• 식물조직배양학회지
• /
• 제22권2호
• /
• pp.71-76
• /
• 1995

자리공 모상근에서 광처리에 따른 항산화효소의 활성을 조사하였다. Catalasa superoxide dismutasae, ascorbate oxidase (AO)의 활성은 광도가 2,000 lx까지 증가할수록 감소하였으며, 특히 AO활성은 2,000 lx에서 암상태보다 92% 감소하였다. Glutathione reductase, glutathione peroxidase (GPO), ascorbate peroxidase 그리고 peroxidase의 활성도는 500 lx까지는 광도가 높아질수록 증가하였으나 그 이상의 높은 광도에서는 현저하게 감소하였다. GPO의 활성은 AO처럼 2,000 lx에서 암상태보다 85%감소하였다. 광파장에 따른 항산화효소의 활성은 청색광의 파장에서 가장 많이 억제되었으며, AO의 활성은 25%까지 감소하였다. 청색광 파장의 광도에 따른 항산화효소의 활성도는 30 lx까지는 증가하다가 200 lx에서는 암상태보다 21-71%까지 감소하는 경향을 나타내었다. AO의 활성은 청색 파장의 광도(300-200 lx)가 증가할수록 급격히 감소하여 200 lx에서는 70%까지 억제되었다. 자리공 모상근의 항산화효소 활성은 청색광 파장의 높은 광도에서 주로 생성된 유해산소 의하여 억제되고 있음을 확인하였다. 광상태하에서 모상근의 생장과 betalain 합성을 향상시키기 위해서는 모상근에서 생성되는 산화제의 효율적인 제거가 요구됨이 시사되었다.

• Applied Biological Chemistry
• /
• 제31권1호
• /
• pp.52-57
• /
• 1988

오이에서 얻어진 AAO조효소를 이용하여 AsA 정량 가능성을 검토할 결과, AAO에 의한 산화 전후의 흡광도 차는 AsA 함량과 정비례한 관계를 나타냈다. AAO를 이용한 AsA분석에 영향을 미치는 pH와 흡광도, 효소의 활성과 pH와의 관계, crude AAO의 pH 안정성, 효소의 농도와 반응시 간과의 관계를 검토한 결과, 흡광도 차가 최대를 나타낸 파장은 243nm였고, 효소의 활성이 최대를 보인 pH는 $pH\;6.0{\sim}7.5$범위였고, 본 실험에서 이용한 효소 농도로는 5분 이내에 산화반응이 종결되었다. 시판 오렌지쥬스의 AsA 함량을 AAO를 이용한 방법과 HPLC 방법에 의해서 분석하여 비교한 결과, 본 방법으로 분석된 AsA함량과 HPLC방법에 의해서 얻어진 수치는 거의 비슷한 값을 나타냈으며, 본 방법에 의한 AsA회수율은 $98.3{\sim}99.8%$로 높은 검출효과를 보였다.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.70-70
• /
• 2003

Active sites and substrate bindings of 1-aminoxyclopropane-1-carboxylate oxidase (MD-ACO1) catalyzing the oxidative conversion of ACC to ethylene have been determined based on site-directed mutagenesis and comparative modeling methods. Molecular modeling based on the crystal structure of Isopenicillin N synthase (IPNS) provided MD-ACO1 structure. MD-ACO1 protein folds into a compact jelly roll shape, consisting of 9 ${\alpha}$-helices, 10 ${\beta}$-strands and several long loops. The MD-ACO1/ACC/Fe(II)/Ascorbate complex conformation was determined from automated docking program, AUTODOCK. The MD-ACO1/Fell complex model was consistent with well known binding motif information (HIS177-ASP179-HIS234). The cosubstrate, ascorbate is placed between iron binding pocket and Arg244 of MD-ACO1 enzyme, supporting the critical role of Arg244 for generating reaction product. These findings are strongly supported by previous biochemical data as well as site-directed mutagenesis data. The structure of enzyme/substrate suggests the structural mechanism for the biochemical role as well as substrate specificity of MD-ACO1 enzyme.

• Journal of Ginseng Research
• /
• 제41권3호
• /
• pp.307-315
• /
• 2017

Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease's origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbate-glutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of $H_2O_2$ and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of $\text\tiny L$-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbate-glutathione cycles, are activated to protect against phenolic compound oxidation.

• 한국식품저장유통학회지
• /
• 제14권6호
• /
• pp.669-675
• /
• 2007

Chitosan-ascorbate (CA)를 표면처리한 후 $40{\sim}60^{\circ}C$에서 감압건조한 과메기(VD-과메기)의 품질특성과 고지방식이 흰쥐의 혈청지질과 항산화계 효소활성에 미치는 영향을 조사하였다. VD-과메기의 제조기간은 $4.5{\sim}8.3시간, 자연건조과메기(ND-과메기)의 제조기간 $360{\sim}480$시간이었다. 총 균수는 VD-과메기에서는 $0.2{\sim}0.5$ log CFU/g, ND-과메기에서는 8.2 log CFU/g였다. 아미노태질소 함량은 $128.3{\sim}135.0$mg%로 ND-과메기와 VD-과메기의 뚜렷한 차이가 없었다. VD-과메기는 ND-과메기에 비하여 산가와 과산화물가가 현저하게 낮으며 비린내가 적고 조직감, 색상 및 종합적기 호도가 높았으며 종합적으로는 $40^{\circ}C$에서 제조한 VD-40-과메기가 가장 우수하였다. 고지방식이 흰쥐에 감압건조한 VD-40-과메기를 10% 혼합하여 4주간 급여한 군 (HVK)은 ND-과메기에 비하여 증체량이 낮고, 혈청 HDL-cholesterol 함량은 높은 반면 total cholesterol과 LDL-cholesterol함량이 낮았으며, glutathione 함량은 뚜렷한 차이가 없으나 lipid peroxide 함량은 현저하게 낮았다. 또한 고지방식이로 증가된 간의 xanthine oxidase total 및 O type 활성도 및 O/T(%)를 유의적으로 감소시켰다. 이상의 결과, 과메기 제조시 CA를 처리한 후 $40^{\circ}C$서 감압건조하는 방법은 제조기간을 크게 단축시킬 뿐만 아니라 과메기의 위생성과 영양성을 높일 수 있는 방법으로 산업적 활용이 기대된다.

• BMB Reports
• /
• 제32권5호
• /
• pp.451-455
• /
• 1999

The concentrations of L-ascorbic acid (AsA, ascorbate, vitamin C) and its biosynthetic and metabolically-related enzymes such as L-galactono-1,4-lactone dehydrogenase (GLDase), ascorbate peroxidase (APX), and ascorbate oxidase (ASO) were investigated in suspension cultures of Scutellaria baicalensis. Cells growing from 4 days after subculture (DAS) to 9 DAS and from 16 DAS to 19 DAS showed a diauxic growth, and then growth rapidly decreased with further culturing. The AsA content slowly increased to 19 DAS, reached a maximum at 21 DAS (ca $120\;{\mu}g/g$ dry cell wt), and then rapidly decreased with further culturing. GLDase and ASO activity were well correlated with the cell growth curve, showing a maximum at 19 DAS, whereas APX activity showed a good correlation with the changes in AsA content, showing a maximum at 21 DAS. The total ascorbate contents (reduced form, AsA, and oxidized form, dehydroascorbate, DHA) were markedly enhanced at 10 DAS when L-galactose and L-galactono-1,4-lactone (25 mM) were added to SH medium supplemented with 20 g/l sucrose at 9 DAS, by 5.5 and 6.8 times, respectively. DHA composed more than 90% of the total ascorbate contents in suspension cultures of S. baicalensis, even though the ratio of reduced to oxidized form slightly varied with cell growth stage. The results indicate that L-galactose and L-galactono-1,4-lactone are effective precursors of AsA in cell cultures of S. baicalensis, and that in vitro cultured cells provide suitable biomaterials for the study of biosynthesis and metabolism of AsA.

• The Korean Journal of Physiology and Pharmacology
• /
• 제3권2호
• /
• pp.147-155
• /
• 1999

Antioxidant effects of serotonin and L-DOPA on neuronal tissues were examined by studying the oxidative damages of brain synaptosomal components. The study further explored the mechanism by which they exert protective actions. Serotonin and L-DOPA (1 ${\mu}M$ to 1 mM) significantly inhibited lipid peroxidation of brain tissues by either $Fe^{2+}$ and ascorbate or t-butyl hydroperoxide in a dose dependent fashion. Protective effect of serotonin on the peroxidative actions of both systems was greater than that of L-DOPA. Protein oxidation of synaptosomes caused by $Fe^{2+}$ and ascorbate was attenuated by serotonin and L-DOPA. Protein oxidation more sensitively responded to L-DOPA rather than serotonin. Serotonin and L-DOPA (100 ${\mu}M$) decreased effectively the oxidation of synaptosomal sulfhydryl groups caused by $Fe^{2+}$ and ascorbate. The production of hydroxyl radical caused by either $Fe^{3+},$ EDTA, H_2O_2$ and ascorbate or xanthine and xanthine oxidase was significantly decreased by serotonin and L-DOPA (1 mM). Equal concentrations of serotonin and L-DOPA restored synaptosomal $Ca^{2+}$ uptake decreased by $Fe^{2+}$ and ascorbate, which is responsible for SOD and catalase. Protective effects of serotonin and L-DOPA on brain synaptosomes may be attributed to their removing action on reactive oxidants, hydroxyl radicals and probably iron-oxygen complex, without chelating action on iron.

• Preventive Nutrition and Food Science
• /
• 제3권1호
• /
• pp.48-55
• /
• 1998

An acute ethanol load(50mmol/kg , i.p) resulted in an increase in peroxidation and a decrease in the levels of $\alpha$-tocopherol and ascorbate in rat cerebellum. Pretreatement with allopurinol(146$\mu$mol/kg, i.p) prevented the ethnol-induced increment in lipid peroxidation and decrease in $\alpha$-tocopherol content. However, the decrease of ascorbate was of greater magnitude when allopurinol was associated with ethanol. These results suggested that allopurinol. besides its action as a radical scavenger and xanthine oxidase inhibitor, might favor the regeneration of $\alpha$-tocopherol antioxidant acitviity was studied using ${\gamma}$-radiolysis in aerated ethanolic solutions. Even though allopurinol did not react by itself with $\alpha$-hydroxyethyl-peroxyl radicals [H3C-CH(OH)OO] , it enhance the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$tocopherol. The regeneration of $\alpha$-tocopherol from the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$-tocophero. The regeneration of $\alpha$-tocopherol from the $\alpha$-tocopherol radical by ascorbate remained as efficient in the presence of allopurinol as in its absence. The effects of allopurinol on the Vitamin E oxidation-reduction mechanism could be involoved in the beneficial effectof allopurinol on the biological cellular damages linked to free radical reactions.

• Plant Biotechnology Reports
• /
• 제2권2호
• /
• pp.113-122
• /
• 2008

Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

• Journal of Plant Biotechnology
• /
• 제29권1호
• /
• pp.7-13
• /
• 2002

Superoxide dismutase (SOD)를 과실에서 고발현시킨 형질전환 토마토 (서광과 꼬꼬)를 개발하였다. 카사바 배양세포에서 분리한 CuZnSOD (mSOD1)를 과실에 우세적으로 발현하는 ascorbate oxidase promoter (ASOp)를 이용하여 ASOp :: mSOD1/pBI101 벡터를 제작한 후 Agrobacterium 매개로 자엽 절편체를 형질전환하였다. Kanamycin 저항성 식물체를 기관발생 경로로 재분화시킨 후 Southern 분석으로 형질전환을 확인하였다. 서광과 꼬꼬 토마토의 형질전환체와 대조구 식물체의 과실을 성숙 단계별로 분류하여 단백질 함량과 SOD 비활성도 (units/mg protein)를 측정한 결과, 단백질 함량은 열매가 익은 단계로 갈수록 점점 감소하여 완전히 익은 단계에서 가장 낮았다. SOD 비활성도는 형질전환 토마토의 열매의 모든 단계에서 대조구보다 높았으며 완전히 성숙한 과실에서 가장 높았다. 성숙한 형질전환 서광과 꼬꼬 과실에서 SOD 비활성도는 비형질전환의 것보다 각각 약 1.6배와 약 2.2배 높았다. SOD isoenzyme gel 분석에서 도입한 mSOD1로 추정되는 CuZnSOD 밴드가 형질전환체에서 과실 성숙에 따라 강하게 발현되었다. 이상의 결과로서 ASO promoter에 의해 SOD 유전자가 토마토 과실에 특이적으로 발현됨이 확인되었다.