• BMB Reports
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• 제41권8호
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• pp.555-559
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• 2008

Reactive oxygen species (ROS) are generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. Although certain ROS production pathways are required for the performance of specific physiological functions, excessive ROS generation is harmful, and has been implicated in the pathogenesis of a number of diseases. Among the ROS-producing enzymes, NADPH oxidase is widely distributed among mammalian cells, and is a crucial source of ROS for physiological and pathological processes. Reactive oxygen species are also generated by arachidonic acid (AA) metabolites, which are released from membrane phospholipids via the activity of cytosolic phospholipase $A_2$ ($cPLA_2$). In this study, we describe recent studies concerning the generation of ROS by AA metabolites. In particular, we have focused on the manner in which AA metabolism via lipoxygenase (LOX) and LOX metabolites contributes to ROS generation. By elucidating the signaling mechanisms that link LOX and LOX metabolites to ROS, we hope to shed light on the variety of physiological and pathological mechanisms associated with LOX metabolism.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.561-565
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• 2005

Bacterial arylsulfate sulfotransferase (ASST) catalyzes the transfer of sulfate group from a phenyl sulfate ester to a phenolic acceptor. The promoter region and the transcripti on start sites of Enterobacter amnigenus astA have been determined by primer extension analysis. Northern blot analysis resolved two mRNA species with lengths of 3.3 and 2.0 kb, which correspond to the distances between the transcriptional initiation sites and the two inverted repeat sequences (IRSs). By length, the 3.3 kb RNA could comprise the three-gene (astA with dsbA and dsbB) operon. ASST has three highly conserved cysteine residues. Reducing and non-reducing SDS-PAGE and activity staining showed that disulfide bond is needed for the activity of the enzyme. To identify the cysteine residues responsible for the disulfide bond formation, a series of Cys to Ser mutants has been constructed and the enzymatic activity was measured. Based on the results, we assumed that the first cysteine (Cys349) might be involved in disulfide bond mainly with the second cysteine (Cys445) and result in active conformation.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.99-107
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• 1988

한국전매공사에서 년차별로 제조 포장된 홍삼시료를 실온조건($12-18^{\circ}C,\;RH\;55-68\%$)으로 1년에서 9년까지 장기저장하여 품질 안정성 및 항산화효과를 조사하였다. 일반성분조성, 여러 용매별 추출물의 수율 및 사포닌의 TLC와 HPLC 패턴은 거의 변화가 없고 안정하였다. 지방질과 지방산에 대한 TLC 및 GLC 패턴도 거의 변화가 없었고, 특히 불포화도가 높아 산화되기 쉬운 linoleic acid(C18 : 2) 및 linolenic acid (C18 : 3)도 매우 안정하였다. 홍삼갈색도는 저장기간이 경과되면서 뚜렷한 증가 경향을 보였고, 물 추출물의 pH 값은 다소 감소되었는데, 이러한 경향은 장기저장중 일어나는 갈색화반응 때문이다. 물 및 에탄올 추출물의 환원성 및 초산에칠 추출물의 항산화 효과도 증가되었는데 이와 같은 활성의 증가는 비효소적 갈색화반응 생성물들의 증가에 기인되는 것으로 생각된다. 그러므로 홍삼의 제조과정이나 장기 저장기간중 비효소적 갈색화 반응에 의해서 점진적으로 형성된 항산화 물질들은 전반적으로 홍삼의 품질을 안정시켜 줄 뿐만아니라 노화억제 약리효능과도 상관성이 매우 깊은 것으로 생각된다.

• Journal of Animal Science and Technology
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• 제49권1호
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• pp.129-136
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• 2007

본 실험은 한우 육단백질의 가수분해물로부터 항고혈압 활성을 측정하기 위하여 실시한 것으로서 한우 등심과 우둔으로부터 추출한 myosin B를 pepsin으로 가수분해하여 가수분해물들의 전기영동 결과, 가열처리와 가수분해 시간의 증가에 따라 단백질의 소실이 증가하였다. 항 고혈압 활성을 측정한 결과 10 ug/ml의 희석된 가수분해물의 ACE 억제효과는 1시간 이상 가수분해 시키면 약 40%의 억제율을 가졌다. 가수분해물 원액으로 ACE 억제효과를 살펴본 결과에서는 등심이 우둔보다 높았으며 (p<0.05), 비가열 가수분해물이 가열한 가수분해물 보다 억제율이 높게 나타났다 (p<0.05). 또한, 가수분해 시간별 처리구에서는 1시간 이상 가수분해 시키면 약 70% 이상의 억제율을 갖는 것으로 나타나 한우의 myosin B를 1시간 이상 가수분해하면 ACE 억제율이 증진되는 것으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.178-182
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• 2002

The authors identified 68 Vibrio strains from Gwangan beach seawater from June to October in 2001. We identified them as 19 strains of Vibrio alginolyticus, 15 strains of V. vulnificus, 15 strains of V. parahaemolyticus, 11 strains of V. cholerae non O1, 7 strains of V. fluvialis and just one strain of V. hollisae. They showed their typical biochemical characteristics by API 20E kit (bioMerieux), respectively. It was examined whether their cultural supernatants had enzymatic activities such as hemolysin, protease or urease. The 46 strains showed hemolytic activities and/or protease activities. But we could not find any strain which had urease activity. All isolates of V. cholerae non O1 showed $\beta$ hemolysis. The others showed $\alpha$ hemolysis or did not show clear zones on sheep blood agar plates. These results of Kanagawa phenomenon were not always correspondant with hemolytic activities of cultural supernatants at late log phase. Some strains had higher hemolytic activities despite of showing protease activities on skim milk agar plates and in litmus milk media. On the other hand, some strains showed protease activities but did not show hemolytic activities. Therefore we could guess that there were the relationships between hemolysins and proteases produced by pathogenic vibrios.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.235-235
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• 2017

Chromium (Cr) toxicity is hazardous to the seed germination, growth, and development of plants. ${\gamma}$-Aminobutyric acid (GABA) is a non-protein amino acid and is involved in stress tolerance in plants. To investigate the effects of GABA in alleviating Cr toxicity, we treated eight-d-old mustard (Brassica juncea L.) seedlings with Cr (0.15 mM and 0.3 mM $K_2CrO_4$, 5 days) alone and in combination with GABA ($125{\mu}M$) in a semi-hydroponic medium. The roots and shoots of the seedlings accumulated Cr in a dose-dependent manner, which led to an increase in oxidative damage [lipid peroxidation; hydrogen peroxide ($H_2O_2$) content; superoxide ($O{_2}^{{\cdot}-}$) generation; lipoxygenase (LOX) activity], MG content, and disrupted antioxidant defense and glyoxalase systems. Chromium stress also reduced growth, leaf relative water content (RWC), and chlorophyll (chl) content but increased phytochelatin (PC) and proline (Pro) content. Furthermore, supplementing the Cr-treated seedlings with GABA reduced Cr uptake and upregulated the non-enzymatic antioxidants (ascorbate, AsA; glutathione, GSH) and the activities of the enzymatic antioxidants including ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II), and finally reduced oxidative damage. Adding GABA also increased leaf RWC and chl content, decreased Pro and PC content, and restored plant growth. These findings shed light on the effect of GABA in improving the physiological mechanisms of mustard seedlings in response to Cr stress.

• Journal of Electrochemical Science and Technology
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• 제9권1호
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• pp.28-36
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• 2018

Metal-organic frameworks have recently been considered very promising modifiers in electrochemical analysis due to their unique characteristics among which tunable pore sizes, crystalline ordered structures, large surface areas and chemical tenability are worth noting. In the present research, $Cu(btec)_{0.5}DMF$ was electrodeposited on the surface of glassy carbon electrode at room temperature under cathodic potential and was initially used as the active materials for the detection of $H_2O_2$. The cyclic voltammogram of $Cu(btec)_{0.5}DMF$ modified GC electrode shows distinct redox peaks potentials at +0.002 and +0.212 V in 0.1 M phosphate buffer solution (pH 6.5) corresponding to $Cu^{(II)}/Cu^{(I)}$ in $Cu(btec)_{0.5}DMF$. Acting as the electrode materials of a non-enzymatic $H_2O_2$ biosensor, the $Cu(btec)_{0.5}DMF$ brings about a promising electrocatalytic performance. The high electrocatalytic activity of the $Cu(btec)_{0.5}DMF$ modified GC electrode is demonstrated by the amperometric response towards $H_2O_2$ reduction with a wide linear range from $5{\mu}M$ to $8000{\mu}M$, a low detection limit of $0.865{\mu}M$, good stability and high selectivity at an applied potential of -0.2 V, which was higher than some $H_2O_2$ biosensors.

• BMB Reports
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• 제28권2호
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• pp.100-106
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• 1995

S-adenosylmethionine (SAM) synthetase was purified to homogeneity from soybean (Glycine max) axes. The enzyme was purified 216-fold with a 1.5% yield by ammonium sulfate fractionation, acetone fractionation, ion exchange chromatography with DEAE-sephacel, gel filtration with Sephacryl S-300, and afffinity chromatography with ATP-agarose. The enzyme activity reached a maximum 3 days after germination. SAM synthetase had a subunit molecular weight of 57,000 daltons from a silver stained single band on SDS-PAGE. The molecular weight of the enzyme was 110,000 daltons from Sephacryl S-300 gel filtration. The enzyme was composed of two identical subunits. The $K_m$ values of the enzyme for L-methionine and ATP were 1.81 and 1.53 mM, respectively. The enzymatic activity was not affected by polyamines, agmatine, or SAM analogues, but was inhibited by SAM. The inhibition pattern was showed non-competitive for L-methionine and uncompetitive for ATP. The activity of SAM synthetase was inhibited by thiol-blocking reagents. The enzyme was induced by treatment with $10^{-3}$ M putrescine at germination. Experimental data revealed a possible novel regulation mechanism of polyamine biosynthesis through several endogenous intermediates.

• 대한약침학회지
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• 제21권2호
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• pp.82-89
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• 2018

Objective: Diabetes mellitus (DM) is the most common metabolic disorder that defined by chronic hyperglycemia for the deficiency in insulin secretion or resistance. Hyperglycemia could induce non-enzymatic glycation of proteins. It has been suggested that some traditional plants can improve blood glucose and inhibit glycation process. This work evaluates and compares the anti-glycation activities of four Iranian plant extracts in vitro. Methods: The methanolic extract of "Fumaria officinalis, Stachys lavandulifolia, Salvia hydrangea and Rosa Damascene" was prepared in three different concentrations. Phenolic, flavonoids content and antioxidant activity were evaluated. The multistage glycation markers- fructosamines (early stage), protein carbonyls (intermediate stage) and ${\beta}$ aggregation of albumin were investigated in the bovine serum albumin (BSA)/ glucose systemt. Results: All plants showed the high potency of scavenging free radicals and glycation inhibition in the following order: Fumaria officinalis> Rosa Damascene> Stachys lavandulifolia > Salvia hydrangea. There was a significant correlation between antioxidant and anti-glycation activity. Also, the antioxidant and anti-glycation capacity of extracts correlated with total phenolic and flavonoids content. Conclusion: Our findings demonstrated that the studied plants are good sources of anti-glycation and antioxidant compounds and, these properties can primarily attributable to phenolics, particularly flavonoids.

• 환경생물
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• 제24권2호
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• pp.119-125
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• 2006

본 연구에서는 붕어를 이용하여 탁도 변화에 따른 여러 조직의 항산화효소 활성을 조사하였다. 탁도 50, 100, 150 NTU에서 사육기간에 따른 붕어 조직의 항산화효소 활성의 변화는 50과 100 NTU에서는 대조구에 비해 큰 변화가 없었으며, 고탁도인 150 NTU에서 비교적 두드러진 차이를 나타냈다. 붕어 조직의 항산화능을 DPPH 소거 활성도에서 보면 아가미, 간 조직에서 높은 활성을 보여 고탁도의 사육 조건에서 장기간 사육될 때 비효소적 항산화작용이 일어나는 것으로 생각된다. 효소적 항산화작용은 50, 100, 150NTU로 탁도가 높아짐에 따라 항산화효소의 활성이 증가하였으며 SOD, CAT및 GST의 활성은 표피를 제외한 모든 조직에서 사육 후 20일까지는 증가한 후 사육 후기로 갈수록 감소하는 경향을 나타냈다. 그러나 GR과 GPX의 활성은 거의 모든 조직에서 활성이 매우 낮으므로 어류의 항산화과정에서 이들 효소의 역할은 매우 적을 것으로 생각된다.