• Biomolecules & Therapeutics
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• 제32권4호
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• pp.474-480
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• 2024

Streptomyces avermitilis genome includes 33 genes encoding monooxygenation-catalyzing cytochrome P450 enzymes. We investigated the structure of CYP107P2 and its interactions with terpenoid compounds. The recombinant CYP107P2 protein was expressed in Escherichia coli and the purified enzyme exhibited a typical P450 spectrum upon CO-binding in its reduced state. Type-I substrate-binding spectral titrations were observed with various terpenoid compounds, including α-pinene, β-pinene, α-terpinyl acetate, and (+)-3-carene. The calculated binding affinities (Kd) ranged from 15.9 to 50.8 µM. The X-ray crystal structure of CYP107P2 was determined at 1.99 Å resolution, with a well-conserved overall P450 folding conformation. The terpenoid compound docking models illustrated that the structural interaction between monoterpenes and CYP107P2, with the distance between heme and terpenes ranging from 3.4 to 5.4 Å, indicates potential substrate binding for P450 enzyme. This study suggests that CYP107P2 is a Streptomyces P450 enzyme capable of catalyzing terpenes as substrates, signifying noteworthy advancements in comprehending a novel P450 enzyme's involvement in terpene reactions.

• Biomolecules & Therapeutics
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• 제23권5호
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• pp.486-492
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• 2015

Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their interassay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.170-170
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• 2002

College of Pharmacy, Ewha womans University, Seoul, 120-750, Korea 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent halogenated aromatic hydrocarbon congener that induces expression of several genes including CYP1A1. Exposure to TCDD results in many toxic actions such as carcinogenesis, hepatotoxicity, immune suppression, and reproductive and developmental toxicity. Dramatic differences in dioxin toxicity have been observed between the sexes of some animal species, suggesting hormonal modulation of dioxin action. Many studies have been reported and propose several mechanisms of anti-estrogenic effects of TCDD. In contrast, the effect of estrogen on the regulation of CYP1A1 are not clear at present. There are several reports showing conflicting results. It seems that induction/inhibition of CYP1A1 may be dependent on cell-type and concentration. The purpose of this study was to investigate the regulation of TCDD-induced CYP1A1 gene expression by estradiol and its metabolites. We examined whether estradiol and its metabolites altered TCDD-mediated induction of CYP1A1 enzyme activity. 17 ${\beta}$ estradiol and 16 ${\alpha}$ estriol at non cytotoxic concentrations caused a significant concentration dependent decline of TCDD-induced EROD activity To determine whether reduced EROD activity reflected altered CYP1A1 mRNA expression, we measured CYP1A1 mRNA level by RT-PCR. And to examine whether estradiol and its metabolites have effects on TCDD-induced CYP1A1 gene expression at the transcription level, we also peformed transient transfection with an AhR responsive reporter plasmid containing the 5' flanking region of the human CYP1A1 gene to examine whether estradiol and its metabolites have effects on TCDD-induced CYP1A1 gene expression at the transcription level.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.188-188
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• 1996

In order to gain insight into the mechanism of the regulation of cytochrome P450IAl by arylhydrocarbon, the 5'-flanking region of a trout CYP450IAl 5'flanking DNA was cloned into pCAT-basic vector and it was transfected into Hepa-1 cells. 3MC treatment to hepa Ⅰ cells transfected with fish CYP450IAl-CAT construct results in mRNA increased by 2.81 fold when it was compared with that of control This increase of mRNA was decreased by concomitantly treated flavonoids such as morin. The levels of CAT mRNA that was treated with morin was 29.2-58.0% of 3MC stimulated CAT mRNA. Further investigation to find out if there are DRE, XRE or negative regulatory cis element in CYP450IA1 gene was undertaken. Results of the deletion study of 5'flanking DNA of trout P450IA indicate the existance of the negative(-1600 ～ -1300). CAT mRNA was about two-fold higher in deleted trout CYP450IAl-CAT construct transfected cells compared to the wi Id type trout CYP450IAl-CAT construct transfected cells. And The stimulatory effect of 3MC was no longer observed in col Is containing deleted CAT construct. [Supported by grants from the Korean Ministry of Education]

• BMB Reports
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• 제41권6호
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• pp.472-478
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• 2008

Three Arabidopsis cDNAs, MAM1, CYP79F1, and CYP83A1, required for aliphatic glucosinolate biosynthesis were introduced into Chinese cabbage by Agrobacterium tumefaciens-mediated transformation. The transgenic lines overexpressing MAM1 or CYP83A1 showed wild-type phenotypes. However, all the lines overexpressing CYP79F1 displayed phenotypes different from wild type with respect to the stem thickness as well as leaf width and shape. Glucosinolate contents of the transgenic plants were compared with those of wild type. In the MAM1 line M1-1, accumulation of aliphatic glucosinolates gluconapin and glucobrassicanapin significantly increased. In the CYP83A1 line A1-1, all the aliphatic glucosinolate levels were increased, and the levels of gluconapin and glucobrassicanapin were elevated by 4.5 and 2 fold, respectively. The three CYP79F1 transgenic lines exhibited dissimilar glucosinolate profiles. The F1-1 line accumulated higher levels of gluconapoleiferin, glucobrassicin, and 4-methoxy glucobrassicin. However, F1-2 and F1-3 lines demonstrated a decrease in the levels of gluconapin and glucobrassicanapin and an increased level of 4-hydroxy glucobrassicin.

• Translational and Clinical Pharmacology
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• 제25권3호
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• pp.147-152
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• 2017

This study focused on the role of cytochrome P450 2D6 (CYP2D6) genotypes to predict phenotypes in the metabolism of dextromethorphan. CYP2D6 genotypes and metabolic ratios (MRs) of dextromethorphan were determined in 201 Koreans. Unsupervised clustering algorithms, hierarchical and k-means clustering analysis, and color visualizations of CYP2D6 activity were performed on a subset of 130 subjects. A total of 23 different genotypes were identified, five of which were observed in one subject. Phenotype classifications were based on the means, medians, and standard deviations of the log MR values for each genotype. Color visualization was used to display the mean and median of each genotype as different color intensities. Cutoff values were determined using receiver operating characteristic curves from the k-means analysis, and the data were validated in the remaining subset of 71 subjects. Using the two highest silhouette values, the selected numbers of clusters were three (the best) and four. The findings from the two clustering algorithms were similar to those of other studies, classifying $^*5/^*5$ as a lowest activity group and genotypes containing duplicated alleles (i.e., $CYP2D6^*1/^*2N$) as a highest activity group. The validation of the k-means clustering results with data from the 71 subjects revealed relatively high concordance rates: 92.8% and 73.9% in three and four clusters, respectively. Additionally, color visualization allowed for rapid interpretation of results. Although the clustering approach to predict CYP2D6 phenotype from CYP2D6 genotype is not fully complete, it provides general information about the genotype to phenotype relationship, including rare genotypes with only one subject.

• 한국환경성돌연변이발암원학회지
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• 제24권3호
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• pp.121-127
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• 2004

Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounds such as policyclic aromatic hydrocarbon(PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in Hepa-I and MCF-7 cells, 5' flanking DNA of human CYP1B1 was cloned into pGL3 basic vector containing luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydrozyestradiol that is considered as carcinogenic metabolite. Luciferase activity was induced about 20 folds over that control by 1 nM TCDD (2,3,7,8-tetrachloto-p-dioxin). Recent industrialized society, human has been widely been exposed to widespread environmental contaminants such as PAHs(polycyclic aromatic hydrocarbon) that are originated from the imcomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR(aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarker for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. We have used the United State of America EPA selected 13 different PAHs, PAHs mixtures and extracts from environmental samples to evaluate the bioassay system. We examined effects of PAHs on the CYP1B1-luciferase reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene and dibenzo(a, h)anthracene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. Acenaphthene, anthracene, benzo(b)fluoranthene, fluorene, fluoranthene, anphthanlene, pyrene, phenanthrene and carbazole were weak responders in MCF-7 cells. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1B1 mRNA.

• Asian Pacific Journal of Cancer Prevention
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• 제17권sup3호
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• pp.71-75
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• 2016

Pancreatic cancer is a leading cause of fatality worldwide. Several population studies have been conducted on genetic diagnosis of pancreatic cancer but the results from epidemiologic studies are very limited. CYP17A gene has a role in disease formation but its influence on pancreatic cancer is unclear. A polymorphism in the 5'UTR promoter region of CYP17A1-34T/C (A1/A2) has been associated with multiple cancers. The aim of the current study was to assess associations of this polymorphism and socio-demographic risk factors with pancreatic cancer. A total of 255 and 320 controls were enrolled in the study, and were genetically analyzed through PCR-RFLP. Statistical analysis was conducted with observed genotype frequencies and odds ratios (ORs) and 95% CIs were estimated using unconditional logistic regression. The impact of socio-demographic factors was accessed through Kaplen-Meir analysis. According to our results, the A2/A2 genotype was significantly associated with pancreatic cancer (OR=2.1, 95%CI = 1.3-3.5). Gender female (OR=2.6, 95%CI=1.8-3.7), age group 80s/80+ years (OR=2.2, 95% CI=1.2-4), smoking both former (OR=4.6, 95% CIs=2.5-8.8) and current (OR=3.6, 95% CI=2-6.7), and family history (OR=7.1; 95%CI = 4.6-11.4) were also found associated with increased risk. Current study suggests that along with established risk factors for pancreatic cancer CYP17A1-34T/C may play a role. However, on the basis of small sample size the argument cannot be fully endorsed and larger scale studies are recommended.

• 생명과학회지
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• 제8권6호
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• pp.695-701
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• 1998

한국산 꽃뱀(Natrix tigrina Lateralis)의 간 마이크로좀에 존재하는 mixed function oxidase system 구성 성분들의 함량과 P45O 의존성 monooxygenase의 활성도를 조사하고 이들을 흰쥐(Sp. D)의 것과 상호 비교하였다. 꽃뱀에서의 P45O, b5 함량 및 NADPH-cytochrome c reductase 활성도는 흰쥐에서 보다 낮았으며, 7-ethoxycoumarin O-deethylase와 benzphetamine N-demethylase 활성도 역시 흰쥐에서 보다 상당히 낮았다. 그러나 aryl hydrocarbon hydroxylase와 testosterone hydroxylase 활성도는 흰쥐와 비교할 때 거의 비슷하거나 오히려 높았다. Testosterone의 수산화 반응에 대한 선택특이성을 조사한 결과, 꽃 뱀은 7$\alpha$ 위치에서, 흰쥐는 6$\beta$ 위치에서 가장 높은 수산화 반응물을 생성했다. 그러나 testosterone의 C2와 C3 위치에서의 수산화 반응에 대한 선택특이성은 꽃뱀과 흰쥐에서 비슷하였다. Radioimmunoassay (RlA)를 실시하여 5종 (CYP2B, CYP1A1, CYP1A2, CYP3A 및 CYP2El)의 P45O 동위효소의 구성비를 비교한 결과, 꽃뱀에서는 CYP1A1/1A2가, 흰쥐에서는 CYP2El이 각각 비교적 많이 존재하였다. 부분정제한 P45O을 SDS-PAGE와 RIA로 분석한 결과, 꽃뱀의 간 마이크로좀에 존재하는 P45O중에는 흰쥐와는 다른 종류의 P45O 동위효소가 존재함을 시사하였다.

• Biomolecules & Therapeutics
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• 제12권3호
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• pp.185-188
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• 2004

The purpose of this study is to evaluate the effect of cigarette smoke condensate (CSC) on toxification/detoxification metabolic pathway in primary cultured rat hepatocytes. We measured the activities of cytochrome P450 monooxygenases (CYP450s) and UDP-glucuronyltransferase, sulfotransferase and glutathione-S-transferase in CSC-treated rat hepatocytes. CSC significantly increased the activities of hepatic CYP4501A1 and CYP4501A2 to 7.5 fold and 1.6 fold respectively, compared with control level. However, CSC did not affect the activities of conjugation enzymes. We a1so examined if treatment of CSC could change thc cytotoxicity of acetaminophen (AA) through modulation of metabolizing enzymes. In rat hepatocytes, pretreatment with CSC potentiated the cytotoxicity of AA. This result indicates that potentiation of AA toxicity by CSC pretreatment may be related to induction of CYP4501A1 and CYP4501A2.