• 한국식품영양과학회지
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• 제22권6호
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• pp.777-784
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• 1993

황산암모늄분획침전, CM-cellulose, DEAE-cellulose 이온교환크로마토그라피를 이용하여 감자에서 2종의 lipoxygenase isoenzymes(LOX-1, LOX-2)을 분리, 정제하여 isoenzyme 각각의 베타-카로텐에 대한 탈색능을 실험하였다. LOX-1, LOX-2는 linoleic acid 존재하에서 베타-카로텐에 대해 탈색효과를 나타냈으며 탈색효과는 공역산의 감소와 더불어 일어났다. 베타-카로텐 탈색시 공역산의 감소는 LOX-2에 비해 LOX-1이 더 컸으나 탈색효과는 LOX-2가 더 높았다.

• 한국작물학회지
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• 제68권4호
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• pp.294-303
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• 2023

Lipoxygenase gives soybeans their grassy flavor, which can disrupt food processing efficiency. This study aimed to identify soybean genotypes with lipoxygenase deficiency among 1,001 soybean accessions and to develop kompetitive allele specific PCR (KASP) markers that can detect lipoxygenase mutations. Three lipoxygenase isozymes (Lox1, Lox2, and Lox3) were analyzed using a colorimetric assay based on a substrate-enzyme reaction. Among the 1,001 accessions examined, two (IT160160 and IT276392) exhibited a deficiency solely in Lox1, and one (IT269984) lacked both Lox1 and Lox2. IT160160 had a 74-bp deletion in exon 8 of Lox1 (Glyma13g347600), whereas IT276392 displayed a missense mutation involving the change of C to A at position 2,880 of Lox1. Moreover, we successfully developed four KASP markers that specifically target Lox1, Lox2, and Lox3 mutations. To validate the Lox1 KASP markers, we used two F_2:3 populations generated through a cross between Daepung 2 (lipoxygenase wild type, maternal parent), IT160160, and IT276392 (null Lox1, paternal parent). The results revealed that the Daepung 2 × IT160160 group followed the expected 3:1 ratio according to Mendel's law, whereas the Daepung 2 × IT276392 group did not. Furthermore, a comparison between the colorimetric and KASP marker analyses results revealed a high agreement rate of 96%. KASP markers offer a distinct advantage by allowing the distinction of heterozygous types independent of other variables. As a result, we present an opportunity to expedite the lipoxygenase-deficient cultivar development.

• 한국식품영양과학회지
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• 제23권6호
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• pp.954-958
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• 1994

The bleaching effect of chlorophyll a by two lipoxygenase isoenzymes (LOX-1, LOX-2) isolated from potato tuber(variety DEinma ) was studied. In the presence of LOX-1 or LOX0-2 with linoleic acid chlorophyll a bleaching occurred during two isoenzymes-mediated oxidation of linoleic acid. Chlorophyll a bleaching porceeded with decreasing in the formation of conjugated dienes form linoleic acidyb LOX-1 and LOX-2 . In the presence of chlorophyll a, LOX-2 showed a markable decrease inproduction of conjugated dienes from linoleic acid and a higher chlorophyll a bleaching activity. compared with LOX-1. These results suggest chlorophyll-bleaching reaction required intermediates formed during the peroxidation of linoleic acid by lipoxygenase isoenzymes, thus preventing formation of conjugated dienes.

• Applied Biological Chemistry
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• 제38권5호
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• pp.414-421
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• 1995

Lipoxygenase (LOX) 효소의 최적 활성 조건과 활성 억제등 LOX 활성 측정의 중요한 정보를 확립하기 위하여, 추출 Buffer의 영향, 기질, pH, 저장, 온도, NaCl, $CaCl_2$외 cations 및 antioxidants의 요소들이 LOX 활성에 미치는 영향을 조사하였다. 그리고 오이 tissue내의 LOX의 편재도 시험하였다. LOX에 대한 우수한 기질은 linolenic acid, linoleic acid, arachidonic acid 순서였다. 오이 껍질이나, mesocarp tissue내에 존재하는 LOX의 활성은 pH 5.5가 최적 조건이었으며, 섭씨 $40^{\circ}C$와 $50^{\circ}C$에서는 비교적 안정성을 보였다. LOX의 활성은 pH 5.0와 0.2M NaCl 조건을 같이 주었을때 opitimum 안정성을 보였다. LOX 활성은 $Mn^{2+},\;Cu^{2+}$ 또는 $Al^{3+}$와 같은 양이온에 의해서는 감소되었지만, 오히려 $Ca^{2+}$은 효소의 활성을 자극시켰다. 한편 butylated hydroxy anisole (BHA)와 propyl gallate의 농도가 증가할수록 LOX 활성은 감소되었다. 오이 껍질에서의 LOX의 활성은 다른 tissue에, locule, mesocarp, 비해 최고치를 보였다.

• Applied Biological Chemistry
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• 제38권5호
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• pp.408-413
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• 1995

Pickle성분이 linolenic acid의 산화효소인 lipoxygenase와 methemoglobin (nonenzymatic oxidant)에 미치는 효과를 조사하였다. 그외, 피클 성분중 건조 양념내의 lipoxygenase, peroxidase와 catalase 활성도 조사하였다. 시중에 판매중인 일부 pickle brine은 lipoxygenase와 methemoglobin에 의한 linolenic acid의 산화를 억제하였다. Dill oil emulsion, 양파 농축액 (onion concentrate), oil cassia, polysorbate 80, turmeric acid와 같은 피클 성분들은 lipoxygenase와 methemoglobin에 의한 산화를 감소시켰다. Lipoxygenase의 활성은 garlic, mustard seed, red pepper에서 발견되었다. Peroxidase의 활성은 mustard seed에서만 존재하였으며, gall black pepper, allspice와 red pepper에서는 catalase의 활성이 있었다.

• 한국식품과학회지
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• 제31권5호
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• pp.1235-1240
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• 1999

본 실험은 콩비린내의 주요 생성효소인 LOX가 결핍된 콩의 가공시 특성을 살펴봄으로 식품학적 이용 가능성을 검토해 보고자 실시하였다. 몇가지 가공상태의 콩의 LOX 활성을 측정한 결과 전지콩분말, 탈지콩분말, 콩단백의 순으로 LOX의 활성이 감소되는 것으로 나타났는데 특히 탈지와 콩단백 제조시 황금콩의 활성 저하가 가장 현저하였다. 콩나물 재배 시에는 황금콩과 진품콩의 자엽 부분에서 LOX 활성이 상당히 나타났다. 두유 제조시에는 진품콩과 진품콩 2호로 만든 경우 황금콩 두유 보다 콩비린내가 적게 난다고 평가되었으며, 콩나물에서는 진품콩 2호가 배축 신장율과 수율은 떨어졌으나 콩나물 비린내는 적은 것으로 평가되었다. 아이스크림 제조 시에는 황금콩 탈지분을 이용한 경우 탈지분으로 만든 대조군 아이스크림에 비하여 콩비린내가 많이 나는 것으로 감지되었으나 진품콩 2호 탈지분을 이용한 경우에는 콩비린내를 거의 감지하지 못하였다. 이상에서 LOX 결핍 콩은 가공시비린내 개선의 효과를 나타내어 가공식품으로서의 이용 가능성을 나타내 주었다.

• Nutritional Sciences
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• 제9권3호
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• pp.212-226
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• 2006

The involvement of arachidonic acid (AA) metabolizing enzyme, lipoxygenase (LOX), in the development of particular tumors in humans has gradually been acknowledged and LOX has emerged as a novel target to prevent or treat human cancers. In the mouse skin carcinogenesis model, which provides an excellent model to study multistage nature of human cancer development, many studies have shown that some of the LOXs are constitutively upregulated in their expression. Moreover, application of LOX inhibitors effectively reduced tumor burdens, which implicates the involvement of LOX in mouse skin tumor development as well. 8S-LOX is a recently cloned LOX, which is specifically expressed in mouse skin after 12-O-tetradecanoyl-phorbol-13-acetate (TPA) treatment but not in normal skin. Unlike other members of the LOX 'family' expressed in mouse skin, this TPA-induced expression of 8S-LOX is prominent only in the skin of the TPA tumor promotion-sensitive strains of mice (SENCAR, CD-1, and NMRI) but not in the promotion-resistant C57BL/6J mice. This is a very unique phenomenon among strains of mice. Constitutive upregulation of 8S-LOX was also found in early stage papillomas and the expression was gradually reduced as the tumors became malignant. Based on these observations, it has been thought that 8S-LOX is involved in TPA-induced tumor promotion as well as in tumor conversion from papillomas to carcinomas. In accordance with this hypothesis, several studies have suggested possible roles of 8S-hydroxyeicosatetraenoic acid (HETE), an AA metabolite of 8S-LOX, in mouse skin tumor development. A clastogenic activity of 8S-HETE was demonstrated in primary keratinocytes and a close correlation between the levels of etheno-DNA adducts and 8S-HETE during skin carcinogenesis was also reported. On the other hand, it has been reported that 8S-LOX protein expression is restricted to a differentiated keratinocyte compartment Moreover, reported findings on the ability of 8S-HETE to cause keratinocyte differentiation appear to be contrary to the procarcinogenic features of the 8S-LOX expression, presenting a question as to the role of 8S-LOX during mouse skin carcinogenesis. In this review, molecular and biological features of 8S-LOX as well as current views on the functional role of 8S-LOX/8S-HETE during mouse skin carcinogenesis are presented.

• 생명과학회지
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• 제5권2호
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• pp.70-75
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• 1995

The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7, 4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

• 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.

• BMB Reports
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• 제29권6호
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• pp.564-568
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• 1996

Bursts of ethylene production occurred in twice at an early exponential (EEP) and prestationary (PSP) phases, respectively, during growth of callus tissue isolated from the root of soybean seedlings. The second burst of ethylene production at PSP was smaller in magnitude than the earlier one at EEP, but was followed by increases in both guaiacol peroxidase (GuPOX) and ascorbate peroxidase (AsPOX). The increase in AsPOX activity was also preceded by an increase in lipoxygenase (LOX) activity. Treatment of the tissue with the ethylene antagonist 2,5-norbonadiene (NBD) resulted in substantial reduction in LOX and AsPOX activities during this period. GuPOX activity was reduced only slightly, if any, by NBD. Role of ethylene in the sequential induction of LOX and AsPOX in senescing callus tissue is discussed.