• Korean journal of applied entomology
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• v.53 no.3
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• pp.271-280
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• 2014

Some bacterial metabolites of Xenorhabdus nematophila (Xn) inhibit phospholipase $A_2$ ($PLA_2$) activity to shutdown eicosanoid biosynthesis in target insects. However, little has been known about the target insect $PLA_2$ of these bacterial metabolites. Eight bacterial metabolites identified in Xn culture broth exhibited significant insecticidal activities against larvae of both lepidopteran species of Plutella xylostella and Spodoptera exigua. Moreover, these bacterial metabolites significantly enhanced insecticidal activities of Bacillus thuringiensis (Bt). To determine target $PLA_2$, we cloned and over-expressed cellular $PLA_2$ ($SecPLA_2$) of S. exigua. Purified $SecPLA_2$ catalyzed phospholipids derived from the fat body and released several polyunsaturated fatty acids. Most Xn metabolites significantly inhibited $SecPLA_2$ activity, but were different in their inhibitory activities. There was a positive correlation between the inhibition of $SecPLA_2$ and the enhancement of Bt insecticidal activity. These results indicate that $SecPLA_2$ is a molecular target inhibited by Xn metabolite.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.334-339
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• 2007

We evaluated the potential of 20 herbal medications (HMs), commonly used in Korea, to inhibit the catalytic activities of several cytochrome P450 (CYP) isoforms. The abilities of 500 ${\mu}g/ml$ of aqueous extracts of 20 HMs to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), rosiglitazone hydroxylation (CYP2C8), tolbutamide 4-methylhydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The HMs Woohwangcheongsimwon suspension and Hwanglyeonhaedok-Tang strongly inhibited CYP2B6 and CYP2D6 isoform activity, respectively. These results suggest that some of the HMs used in Korea have potential to inhibit CYP isoforms in vitro. Although the plasma concentrations of the active constituents of the HMs were not determined, some herbs could cause clinically significant interactions because the usual doses of those individual herbs are several grams of freeze-dried extracts.

• Journal of Life Science
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• v.34 no.8
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• pp.588-593
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• 2024

An extensive analysis of 3,490 metabolic pathways in 471 archaebacterial species was conducted using the MetaCyc database. The number of metabolic pathways in these species varied significantly, ranging from 13 to 184 per species. Notably, no single metabolic pathway was found to be common in all archaebacteria. However, the "UTP and CTP de novo biosynthesis" and "tRNA charging" pathways were present in the 470 species. Among the top 12 most prevalent metabolic pathways in archaebacteria, five were associated with nucleic acids and five with proteins. The remaining pathways included the "synthetic pathway of S-adenosyl-L-methionine (SAM)," a critical cofactor in various bioreactions, and "phosphopantothenate biosynthesis III (archaea)," which is required for essential post-translational modifications. These findings underscore the importance of nucleic acids and protein metabolism in archaeal biology. When the average and standard deviation of the distance values obtained from the phylogenetic tree of metabolic pathways, each class of archaebacteria was divided into main two groups and the others, showing that the distribution of metabolic pathways was diverse. This study's insights hold potential applications in both foundational science and drug development.

• Korean Journal of Crystallography
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• v.4 no.2
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• pp.100-104
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• 1993

Reduced glutathione (GSH) plays a vital role in the metabolism of all cells. Glutathions, a tripeptide cowfosed of glutamic acid, cysteane, and gtycina is synthesized by two synthesized reutions. The first is catalyzed by Y-glutamylcysteine synthetase (GSH-I) and the second by glutathione synthetase (GSH-ll). The glutathione biosynthetic pathway of E. coziis mainly controlled by nonallosteric feedback inhibition of GHS-I by GSH. Determination of the three-dimensional structure of GSH-I by X-ray crystallography is necessary in order to understand the structure-function relationship at the molecular level. As the (irst step toward its structure determination, crystallization of 5. coli V-glutamylcystfine synthetase (GSH-I) has been achived using the hanging drop vapor diffusion method and capillaw method. Crystals of GSH-I have been grown from ammonium sulfate solution. The crystals grew at room temperature within 10 days to dimensions of 0.2 m x 0.2 m x 0.2 ml by hanging drop vapor diffusion method and diffracted to about 4 A resolution using synchrotron X-rays. Another crystal, grown by the capillary method to dimensions of 0.25 mm x 0.25 mm x 0.3 mm within 40 days, diffracted to about 4 A resolution using X-rays from a rotating anode.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.171-174
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• 2001

식물의 대사과정을 통하여 흡수된 대기오염물질은 많은 단계의 해독과정 거치게 된다. SO$_2$ 의 경우는 세포질에서 그 대부분이 SO$_{3}$$^{2-}$ 로 용해되고 일부는 HSO$_{3}$ $^{-}$의 형태로 용해된다. 용해된 SO$_{3}$$^{2-}$ 는 아황산산화효소에 의해서 엽록체에서 생성된 $O_{2}$$^{-}$와 산화 반응하여 비교적 독성이 낮은 SO$_{4}$$^{2-}$ 로 변화한다.(중략)

• Journal of Life Science
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• v.33 no.3
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• pp.295-303
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• 2023

Immune and metabolic systems are important factors in maintaining homeostasis. Immune response and metabolic regulation are highly associated, so, when the normal metabolism is disturbed, the immune response changed followed the metabolic diseases occur. Likewise, obesity is highly related to immune response. Obesity, which is caused by an imbalance in energy metabolism, is associated with metabolic diseases, such as insulin resistance, type 2 diabetes, fatty liver diseases, atherosclerosis and hypertension. As known, obesity is characterized in chronic low-grade inflammation. In obesity, the microenvironment of immune cells became inflammatory by the unique activation phenotypes of immune cells such as macrophage, natural killer cell, T cell. Also, the immune cells interact each other in cellular or cytokine mechanisms, which intensify the obesity-induced inflammatory response. This phenomenon suggests the possibility of regulating the activation of immune cells as a pharmacological therapeutic strategy for obesity in addition to the common pharmacological treatment of obesity which is aimed at inhibiting enzymes such as pancreatic lipase and α-amylase or inhibiting differentiation of preadipocytes. In this review, we summarize the activation phenotypes of macrophage, natural killer cell and T cell, and their aspects in obesity. We also summarize the pharmacological substances that alleviates obesity by regulating the activation of immune cells.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.329-332
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• 2004

Changes in activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in vitro were examined by measuring maximum absorbances of ADH and ALDH at 340 nm to determine influence of Maesil (Prunus mume) on alcohol metabolism. Facilitating rates of ADH activity were 137.92, 131.58, 152,96, 218.70, 111.76, and 144.27% in Maesil juice, 5, 10, and 15% GMT, and 0.5 and 1.0% aspartic acid, respectively, ALDH activity increased in the order of Maesil juice > ALDH > GMT > aspartic acid, and facilitating rate of ALDH activity in Maesil juice was the highest at 976.44%. These results indicate alcohol metabolizing activity can be enhanced by Maesil juice.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1222-1228
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• 1998

Stress will induce various changes in human metabolism. The remarkable phenomenon of these changes is increased energy metabolism that can induce many reactive oxygen species (ROS) production. ROS can peroxidize cellular macromolecules including lipid and protein. The object of this study was to investigate that stress may induce cellular damage by producing ROS and that Rooibos tea can protect cells against reactive oxygen species by immobilization stress in SD rat. The stress group significantly increased in 5-hydroxyindole acetic acid (5-HIAA), one of the stress hormone. Rooibos tea treatment had no effects on 5-HIAA contents, but body weight of Rooibos tea treated rat more increased than that of only the stress group. It was suggested that Rooibos tea colud not affect stress response itself, but protect against the another mechanism. We thought that the oxidative damage was caused by increased energy metabolism. Protein degradation level and lipid peroxide formation on index of oxidative damage significantly increased in the stress group. But the stress-induced activity change could not be observed in antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase. But the catalase activity of the brain significantly was inhibited by the stress. From these results, it was suggested that the immobilization stress induce the brain oxidative damage. However the oxidative damage was inhibited by feeding Rooibos tea containing various antioxidants, such as polyphenol, flavonoid and so on. Therefore, Rooibos tea have the protective effects against the stress caused by the ROS mediated cellular damage.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.151-157
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• 1984

Skyrin was extracted from Penicillium islandicum cultivated on synthetic Czapek-Dox medium. A preliminary experiment in Penicillium islandium using $[^{14}C]$-acetate proved the incorporation of $[^{14}C]$ into skyrin. In the cell-free system using the fungus $[^3H]$-emodin and $[^3H]$-emodinanthrone were shown to give some reliable evidences far the biosynthesis of skyrin. The incorporation of $[^3H]$-emodin was less significant than that of $[^{3}H]$-emodinanthrone. As a result of the cell-free experiment, the biosynthetic pathway of skyrin by the fungus was suggested as follows: $emodinanthrone{\rightarrow}emodin{\rightarrow}skyrin$.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.501-507
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• 1997

Chloroplasts isolated from Stevia rebaudiana Bertoni leaves contained an enzyme activity which catalyzed hydroxylation of ent-kaurenoic acid (ent-kaur-16-en-19-oic acid; ent-KA) to steviol (ent-13-hydroxy kaur-16-en-19-oic acid), the diterpenoid carboxylic alcohol which is the aglycone of sweet stevioside-related glycosides. $[^(14)C]-methylated$ ent-KA was used to localize ent-KA hydroxylase. $[^(14)C]-methyl-KA$ was most actively was transformed into methyl-steviol in chloroplast. The enzymatic activity was found in stroma fraction but not in thylakoid membrane in Stevia rebaudiana Bertoni. However, ent-KA 13-hydroxylase activity was not detected in stroma fraction of either Spinacia oleracea and Solidago altissima. The reaction products using $[^(14)C]-methyl-KA$ were purified and identified on TLC autoradiogram. The hydroxylation of ent-KA from stromal protein to form steviol required NADPH and oxygen. FAD and riboflavin stimulated the enzyme activity 1.5-and 1.7-fold, respectively. It also turned out that the activity of this enzyme using methyl-KA as a substrate was 16.7% that of ent-KA. The purified ent-KA 13-hydroxylase did not act on t-cinnamic acid, 4-hydroxyphenyl acetic acid, choline and resorcinol, known as monooxygenase and hydroxylase substrates.