroid glycoside and triterpene saponin in Panax ginseng. Many studies suggest that Rg1 suppresses adipocyte differentiation in 3T3-L1. However, the detail molecular mechanism of Rg1 on adipogenesis in 3T3-L1 is still not fully understood. Methods: 3T3-L1 preadipocyte was used to evaluate the effect of Rg1 on adipocyte development in the differentiation in a stage-dependent manner in vitro. Oil Red O staining and Nile red staining were conducted to measure intracellular lipid accumulation and superoxide production, respectively. We analyzed the protein expression using Western blot in vitro. The zebrafish model was used to investigate whether Rg1 suppresses the early stage of fat accumulation in vivo. Results: Rg1 decreased lipid accumulation in early-stage differentiation of 3T3-L1 compared with intermediate and later stages of adipocyte differentiation. Rg1 dramatically increased CAAT/enhancer binding protein (C/EBP) homologous protein-10 (CHOP10) and subsequently reduced the $C/EBP{\beta}$ transcriptional activity that prohibited the initiation of adipogenic marker expression as well as triglyceride synthase. Rg1 decreased the expression of extracellular signal-regulated kinase 1/2 and glycogen synthase kinase $3{\beta}$, which are also essential for stimulating the expression of $CEBP{\beta}$. Rg1 also reduced reactive oxygen species production because of the downregulated protein level of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 4 (NOX4). While Rg1 increased the endogenous antioxidant enzymes, it also dramatically decreased the accumulation of lipid and triglyceride in high fat diet-induced obese zebrafish. Conclusion: We demonstrated that Rg1 suppresses early-stage differentiation via the activation of CHOP10 and attenuates fat accumulation in vivo. These results indicate that Rg1 might have the potential to reduce body fat accumulation in the early stage of obesity.

• 생명과학회지
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• 제20권5호
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• pp.768-774
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• 2010

전통발효주 막걸리의 기능성을 증명하기 위하여 S사막걸리로부터 구입한 막걸리 침전물의 여러 가지 생리활성에 대하여 조사하였다. 우선 막걸리 침전물 열수 추출물의 항산화 효과를 측정하기 위해 DPPH radical 소거능과 SOD 유사활성을 측정하였다. 그 결과 DPPH법을 통해 측정한 막걸리 침전물 열수 추출물의 radical 소거능은 10 mg/ml에서 48.0%으로 나타났으며, 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었다. 또한 SOD 유사활성은 10 mg/ml 농도에서 98.7%로 비교적 높은 SOD 유사활성을 보였다. 항고혈압 활성 측정 실험에서는 현재 시판되고 있는 항고혈압제인 captopril은 0.1 mg/ml에서 93.4%의 ACE 억제효과가 나타났고, 막걸리 침전물 열수 추출물 10 mg/ml에서는 74.0%의 높은 저해 활성을 나타내었다. 따라서, 막걸리 침전물 열수 추출물은 인체에 부작용이 적은 천연 항고혈압소재로서 이용가능성이 높은 것으로 사료된다. 아질산염 소거능 측정 실험에서는 positive control인 Vit. C1 mg/ml의 경우 pH 1.2와 3.0에서는 74~64%, pH 6.0에서는 45%의 소거능을 보인반면, 막걸리 침전물 열수 추출물의 경우 pH 1.2와 3.0에서는 51~42%, pH 6.0에서는 28%의 소거능을 나타내었다. 막걸리 침전물 열수 추출물의 숙취해소 효능은 ADH와 ALDH 활성증진에 막걸리 침전물 열수 추출물이 미치는 영향을 조사함으로써 증명하고자 하였다. 그 결과, 알콜과 acetaldehyde 분해능은 높게 나타났다. 이상의 결과들은 막걸리 침전물의 우수한 기능성으로서의 이용 가능성에 대한 기초자료로 그 가치가 기대된다.

• 대한약침학회지
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• 제18권2호
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• pp.7-18
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• 2015

Objectives: Lawsone (1,4 naphthoquinone) is a non redox cycling compound that can be catalyzed by DT diaphorase (DTD) into 1,2,4-trihydroxynaphthalene (THN), which can generate reactive oxygen species by auto oxidation. The purpose of this study was to evaluate the toxicity of the phytomarker 1,4 naphthoquinone and its metabolite THN by using the molecular docking program AutoDock 4. Methods: The 3D structure of ligands such as hydrogen peroxide ($H_2O_2$), nitric oxide synthase (NOS), catalase (CAT), glutathione (GSH), glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH) and nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) were drawn using hyperchem drawing tools and minimizing the energy of all pdb files with the help of hyperchem by $MM^+$ followed by a semi-empirical (PM3) method. The docking process was studied with ligand molecules to identify suitable dockings at protein binding sites through annealing and genetic simulation algorithms. The program auto dock tools (ADT) was released as an extension suite to the python molecular viewer used to prepare proteins and ligands. Grids centered on active sites were obtained with spacings of $54{\times}55{\times}56$, and a grid spacing of 0.503 was calculated. Comparisons of Global and Local Search Methods in Drug Docking were adopted to determine parameters; a maximum number of 250,000 energy evaluations, a maximum number of generations of 27,000, and mutation and crossover rates of 0.02 and 0.8 were used. The number of docking runs was set to 10. Results: Lawsone and THN can be considered to efficiently bind with NOS, CAT, GSH, GR, G6PDH and NADPH, which has been confirmed through hydrogen bond affinity with the respective amino acids. Conclusion: Naphthoquinone derivatives of lawsone, which can be metabolized into THN by a catalyst DTD, were examined. Lawsone and THN were found to be identically potent molecules for their affinities for selected proteins.

• Toxicological Research
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• 제33권4호
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• pp.265-272
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• 2017

Aryl hydrocarbons such as 3-nitrobenzanthrone (NBA), 4-aminobiphenyl (ABP), acetylaminofluorene (AAF), benzo(a)pyrene (BaP), and 1-nitropyrene (NP) form bulky DNA adducts when absorbed by mammalian cells. These chemicals are metabolically activated to reactive forms in mammalian cells and preferentially get attached covalently to the $N^2$ or C8 positions of guanine or the $N^6$ position of adenine. The proportion of $N^2$ and C8 guanine adducts in DNA differs among chemicals. Although these adducts block DNA replication, cells have a mechanism allowing to continue replication by bypassing these adducts: translesion DNA synthesis (TLS). TLS is performed by translesion DNA polymerases-Pol ${\eta}$, ${\kappa}$, ${\iota}$, and ${\zeta}$ and Rev1-in an error-free or error-prone manner. Regarding the NBA adducts, namely, 2-(2'-deoxyguanosin-$N^2$-yl)-3-aminobenzanthrone (dG-$N^2$-ABA) and N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (dG-C8-ABA), dG-$N^2$-ABA is produced more often than dG-C8-ABA, whereas dG-C8-ABA blocks DNA replication more strongly than dG-$N^2$-ABA. dG-$N^2$-ABA allows for a less error-prone bypass than dG-C8-ABA does. Pol ${\eta}$ and ${\kappa}$ are stronger contributors to TLS over dG-C8-ABA, and Pol ${\kappa}$ bypasses dG-C8-ABA in an error-prone manner. TLS efficiency and error-proneness are affected by the sequences surrounding the adduct, as demonstrated in our previous study on an ABP adduct, N-(2'-deoxyguanosine-8-yl)-4-aminobiphenyl (dG-C8-ABP). Elucidation of the general mechanisms determining efficiency, error-proneness, and the polymerases involved in TLS over various adducts is the next step in the research on TLS. These TLS studies will clarify the mechanisms underlying aryl hydrocarbon mutagenesis and carcinogenesis in more detail.