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Sample records for 2d6 substrate activity

  1. QSAR Models for P-450 (2D6) Substrate Activity

    DEFF Research Database (Denmark)

    Ringsted, Tine; Nikolov, Nikolai Georgiev; Jensen, Gunde Egeskov;

    2009-01-01

    drugs and other chemicals. A training set of 747 chemicals primarily based on in vivo human data for the CYP isoenzyme 2D6 was collected from the literature. QSAR models focusing on substrate/non substrate activity were constructed by the use of MultiCASE, Leadscope and MDL quantitative structure......Human Cytochrome P450 (CYP) is a large group of enzymes that possess an essential function in metabolising different exogenous and endogenous compounds. Humans have more than 50 different genes encoding CYP enzymes, among these a gene encoding for the CYP isoenzyme 2D6, a CYP able to metabolise...

  2. CYP2D6*1,CYP2D6*10 co-expressed with CYPOR in Bac-to-Bac expression system and activity determination%与CYPOR共表达CYP2D6*1和CYP2D6*10及其代谢活性比较

    Institute of Scientific and Technical Information of China (English)

    钱鸣蓉; 陈静; 刘瑶; 余露山; 陈枢青; 曾苏

    2011-01-01

    FastBac-CYPOR were constructed and transformed into DH10Bac cell to obtain the recombinant Bacmid-CYPOR, Bacmid-CYP2D6 *1 and Bacmid-CYP2D6*10. And then the recombinant CYP2D6 *1 and CYP2D6 *10 virus were obtained by transfecting Sf9. Then homogenate protein activity was determined witb dextromethorphan as substrate. The multiple of infection (MOI) and its ratio of recombinant CYP2D6 virus to CYPOR virus were adjusted by detecting the activity of the homogenate protein. The Km and Vmax are 26.67±2.71 μmol·L-1 (n=3) and 666.7±56.78 pmol·nmol-1(CYP2D6)·min-1 (n=3) for CYP2D6*1 to catalyze dextromethaphan. The Km and Vmax are 111.36±10.89 μmol·L-1 (n=3) and 222.2±20.12 pmol·nmol-1(CYP2D6)·min-1 (n=3) for CYP2D6*10 to catalyze dextromethorphan. There is significant difference between CYP2D6*1 and CYP2D6*10 for Vmax and Km (P<0.01). The clearance ratio of CYP2D6*1 is 25.0 and the clearance ratio of CYP2D6*10 is 2.0. The expressed CYP2D6*1 and CYP2D6*10 are useful tools to screen the metabolism profile of many xenobiotics and endobiotics in vitro, which are benefit to understand individual metabolism difference.

  3. Identification of cytochrome P450 2D6 and 2C9 substrates and inhibitors by QSAR analysis

    DEFF Research Database (Denmark)

    Jónsdóttir, Svava Ósk; Ringsted, Tine; Nikolov, Nikolai G.;

    2012-01-01

    these compounds. A large fraction of these chemicals were found to be CYP active, and thus potentially capable of affecting human physiology. 20% of the compounds within applicability domain of the models were predicted to be CYP2C9 substrates, and 17% to be inhibitors. The corresponding numbers for CYP2D6 were 9...... of specific CYP activity. An overrepresentation was seen for poly-aromatic hydrocarbons (group of procarcinogens) among CYP2C9 active and mutagenic compounds compared to CYP2C9 inactive and mutagenic compounds. The mutagenicity was predicted with a QSAR model based on Ames in vitro test data.......% and 21%. Where the majority of CYP2C9 active compounds were predicted to be both a substrate and an inhibitor at the same time, the CYP2D6 active compounds were primarily predicted to be only inhibitors. It was demonstrated that the models could identify compound classes with a high occurrence...

  4. Roles of phenylalanine at position 120 and glutamic acid at position 222 in the oxidation of chiral substrates by cytochrome P450 2D6.

    Science.gov (United States)

    Masuda, Kazufumi; Tamagake, Keietsu; Katsu, Takashi; Torigoe, Fumihiro; Saito, Keita; Hanioka, Nobumitsu; Yamano, Shigeru; Yamamoto, Shigeo; Narimatsu, Shizuo

    2006-02-01

    The roles of Phe-120 and Glu-222 in the oxidation of chiral substrates bunitrolol (BTL) and bufuralol (BF) by CYP2D6 are discussed. Wild-type CYP2D6 (CYP2D6-WT) oxidized BTL to 4-hydroxybunitrolol (4-OH-BTL) with substrate enantioselectivity of (R)-(+)-BTL > (S)-(-)-BTL. The same enzyme converted BF into 1''-hydroxybufuralol with substrate enantioselectivity of (R)-BF > (S)-BF and metabolite diastereoselectivity of (1''R)-OH kinetic parameters (K(m) and V(max) values) for (R)-BF 1''-hydroxylation remained unchanged. Furthermore, the substitution of Glu-222 as well as Glu-216 by alanine remarkably decreased both the apparent K(m) and V(max) values without changing substrate enantioselectivity or metabolite diastereoselectivity. A computer-assisted simulation study using energy minimization and molecular dynamics techniques indicated that the hydrophobic interaction of an aromatic moiety of the substrate with Phe-120 and the ionic interaction of a basic nitrogen atom of the substrate with Glu-222 in combination with Glu-216 play important roles in the binding of BF and BTL by CYP2D6 and the orientation of these substrates in the active-site cavity. This modeling yielded a convincing explanation for the reversal of substrate enantioselectivity in BTL 4-hydroxylation between CYP2D6-WT and CYP2D6-V374M having methionine in place of Val-374, which supports the validity of this modeling.

  5. The antitussive effect of dextromethorphan in relation to CYP2D6 activity

    Science.gov (United States)

    Abdul Manap, R; Wright, C E; Gregory, A; Rostami-Hodjegan, A; Meller, S T; Kelm, G R; Lennard, M S; Tucker, G T; Morice, A H

    1999-01-01

    Aims To test the hypothesis that inhibition of cytochrome P450 2D6 (CYP2D6) by quinidine increases the antitussive effect of dextromethorphan (DEX) in an induced cough model. Methods Twenty-two healthy extensive metaboliser phenotypes for CYP2D6 were studied according to a double-blind, randomised cross-over design after administration of: (1) Placebo antitussive preceded at 1 h by placebo inhibitor; (2) 30 mg oral DEX preceded at 1 h by placebo inhibitor (DEX30); (3) 60 mg oral DEX preceded at 1 h by placebo inhibitor (DEX60); (4) 30 mg oral DEX preceded at 1 h by 50 mg oral quinidine sulphate (QDEX30). Cough frequency following inhalation of 10% citric acid was measured at baseline and at intervals up to 12 h. Plasma concentrations of DEX and its metabolites were measured up to 96 h by h.p.l.c. Results Inhibition of CYP2D6 by quinidine caused a significant increase in the mean ratio of DEX to dextrorphan (DEX:DOR) plasma AUC(96) (0.04 vs 1.81, P < 0.001). The mean (±s.d.) decrements in cough frequency below baseline over 12 h (AUEC) were: 8% (11), 17% (14.5), 25% (16.2) and 25% (16.9) for placebo, DEX30, DEX60 and QDEX30 treatments, respectively. Statistically significant differences in antitussive effect were detected for the contrasts between DEX60/placebo (P < 0.001; 95% CI of difference +80, +327) and QDEX30/placebo (P < 0.001, +88, +336), but not for DEX30/placebo, DEX30/DEX60 or DEX30/QDEX30 (P = 0.071, −7, +241; P = 0.254, −37, +211; P = 0.187, −29, +219, respectively). Conclusions A significant antitussive effect was demonstrated after 60 mg dextromethorphan and 30 mg dextromethorphan preceded by 50 mg quinidine using an induced cough model. However, although the study was powered to detect a 10% difference in cough response, the observed differences for other contrasts were less than 10%, such that it was possible only to imply a dose effect (30 vs 60 mg) in the antitussive activity of DEX and enhancement of this effect by CYP2D6 inhibition. PMID

  6. CYP2D6 and CYP2C19 activity in a large population of Dutch healthy volunteers : indications for oral contraceptive-related gender differences

    NARCIS (Netherlands)

    Tamminga, WJ; Wemer, J; Oosterhuis, B; Wieling, J; Wilffert, B; de Leij, LFMH; de Zeeuw, RA; Jonkman, JHG

    1999-01-01

    Objective: We examined a large database containing results on CYP2D6 and CYP2C19 activity of 4301 Dutch volunteers phenotyped in the context of various clinical pharmacology studies. Methods: The subjects were given 22 mg dextromethorphan, 100 mg mephenytoin and 200 mg caffeine. For CYP2D6, the dext

  7. New aQTL SNPs for the CYP2D6 Identified by a Novel Mediation Analysis of Genome-Wide SNP Arrays, Gene Expression Arrays, and CYP2D6 Activity

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    Guanglong Jiang

    2013-01-01

    Full Text Available Background. The genome-wide association studies (GWAS have been successful during the last few years. A key challenge is that the interpretation of the results is not straightforward, especially for transacting SNPs. Integration of transcriptome data into GWAS may provide clues elucidating the mechanisms by which a genetic variant leads to a disease. Methods. Here, we developed a novel mediation analysis approach to identify new expression quantitative trait loci (eQTL driving CYP2D6 activity by combining genotype, gene expression, and enzyme activity data. Results. 389,573 and 1,214,416 SNP-transcript-CYP2D6 activity trios are found strongly associated (P<10-5, FDR=16.6% and 11.7% for two different genotype platforms, namely, Affymetrix and Illumina, respectively. The majority of eQTLs are trans-SNPs. A single polymorphism leads to widespread downstream changes in the expression of distant genes by affecting major regulators or transcription factors (TFs, which would be visible as an eQTL hotspot and can lead to large and consistent biological effects. Overlapped eQTL hotspots with the mediators lead to the discovery of 64 TFs. Conclusions. Our mediation analysis is a powerful approach in identifying the trans-QTL-phenotype associations. It improves our understanding of the functional genetic variations for the liver metabolism mechanisms.

  8. Molecular dynamics of CYP2D6 polymorphisms in the absence and presence of a mechanism-based inactivator reveals changes in local flexibility and dominant substrate access channels.

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    Parker W de Waal

    Full Text Available Cytochrome P450 enzymes (CYPs represent an important enzyme superfamily involved in metabolism of many endogenous and exogenous small molecules. CYP2D6 is responsible for ∼ 15% of CYP-mediated drug metabolism and exhibits large phenotypic diversity within CYPs with over 100 different allelic variants. Many of these variants lead to functional changes in enzyme activity and substrate selectivity. Herein, a molecular dynamics comparative analysis of four different variants of CYP2D6 was performed. The comparative analysis included simulations with and without SCH 66712, a ligand that is also a mechanism-based inactivator, in order to investigate the possible structural basis of CYP2D6 inactivation. Analysis of protein stability highlighted significantly altered flexibility in both proximal and distal residues from the variant residues. In the absence of SCH 66712, *34, *17-2, and *17-3 displayed more flexibility than *1, and *53 displayed more rigidity. SCH 66712 binding reversed flexibility in *17-2 and *17-3, through *53 remained largely rigid. Throughout simulations with docked SCH 66712, ligand orientation within the heme-binding pocket was consistent with previously identified sites of metabolism and measured binding energies. Subsequent tunnel analysis of substrate access, egress, and solvent channels displayed varied bottle-neck radii. Taken together, our results indicate that SCH 66712 should inactivate these allelic variants, although varied flexibility and substrate binding-pocket accessibility may alter its interaction abilities.

  9. The effect of TongXuan LiFei pill on the activity of CYP2D6%通宣理肺丸对CYP2D6酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    徐娟; 赵钢涛; 邸晓辉; 张梅; 郑绯

    2013-01-01

    目的 研究通宣理肺丸对CYP2D6酶活性的影响,探讨通宣理肺丸的代谢途径,为临床指导合理用药提供依据.方法 筛选30名健康志愿者作为受试者.以右美沙芬作为CYP2D6的探针药,研究服用通宣理肺丸对人体内代谢酶CYP2D6活性的影响.采用高效液相色谱法-质谱(HPLC-MS/MS)法测定探针药及其代谢产物的血药浓度.连续服用14 d通宣理肺丸.以曲线下面积(AUC0~12)为指标,评价CYP2D6代谢酶的活性.结果 受试者用药前CYP2D6代谢酶活性为6.1±1.5,服用通宣理肺丸后代谢酶活性为6.5±1.7,差异无统计学意义.结论 服用通宣理肺丸对CYP2D6代谢酶活性没有明显影响.

  10. The correlation between CYP2D6 isoenzyme activity and haloperidol efficacy and safety profile in patients with alcohol addiction during the exacerbation of the addiction

    Science.gov (United States)

    Sychev, Dmitry Alekseevich; Zastrozhin, Mikhail Sergeevich; Smirnov, Valery Valerieevich; Grishina, Elena Anatolievna; Savchenko, Ludmila Mikhailovna; Bryun, Evgeny Alekseevich

    2016-01-01

    Background Today, it is proved that isoenzymes CYP2D6 and CYP3A4 are involved in metabolism of haloperidol. In our previous investigation, we found a medium correlation between the efficacy and safety of haloperidol and the activity of CYP3A4 in patients with alcohol abuse. Objective The aim of this study was to evaluate the correlation between the activity of CYP2D6 and the efficacy and safety of haloperidol in patients with diagnosed alcohol abuse. Methods The study involved 70 men (average age: 40.83±9.92 years) with alcohol addiction. A series of psychometric scales were used in the research. The activity of CYP2D6 was evaluated by high-performance liquid chromatography with mass spectrometry using the ratio of 6-hydroxy-1,2,3,4-tetrahydro-beta-carboline to pinoline. Genotyping of CYP2D6 (1846G>A) was performed using real-time polymerase chain reaction. Results According to results of correlation analysis, statistically significant values of Spearman correlation coefficient (rs) between the activity of CYP2D6 and the difference of points in psychometric scale were obtained in patients receiving haloperidol in injection form (Sheehan Clinical Anxiety Rating Scale =−0.721 [P<0.001] and Udvald for Kliniske Undersogelser Side Effect Rating Scale =0.692 [P<0.001]) and in those receiving haloperidol in tablet form (Covi Anxiety Scale =−0.851 [P<0.001] and Udvald for Kliniske Undersogelser Side Effect Rating Scale =0.797 [P<0.001]). Conclusion This study demonstrated the correlations between the activity of CYP2D6 isozyme and the efficacy and safety of haloperidol in patients with alcohol addiction. PMID:27695358

  11. 以普罗帕酮为探针测定人肝微粒体中CYP2D6的活性%Determination of CYP2D6 activity in human liver microsomes using propafenone as a probe

    Institute of Scientific and Technical Information of China (English)

    张顺国; 唐跃年; 卜书红

    2004-01-01

    目的:测定普罗帕酮(PPF)和5-羟基普罗帕酮(5-OHP)的比值以表达人肝微粒体中CYP2D6的活性.方法:以1g·L-1微粒体蛋白浓度37℃孵育PPF 1 h,以HPLC测定PPF和5-OHP的含量.结果:PPF和5-OHP的线性方程分别为Y=0.452 0 C+0.003 0,r=0.999 7;Y=0.749 4 C-0.020 5,r=0.997 5.结论:人肝微粒体CYP2D6酶的活性可以通过测定5-OHP与PPF的比值进行预测.

  12. The correlation between CYP2D6 isoenzyme activity and haloperidol efficacy and safety profile in patients with alcohol addiction during the exacerbation of the addiction

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    Sychev DA

    2016-09-01

    Full Text Available Dmitry Alekseevich Sychev,1 Mikhail Sergeevich Zastrozhin,1–3 Valery Valerieevich Smirnov,4 Elena Anatolievna Grishina,1 Ludmila Mikhailovna Savchenko,1 Evgeny Alekseevich Bryun1,2 1Russian Medical Academy of Postgraduate Education, Ministry of Health of the Russian Federation, 2Department of Public Health, Moscow Research and Practical Centre for Narcology, 3Peoples’ Friendship University of Russia, 4National Research Center, Institute of Immunology Federal Medical-Biological Agency of Russia, Moscow, Russia Background: Today, it is proved that isoenzymes CYP2D6 and CYP3A4 are involved in metabolism of haloperidol. In our previous investigation, we found a medium correlation between the efficacy and safety of haloperidol and the activity of CYP3A4 in patients with alcohol abuse.Objective: The aim of this study was to evaluate the correlation between the activity of CYP2D6 and the efficacy and safety of haloperidol in patients with diagnosed alcohol abuse.Methods: The study involved 70 men (average age: 40.83±9.92 years with alcohol addiction. A series of psychometric scales were used in the research. The activity of CYP2D6 was evaluated by high-performance liquid chromatography with mass spectrometry using the ratio of 6-hydroxy-1,2,3,4-tetrahydro-beta-carboline to pinoline. Genotyping of CYP2D6 (1846G>A was performed using real-time polymerase chain reaction.Results: According to results of correlation analysis, statistically significant values of Spearman correlation coefficient (rs between the activity of CYP2D6 and the difference of points in psychometric scale were obtained in patients receiving haloperidol in injection form (Sheehan Clinical Anxiety Rating Scale =-0.721 [P<0.001] and Udvald for Kliniske Undersogelser Side Effect Rating Scale =0.692 [P<0.001] and in those receiving haloperidol in tablet form (Covi Anxiety Scale =-0.851 [P<0.001] and Udvald for Kliniske Undersogelser Side Effect Rating Scale =0.797 [P<0.001].Conclusion

  13. Meta-analysis of correlation between CYP2 D6 polymorphisms and tamoxifen concentrations and its activity in Chinese breast cancer patients%中国人群CYP2D6的基因多态性与乳腺癌患者他莫昔芬及其代谢物血药浓度关系的Meta分析

    Institute of Scientific and Technical Information of China (English)

    熊萱; 张思超; 朱昶宇

    2015-01-01

    目的:系统评价 CYP2 D6基因型与乳腺癌患者他莫昔芬及其活性代谢物血药浓度的关系。方法计算机检索Cochrane图书馆、PubMed、EMBase、CNKI、CBM、Weipu Data、Wanfang Data等数据库,并手工检索相关文献,查找关于CYP2D6基因型与他莫昔芬及其活性代谢物血药浓度的文献。检索时间1995年1月~2014年10月。采用RevMan5.3软件进行meta分析。结果共纳入4篇文献,包含438例研究对象。 Meta分析结果显示,携带CYP2D6*10/*10基因型患者的他莫昔芬活性代谢物( HTAM、endoxifen)血药浓度明显低于携带其他基因型患者(P<0.0001);携带CYP2D6*10/*10基因型患者的他莫昔芬血药浓度低于携带CYP2D6Wt/Wt基因型患者(P<0.05)。而CYP2D6Wt/Wt及CYP2D6Wt/*10基因型携带患者间,TAM及其活性代谢物血药浓度比较,差异无统计学意义。结论中国人群CYP2D6的基因多态型对乳腺癌患者体内他莫西芬及其代谢物的浓度有影响。%Objective To systematically review the correlation between polymorphisms of CYP2D6 genotypes and concentrations of tamoxifen and its activity in Chinese breast cancer patients.Methods Such databases as Cochrane Library, PubMed, EMBase, CNKI, CBM, WeipuData and WanfangDate,from January 1995 to October 2014 were searched on line for the studies about the correlation between polymorphisms of CYP2D6 genotypes concentrations of tamoxifen and its activity in Chinese breast cancer patients.And references about it were checked.The meta-analysis was performed with RevMan 5.3 software.Results A total of 4 articles involving 438 patients were included.The results of meta-analysis showed that,the concentrations of HTAM and endoxifen in patients who had CYP2D6*10/*10 genotypes were lower than the other genotypes ( P<0.0001 ) .The concentration of tamoxifen in patients who had CYP2D6*10/*10 genotypes was lower than CYP2D6Wt/Wt ( P<0.05 ) .There was no significant

  14. Modeling Chemical Interaction Profiles: I. Spectral Data-Activity Relationship and Structure-Activity Relationship Models for Inhibitors and Non-inhibitors of Cytochrome P450 CYP3A4 and CYP2D6 Isozymes

    Directory of Open Access Journals (Sweden)

    Richard D. Beger

    2012-03-01

    techniques, providing an independent estimator that can increase confidence in a structure-activity assessment. When modeling was applied to hazardous environmental chemicals, it was found that up to 20% of them may be substrates and up to 10% of them may be inhibitors of the CYP3A4 and CYP2D6 isoforms. The developed models provide a rare opportunity for the environmental health branch of the public health service to extrapolate to hazardous chemicals directly from human clinical data. Therefore, the pharmacological and environmental health branches are both expected to benefit from these reported models.

  15. Modeling chemical interaction profiles: I. Spectral data-activity relationship and structure-activity relationship models for inhibitors and non-inhibitors of cytochrome P450 CYP3A4 and CYP2D6 isozymes.

    Science.gov (United States)

    McPhail, Brooks; Tie, Yunfeng; Hong, Huixiao; Pearce, Bruce A; Schnackenberg, Laura K; Ge, Weigong; Valerio, Luis G; Fuscoe, James C; Tong, Weida; Buzatu, Dan A; Wilkes, Jon G; Fowler, Bruce A; Demchuk, Eugene; Beger, Richard D

    2012-03-15

    techniques, providing an independent estimator that can increase confidence in a structure-activity assessment. When modeling was applied to hazardous environmental chemicals, it was found that up to 20% of them may be substrates and up to 10% of them may be inhibitors of the CYP3A4 and CYP2D6 isoforms. The developed models provide a rare opportunity for the environmental health branch of the public health service to extrapolate to hazardous chemicals directly from human clinical data. Therefore, the pharmacological and environmental health branches are both expected to benefit from these reported models.

  16. Role of cytochrome P450 2D6 genetic polymorphism in carvedilol hydroxylation in vitro

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    Wang Z

    2016-06-01

    Full Text Available Zhe Wang,1,* Li Wang,2,3,* Ren-ai Xu,4 Yun-yun Zhan,2 Cheng-ke Huang,1 Da-peng Dai,5 Jian-ping Cai,5 Guo-xin Hu2 1Department of Pharmacy, The Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, 2Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, 3Department of Pharmacy, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 4Department of Pharmacy, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 5The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Cytochrome P450 2D6 (CYP2D6 is a highly polymorphic enzyme that catalyzes the metabolism of a great number of therapeutic drugs. Up to now, >100 allelic variants of CYP2D6 have been reported. Recently, we identified 22 novel variants in the Chinese population in these variants. The purpose of this study was to examine the enzymatic activity of the variants toward the CYP2D6 substrate carvedilol in vitro. The CYP2D6 proteins, including CYP2D6.1 (wild type, CYP2D6.2, CYP2D6.10, and 22 other novel CYP2D6 variants, were expressed from insect microsomes and incubated with carvedilol ranging from 1.0 µM to 50 µM at 37°C for 30 minutes. After termination, the carvedilol metabolites were extracted and detected using ultra-performance liquid chromatography tandem mass-spectrometry. Among the 24 CYP2D6 variants, CYP2D6.92 and CYP2D6.96 were catalytically inactive and the remaining 22 variants exhibited significantly decreased intrinsic clearance values (ranging from ~25% to 95% compared with CYP2D6.1. The present data in vitro suggest that the newly found variants significantly reduced catalytic activities compared with CYP2D6.1. Given that CYP2D6 protein activities could affect carvedilol plasma levels, these findings are greatly relevant to

  17. High Frequency of CYP2D6 Ultrarapid Metabolizer Genotype in the Finnish Population.

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    Pietarinen, Paavo; Tornio, Aleksi; Niemi, Mikko

    2016-09-01

    CYP2D6 participates in the biotransformation of many commonly used drugs. Large genetic variability in CYP2D6 results in a wide interindividual variability in the response to CYP2D6 substrate drugs. Previous studies have assessed the phenotype and genotype distributions of CYP2D6 in relatively small Finnish population samples. The aim of our study was to investigate the frequencies of CYP2D6 genotypes in a larger Finnish population cohort of 857 healthy volunteers. The volunteers were genotyped for 10 CYP2D6 genetic variants (*2, *3, *4, *5, *6, *9, *10, *17, *39, *41) and copy number variation performed with TaqMan genotyping assays and copy number assay targeting exon 9. CYP2D6 phenotypes were inferred from the genotype data with the classical and activity score methods. According to the classical method, a large majority of the study cases were extensive metabolizers (EM; 87.3%; 95% confidence interval 84.9-89.3) and the second largest group was ultrarapid metabolizers (UM; 7.2%; 5.7-9.2%). Intermediate (IM) and poor metabolizers (PM) were in clear minority (3.0%; 2.1-4.4% and 2.3%; 1.5-3.6%, respectively). The activity score method yielded similar phenotype predictions. These results show that the frequency of UM genotype is higher and that of PM and IM genotype is lower in the Finnish population than in other North European populations. Accordingly, CYP2D6 genetic profile of the Finnish population differs from its geographically close neighbours, which has implications for the effective and safe use of drugs metabolized by CYP2D6. PMID:27038154

  18. Impact of fraction unbound, CYP3A, and CYP2D6 in vivo activities, and other potential covariates to the clearance of tramadol enantiomers in patients with neuropathic pain.

    Science.gov (United States)

    de Moraes, Natália V; Lauretti, Gabriela R; Coelho, Eduardo B; Godoy, Ana Leonor P C; Neves, Daniel V; Lanchote, Vera L

    2016-04-01

    The pharmacokinetics of tramadol is characterized by a large interindividual variability, which is partially attributed to polymorphic CYP2D6 metabolism. The contribution of CYP3A, CYP2B6, fraction unbound, and other potential covariates remains unknown. This study aimed to investigate the contribution of in vivo activities of cytochrome P450 (CYP) 2D6 and 3A as well as other potential covariates (CYP2B6 genotype to the SNP g.15631G>T, fraction unbound, age, body weight, creatinine clearance) to the enantioselective pharmacokinetics of tramadol. Thirty patients with neuropathic pain and phenotyped as CYP2D6 extensive metabolizers were treated with a single oral dose of 100 mg tramadol. Multiple linear regressions were performed to determine the contribution of CYP activities and other potential covariates to the clearance of tramadol enantiomers. The apparent total clearances were 44.9 (19.1-102-2) L/h and 55.2 (14.8-126.0) L/h for (+)- and (-)-tramadol, respectively [data presented as median (minimum-maximum)]. Between 79 and 83% of the overall variation in apparent clearance of tramadol enantiomers was explained by fraction unbound, CYP2D6, and CYP3A in vivo activities and body weight. Fraction unbound explained 47 and 41% of the variation in clearance of (+)-tramadol and (-)-tramadol, respectively. Individually, CYP2D6 and CYP3A activities were shown to have moderate contribution on clearance of tramadol enantiomers (11-16% and 11-18%, respectively). In conclusion, factors affecting fraction unbound of drugs (such as hyperglycemia or co-administration of drugs highly bound to plasma proteins) should be monitored, because this parameter dominates the elimination of tramadol enantiomers.

  19. Effects of Flos carthami on CYP2D6 and on the Pharmacokinetics of Metoprolol in Rats

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    Gaofeng Liu

    2011-01-01

    Full Text Available Flos carthami is a traditional Chinese herbal medicine. Clinically, the Flos carthami Injection has been used concomitantly with other Western drugs and may be used concomitantly with β-blockers, such as metoprolol, to treat cerebrovascular and coronary heart diseases, in China. Metoprolol is a CYP2D6 substrate and is predominantly metabolized by this isozyme. However, we do not know whether there is an effect of Flos carthami on CYP2D6 and the consequences of such an effect. Concern is raised regarding the possible herb-drug interaction. In this report, the effects of Flos carthami on the activity of CYP2D6 in vivo and in vitro and on the pharmacokinetics of metoprolol, in rats, are investigated. To assess the inhibitory potency of Flos carthami, the concentration associated with 50% inhibition (IC50 of dextromethorphan metabolism was determined based on the concentration-inhibition curves. The inhibitory effect of Flos carthami on CYP2D6 was also compared with cimetidine in vitro. Flos carthami could significantly inhibit CYP2D6 in rats both in vitro and in vivo (P<.05 and could slow down the metabolic rate of metoprolol as suggested by prolonged t1/2 (67.45%, by increased Cmax (74.51% and AUC0−∞ (76.89%. These results suggest that CYP2D6 is a risk factor when Flos carthami is administered concomitantly with metoprolol or other CYP2D6 substrates.

  20. The Impact of CYP2D6 Genotyping on Tamoxifen Treatment

    OpenAIRE

    Ferraldeschi, Roberta; William G Newman

    2010-01-01

    Tamoxifen remains a cornerstone of treatment for patients with oestrogen-receptor-positive breast cancer. Tamoxifen efficacy depends on the biotransformation, predominantly via the cytochrome P450 2D6 (CYP2D6) isoform, to the active metabolite endoxifen. Both genetic and environmental (drug-induced) factors may alter CYP2D6 enzyme activity directly affecting the concentrations of active tamoxifen metabolites. Several studies suggest that germline genetic variants in CYP2D6 influence the clini...

  1. CYP2D6 genotype and phenotype relationship in South Indians

    Directory of Open Access Journals (Sweden)

    Naveen A

    2006-01-01

    Full Text Available Background : Genotypes of the drug-metabolizing enzyme CYP2D6 influence plasma levels of 25% of commonlyprescribed drugs. This is the first study in India to investigate the genotype-phenotype relationship of CYP2D6. Aim : To study the influence of some CYP2D6 genotypes on the metabolism of its substrate dextromethorphanin healthy South Indian volunteers and to assess the contribution of the CYP2D6FNx0110 and CYP2D6FNx014 alleles. Materials and Methods : Twenty-six subjects from a previous CYP2D6 genotyping study of healthy volunteerswere included for phenotyping in this study. Selected volunteers belonged to any one of three genotype groups:Group I - two normal activity alleles, Group II - one reduced activity allele and one normal activity allele andGroup III - one loss of function allele along with either a wild type or reduced activity allele. Volunteers werephenotyped for the CYP2D6 enzyme using dextromethorphan as probe drug. Concentrations of the parent drugand metabolite dextrorphan were estimated using high performance liquid chromatography. Metabolic ratioswere calculated as the ratio of parent drug to metabolite in 0-8h urine samples. Statistical Analysis : Metabolic ratios from each genotype group were compared using the Mann-Whitney testat 5% significance, to observe their difference between genotype groups. Results : The mean metabolic ratios±SD in Groups I, II and III were 0.0039±0.0031, 0.0032±0.0017 and0.0391±0.0331 respectively. The mean metabolic ratio of Group III was significantly higher when comparedwith Groups I or II. In heterozygous individuals, the FNx011 or FNx012 alleles compensated for the reduced enzymeactivity due to the FNx0110 allele. However, if a heterozygous individual had a FNx014 allele, the reduced enzyme activitycould not be compensated by the FNx011 or FNx012 alleles. Conclusions : The CYP2D6 enzyme activity was found to be decreased in individuals carrying FNx014 or FNx015 alleles.The FNx011 or FNx

  2. The Impact of CYP2D6 Genotyping on Tamoxifen Treatment

    Directory of Open Access Journals (Sweden)

    Roberta Ferraldeschi

    2010-04-01

    Full Text Available Tamoxifen remains a cornerstone of treatment for patients with oestrogen-receptor-positive breast cancer. Tamoxifen efficacy depends on the biotransformation, predominantly via the cytochrome P450 2D6 (CYP2D6 isoform, to the active metabolite endoxifen. Both genetic and environmental (drug-induced factors may alter CYP2D6 enzyme activity directly affecting the concentrations of active tamoxifen metabolites. Several studies suggest that germline genetic variants in CYP2D6 influence the clinical outcomes of patients treated with adjuvant tamoxifen. Here, we review the existing data relating CYP2D6 genotypes to tamoxifen efficacy.

  3. Variation in the CYP2D6 gene is associated with a lower serum sodium concentration in patients on antidepressants

    NARCIS (Netherlands)

    S. Kwadijk-De Gijsel (Sonja); M.J. Bijl (Monique); L.E. Visser (Loes); R.H.N. van Schaik (Ron); A. Hofman (Albert); A.G. Vulto (Arnold); T. van Gelder (Teun); B.H.Ch. Stricker (Bruno)

    2009-01-01

    textabstractWHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Several antidepressants are metabolized by the polymorphic enzyme cytochrome P450 2D6 (CYP2D6). • The variant allele CYP2D6*4 is the main polymorphism resulting in decreased enzyme activity in Caucasians. • Decreased CYP2D6 enzyme activity poten

  4. Duplication of CYP2D6 predicts high clearance of desipramine but high clearance does not predict duplication of CYP2D6

    DEFF Research Database (Denmark)

    Bergmann, T K; Bathum, L; Brøsen, Kim

    2001-01-01

    OBJECTIVE: Duplication of CYP2D6 causes very rapid metabolism of CYP2D6 substrates such as desipramine. However, we have previously shown that in the Danish population, only about 15% of very rapid metabolisers, defined as subjects with a metabolic ratio of sparteine of 0.15 or less, carried a...... duplicated allele. The question is whether gene duplication is a relatively rare cause (perhaps predictor) of very rapid metabolism or whether a low metabolic ratio is a poor predictor of this. METHODS: After measuring metabolic ratios anew, we selected six volunteers with duplication of CYP2D6 and metabolic...... duplication of CYP2D6 is poor; there must be other causes (or predictors) of very rapid metabolism and with much higher frequency than duplication of CYP2D6....

  5. The impact of CYP2D6-predicted phenotype on tamoxifen treatment outcome in patients with metastatic breast cancer

    NARCIS (Netherlands)

    L.A. Lammers (Laureen); R.H.J. Matthijsen (Ron); T. van Gelder (Teun); M.J. Bijl (Monique); A.J.M. de Graan (Anne-Joy); C.M. Seynaeve (Caroline); M.A. van Fessem (Marianne); P.M.J.J. Berns (Els); A.G. Vulto (Arnold); R.H.N. van Schaik (Ron)

    2010-01-01

    textabstractAbstract BACKGROUND: Cytochrome P450 2D6 (CYP2D6) has a crucial role in the metabolic conversion of tamoxifen into the active metabolite endoxifen. In this cohort study, the effect of CYP2D6-predicted phenotype, defined as the combined effect of CYP2D6 genetic variation and concomitant

  6. Clinical Utility and Economic Impact of CYP2D6 Genotyping.

    Science.gov (United States)

    Reynolds, Kristen K; McNally, Beth A; Linder, Mark W

    2016-09-01

    Pharmacogenetics examines an individual's genetic makeup to help predict the safety and efficacy of medications. Practical application optimizes treatment selection to decrease the failure rate of medications and improve clinical outcomes. Lack of efficacy is costly due to adverse drug reactions and increased hospital stays. Cytochrome P450 2D6 (CYP2D6) metabolizes roughly 25% of all drugs. Detecting variants that cause altered CYP2D6 enzymatic activity identifies patients at risk of adverse drug reactions or therapeutic failure with standard dosages of medications metabolized by CYP2D6. This article discusses the clinical application of pharmacogenetics to improve care and decrease costs. PMID:27514466

  7. The Effects of H2S on the Activities of CYP2B6, CYP2D6, CYP3A4, CYP2C19 and CYP2C9 in Vivo in Rat

    Directory of Open Access Journals (Sweden)

    Xianqin Wang

    2013-12-01

    Full Text Available Hydrogen sulfide (H2S is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. The human body produces small amounts of H2S and uses it as a signaling molecule. The cocktail method was used to evaluate the influence of H2S on the activities of CYP450 in rats, which were reflected by the changes of pharmacokinetic parameters of five specific probe drugs: bupropion, metroprolol, midazolam, omeprazole and tolbutamide, respectively. The rats were randomly divided into two groups, control group and H2S group. The H2S group rats were given 5 mg/kg NaHS by oral administration once a day for seven days. The mixture of five probes was given to rats through oral administration and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by LC-MS. In comparing the H2S group with the control group, there was a statistically pharmacokinetics difference for midazolam and tolbutamide; the area under the plasma concentration-time curve (AUC was decreased for midazolam (p < 0.05 and increased for tolbutamide (p < 0.05; while there was no statistical pharmacokinetics difference for bupropion, metroprolol and omeprazole. H2S could not influence the activities of CYP2B6, CYP2D6 and CYP2C19 in rats, while H2S could induce the activity of CYP3A4 and inhibit the activity of CYP2C9 in rats.

  8. MDMA, methamphetamine, and CYP2D6 pharmacogenetics: what is clinically relevant?

    Directory of Open Access Journals (Sweden)

    Rafael eDe La Torre

    2012-11-01

    Full Text Available In vitro human studies show that the metabolism of most amphetamine-like psychostimulants is regulated by the polymorphic cytochrome P450 isozyme CYP2D6. Two compounds, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA, were selected as archetypes to discuss the translation and clinical significance of in vitro to in vivo findings. Both compounds were chosen based on their differential interaction with CYP2D6 and their high abuse prevalence in society. Methamphetamine behaves as both a weak substrate and competitive inhibitor of CYP2D6, while MDMA acts as a high affinity substrate and potent mechanism-based inhibitor (MBI of the enzyme. The MBI behavior of MDMA on CYP2D6 implies that subjects, irrespective of their genotype/phenotype, are phenocopied to the poor metabolizer phenotype. The fraction of metabolic clearance regulated by CYP2D6 for both drugs is substantially lower than expected from in vitro studies. Other isoenzymes of cytochrome P450 and a relevant contribution of renal excretion play a part in their clearance. These facts tune down the potential contribution of CYP2D6 polymorphism in the clinical outcomes of both substances. Globally, the clinical relevance of CYP2D6 polymorphism is lower than that predicted by in vitro studies.

  9. Effect of Curcuma longa on CYP2D6- and CYP3A4-mediated metabolism of dextromethorphan in human liver microsomes and healthy human subjects.

    Science.gov (United States)

    Al-Jenoobi, Fahad Ibrahim; Al-Thukair, Areej A; Alam, Mohd Aftab; Abbas, Fawkeya A; Al-Mohizea, Abdullah M; Alkharfy, Khalid M; Al-Suwayeh, Saleh A

    2015-03-01

    Effect of Curcuma longa rhizome powder and its ethanolic extract on CYP2D6 and CYP3A4 metabolic activity was investigated in vitro using human liver microsomes and clinically in healthy human subjects. Dextromethorphan (DEX) was used as common probe for CYP2D6 and CYP3A4 enzymes. Metabolic activity of CYP2D6 and CYP3A4 was evaluated through in vitro study; where microsomes were incubated with NADPH in presence and absence of Curcuma extract. In clinical study phase-I, six healthy human subjects received a single dose (30 mg) of DEX syrup, and in phase-II DEX syrup was administered with Curcuma powder. The enzyme CYP2D6 and CYP3A4 mediated O- and N-demethylation of dextromethorphan into dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Curcuma extract significantly inhibited the formation of DOR and 3-MM, in a dose-dependent and linear fashion. The 100 μg/ml dose of curcuma extract produced highest inhibition, which was about 70 % for DOR and 80 % for 3-MM. Curcuma significantly increases the urine metabolic ratio of DEX/DOR but the change in DEX/3-MM ratio was statistically insignificant. Present findings suggested that curcuma significantly inhibits the activity of CYP2D6 in in vitro as well as in vivo; which indicates that curcuma has potential to interact with CYP2D6 substrates.

  10. CYP2D6 genotype and tamoxifen response in postmenopausal women with endocrine-responsive breast cancer

    DEFF Research Database (Denmark)

    Regan, Meredith M; Leyland-Jones, Brian; Bouzyk, Mark;

    2012-01-01

    Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated th...

  11. Farnesoid X Receptor Agonist Represses Cytochrome P450 2D6 Expression by Upregulating Small Heterodimer Partner.

    Science.gov (United States)

    Pan, Xian; Lee, Yoon-Kwang; Jeong, Hyunyoung

    2015-07-01

    Cytochrome P450 2D6 (CYP2D6) is a major drug-metabolizing enzyme responsible for eliminating approximately 20% of marketed drugs. Studies have shown that differential transcriptional regulation of CYP2D6 may contribute to large interindividual variability in CYP2D6-mediated drug metabolism. However, the factors governing CYP2D6 transcription are largely unknown. We previously demonstrated small heterodimer partner (SHP) as a novel transcriptional repressor of CYP2D6 expression. SHP is a representative target gene of the farnesoid X receptor (FXR). The objective of this study is to investigate whether an agonist of FXR, 3-(2,6-dichlorophenyl)-4-(3'-carboxy-2-chlorostilben-4-yl)oxymethyl-5-isopropylisoxazole (GW4064), alters CYP2D6 expression and activity. In CYP2D6-humanized transgenic mice, GW4064 decreased hepatic CYP2D6 expression and activity (by 2-fold) while increasing SHP expression (by 2-fold) and SHP recruitment to the CYP2D6 promoter. CYP2D6 repression by GW4064 was abrogated in Shp(-/-);CYP2D6 mice, indicating a critical role of SHP in CYP2D6 regulation by GW4064. Also, GW4064 decreased CYP2D6 expression (by 2-fold) in primary human hepatocytes, suggesting that the results obtained in CYP2D6-humanized transgenic mice can be translated to humans. This proof of concept study provides evidence for CYP2D6 regulation by an inducer of SHP expression, namely, the FXR agonist GW4064. PMID:25926433

  12. Effects of 22 novel CYP2D6 variants found in Chinese population on the metabolism of dapoxetine

    Directory of Open Access Journals (Sweden)

    Xu RA

    2016-02-01

    Full Text Available Ren-ai Xu,1,* Er-min Gu,2,* Quan Zhou,2 Lingjing Yuan,2 Xiaoxia Hu,2 Jianping Cai,3 Guoxin Hu1,2 1Department of Pharmacy, The First Affiliated Hospital of Wenzhou Medical University, 2Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, 3The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, People’s Republic of China *These authors contributed equally to this work Background: CYP2D6 is one of the most important members of the cytochrome P450 superfamily. Its genetic polymorphism significantly influences the efficacy and safety of some drugs, which might cause adverse effects and therapeutic failure. Methods and results: The aim of this research was mainly to explore the catalytic activities of 22 newly reported CYP2D6 isoforms (2D6*87, *88, *89, *90, *91, *92, *93, *94, *95, *96,*97, *98, *R25Q, F164L, E215K, F219S, V327M, D336N, V342M, R344Q, R440C, R497C on dapoxetine in vitro. The research was designed with an appropriate incubation system in test tubes and carried out in the constant temperature water. Through detecting its two metabolites desmethyldapoxetine and dapoxetine-N-oxide, the available data were obtained to explain the influence of CYP2D6 polymorphism on the substrate drug dapoxetine. As a result, the intrinsic clearance (Vmax/Km values of most variants were significantly altered when compared with the counterpart of CYP2D6*1, with most of these variants exhibiting either reduced Vmax and/or increased Km values. For dapoxetine demethylation pathway (which produces desmethyldapoxetine, 2D6*89 and E215K exhibited no markedly decreased relative clearance of 92.81% and 97.70%, respectively. The relative clearance of rest 20 variants exhibited decrease in different levels, ranging from 20.44% to 90.90%. For the dapoxetine oxidation pathway (which produces dapoxetine-N-oxide, the relative clearance values of three variants, 2D6*90, *94, and

  13. CYP2D6基因多态性及对药物代谢的影响%Polymorphism of CYP2D6 and the influence to the drug metabolism

    Institute of Scientific and Technical Information of China (English)

    韩璐; 刘洁

    2011-01-01

    CYP2D6代谢酶是细胞色素P450家族中的成员之一,是参与I相代谢和众多内源性物质和不同药物消除的酶.虽然它在肝脏中的含量大约只占肝脏总量的200,但在临床上却参与了25%以上的常用药物的代谢活动.在所有参与药物代谢的细胞色素P450基因家族中,CYP2D6 是唯一不能被诱导的酶,这种酶具有广泛的多态性,这种多态性对酶的药物代谢功能具有重要影响,CYP2D6的这种多态性和药物代谢功能所表现的对个体活性的差异,在遗传药理学上具有重要意义.本文从CYP2 D6基因多态性和它对药物代谢的影响这两方面进行了阐述.%CYP2D6 is a member of cytochrome P450 gene family - a group of enzymes that is responsible for phase Ⅰ metabolism and elimination of numerous endogenous substrates and a diverse array of drugs.It is now thought to be involved in the metabolism of up to 25 % of the drugs that are in common use in the clinic,despite its low hepatic content (about 2 %).Among the drug-metabolizing cytochrome P450s,CYP2D6 is the only non-inducible enzyme and is highly polymorphic, which results in a large contribution of genetic variation to its inter-individual variation in enzyme activity and is an enzyme of great historical importance for pharmacogenetics.Here we summarize the polymorphism of CYP2D6 gene and their influence to drug metabolism.

  14. Cytochrome P450 2D6 variants in a Caucasian population: Allele frequencies and phenotypic consequences

    Energy Technology Data Exchange (ETDEWEB)

    Sachse, C.; Brockmoeller, J.; Bauer, S.; Roots, I. [Humboldt Univ., Berlin (Germany)

    1997-02-01

    Cytochrome P450 2D6 (CYP2D6) metabolizes many important drugs. CYP2D6 activity ranges from complete deficiency to ultrafast metabolism, depending on at least 16 different known alleles. Their frequencies were determined in 589 unrelated German volunteers and correlated with enzyme activity measured by phenotyping with dextromethorphan or debrisoquine. For genotyping, nested PCR-RFLP tests from a PCR amplificate of the entire CYP2D6 gene were developed. The frequency of the CYP2D6*1 allele coding for extensive metabolizer (EM) phenotype was .364. The alleles coding for slightly (CYP2D6*2) or moderately (*9 and *10) reduced activity (intermediate metabolizer phenotype [IM]) showed frequencies of .324, .018, and .015, respectively. By use of novel PCR tests for discrimination, CYP2D6 gene duplication alleles were found with frequencies of.005 (*1 x 2), .013 (* 2 x 2), and .001 (*4 x 2). Frequencies of alleles with complete deficiency (poor metabolizer phenotype [PM]) were .207 (*4), .020 (*3 and *5), .009 (*6), and .001 (*7, *15, and *16). The defective CYP2D6 alleles *8, *11, *12, *13, and *14 were not found. All 41 PMs (7.0%) in this sample were explained by five mutations detected by four PCR-RFLP tests, which may suffice, together with the gene duplication test, for clinical prediction of CYP2D6 capacity. Three novel variants of known CYP2D6 alleles were discovered: *1C (T{sub 1957}C), *2B (additional C{sub 2558}T), and *4E (additional C{sub 2938}T). Analysis of variance showed significant differences in enzymatic activity measured by the dextromethorphan metabolic ratio (MR) between carriers of EN/PM (mean MR = .006) and IM/PM (mean MR = .014) alleles and between carriers of one (mean MR = .009) and two (mean MR = .003) functional alleles. The results of this study provide a solid basis for prediction of CYP2D6 capacity, as required in drug research and routine drug treatment. 35 refs., 4 figs., 5 tabs.

  15. Impact of the CYP2D6 genotype on post-operative intravenous oxycodone analgesia

    DEFF Research Database (Denmark)

    Zwisler, S T; Enggaard, T P; Mikkelsen, S;

    2009-01-01

    Background: Oxycodone is a semi-synthetic opioid with a mu-receptor agonist-mediated effect in several pain conditions, including post-operative pain. Oxycodone is metabolized to its active metabolite oxymorphone by O-demethylation via the polymorphic CYP2D6. The aim of this study was to...... investigate whether CYP2D6 poor metabolizers (PMs) yield the same analgesia post-operatively from intravenous oxycodone as extensive metabolizers (EMs). Methods: Two hundred and seventy patients undergoing primarily thyroid surgery or hysterectomy were included and followed for 24 h post-operatively. The CYP2...... for the first time in patients that the oxymorphone formation depends on CYP2D6, but we found no difference in the post-operative analgesic effect of intravenous oxycodone between the two CYP2D6 genotypes....

  16. Nomenclature for human CYP2D6 alleles.

    Science.gov (United States)

    Daly, A K; Brockmöller, J; Broly, F; Eichelbaum, M; Evans, W E; Gonzalez, F J; Huang, J D; Idle, J R; Ingelman-Sundberg, M; Ishizaki, T; Jacqz-Aigrain, E; Meyer, U A; Nebert, D W; Steen, V M; Wolf, C R; Zanger, U M

    1996-06-01

    To standardize CYP2D6 allele nomenclature, and to conform with international human gene nomenclature guidelines, an alternative to the current arbitrary system is described. Based on recommendations for human genome nomenclature, we propose that alleles be designated by CYP2D6 followed by an asterisk and a combination of roman letters and arabic numerals distinct for each allele with the number specifying the key mutation and, where appropriate, a letter specifying additional mutations. Criteria for classification as a separate allele and protein nomenclature are also presented. PMID:8807658

  17. CYP2D6 genotype dependent oxycodone metabolism in postoperative patients.

    Directory of Open Access Journals (Sweden)

    Ulrike M Stamer

    Full Text Available BACKGROUND: The impact of polymorphic cytochrome P450 CYP2D6 enzyme on oxycodone's metabolism and clinical efficacy is currently being discussed. However, there are only spare data from postoperative settings. The hypothesis of this study is that genotype dependent CYP2D6 activity influences plasma concentrations of oxycodone and its metabolites and impacts analgesic consumption. METHODS: Patients received oxycodone 0.05 mg/kg before emerging from anesthesia and patient-controlled analgesia (PCA for the subsequent 48 postoperative hours. Blood samples were drawn at 30, 90 and 180 minutes after the initial oxycodone dose. Plasma concentrations of oxycodone and its metabolites oxymorphone, noroxycodone and noroxymorphone were analyzed by liquid chromatography-mass spectrometry with electrospray ionization. CYP2D6 genotyping was performed and 121 patients were allocated to the following genotype groups: PM (poor metabolizer: no functionally active CYP2D6 allele, HZ/IM (heterozygous subjects, intermediate metabolizers with decreased CYP2D6 activity, EM (extensive metabolizers, normal CYP2D6 activity and UM (ultrarapid metabolizers, increased CYP2D6 activity. Primary endpoint was the genotype dependent metabolite ratio of plasma concentrations oxymorphone/oxycodone. Secondary endpoint was the genotype dependent analgesic consumption with calculation of equianalgesic doses compared to the standard non-CYP dependent opioid piritramide. RESULTS: Metabolism differed between CYP2D6 genotypes. Mean (95%-CI oxymophone/oxycodone ratios were 0.10 (0.02/0.19, 0.13 (0.11/0.16, 0.18 (0.16/0.20 and 0.28 (0.07/0.49 in PM, HZ/IM, EM and UM, respectively (p = 0.005. Oxycodone consumption up to the 12(th hour was highest in PM (p = 0.005, resulting in lowest equianalgesic doses of piritramide versus oxycodone for PM (1.6 (1.4/1.8; EM and UM 2.2 (2.1/2.3; p<0.001. Pain scores did not differ between genotypes. CONCLUSIONS: In this postoperative setting, the number of

  18. CYP2D6 polymorphism and mental and personality disorders in suicide attempters.

    Science.gov (United States)

    Blasco-Fontecilla, Hilario; Peñas-Lledó, Eva; Vaquero-Lorenzo, Concepción; Dorado, Pedro; Saiz-Ruiz, Jerónimo; Llerena, Adrián; Baca-García, Enrique

    2014-12-01

    Prior studies on the association between the CYP2D6 polymorphism and suicide did not explore whether mental and personality disorders mediate this association. The main objective of the present study was to test an association between CYP2D6 polymorphism and mental and personality disorders among suicide attempters. The MINI and the DSM-IV version of the International Personality Disorder Examination Screening Questionnaire were used to diagnose mental and personality disorders, respectively, in 342 suicide attempters. Suicide attempters were divided into four groups according to their number of CYP2D6 active genes (zero, one, and two or more). Differences in mental and personality disorders across the four groups were measured using linear-by-linear association, chi square-test, and 95% confidence intervals. Suicide attempters carrying two or more active CYP2D6 genes were more likely to be diagnosed with at least one personality disorder than those with one or zero CYP2D6 active genes.

  19. CYP2D6基因与药物代谢%CYP2D6 gene and drug metabolism

    Institute of Scientific and Technical Information of China (English)

    施安国

    2003-01-01

    细胞色素P-450(CYP)中的CYP2D6酶在抗抑郁药、安定药及某些抗心律失常药的代谢中起重要作用,CYP2D6基因位于22号常染色体上为隐性遗传,CYP2D6基因呈多态性约有70余种等位基因变异型,也存在特异人群差别,因而导致所编码的酶活性不同,这些数据有助于理解药物代谢的个体差异、有助于预测药物之间的相互作用.

  20. Identification of novel CYP2D7-2D6 hybrids: non-functional and functional variants

    Directory of Open Access Journals (Sweden)

    Andrea Gaedigk

    2010-10-01

    Full Text Available Polymorphic expression of CYP2D6 contributes to the wide range of activity observed for this clinically important drug metabolizing enzyme. In this report we describe novel CYP2D7/2D6 hybrid genes encoding non-functional and functional CYP2D6 protein and a CYP2D7 variant that mimics a CYP2D7/2D6 hybrid gene. Five kb long PCR products encompassing the novel genes were entirely sequenced. A quantitative assay probing in different gene regions was employed to determine CYP2D6 and 2D7 copy number variations and the relative position of the hybrid genes within the locus was assessed by long-range PCR. In addition to the previously known CYP2D6*13 and *66 hybrids, we describe three novel non-functional CYP2D7-2D6 hybrids with gene switching in exon 2 (CYP2D6*79, intron 2 (CYP2D6*80 and intron 5 (CYP2D6*67. A CYP2D7-specific T-ins in exon 1 causes a detrimental frame shift. One subject revealed a CYP2D7 conversion in the 5’-flanking region of a CYP2D6*35 allele, was otherwise unaffected (designated CYP2D6*35B. Finally, three DNAs revealed a CYP2D7 gene with a CYP2D6-like region downstream of exon 9 (designated CYP2D7[REP6]. Quantitative copy number determination, sequence analyses and long-range PCR mapping were in agreement and excluded the presence of additional gene units. Undetected hybrid genes may cause over-estimation of CYP2D6 activity (CYP2D6*1/*1 vs *1/hybrid, etc, but may also cause results that may interfere with the genotype determination. Detection of hybrid events, ‘single’ and tandem, will contribute to more accurate phenotype prediction from genotype data.

  1. Investigation of CYP3A4 and CYP2D6 Interactions of Withania somnifera and Centella asiatica in Human Liver Microsomes.

    Science.gov (United States)

    Savai, Jay; Varghese, Alice; Pandita, Nancy; Chintamaneni, Meena

    2015-05-01

    Withania somnifera is commonly used as a rejuvenator, whereas Centella asiatica is well known for its anxiolytic and nootropic effects. The present study aims at investigating the effect of crude extracts and principal phytoconstituents of both the medicinal plants with CYP3A4 and CYP2D6 enzyme activity in human liver microsomes (HLM). Phytoconstituents were quantified in the crude extracts of both the medicinal plants using reverse phase HPLC. Crude extracts and phytoconstituents of W. somnifera showed no significant interaction with both CYP3A4 and CYP2D6 enzymes in HLM. Of the crude extracts of C. asiatica screened in vitro, methanolic extract showed potent noncompetitive inhibition of only CYP3A4 enzyme (Ki-64.36 ± 1.82 µg/mL), whereas ethanol solution extract showed potent noncompetitive inhibition of only CYP2D6 enzyme (Ki-36.3 ± 0.44 µg/mL). The flavonoids, quercetin, and kaempferol showed potent (IC50 values less than 100 μM) inhibition of CYP3A4 activity, whereas quercetin alone showed potent inhibition of CYP2D6 activity in HLM. Because methanolic extract of C. asiatica showed a relatively high percentage content of quercetin and kaempferol than ethanol solution extract, the inhibitory effect of methanolic extract on CYP3A4 enzyme activity could be attributed to the flavonoids. Thus, co-administration of the alcoholic extracts of C. asiatica with drugs that are substrates of CYP3A4 and CYP2D6 enzymes may lead to undesirable herb-drug interactions in humans.

  2. Cytochrome P450-2D6 Screening Among Elderly Using Antidepressants (CYSCE)

    Science.gov (United States)

    2015-12-09

    Depression; Depressive Disorder; Poor Metabolizer Due to Cytochrome P450 CYP2D6 Variant; Intermediate Metabolizer Due to Cytochrome P450 CYP2D6 Variant; Ultrarapid Metabolizer Due to Cytochrome P450 CYP2D6 Variant

  3. N=2, D=6 supergravity with $E_7$ gauge matter

    CERN Document Server

    Zyablyuk, K N

    1997-01-01

    The lagrangian of N=2, D=6 supergravity coupled to E_7 X SU(2) vector- and hyper-multiplets is derived. For this purpose the coset manifold E_8/E_7 X SU(2), parametrized by the scalars of the hypermultiplet, is constructed. A difference from the case of Sp(n)-matter is pointed out. This model can be considered as an intermediate step in the compactification of D=10 supergravity coupled to E_8 X E_8 matter to four-dimensional model of E_6 unification.

  4. National Prociency Testing Result of CYP2D6*10 Genotyping for Adjuvant Tamoxifen Therapy in China.

    Science.gov (United States)

    Lin, Guigao; Zhang, Kuo; Yi, Lang; Han, Yanxi; Xie, Jiehong; Li, Jinming

    2016-01-01

    Tamoxifen has been successfully used for treating breast cancer and preventing cancer recurrence. Cytochrome P450 2D6 (CYP2D6) plays a key role in the process of metabolizing tamoxifen to its active moiety, endoxifen. Patients with variants of the CYP2D6 gene may not receive the full benefit of tamoxifen treatment. The CYP2D6*10 variant (the most common variant in Asians) was analyzed to optimize the prescription of tamoxifen in China. To ensure referring clinicians have accurate information for genotype-guided tamoxifen treatment, the Chinese National Center for Clinical Laboratories (NCCL) organized a national proficiency testing (PT) to evaluate the performance of laboratories providing CYP2D6*10 genotyping. Ten genomic DNA samples with CYP2D6 wild-type or CYP2D6*10 variants were validated by PCR-sequencing and sent to 28 participant laboratories. The genotyping results and pharmacogenomic test reports were submitted and evaluated by NCCL experts. Additional information regarding the number of samples tested, the accreditation/certification status, and detecting technology was also requested. Thirty-one data sets were received, with a corresponding analytical sensitivity of 98.2% (548/558 challenges; 95% confidence interval: 96.7-99.1%) and an analytic specificity of 96.5% (675/682; 95% confidence interval: 97.9-99.5%). Overall, 25/28 participants correctly identified CYP2D6*10 status in 10 samples; however, two laboratories made serious genotyping errors. Most of the essential information was included in the 20 submitted CYP2D6*10 test reports. The majority of Chinese laboratories are reliable for detecting the CYP2D6*10 variant; however, several issues revealed in this study underline the importance of PT schemes in continued external assessment and provision of guidelines. PMID:27603206

  5. Progress on research for genetic polymorphism of drug metabolic enzyme cytochrome P450 2D6%药物代谢酶细胞色素P450 2D6的遗传多态性研究进展

    Institute of Scientific and Technical Information of China (English)

    徐田雪; 杨信怡; 赵昆; 张喜川; 游雪甫

    2009-01-01

    CYP2D6是肝脏中重要的药物代谢酶,其代谢的药物占临床应用药物的20%~25%.其遗传多态性对依赖CYP2D6代谢的药物具有重要的影响.本文综述了CYP2D6在遗传多态性方面的研究进展及其临床意义.%Cytochrome P450 2D6 (CYP2D6) is an important microsome enzyme in liver which metabolizes about 20%~25% of drugs used in clinic. And these substrates of CYP2D6 are affected intensively by its genetic polymorphism. In the present article, genetic polymorphism of CYP2D6 and its clinical implications were reviewed.

  6. Tamoxifen Pharmacogenomics: The Role of CYP2D6 as a Predictor of Drug Response

    OpenAIRE

    Goetz, MP; Kamal, A; Ames, MM

    2007-01-01

    Tamoxifen continues to be a standard endocrine therapy for the prevention and treatment of estrogen receptor (ER)-positive breast cancer. Tamoxifen can be considered a classic “pro-drug,” requiring metabolic activation to elicit pharmacological activity. CYP2D6 is the rate-limiting enzyme catalyzing the conversion of tamoxifen into metabolites with significantly greater affinity for the ER and greater ability to inhibit cell proliferation. Both genetic and environmental (drug-induced) factors...

  7. Establishment and Optimization of Incubation System of Bactrian Camel Studying CYP2D6 Enzyme in Vitro%双峰驼 CYP2D6酶体外孵育体系的建立与优化

    Institute of Scientific and Technical Information of China (English)

    王艳; 高飞; 哈斯苏荣

    2016-01-01

    为了研究双峰驼 CYP2D6酶体外活性,建立双峰驼肝微粒体孵育体系并对孵育体系中探针底物浓度、肝微粒体蛋白浓度和孵育时间等进行优化研究。首先采用改良差速离心法制备双峰驼肝微粒体、BCA 法测定双峰驼肝微粒体蛋白浓度、CO 还原差示光谱法检测 CYP 总酶含量,然后采用 HPLC 法跟踪检测孵育体系中 CYP2D6酶特异性底物的主要代谢产物去甲右美沙芬含量进而优化孵育条件。结果表明,双峰驼肝微粒体蛋白浓度为5.5650 mg/mL±0.5197 mg/mL,CYP 总酶含量为0.1777 nmol/mg±0.0503 nmol/mg;肝微粒体孵育体系的最适底物浓度为250μg/mL,肝微粒体蛋白浓度为5.5650 mg/mL,最适孵育时间为40 min 。所制备的双峰驼肝微粒体各项指标和优化后的肝微粒体孵育条件均能满足后续对双峰驼 CYP2D6酶体外活性研究的基本要求。%In order to study the in vitro activities of Bactrian Camel CYP2D6 enzyme,the liver microsome in-cubation system was established and optimized by studying the concentration of probe substrate,protein content of liver microsome and incubation time,etc.Firstly,liver microsomes of bactrian camel was pre-pared by modified differential centrifugation method,the protein content of bactrian camel liver microsomes was detected by using BCA method and the total content of CYP enzyme was determined by using CO re-duction method.Secondly,the incubation system was optimized by detecting and tracking the concentration of dextrophan,an active essential metabolite of dextromethorphan,in incubation system by using HPLC method.The results showed that the liver microsomal protein content of bactrian camel was 5.565 0 mg/mL±0.519 7 mg/mL,total CYP enzyme content was 0.177 7 nmol/mg±0.050 3 nmol/mg and the optimum substrate concentration in the liver microsome incubation system was 250 μg/mL,the op-timum concentration of protein in liver microsomes was 5

  8. Comparison of Paeoniflorin and Albiflorin on Human CYP3A4 and CYP2D6

    Directory of Open Access Journals (Sweden)

    Li-Na Gao

    2015-01-01

    Full Text Available Peony (Paeonia lactiflora Pall- is a plant medicine and a functional food ingredient with wide application for more than 2000 years. It can be coadministrated with many other drugs, composed of traditional Chinese medicine compound such as shaoyao-gancao decoction. In order to explore the efficacy and safety of peony, effects of paeoniflorin and albiflorin (the principal components of peony on cytochrome P450 (CYP 3A4 and CYP2D6 were analyzed in human hepatoma HepG2 cells and evaluated from the level of recombinant CYP enzymes in vitro. The findings indicated that albiflorin possessed stronger regulation on the mRNA expression of CYP3A4 and CYP2D6 than paeoniflorin. For the protein level of CYP3A4, albiflorin showed significant induction or inhibition with the concentration increasing from 10−7 M to 10−5 M, but no remarkable variation was observed in paeoniflorin-treated group. Enzyme activity assay implied that both paeoniflorin and albiflorin could regulate CYP3A4 and CYP2D6 with varying degrees. The results showed that albiflorin should be given more attention because it may play a vital role on the overall efficacy of peony. The whole behavior of both paeoniflorin and albiflorin should be focused on ensuring the rationality and effectiveness of clinical application.

  9. Stable expression of human cytochrome P450 2D6*10 in HepG2 cells

    Institute of Scientific and Technical Information of China (English)

    Jian Zhuge; Ying-Nian Yu; Xiao-Dan Wu

    2004-01-01

    AIM: Over 90% of drugs are metabolized by the cytochrome P-450 (CYP) family of liver isoenzymes. The most important enzymes are CYP1A2, 3A4, 2C9/19, 2D6 and 2E1. Although CYP2D6 accounts for <2% of the total CYP liver enzyme content, it mediates metabolism in almost 25% of drugs. In order to study its enzymatic activity for drug metabolism, its cDNA was cloned and a HepG2 cell line stably expressing CYP2D6 was established.METHODS: Human CYP2D6 cDNA was amplified with reverse transcription-polymerase chain reaction (RT-PCR)from total RNA extracted from human liver tissue and cloned into pGEM-T vector, cDNA segment was identified by DNA sequencing and subcloned into a mammalian expression vector pREP9. A cell line was established by transfecting the recombinant plasmid of pREP9-CYP2D6 to hepatoma HepG2 cells. Expression of mRNA was validated by RT-PCR.Enzyme activity of catalyzing dextromethorphan O-demethylation in postmitochondrial supernant (S9) fraction of the cells was determined by high performance liquid chromatography (HPLC).RESULTS: The cloned cDNA had 4 base differences, e.g.100 C→T, 336 T→C, 408 C→G and 1 457 G→C, which resulted in P34S, and S486T amino acid substitutions, and two samesense mutations were 112 F and 136 V compared with that reported by Kimura et al(GenBank accession number: M33388). P34S and S486T amino acid substitutions were the characteristics of CYP2D6*10 allele. The relative activity of S9 fraction of HepG2-CYP2D6*10 metabolized detromethorphan O-demethylation was found to be 2.31±0.19 nmol.min-1.mg-1 S9 protein (n=3), but was undetectable in parental HepG2 cells.CONCLUSION: cDNA of human CYP2D6*10can be successfully doned. A cell line, HepG2-CYP2D6*10, expressing CYP2D6*10 mRNA and having metabolic activity, has been established.

  10. Detection of Cytochrome P450 2D6 Allele CYP2D6*6 by Using Allele-specific Amplification%ASA法测定细胞色素P450 2D6等位基因CYP2D6*6

    Institute of Scientific and Technical Information of China (English)

    陈枢青; Wedl.,PJ

    1999-01-01

    细胞色素P450 2D6(CYP2D6)基因2064G→A突变,造成表达产物212位上谷氨酸变成甘氨酸,从而引起酶分子失活,被称为CYP2D6*6.利用等位基因特异扩增法,建立了ASA-PCR测定CYP2D6*6的方法.经396例测定,说明本法快捷、准确.测定结果显示CYP2D6*6与CYP2D6T共存,如果只为准确预测CYP2D6酶活性,对CYP2D6*6进行测定并无意义.

  11. CYP2D6*2 Polymorphism as a Predictor of Failed Outpatient Tramadol Therapy in Postherpetic Neuralgia Patients.

    Science.gov (United States)

    Nasare, Namita Vilas; Banerjee, Basu Dev; Suryakantrao Deshmukh, Pravin; Mediratta, Pramod Kumari; Saxena, Ashok Kumar; Ahmed, Rafat Sultana; Bhattacharya, Sambit Nath

    2016-01-01

    Human cytochrome P4502D6 (CYP2D6) gene is highly polymorphic, leading to wide interindividual ethnic differences in CYP2D6-mediated drug metabolism. Its activity ranges from complete deficiency to excessive activity, potentially causing toxicity of the medication or therapeutic failure with recommended drug dosages. The aim of the study was to find the association of CYP2D6*2 polymorphisms with demographic characters (age, sex, and weight), pain intensity scales [numerical rating scale (NRS) sleep, global perceived effect (GPE)], and adverse drug effects in postherpetic neuralgia (PHN) patients receiving tramadol. The study comprised 246 patients [including 123 nonresponders (NRs) and 123 responders (Rs)] with PHN undergoing analgesic treatment at the pain clinic, Out Patient Department, University College of Medical Sciences, Guru Teg Bahadur Hospital, Delhi, India. Patients with any history of diabetes mellitus, human immunodeficiency virus, malignancy, hematological or liver disease, psychiatric illness, alcohol abuse, and tramadol sensitivity were excluded from the study. The NRSs of (resting and movement), NRS-sleep, and GPE were evaluated by the treating physician. Adverse drug effects during the time of the study were recorded. All samples were analyzed for CYP2D6*2 polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. The genotype distribution did not vary significantly among genders [NR (P = 0.723); R (P = 0.947)] and different age groups in NRs (P = 0.763) and Rs (P = 0.268). Clinically, statistically significant (P 0.05). In addition, CYP2D6*2 genotype was not related to the adverse effects of analgesic therapy. The overall results suggested that CYP2D6*2 polymorphism plays no role in the PHN patients receiving tramadol treatment. The CYP2D6*2 polymorphism may not be a predictor of treatment outcome of patients with respect to PHN-receiving tramadol. PMID:23567787

  12. A novel simple method for determining CYP2D6 gene copy number and identifying allele(s with duplication/multiplication.

    Directory of Open Access Journals (Sweden)

    Taimour Langaee

    Full Text Available Cytochrome P450 2D6 (CYP2D6 gene duplication and multiplication can result in ultrarapid drug metabolism and therapeutic failure or excessive response in patients. Long range polymerase chain reaction (PCR, restriction fragment length polymorphism (RFLP and sequencing are usually used for genotyping CYP2D6 duplication/multiplications and identification, but are labor intensive, time consuming, and costly.We developed a simple allele quantification-based Pyrosequencing genotyping method that facilitates CYP2D6 copy number variation (CNV genotyping while also identifying allele-specific CYP2D6 CNV in heterozygous samples. Most routine assays do not identify the allele containing a CNV. A total of 237 clinical and Coriell DNA samples with different known CYP2D6 gene copy numbers were genotyped for CYP2D6 *2, *3, *4, *6, *10, *17, *41 polymorphisms and CNV determination.The CYP2D6 gene allele quantification/identification were determined simultaneously with CYP2D6*2, *3, *4, *6, *10, *17, *41 genotyping. We determined the exact CYP2D6 gene copy number, identified which allele had the duplication or multiplication, and assigned the correct phenotype and activity score for all samples.Our method can efficiently identify the duplicated CYP2D6 allele in heterozygous samples, determine its copy number in a fraction of time compared to conventional methods and prevent incorrect ultrarapid phenotype calls. It also greatly reduces the cost, effort and time associated with CYP2D6 CNV genotyping.

  13. Possible impact of the CYP2D6*10 polymorphism on the nonlinear pharmacokinetic parameter estimates of paroxetine in Japanese patients with major depressive disorders

    Directory of Open Access Journals (Sweden)

    Saruwatari J

    2014-04-01

    Full Text Available Junji Saruwatari,1 Hiroo Nakashima,1 Shoko Tsuchimine,2 Miki Nishimura,1 Naoki Ogusu,1 Norio Yasui-Furukori21Division of Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan; 2Department of Neuropsychiatry, Graduate School of Medicine, Hirosaki University, Hirosaki, JapanAbstract: It has been suggested that the reduced function allele with reduced cytochrome P450 (CYP 2D6 activity, CYP2D6*10, is associated with the interindividual differences in the plasma paroxetine concentrations, but there is no data presently available regarding the influence of the CYP2D6*10 polymorphism on the pharmacokinetic parameters, eg, Michaelis–Menten constant (Km and maximum velocity (Vmax, in Asian populations. The present study investigated the effects of the CYP2D6 polymorphisms, including CYP2D6*10, on the pharmacokinetic parameters of paroxetine in Japanese patients with major depressive disorders. This retrospective study included 15 Japanese patients with major depressive disorders (four males and eleven females who were treated with paroxetine. The CYP2D6*2, CYP2D6*4, CYP2D6*5, CYP2D6*10, CYP2D6*18, CYP2D6*39, and CYP2D6*41 polymorphisms were evaluated. A total of 56 blood samples were collected from the patients. The Km and Vmax values of paroxetine were estimated for each patient. The allele frequencies of CYP2D6*2, CYP2D6*4, CYP2D6*5, CYP2D6*10, CYP2D6*18, CYP2D6*39, and CYP2D6*41 were 6.7%, 0%, 10.0%, 56.7%, 0%, 26.7%, and 0%, respectively. The mean values of Km and Vmax were 50.5±68.4 ng/mL and 50.6±18.8 mg/day, respectively. Both the Km and Vmax values were significantly smaller in CYP2D6*10 allele carriers than in the noncarriers (24.2±18.3 ng/mL versus 122.5±106.3 ng/mL, P=0.008; 44.2±16.1 mg/day versus 68.3±15.0 mg/day, P=0.022, respectively. This is the first study to demonstrate that the CYP2D6*10 polymorphism could affect the nonlinear pharmacokinetic parameter estimates of

  14. Effects of monoamine oxidase inhibitor and cytochrome P450 2D6 status on 5-methoxy-N,N-dimethyltryptamine metabolism and pharmacokinetics.

    Science.gov (United States)

    Shen, Hong-Wu; Wu, Chao; Jiang, Xi-Ling; Yu, Ai-Ming

    2010-07-01

    5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a natural psychoactive indolealkylamine drug that has been used for recreational purpose. Our previous study revealed that polymorphic cytochrome P450 2D6 (CYP2D6) catalyzed 5-MeO-DMT O-demethylation to produce active metabolite bufotenine, while 5-MeO-DMT is mainly inactivated through deamination pathway mediated by monoamine oxidase (MAO). This study, therefore, aimed to investigate the impact of CYP2D6 genotype/phenotype status and MAO inhibitor (MAOI) on 5-MeO-DMT metabolism and pharmacokinetics. Enzyme kinetic studies using recombinant CYP2D6 allelic isozymes showed that CYP2D6.2 and CYP2D6.10 exhibited 2.6- and 40-fold lower catalytic efficiency (V(max)/K(m)), respectively, in producing bufotenine from 5-MeO-DMT, compared with wild-type CYP2D6.1. When co-incubated with MAOI pargyline, 5-MeO-DMT O-demethylation in 10 human liver microsomes showed significantly strong correlation with bufuralol 1'-hydroxylase activities (R(2)=0.98; P<0.0001) and CYP2D6 contents (R(2)=0.77; P=0.0007), whereas no appreciable correlations with enzymatic activities of other P450 enzymes. Furthermore, concurrent MAOI harmaline sharply reduced 5-MeO-DMT depletion and increased bufotenine formation in human CYP2D6 extensive metabolizer hepatocytes. In vivo studies in wild-type and CYP2D6-humanized (Tg-CYP2D6) mouse models showed that Tg-CYP2D6 mice receiving the same dose of 5-MeO-DMT (20mg/kg, i.p.) had 60% higher systemic exposure to metabolite bufotenine. In addition, pretreatment of harmaline (5mg/kg, i.p.) led to 3.6- and 4.4-fold higher systemic exposure to 5-MeO-DMT (2mg/kg, i.p.), and 9.9- and 6.1-fold higher systemic exposure to bufotenine in Tg-CYP2D6 and wild-type mice, respectively. These findings indicate that MAOI largely affects 5-MeO-DMT metabolism and pharmacokinetics, as well as bufotenine formation that is mediated by CYP2D6. PMID:20206139

  15. Relationship between genotypes Sult1a2 and Cyp2d6 and tamoxifen metabolism in breast cancer patients.

    Directory of Open Access Journals (Sweden)

    Ana Fernández-Santander

    Full Text Available Tamoxifen is a pro-drug widely used in breast cancer patients to prevent tumor recurrence. Prior work has revealed a role of cytochrome and sulfotransferase enzymes in tamoxifen metabolism. In this descriptive study, correlations were examined between concentrations of tamoxifen metabolites and genotypes for CYP2D6, CYP3A4, CYP3A5, SULT1A1, SULT1A2 and SULT1E1 in 135 patients with estrogen receptor-positive breast cancer. Patients were genotyped using the Roche-AmpliChip® CYP450 Test, and Real-Time and conventional PCR-RFLP. Plasma tamoxifen, 4-hydroxy-tamoxifen, N-desmethyl-tamoxifen, endoxifen and tamoxifen-N-oxide were isolated and quantified using a high-pressure liquid chromatography-tandem mass spectrometry system. Significantly higher endoxifen levels were detected in patients with the wt/wt CYP2D6 compared to the v/v CYP2D6 genotype (p<0.001. No differences were detected in the remaining tamoxifen metabolites among CYP2D6 genotypes. Patients featuring the SULT1A2*2 and SULT1A2*3 alleles showed significantly higher plasma levels of 4-hydroxy-tamoxifen and endoxifen (p = 0.025 and p = 0.006, respectively, as likely substrates of the SULT1A2 enzyme. Our observations indicate that besides the CYP2D6 genotype leading to tamoxifen conversion to potent hydroxylated metabolites in a manner consistent with a gene-dose effect, SULT1A2 also seems to play a role in maintaining optimal levels of both 4-hydroxy-tamoxifen and endoxifen.

  16. Relationship between Genotypes Sult1a2 and Cyp2d6 and Tamoxifen Metabolism in Breast Cancer Patients

    Science.gov (United States)

    Fernández-Santander, Ana; Gaibar, María; Novillo, Apolonia; Romero-Lorca, Alicia; Rubio, Margarita; Chicharro, Luis Miguel; Tejerina, Armando; Bandrés, Fernando

    2013-01-01

    Tamoxifen is a pro-drug widely used in breast cancer patients to prevent tumor recurrence. Prior work has revealed a role of cytochrome and sulfotransferase enzymes in tamoxifen metabolism. In this descriptive study, correlations were examined between concentrations of tamoxifen metabolites and genotypes for CYP2D6, CYP3A4, CYP3A5, SULT1A1, SULT1A2 and SULT1E1 in 135 patients with estrogen receptor-positive breast cancer. Patients were genotyped using the Roche-AmpliChip® CYP450 Test, and Real-Time and conventional PCR-RFLP. Plasma tamoxifen, 4-hydroxy-tamoxifen, N-desmethyl-tamoxifen, endoxifen and tamoxifen-N-oxide were isolated and quantified using a high-pressure liquid chromatography-tandem mass spectrometry system. Significantly higher endoxifen levels were detected in patients with the wt/wt CYP2D6 compared to the v/v CYP2D6 genotype (p<0.001). No differences were detected in the remaining tamoxifen metabolites among CYP2D6 genotypes. Patients featuring the SULT1A2*2 and SULT1A2*3 alleles showed significantly higher plasma levels of 4-hydroxy-tamoxifen and endoxifen (p = 0.025 and p = 0.006, respectively), as likely substrates of the SULT1A2 enzyme. Our observations indicate that besides the CYP2D6 genotype leading to tamoxifen conversion to potent hydroxylated metabolites in a manner consistent with a gene-dose effect, SULT1A2 also seems to play a role in maintaining optimal levels of both 4-hydroxy-tamoxifen and endoxifen. PMID:23922954

  17. Prolactin release in children treated with risperidone: impact and role of CYP2D6 metabolism.

    NARCIS (Netherlands)

    Troost, P.W.; Lahuis, B.E.; Hermans, M.H.; Buitelaar, J.K.; Engeland, H. van; Scahill, L.; Minderaa, R.B.; Hoekstra, P.J.

    2007-01-01

    OBJECTIVE: Little is known about the role of CYP2D6 polymorphism in risperidone-induced prolactin release in children. METHOD: Twenty-five children (aged 5-15 years) with pervasive developmental disorders were genotyped for CYP2D6 polymorphisms. Serum prolactin, risperidone, and 9-hydroxyrisperidone

  18. ASA法测定细胞色素P450 2D6酶缺陷等位基因CYP2D6E%Analysis of cytochrome P450 2D6 enzyme defect allele CYP2D6E by allele-specific amplification

    Institute of Scientific and Technical Information of China (English)

    陈枢青; Wedl.,PJ

    1999-01-01

    目的:建立细胞色素P450 2D6(CYP2D6)第3023位A→C突变造成CYP2D6酶活性缺陷的等位基因CYP2D6E的测定方法.方法:利用等位基因特异扩增法(ASA)为基本原理,设计两对引物分别扩增野生型等位基因和突变型等位基因.结果:经396例测定,发现2例CYP2D6E与CYP2D6B的异突变型纯合子,其表现型均为慢代谢者.阳性对照说明本法重复性好,阴性对照显示本法无污染问题.结论:本法比PCR-RFLP法更为快捷、更少污染.对CYP2D6E的测定有助于准确预测CYP2D6表现型.

  19. Novel +90G>A Intronic Polymorphism of CYP2D6

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    Monir Modaresi-nejad

    2015-04-01

    Full Text Available Objective: CYP2D6, an enzyme, metabolizes a large number of commonly prescribed drugs. Variations in CYP2D6 gene encoding this enzyme have been associated with individual differences in drug metabolism rates. The purpose of our study was to identify some allelic variants of CYP2D6 gene and to detect defective CYP2D6 alleles, as part of a pharmacogenetic screening program. Materials and Methods: A prospective study was done on 120 participants referred to Royan Institute in 2013. Allele and genotype frequencies for polymorphism of CYP2D6 gene in exons 1 and 4 were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis and sequencing on PCR products, respectively. Results: We identified a novel variant of the gene encoding cytochrome P450 2D6 (CYP2D6 at position +90 of intron 4 by sequencing method. This novel polymorphism of CYP2D6 has been deposited in GeneBank® under the accession number KF225465 in Jun 2013. Conclusion: In the current study, we identified novel polymorphism in intron 4. This single nucleotide polymorphism (SNP is known as +90G>A in the fourth intron.

  20. Effects of monoamine oxidase inhibitor and cytochrome P450 2D6 status on 5-Methoxy-N,N-dimethyltryptamine Metabolism and Pharmacokinetics

    OpenAIRE

    Shen, Hong-Wu; Wu, Chao; Jiang, Xi-Ling; Yu, Ai-Ming

    2010-01-01

    5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a natural psychoactive indolealkylamine drug that has been used for recreational purpose. Our previous study revealed that polymorphic cytochrome P450 2D6 (CYP2D6) catalyzed 5-MeO-DMT O-demethylation to produce active metabolite bufotenine, while 5-MeO-DMT is mainly inactivated through deamination pathway mediated by monoamine oxidase (MAO). This study, therefore, aimed to investigate the impact of CYP2D6 genotype/phenotype status and MAO inhibi...

  1. Distribution of CYP2D6 Alleles and Phenotypes in the Brazilian Population

    Science.gov (United States)

    Sortica, Vinicius A.; Suarez-Kurtz, Guilherme; de Moraes, Maria Elizabete; Pena, Sergio D. J.; dos Santos, Ândrea K. Ribeiro; Romano-Silva, Marco A.; Hutz, Mara H.

    2014-01-01

    Abstract The CYP2D6 enzyme is one of the most important members of the cytochrome P450 superfamily. This enzyme metabolizes approximately 25% of currently prescribed medications. The CYP2D6 gene presents a high allele heterogeneity that determines great inter-individual variation. The aim of this study was to evaluate the variability of CYP2D6 alleles, genotypes and predicted phenotypes in Brazilians. Eleven single nucleotide polymorphisms and CYP2D6 duplications/multiplications were genotyped by TaqMan assays in 1020 individuals from North, Northeast, South, and Southeast Brazil. Eighteen CYP2D6 alleles were identified in the Brazilian population. The CYP2D6*1 and CYP2D6*2 alleles were the most frequent and widely distributed in different geographical regions of Brazil. The highest number of CYPD6 alleles observed was six and the frequency of individuals with more than two copies ranged from 6.3% (in Southern Brazil) to 10.2% (Northern Brazil). The analysis of molecular variance showed that CYP2D6 is homogeneously distributed across different Brazilian regions and most of the differences can be attributed to inter-individual differences. The most frequent predicted metabolic status was EM (83.5%). Overall 2.5% and 3.7% of Brazilians were PMs and UMs respectively. Genomic ancestry proportions differ only in the prevalence of intermediate metabolizers. The IM predicted phenotype is associated with a higher proportion of African ancestry and a lower proportion of European ancestry in Brazilians. PM and UM classes did not vary among regions and/or ancestry proportions therefore unique CYP2D6 testing guidelines for Brazilians are possible and could potentially avoid ineffective or adverse events outcomes due to drug prescriptions. PMID:25329392

  2. Distribution of CYP2D6 alleles and phenotypes in the Brazilian population.

    Directory of Open Access Journals (Sweden)

    Deise C Friedrich

    Full Text Available The CYP2D6 enzyme is one of the most important members of the cytochrome P450 superfamily. This enzyme metabolizes approximately 25% of currently prescribed medications. The CYP2D6 gene presents a high allele heterogeneity that determines great inter-individual variation. The aim of this study was to evaluate the variability of CYP2D6 alleles, genotypes and predicted phenotypes in Brazilians. Eleven single nucleotide polymorphisms and CYP2D6 duplications/multiplications were genotyped by TaqMan assays in 1020 individuals from North, Northeast, South, and Southeast Brazil. Eighteen CYP2D6 alleles were identified in the Brazilian population. The CYP2D6*1 and CYP2D6*2 alleles were the most frequent and widely distributed in different geographical regions of Brazil. The highest number of CYPD6 alleles observed was six and the frequency of individuals with more than two copies ranged from 6.3% (in Southern Brazil to 10.2% (Northern Brazil. The analysis of molecular variance showed that CYP2D6 is homogeneously distributed across different Brazilian regions and most of the differences can be attributed to inter-individual differences. The most frequent predicted metabolic status was EM (83.5%. Overall 2.5% and 3.7% of Brazilians were PMs and UMs respectively. Genomic ancestry proportions differ only in the prevalence of intermediate metabolizers. The IM predicted phenotype is associated with a higher proportion of African ancestry and a lower proportion of European ancestry in Brazilians. PM and UM classes did not vary among regions and/or ancestry proportions therefore unique CYP2D6 testing guidelines for Brazilians are possible and could potentially avoid ineffective or adverse events outcomes due to drug prescriptions.

  3. Meta-Analysis of Cytochrome P2D6 Gene Polymorphisms and Susceptibility to Acute Leukemia

    Institute of Scientific and Technical Information of China (English)

    Ma Limin; Ruan Linhai

    2013-01-01

    Objective:To provide a more robust assessment to the effect of cytochrome P2D6 (CYP2D6) polymorphisms on the risk of acute leukemia (AL), and to evaluate the association between the two most commonly studied CYP2D6 polymorphisms (CYP2D6*3 and CYP2D6*4) and AL risk by meta-analysis. Methods:All case-control studies investigating an association between the CYP2D6*3 or CYP2D6*4 polymorphisms and AL risk were included. Either fixed-effects or random-effects models were applied to combine odds ratios (ORs) and 95%conifdence intervals (CIs) by RevMan 5.1. Q-statistic was used to evaluate the heterogeneity, and both Egger’s test and funnel plots were used to assess publication bias. Results:Six studies were included in the meta-analysis. The results we acquired were that the OR value and 95%CI of CYP2D6*4 wild type, heterozygous mutant and homozygous mutant were 0.94 (0.66-1.35), 1.04(0.74-1.45) and 1.63 (0.95-2.81), respectively with Z=0.33, 0.23 and 1.76 (P>0.05), indicating that there was no signiifcant association between CYP2D6*4 polymorphism and the risk of AL. We also performed subgroup analysis by the AL immunophenotype for those groups with heterogeneity. The results of the combined analysis of CYP2D6*4 wild type, heterozygous mutant and acute lymphoblastic leukemia (ALL) were Z=0.08, 0.08 (P>0.05), for acute myeloblastic leukemia (AML) were Z=0.17, 0.26 (P>0.05), indicating that there was no signiifcant association between CYP2D6*4 polymorphism and the development of both ALL and AML. Conclusion:CYP2D6 polymorphisms are not associated with AL risk.

  4. Lack of association between schizophrenia and the CYP2D6 gene polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Pirmohamed, M.; Wild, M.J.; Kitteringham, N.R. [Univ. of Liverpool (United Kingdom)] [and others

    1996-04-09

    Approximately 5-10% of the Caucasian population lack the P450 isoform, CYP2D6. This polymorphism may be of importance in determining individual susceptibility to Parkinson`s disease. In this journal, Daniels et al. recently reported a negative association between the CYP2D6 gene locus and schizophrenia, a disease characterized by dopamine overactivity. It is important to exclude such an association because CYP2D6 is expressed in the brain and it is involved in dopamine catabolism. Between 1992 and 1993, we also performed a study similar to that, and reached the same conclusion. 7 refs., 1 tab.

  5. Three new alternative splicing variants of human cytochrome P450 2D6 mRNA in human extratumoral liver tissue

    Institute of Scientific and Technical Information of China (English)

    Jian Zhuge; Ying-Nian Yu

    2004-01-01

    AIM: To identify the new alternative splicing variants of human CYP2D6 in human extratumoral liver tissue with RT-PCR and sequencing.METHODS: Full length of human CYP2D6 cDNAs was amplificated by reverse transcription-polymerase chain reaction (RT-PCR) from a human extratumoral liver tissue and cloned into pGEM-T vector. The cDNA was sequenced.Exons from 1 to 4 of human CYP2D6 cDNAs were also amplificated by RT-PCR from extratumoral liver tissues of17 human hepatocellular carcinomas. Some RT-PCR products were sequenced. Exons 1 to 4 of CYP2D6 gene were amplified by PCR from extratumoral liver tissue DNA.Two PCR products from extratumoral liver tissues expressing skipped mRNA were partially sequenced.RESULTS: One of the CYP2D6cDNAs had 470 nucleotides from 79 to 548 (3' portion of exons 1 to 5' portion of exon 4),and was skipped. Exons 1 to 4 of CYP2D6 cDNA were assayed with RT-PCR in 17 extratumoral liver tissues. Both wild type and skipped mRNAs were expressed in 4 samples,only wild type mRNA was expressed in 5 samples, and only skipped mRNA was expressed in 8 samples. Two more variants were identified by sequencing the RT-PCR products of exons 1 to 4 of CYP2D6cDNA. The second variant skipped 411 nucleotides from 175 to 585. This variant was identified in 4 different liver tissues by sequencing the RT-PCR products. We sequenced partially 2 of the PCR products amplified of CYP2D6 exon 1 to exon 4 from extratumoral liver tissue genomic DNA that only expressed skipped mRNA by RT-PCR. No point mutations around exon 1, intron 1, and exon 4, and no deletion in CYP2D6gene were detected. The third variant was the skipped exon 3, and 153 bp was lost.CONCLUSION: Three new alternative splicing variants of CYP2D6 mRNA have been identified. They may not be caused by gene mutation and may lose CYP2D6 activity and act as a down-regulator of CYP2D6.

  6. CYP2D6 polymorphisms influence the efficacy of adjuvant tamoxifen in Thai breast cancer patients

    Directory of Open Access Journals (Sweden)

    Sirachainan E

    2012-10-01

    Full Text Available Ekaphop Sirachainan,1 Sureerat Jaruhathai,1 Narumol Trachu,2 Ravat Panvichian,1 Thitiya Sirisinha,1 Touch Ativitavas,1 Vorachai Ratanatharathorn,1 Montri Chamnanphon,3 Chonlaphat Sukasem31Division of Medical Oncology, Department of Medicine, 2Research Center, Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand, 3Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, ThailandAim: We evaluated single nucleotide polymorphisms (SNPs of CYP2D6 to identify those that influence the efficiency of tamoxifen in adjuvant treatment of breast cancer through a matched case–control study.Methods: Peripheral blood DNA was collected from 20 patients with disease recurrence during adjuvant tamoxifen treatment and from 19 patients who had completed 5 years of tamoxifen therapy without recurrence of breast cancer. CYP2D6*4 (1846G > A; rs3892097, CYP2D6*10 (100C > T, rs1065852, and CYP2D6*5 (deletion were genotyped. The correlation between disease-free survival (DFS and genotype and clinical outcome were assessed using Kaplan–Meier analysis and a log-rank test.Results: We found the allelic frequency of CYP2D6*10 during this study. Patients with the CYP2D6*10 homozygous variant T/T genotype had a significantly shorter median of DFS than those with C/T (P = 0.036, but DFS was not significantly different from that of patients with the C/C genotype (P = 0.316. One patient who was a carrier both of CYP2D6 G/A (1846G > A and T/T (100C > T had DFS of 22.7 months.Conclusions: This study demonstrated that CYP2D6*10/*10 was significantly associated with shorter DFS in Thai breast cancer patients receiving tamoxifen. This was a pilot study investigating the correlation of CYP2D6 polymorphisms and their influence on clinical outcomes in Thai estrogen receptor

  7. Sequencing CYP2D6 for the detection of poor-metabolizers in post-mortem blood samples with tramadol.

    Science.gov (United States)

    Fonseca, Suzana; Amorim, António; Costa, Heloísa Afonso; Franco, João; Porto, Maria João; Santos, Jorge Costa; Dias, Mário

    2016-08-01

    Tramadol concentrations and analgesic effect are dependent on the CYP2D6 enzymatic activity. It is well known that some genetic polymorphisms are responsible for the variability in the expression of this enzyme and in the individual drug response. The detection of allelic variants described as non-functional can be useful to explain some circumstances of death in the study of post-mortem cases with tramadol. A Sanger sequencing methodology was developed for the detection of genetic variants that cause absent or reduced CYP2D6 activity, such as *3, *4, *6, *8, *10 and *12 alleles. This methodology, as well as the GC/MS method for the detection and quantification of tramadol and its main metabolites in blood samples was fully validated in accordance with international guidelines. Both methodologies were successfully applied to 100 post-mortem blood samples and the relation between toxicological and genetic results evaluated. Tramadol metabolism, expressed as its metabolites concentration ratio (N-desmethyltramadol/O-desmethyltramadol), has been shown to be correlated with the poor-metabolizer phenotype based on genetic characterization. It was also demonstrated the importance of enzyme inhibitors identification in toxicological analysis. According to our knowledge, this is the first study where a CYP2D6 sequencing methodology is validated and applied to post-mortem samples, in Portugal. The developed methodology allows the data collection of post-mortem cases, which is of primordial importance to enhance the application of these genetic tools to forensic toxicology and pathology.

  8. Physiologically-based pharmacokinetic modeling of tamoxifen and its metabolites in women of different CYP2D6 phenotypes provides new insight into the tamoxifen mass balance

    Directory of Open Access Journals (Sweden)

    Kristin eDickschen

    2012-05-01

    Full Text Available Tamoxifen is a first-line endocrine agent in the mechanism-based treatment of estrogen receptor positive (ER+ mammary carcinoma and applied to breast cancer patients all over the world. Endoxifen is a secondary and highly active metabolite of tamoxifen that is formed among others by the polymorphic cytochrome P450 2D6 (CYP2D6. It is widely accepted that CYP2D6 poor metabolizers (PM exert a pronounced decrease in endoxifen steady-state plasma concentrations compared to CYP2D6 extensive metabolizers (EM. Nevertheless, an in-depth understanding of the chain of cause and effect between CYP2D6 genotype, endoxifen steady-state plasma concentration, and subsequent tamoxifen treatment benefit still remains to be evolved.In this context, physiologically-based pharmacokinetic (PBPK-modeling provides a useful tool to mechanistically investigate the impact of CYP2D6 phenotype on endoxifen formation in female breast cancer patients undergoing tamoxifen therapy.It has long been thought that only a minor percentage of endoxifen is formed via 4-hydroxytamoxifen. However, the current investigation supports very recently published data that postulates a contribution of 4-hydroxytamoxifen above 20 % to total endoxifen formation. The developed PBPK-model describes tamoxifen PK in rats and humans. Moreover, tamoxifen metabolism in dependence of CYP2D6 phenotype in populations of European female individuals is well described, thus providing a good basis to further investigate the linkage of PK, mode of action, and treatment outcome in dependence of factors such as phenotype, ethnicity or co-treatment with CYP2D6 inhibitors.

  9. Dose-dependent inhibition of CYP1A2, CYP2C19 and CYP2D6 by citalopram, fluoxetine, fluvoxamine and paroxetine

    DEFF Research Database (Denmark)

    Jeppesen, U; Gram, L F; Vistisen, K;

    1996-01-01

    OBJECTIVE: The purpose of this pharmacokinetic study was to investigate the dose-dependent inhibition of model substrates for CYP2D6, CYP2C19 and CYP1A2 by four marketed selective serotonin reuptake inhibitors (SSRIs): citalopram, fluoxetine, fluvoxamine and paroxetine. METHODS: The study was...... by sparteine (CYP2D6), mephenytoin (CYP2C19) and caffeine (CYP1A2) tests. Fluoxetine was given at 3-week intervals because of the long half-life of fluoxetine and its metabolite norfluoxetine. Citalopram, fluoxetine and paroxetine were given in doses of 10, 20, 40 and 80 mg and fluvoxamine was given...... fluoxetine are potent inhibitors of CYP2D6, that fluvoxamine and fluoxetine are moderate inhibitors of CYP2C19 and that fluvoxamine is a potent inhibitor of CYP1A2 in humans in vivo. The clinical prediction of interaction from single-dose experiments may have to take the degree of accumulation during steady...

  10. CYP2D6基因多态性及其临床意义

    Institute of Scientific and Technical Information of China (English)

    徐艳娇; 龚森; 纪洪艳; 刘东

    2012-01-01

    CYP2D6是CYP酶系中重要的一种氧化代谢酶,参与多种药物的代谢.CYP2D6具有基因多态性,使药物代谢在不同种族之间,甚至在同种族不同人群中产生较大的差异,从而影响药物的疗效.因此,深入了解CYP2D6基因的多态性以及对药物代谢的影响,对指导临床合理用药和调整用药方案具有重大意义.

  11. CARACTERIZACIÓN DE VARIANTES ALÉLICAS DE CITOCROMO CYP2D6 EN LA POBLACIÓN DE LA REGIÓN CENTROCCIDENTAL DE VENEZUELA

    Directory of Open Access Journals (Sweden)

    GRIMÁN PEDRO

    2009-04-01

    Full Text Available

    RESUMEN

    El gen CYP2D6 codifica para una monooxigenasa perteneciente al citocromo P450, la cual está involucrada en la biotransformación de un gran número de drogas comúnmente prescritas, como antidepresivos, antineoplásicos y antihipertensivos. Algunos efectos adversos, así como falla terapéutica pueden ser relacionados con la actividad anormal de CYP2D6 producto de polimorfismos en el gen de dicha enzima. Con el fin de predecir la frecuencia de algunos fenotipos metabolizadores pobres de CYP2D6 en la población de la región centroccidental de Venezuela se determinaron las frecuencias alélicas y genotípicas de las variantes alélicas CYP2D6*3, *4 y *6. Se extrajo ADN genómico a partir de sangre periférica de 100 individuos voluntarios aparentemente sanos, y se procedió a la genotipificación por PCR tetra-primer alelo-específica y análisis por electroforesis en geles de agarosa. Se compararon las frecuencias obtenidas con poblaciones de otros países. El alelo más frecuente fue CYP2D6*4 con 16,5%, mostrando una diferencia significativa con la reportada con poblaciones asiáticas. Este trabajo constituye un estudio preliminar en la caracterización de un grupo más amplio de alelos de CYP2D6 con el fin de asistir al desarrollo de una farmacoterapia individualizada en nuestro país.

    Palabras clave: Citocromo P450, CYP2D6, Farmacogenética.


    ABSTRACT

    The CYP2D6 gene encodes for a monooxygenase belonging to the cytochrome P450, which is involved in the biotransformation of a large number of commonly prescribed drugs such as antidepressants, antihypertensive and antineoplastic. Some side effects, as well as therapeutic failure may be related to abnormal activity of CYP2D6 product of polymorphisms in the CYP2D6 gene. In order to predict the frequency of some poor metabolisers phenotypes of CYP2D6 in the population of the

  12. Allelic distributions of CYP2D6 gene copy number variation in the Eastern Han Chinese population

    Institute of Scientific and Technical Information of China (English)

    Hai-hui SHENG; Yun-lan DU; Jian SUN; Hua-sheng XIAO; Ai-ping ZENG; Wen-xiang ZHU; Ren-fang ZHU; Hong-mei LI; Zhi-dong ZHU; Ying QIN; Wei JIN; Yan LIU

    2007-01-01

    Aim: The human cytochrome P450 2D6 (CYP2D6) gene copy number variation, involving CYP2D6 gene deletion (CYP2D6*5) and duplication or multiduplication (CYP2D6*×N), can result in reduced or increased metabolism of many clinically used drugs. The identification of CYP2D6*5 and CYP2D6*×N and the investigation of their allelic distributions in ethnic populations can be important in deter-mining the right drug and dosage for each patient. Methods: The CYP2D6*5 andCYP2D6 genes, and CYP2D6 gene duplication were identified by 2 modified long PCR, respectively. To determine duplicated alleles, a novel long PCR was developed to amplify the entire duplicated CYP2D6 gene which was used as template for subsequent PCR amplification. A total of 363 unrelated Eastern Han Chinese individuals were analyzed for CYP2D6 gene copy number variation. Results: The frequency of CYP2D6*5 and CYP2D6*×N were 4.82% (n=35) and 0.69% (n=5) in the Eastern Han Chinese population, respectively. Of the 5 duplicated alleles, 3were CYP2D6*1×N and 2 were CYP2D6*10×N. One individual was a carrier of both CYP2D6*5 and CYP2D6*1×N. Taken together, the CYP2D6 gene rear-rangements were present in 10.74% of subjects. Conclusion: Allelic distributions of the CYP2D6 gene copy number variation differ among Chinese from different regions, indicating ethnic variety in Chinese. Long PCR are convenient, cost effective, specific and semiquantitative for the detection of the CYP2D6 gene copy number variation, and amplification of the entire duplicated CYP2D6 gene is necessary for the accurate identification of duplicated alleles.

  13. Determination of Cytochrome P450 2D6 (CYP2D6 Gene Copy Number by Real-Time Quantitative PCR

    Directory of Open Access Journals (Sweden)

    Laurent Bodin

    2005-01-01

    Full Text Available Gene dosage by real-time quantitative PCR has proved to be accurate for measuring gene copy number. The aim of this study was to apply this approach to the CYP2D6 gene to allow for rapid identification of poor and ultrarapid metabolizers (0, 1, or more than 2 gene copy number. Using the 2−ΔΔCt calculation method and a duplex reaction, the number of CYP2D6 gene copies was determined. Quantitative PCR was performed on 43 samples previously analyzed by Southern blotting and long PCR including 20 samples with a heterozygous deletion, 11 with normal copy number (2 copies, and 12 samples with duplicated genes. The average ratio ranged from 1.02 to 1.28, 1.85 to 2.21, and 2.55 to 3.30, respectively, for the samples with 1 copy, 2 copies, and 3 copies. This study shows that this method is sensitive enough to detect either a heterozygous gene deletion or duplication.

  14. Does the Medication Pattern Reflect the CYP2D6 Genotype in Patients With Diagnoses Within the Schizophrenic Spectrum?

    DEFF Research Database (Denmark)

    Jürgens, Gesche; Rasmussen, Henrik B; Werge, Thomas;

    2012-01-01

    Cytochrome P450 2D6 enzyme (CYP2D6) is an important metabolic pathway for many antipsychotics. Its genetic polymorphism causes pharmacokinetic variability that might lead to adverse drug reactions or treatment failure unless countered by appropriate dose adjustments or shift to CYP2D6-independent...

  15. The influence of the CYP2D6*4 polymorphism on drug response and disease susceptibility

    NARCIS (Netherlands)

    M.J. Bijl (Monique)

    2009-01-01

    textabstractThis thesis is about the role of CYP2D6, a drug-metabolizing enzyme, in today’s pharmacotherapy. Cytochrome P450 2D6 (CYP2D6) is an important member of a large family of enzymes with the name cytochrome P450 which is abundantly present in most non-monocellular living organisms. Its histo

  16. An optimized methodology for combined phenotyping and genotyping on CYP2D6 and CYP2C19

    NARCIS (Netherlands)

    Tamminga, C.A; Wemer, J; Oosterhuis, B; Brakenhoff, J.P G; Gerrits, M.G F; de Zeeuw, R.A; de Leij, Lou; Jonkman, J.H.G.

    2001-01-01

    A method for simultaneous phenotyping and genotyping for CYP2D6 and CYP2C19 was tested. Six healthy volunteers were selected (three extensive and three poor metabolisers for CYP2D6). CYP2D6 was probed with dextromethorphan and metoprolol and CYP2C19 was probed with omeprazole. Blood samples were col

  17. Genomics of Dementia: APOE- and CYP2D6-Related Pharmacogenetics

    Directory of Open Access Journals (Sweden)

    Ramón Cacabelos

    2012-01-01

    Full Text Available Dementia is a major problem of health in developed societies. Alzheimer’s disease (AD, vascular dementia, and mixed dementia account for over 90% of the most prevalent forms of dementia. Both genetic and environmental factors are determinant for the phenotypic expression of dementia. AD is a complex disorder in which many different gene clusters may be involved. Most genes screened to date belong to different proteomic and metabolomic pathways potentially affecting AD pathogenesis. The ε4 variant of the APOE gene seems to be a major risk factor for both degenerative and vascular dementia. Metabolic factors, cerebrovascular disorders, and epigenetic phenomena also contribute to neurodegeneration. Five categories of genes are mainly involved in pharmacogenomics: genes associated with disease pathogenesis, genes associated with the mechanism of action of a particular drug, genes associated with phase I and phase II metabolic reactions, genes associated with transporters, and pleiotropic genes and/or genes associated with concomitant pathologies. The APOE and CYP2D6 genes have been extensively studied in AD. The therapeutic response to conventional drugs in patients with AD is genotype specific, with CYP2D6-PMs, CYP2D6-UMs, and APOE-4/4 carriers acting as the worst responders. APOE and CYP2D6 may cooperate, as pleiotropic genes, in the metabolism of drugs and hepatic function. The introduction of pharmacogenetic procedures into AD pharmacological treatment may help to optimize therapeutics.

  18. Prolactin release in children treated with risperidone - Impact and role of CYP2D6 metabolism

    NARCIS (Netherlands)

    Troost, Pieter W.; Lahuis, Bertine E.; Hermans, Mirjam H.; Buitelaar, Jan K.; van Engeland, Herman; Scahill, Lawrence; Minderaa, Ruud B.; Hoekstra, Pieter J.

    2007-01-01

    Objective: Little is known about the role of CYP2136 polymorphism in risperidone-induced prolactin release in children. Method: Twenty-five children (aged 5-15 years) with pervasive developmental disorders were genotyped for CYP2D6 polymorphisms. Serum prolactin, risperidone, and 9-hydroxyrisperidon

  19. Correlation between polymorphism of CYP2D6 gene with effect of tamoxifen in patients with breast cancer%CYP2D6多态性与乳腺癌患者他莫昔芬疗效的相关性

    Institute of Scientific and Technical Information of China (English)

    田超; 杨义; 李卉

    2014-01-01

    目的 探讨CYP2D6基因多态性与乳腺癌患者他莫昔芬(TAM)及其活性代谢产物4-羟基他莫昔芬(4-OH-TAM)血清浓度的相关性,并探讨CYP2D6基因多态性与乳腺癌患者预后的相关性.方法 收集2008年1月至2010年10月期间200例服用TAM的乳腺癌患者的口腔黏膜及血清标本,采用Real-time RT-PCR法检测CYP2D6* 10基因多态性,并分析其与临床病理特征和预后的关系.采用液相色谱-质谱方法(LC-MS)测定患者体内TAM及其活性代谢物4-OH-TAM的血清浓度.结果 200例乳腺癌中检测到CYP2D6* 10/* 10纯合子94例(47%),CYP2D6 wt/wt野生型48例(24%),CYP2D6 wt/* 10杂合型58例(29%).CYP2D6 wt/wt野生型和wt/* 10杂合型两组4-OH-TAM的血清浓度都明显高于*10/*10纯合型(F=4.31,P=0.01).CYP2D6* 10基因多态性与患者各项临床病理因素均无关(均P >0.05).Log-rank检验分析显示CYP2D6突变组患者平均无病生存时间(47.2个月)明显短于CYP2D6正常组患者(51.2个月),P=0.018.Cox回归分析显示CYP2D6基因型与患者无病生存时间明显相关(HR=2.755,95%CI:1.230 ~6.173,P=0.014).结论 CYP2D6*10/*10基因型与乳腺癌他莫昔芬的疗效相关,检测CYP2D6基因型可能有助于临床上有效选择他莫昔芬.%Objective To investigate the correlation of CYP2D6 gene polymorphism and serum tamoxifen (TAM) and its active metabolites (4-hydroxy tamoxifen,4-OH-TAM) in terms of prognosis of breast cancer patients.Methods The oral mucosas and serum were obtained from 200 breast cancer patients receiving oral TAM from Jan 2008 to Oct 2010.Real-time RT-PCR was used to determine CYP2D6* 10 gene polymorphism.The relationship between CYP2D6* 10 gene polymorphism and clinicopathological features and prognosis was assessed by Chi-square test and Cox proportional model.Serum TAM and 4-OH-TAM concentration were determined by liquid chromatography-trap mass spectrometry (LC-MS).Results Of 200 breast cancer patients,CYP2D6 * 10/* 10

  20. CYP2D6 function moderates the pharmacokinetics and pharmacodynamics of 3,4-methylene-dioxymethamphetamine in a controlled study in healthy individuals.

    Science.gov (United States)

    Schmid, Yasmin; Vizeli, Patrick; Hysek, Cédric M; Prestin, Katharina; Meyer Zu Schwabedissen, Henriette E; Liechti, Matthias E

    2016-08-01

    The role of genetic polymorphisms in cytochrome (CYP) 2D6 involved in the metabolism of 3,4-methylene-dioxymethamphetamine (MDMA, ecstasy) is unclear. Effects of genetic variants in CYP2D6 on the pharmacokinetics and pharmacodynamic effects of MDMA were characterized in 139 healthy individuals (70 men, 69 women) in a pooled analysis of eight double-blind, placebo-controlled crossover studies. In CYP2D6 poor metabolizers, the maximum concentrations (Cmax) of MDMA and its active metabolite 3,4-methylene-dioxyamphetamine were +15 and +50% higher, respectively, compared with extensive metabolizers and the Cmax of the inactive metabolite 4-hydroxy-3-methoxymethamphetamine was 50-70% lower. Blood pressure and subjective drug effects increased more rapidly after MDMA administration in poor metabolizers than in extensive metabolizers. In conclusion, the disposition of MDMA and its effects in humans are altered by polymorphic CYP2D6 activity, but the effects are small because of the autoinhibition of CYP2D6. PMID:27253829

  1. Novel variant of CYP2D6*6 is undetected by a commonly used genotyping procedure

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Werge, Thomas

    2011-01-01

    We report the identification of a novel and defective variant of the gene encoding cytochrome P450 2D6 (CYP2D6). This novel variant is a subtype of CYP2D6*6 that was undetected by a commercially available 5' exonuclease-based assay. Because the novel variant was found in only one of 609 individuals......, it represents a rare subtype of CYP2D6*6 that may be restricted to a single family or a subpopulation. A procedure for the identification of the novel CYP2D6*6 variant using restriction enzyme treatment of amplified fragments was developed....

  2. Novel variant of CYP2D6*6 is undetected by a commonly used genotyping procedure

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Werge, Thomas

    2011-01-01

    We report the identification of a novel and defective variant of the gene encoding cytochrome P450 2D6 (CYP2D6). This novel variant is a subtype of CYP2D6*6 that was undetected by a commercially available 5' exonuclease-based assay. Because the novel variant was found in only one of 609 individua......, it represents a rare subtype of CYP2D6*6 that may be restricted to a single family or a subpopulation. A procedure for the identification of the novel CYP2D6*6 variant using restriction enzyme treatment of amplified fragments was developed....

  3. Pharmacokinetic interactions between monoamine oxidase A inhibitor harmaline and 5-methoxy-N,N-dimethyltryptamine, and the impact of CYP2D6 status.

    Science.gov (United States)

    Jiang, Xi-Ling; Shen, Hong-Wu; Mager, Donald E; Yu, Ai-Ming

    2013-05-01

    5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT or street name "5-MEO") is a newer designer drug belonging to a group of naturally occurring indolealkylamines. Our recent study has demonstrated that coadministration of monoamine oxidase A (MAO-A) inhibitor harmaline (5 mg/kg) increases systemic exposure to 5-MeO-DMT (2 mg/kg) and active metabolite bufotenine. This study is aimed at delineating harmaline and 5-MeO-DMT pharmacokinetic (PK) interactions at multiple dose levels, as well as the impact of CYP2D6 that affects harmaline PK and determines 5-MeO-DMT O-demethylation to produce bufotenine. Our data revealed that inhibition of MAO-A-mediated metabolic elimination by harmaline (2, 5, and 15 mg/kg) led to a sharp increase in systemic and cerebral exposure to 5-MeO-DMT (2 and 10 mg/kg) at all dose combinations. A more pronounced effect on 5-MeO-DMT PK was associated with greater exposure to harmaline in wild-type mice than CYP2D6-humanized (Tg-CYP2D6) mice. Harmaline (5 mg/kg) also increased blood and brain bufotenine concentrations that were generally higher in Tg-CYP2D6 mice. Surprisingly, greater harmaline dose (15 mg/kg) reduced bufotenine levels. The in vivo inhibitory effect of harmaline on CYP2D6-catalyzed bufotenine formation was confirmed by in vitro study using purified CYP2D6. Given these findings, a unified PK model including the inhibition of MAO-A- and CYP2D6-catalyzed 5-MeO-DMT metabolism by harmaline was developed to describe blood harmaline, 5-MeO-DMT, and bufotenine PK profiles in both wild-type and Tg-CYP2D6 mouse models. This PK model may be further employed to predict harmaline and 5-MeO-DMT PK interactions at various doses, define the impact of CYP2D6 status, and drive harmaline-5-MeO-DMT pharmacodynamics. PMID:23393220

  4. Effects of CYP2D6 and UGT2B7 polymorphisms on pharmacokinetics of tamoxifen in Thai breast cancer patients

    Directory of Open Access Journals (Sweden)

    Areepium N

    2013-08-01

    Full Text Available N Areepium,1 D Panomvana,1 P Rungwanonchai,1 S Sathaporn,2 N Voravud3 1Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 2Department of Surgery, Phramongkutklao Hospital, Bangkok, 3Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Purpose: The objective of this study was to evaluate the impact of CYP2D6 and UGT2B7 polymorphisms on tamoxifen (TAM pharmacokinetics in Thai breast cancer patients. Methods: Thai female breast cancer patients treated with TAM were included in the study. Patients were genotyped for CYP2D6 and UGT2B7 polymorphism, and plasma levels of TAM and its potent active metabolite endoxifen (END, at steady state, were identified. Results: Fifty-nine female breast cancer patients were included in the study. The average age was 50 ± 9.3 years old; 76% were premenopausal and 85% had estrogen receptor-positive breast cancer. The allele frequencies of CYP2D6*10 and UGT2B7*2 were 53% and 28%, respectively. Patients with CYP2D6*10/*10 had lower END concentrations compared with CYP2D26*1/*10 and CYP2D6*1/*1 (9.62 ng/mL versus 15.67 ng/mL and 21.55 ng/mL, respectively, P = 0.045. Polymorphisms of UGT2B7 alone did not have any impact on TAM metabolism. However, among 20 patients with CYP2D6*10/*10, one with UGT2B7*2/*2 had higher END concentrations compared against patients with UGT2B7*1/*1 and UGT2B7*1/*2 (31.36 ng/mL versus 7.86 ng/mL, respectively, P = 0.023. Conclusion: Results from this study confirmed the impacts of CYP2D6 polymorphisms on the pharmacokinetics of TAM, while UGT2B7 polymorphisms tended to have impact on TAM metabolism in patients with homozygous CYP2D6*10. Keywords: tamoxifen, pharmacogenomics, CYP2D6, UGT2B7, breast cancer

  5. Population pharmacokinetic modelling to assess the impact of CYP2D6 and CYP3A metabolic phenotypes on the pharmacokinetics of tamoxifen and endoxifen

    NARCIS (Netherlands)

    ter Heine, Rob; Binkhorst, Lisette; de Graan, Anne Joy M; de Bruijn, Peter; Beijnen, Jos H; Mathijssen, Ron H J; Huitema, Alwin D R

    2014-01-01

    AIMS: Tamoxifen is considered a pro-drug of its active metabolite endoxifen. The major metabolic enzymes involved in endoxifen formation are CYP2D6 and CYP3A. There is considerable evidence that variability in activity of these enzymes influences endoxifen exposure and thereby may influence the clin

  6. Molecular Dynamics Simulations to Investigate the Influences of Amino Acid Mutations on Protein Three-Dimensional Structures of Cytochrome P450 2D6.1, 2, 10, 14A, 51, and 62.

    Directory of Open Access Journals (Sweden)

    Shuichi Fukuyoshi

    Full Text Available Many natural mutants of the drug metabolizing enzyme cytochrome P450 (CYP 2D6 have been reported. Because the enzymatic activities of many mutants are different from that of the wild type, the genetic polymorphism of CYP2D6 plays an important role in drug metabolism. In this study, the molecular dynamics simulations of the wild type and mutants of CYP2D6, CYP2D6.1, 2, 10, 14A, 51, and 62 were performed, and the predictions of static and dynamic structures within them were conducted. In the mutant CYP2D6.10, 14A, and 61, dynamic properties of the F-G loop, which is one of the components of the active site access channel of CYP2D6, were different from that of the wild type. The F-G loop acted as the "hatch" of the channel, which was closed in those mutants. The structure of CYP2D6.51 was not converged by the simulation, which indicated that the three-dimensional structure of CYP2D6.51 was largely different from that of the wild type. In addition, the intramolecular interaction network of CYP2D6.10, 14A, and 61 was different from that of the wild type, and it is considered that these structural changes are the reason for the decrease or loss of enzymatic activities. On the other hand, the static and dynamic properties of CYP2D6.2, whose activity was normal, were not considerably different from those of the wild type.

  7. Genetic polymorphism of CYP2D6 and its influence on the personalized usage of antipsychotics%CYP2D6基因多态性与抗精神病药物的个体化应用

    Institute of Scientific and Technical Information of China (English)

    陈冰; 蔡卫民; 杨婉花

    2012-01-01

    CYP2D6是一种重要的细胞色素P450酶,存在着显著的基因多态性.CYP2D6在抗精神病类药物的代谢中发挥着重要作用,与许多抗精神病药物药动学及药效学的个体间变异存在着密切联系,检测CYP2D6基因型有助于患者抗精神病药物治疗方案的选择和调整,提高用药的安全性和有效性.本文综述CYP2D6基因多态性对抗精神病药物的药动学、不良反应及药物相互作用的影响,探讨了CYP2D6基因型检测在抗精神病个体化治疗中的应用前景.%CYP2D6 is one of the most important cytochrome P450 enzymes. There is remarkable genetic polymorphism of CYP2D6. CYP2D6 play an important role in the metabolism of antipsychotics, and has significant correlation with the inter-individual difference ol pharmacokinetics and pharmacodynamics of antipsychotics. Determination of CYP2D6 genotypes is helpful in the selection and regulation of antip-sychotic therapy regimen for the elevation of ef-ficiency and safety. The influence of CYP2D6 genetic polymorphism on the pharmacokinetics, adverse effect and drug-drug interaction was reviewed and the usefulness of CYP2D6 genoty-ping in the personalized antipsychotic therapy was discussed

  8. Genetic polymorphisms of CYP2D6 in Chinese mainland%中国大陆人群CYP2D6基因多态性的检测

    Institute of Scientific and Technical Information of China (English)

    纪玲; 潘世秀; 等

    2002-01-01

    目的检测中国人群CYP2D6序列的差异性.方法在223个中国大陆人中,使用四引物聚合酶链反应、等位基因特异性扩增聚合酶链反应和多重长聚合酶链反应方法检测CYP2D6等位基因*2、*3、*4、*5、*6、*8、*10和*14.结果在中国人群中,频率最高的弱代谢(PM)等位基因是CYP2D6*5(7.2%),其次是仅存在于东方人中的CYP2D6*14(2.0%),再次为CYP2D6*4(0.2%),未发现CYP2D6*3、*6和*8等位基因.与白种人相比,中国大陆人群中分布频率最高的等位基因是CYP2D6*10(51.6%).结论在中国大陆人群中,PM等位基因CYP2D6* 5和CYP2D6* 14的频率比其它东方人高,但CYP2D6*10的频率比其它东方人低.%Objective To observe the significant differences in the frequencies of the cytochrome P450 2D6 (CYP2D6) alleles in Chinese popoulations. Methods Tetra-primer polymerase chain reaction (PCR), allele specific amplification (ASA) PCR and multiplex long PCR were developed to detect the CYP2D6 alleles * 2, * 3, * 4, * 5, * 6, * 8, * 10 and * 14 in 223 subjects from Chinese mainland.Results The CYP2D6*5 allele was the most frequent poor metabolizer (PM) allele in Chinese (7.2%), followed by CYP2D6*14 (2.0%) which was only detected in orientals. There was only 0.2% CYP2D6*4, and no CYP2D6*3, * 6 and * 8 were detected. In contrast to the Caucasians, the most frequent allele in Chinese was the * 10 allele with a frequency of 51.6%. Conclusion The frequencies of PM alleles, CYP2D6*5 and CYP2D6* 14, were higher; but the frequency of CYP2D6*10 was lower in mainland Chinese population than that in other orientals.

  9. Polymorphism of CYP2D6 gene and the influence on the metabolism of metoprolol%CYP2D6基因多态性及对美托洛尔代谢的影响

    Institute of Scientific and Technical Information of China (English)

    熊丹; 熊玉卿

    2011-01-01

    CYP2D6是一种重要的P450系氧化代谢酶,主要参与多种重要药物的代谢.CYP2D6基因多态性会引起药物代谢有显著的个体和种族差异.美托洛尔为选择性β1受体阻滞剂,临床应用上存在巨大个体差异,主要在肝脏经多条途径代谢,大约70%的代谢由CYP2D6介导,CPY2D6基因多态性对美托洛尔代谢有较大影响.本文从CYP2D6的基因多态性及它对美托洛尔代谢的影响这两方面作一综述.%As one of major cytochrome P450s, CYP2D6 is responsible for the metabolism of many important drugs. Genetic polymorphism of CYP2D6 is the basis of lager interindividual and racial variability in the metabolism of drug. Metoprolol is a selective β1-adrenoceptor antagonist, there is an obvious individual difference in clinic. It is metabolized in the liver, in vivo data indicate that approximately 70% of themetabolism of metoptolol depends upon CYP2D6. Genetic polymorphism of CYP2D6 have a great influence on the metabolism of metoprolol. Here we summarize the polymorphism of CYP2D6 gene and the influence on the metabolism of metoprolol.

  10. Studies of novel deuterides RMn2D6 (R — rare earth) compressed in DAC up to 30 GPa

    Science.gov (United States)

    Filipek, S. M.; Sugiura, H.; Paul-Boncour, V.; Wierzbicki, R.; Liu, R. S.; Bagkar, N.

    2008-07-01

    The exposure of RMn2 (C15 or C14 cubic Laves phase, where R = Y; Dy; Ho or Er) to high deuterium pressure leads to formation of novel, unique YMn2D6, DyMn2D6, HoMn2D6 and ErMn2D6 deuterides with cubic Fm-3m symmetry. In spite of different structures and molecular volumes of parent RMn2 compounds, the molar volumes of RMn2D6 deuterides are almost identical. In this paper, we present results of studies on RMn2Dx (where R = Y, Dy, Ho and Er) submitted to compression up to 30 GPa in diamond anvil cell (DAC) combined with energy dispersive X-ray diffraction. The EOS (equation of state) parameters of the above four RMn2D6 samples and YMn2Dx, with x RMn2D6 but very different than those of interstitial deuterides YMn2Dx (x RMn2D6 up to 30 GPa.

  11. The prevalence of CYP2D6 and CYP2C19 genotypes in a population of healthy Dutch volunteers

    NARCIS (Netherlands)

    Tamminga, W.J; Wemer, J; Oosterhuis, B; de Zeeuw, R.A; de Leij, Lou; Jonkman, J.H.G.

    2001-01-01

    Aim: This study was performed in a sample of the Dutch population to estimate the prevalence of noncoding mutations of CYP2D6 and CYP2C19 as obtained by genotyping. In addition, the predictability of the genotyping strategy was assessed. Methods: The CYP2D6 and CYP2C19 status of 765 unrelated health

  12. Association of polymorphism in the cytochrome CYP2D6 and the efficacy and tolerability of simvastatin

    NARCIS (Netherlands)

    Mulder, A B; van Lijf, H J; Bon, M A; van den Bergh, F A; Touw, D J; Neef, C; Vermes, I

    2001-01-01

    OBJECTIVE: Because clinical data about the therapeutic consequences of polymorphic oxidation of simvastatin by CYP2D6 have not been well reported, we sought to investigate the possible link between polymorphism of CYP2D6 and the efficacy and tolerability of simvastatin treatment in a group of 88 pat

  13. Antipsychotic-induced extrapyramidal syndromes and cytochrome P-450 2D6 genotype : a case-control study

    NARCIS (Netherlands)

    Schillevoort, [No Value; de Boer, A; van der Weide, J; Steijns, LSW; Roos, RAC; Jansen, PAF; Leufkens, HGM

    2002-01-01

    To study the association between polymorphism of the cytochrome P-450 2D6 gene (CYP2D6) and the risk of antipsychotic-induced extrapyramidal syndromes, as measured by the use of anti parkinsonian medication. Data for this case-control study were obtained from a psychiatric hospital where newly admit

  14. CYP2D6基因多态性与他奠昔芬治疗

    Institute of Scientific and Technical Information of China (English)

    杨汐

    2011-01-01

    CYP2D6是细胞色素P450酶系中的一种重要的药物代谢酶,CYP2D6基因的遗传变异可导致CYP2D6酶活性的不同,从而影响他莫昔芬的代谢,使携带不同基因型的乳腺癌病人对他莫昔芬的治疗反应不同.本文从CYP2D6基因多态性与他莫昔芬代谢、疗效及预后、副反应的关系,CYP2D6抑制剂对他莫昔芬代谢的影响等方面进行了简要综述.

  15. CARACTERIZACIÓN DE VARIANTES ALÉLICAS DE CITOCROMO CYP2D6 EN LA POBLACIÓN DE LA REGIÓN CENTROCCIDENTAL DE VENEZUELA Characterization Of Cytochrome Cyp2d6 Allele Variants In The Population Of The Central-Western Region Of Venezuela

    Directory of Open Access Journals (Sweden)

    PEDRO GRIMÁN

    Full Text Available El gen CYP2D6 codifica para una monooxigenasa perteneciente al citocromo P450, la cual está involucrada en la biotransformación de un gran número de drogas comúnmente prescritas, como antidepresivos, antineoplásicos y antihipertensivos. Algunos efectos adversos, así como falla terapéutica pueden ser relacionados con la actividad anormal de CYP2D6 producto de polimorfismos en el gen de dicha enzima. Con el fin de predecir la frecuencia de algunos fenotipos metabolizadores pobres de CYP2D6 en la población de la región centroccidental de Venezuela se determinaron las frecuencias alélicas y genotípicas de las variantes alélicas CYP2D6*3, *4 y *6. Se extrajo ADN genómico a partir de sangre periférica de 100 individuos voluntarios aparentemente sanos, y se procedió a la genotipificación por PCR tetra-primer alelo-específica y análisis por electroforesis en geles de agarosa. Se compararon las frecuencias obtenidas con poblaciones de otros países. El alelo más frecuente fue CYP2D6*4 con 16,5%, mostrando una diferencia significativa con la reportada con poblaciones asiáticas. Este trabajo constituye un estudio preliminar en la caracterización de un grupo más amplio de alelos de CYP2D6 con el fin de asistir al desarrollo de una farmacoterapia individualizada en nuestro país.The CYP2D6 gene encodes for a monooxygenase belonging to the cytochrome P450, which is involved in the biotransformation of a large number of commonly prescribed drugs such as antidepressants, antihypertensive and antineoplastic. Some side effects, as well as therapeutic failure may be related to abnormal activity of CYP2D6 product of polymorphisms in the CYP2D6 gene. In order to predict the frequency of some poor metabolisers phenotypes of CYP2D6 in the population of the Central-Western region of Venezuela it was determined the allelic and genotypic frequencies of CYP2D6 *3, *4, *6 allelic variants. DNA was extracted from peripheral blood of 100 apparently

  16. CYP2D7 sequence variation interferes with TaqMan CYP2D6*15 and *35 genotyping

    Directory of Open Access Journals (Sweden)

    Amanda K Riffel

    2016-01-01

    Full Text Available TaqMan™ genotyping assays are widely used to genotype CYP2D6, which encodes a major drug metabolizing enzyme. Assay design for CYP2D6 can be challenging owing to the presence of two pseudogenes, CYP2D7 and CYP2D8, structural and copy number variation and numerous single nucleotide polymorphisms (SNPs some of which reflect the wild-type sequence of the CYP2D7 pseudogene. The aim of this study was to identify the mechanism causing false positive CYP2D6*15 calls and remediate those by redesigning and validating alternative TaqMan genotype assays. Among 13,866 DNA samples genotyped by the CompanionDx® lab on the OpenArray platform, 70 samples were identified as heterozygotes for 137Tins, the key SNP of CYP2D6*15. However, only 15 samples were confirmed when tested with the Luminex xTAG CYP2D6 Kit and sequencing of CYP2D6-specific long range (XL-PCR products. Genotype and gene resequencing of CYP2D6 and CYP2D7-specific XL-PCR products revealed a CC>GT dinucleotide SNP in exon 1 of CYP2D7 that reverts the sequence to CYP2D6 and allows a TaqMan assay PCR primer to bind. Because CYP2D7 also carries a Tins, a false-positive mutation signal is generated. This CYP2D7 SNP was also responsible for generating false-positive signals for rs769258 (CYP2D6*35 which is also located in exon 1. Although alternative CYP2D6*15 and *35 assays resolved the issue, we discovered a novel CYP2D6*15 subvariant in one sample that carries additional SNPs preventing detection with the alternate assay. The frequency of CYP2D6*15 was 0.1% in this ethnically diverse U.S. population sample. In addition, we also discovered linkage between the CYP2D7 CC>GT dinucleotide SNP and the 77G>A (rs28371696 SNP of CYP2D6*43. The frequency of this tentatively functional allele was 0.2%. Taken together, these findings emphasize that regardless of how careful genotyping assays are designed and evaluated before being commercially marketed, rare or unknown SNPs underneath primer and/or probe

  17. A physiologically based pharmacokinetic model to predict disposition of CYP2D6 and CYP1A2 metabolized drugs in pregnant women.

    Science.gov (United States)

    Ke, Alice Ban; Nallani, Srikanth C; Zhao, Ping; Rostami-Hodjegan, Amin; Isoherranen, Nina; Unadkat, Jashvant D

    2013-04-01

    Conducting pharmacokinetic (PK) studies in pregnant women is challenging. Therefore, we asked if a physiologically based pharmacokinetic (PBPK) model could be used to evaluate different dosing regimens for pregnant women. We refined and verified our previously published pregnancy PBPK model by incorporating cytochrome P450 CYP1A2 suppression (based on caffeine PK) and CYP2D6 induction (based on metoprolol PK) into the model. This model accounts for gestational age-dependent changes in maternal physiology and hepatic CYP3A activity. For verification, the disposition of CYP1A2-metabolized drug theophylline (THEO) and CYP2D6-metabolized drugs paroxetine (PAR), dextromethorphan (DEX), and clonidine (CLO) during pregnancy was predicted. Our PBPK model successfully predicted THEO disposition during the third trimester (T3). Predicted mean postpartum to third trimester (PP:T3) ratios of THEO area under the curve (AUC), maximum plasma concentration, and minimum plasma concentration were 0.76, 0.95, and 0.66 versus observed values 0.75, 0.89, and 0.72, respectively. The predicted mean PAR steady-state plasma concentration (Css) ratio (PP:T3) was 7.1 versus the observed value 3.7. Predicted mean DEX urinary ratio (UR) (PP:T3) was 2.9 versus the observed value 1.9. Predicted mean CLO AUC ratio (PP:T3) was 2.2 versus the observed value 1.7. Sensitivity analysis suggested that a 100% induction of CYP2D6 during T3 was required to recover the observed PP:T3 ratios of PAR Css, DEX UR, and CLO AUC. Based on these data, it is prudent to conclude that the magnitude of hepatic CYP2D6 induction during T3 ranges from 100 to 200%. Our PBPK model can predict the disposition of CYP1A2, 2D6, and 3A drugs during pregnancy. PMID:23355638

  18. Analysis of CYP2D6 gene duplication of Chinese population in Hubei%湖北地区人群的CYP2D6二倍体多态性基因分析

    Institute of Scientific and Technical Information of China (English)

    纪玲; 马江涛; 何林; Martin Hersberger

    2004-01-01

    使用长模板PCR方法检测223例湖北地区人群中CYP2D6二倍体.在被检人群中,CYP2D6二倍体的基因频率为2.7%.检测到6例CYP2D6二倍体,基因型分别为*1×2(3/6),*2×2(2/6);*10×2(1/6).表明湖北地区人群中CYP2D6二倍体的基因频率比其他地区中国人群稍高.

  19. Stimulus control by 5methoxy-N,N-dimethyltryptamine in wild-type and CYP2D6-humanized mice

    OpenAIRE

    Winter, J. C.; Amorosi, D.J.; Rice, Kenner C.; Cheng, Kejun; Yu, Ai-Ming

    2011-01-01

    In previous studies we have observed that, in comparison with wild type mice, Tg-CYP2D6 mice have increased serum levels of bufotenine [5-hydroxy-N,N-dimethyltryptamine] following the administration of 5-MeO-DMT. Furthermore, following the injection of 5-MeO-DMT, harmaline was observed to increase serum levels of bufotenine and 5-MeO-DMT in both wild-type and Tg-CYP2D6 mice. In the present investigation, 5-MeO-DMT-induced stimulus control was established in wild-type and Tg-CYP2D6 mice. The t...

  20. CYP2D6基因多态性与药物基因组学研究的进展%Research advance in CYP2D6 genetic polymorphism and pharmacogenomics

    Institute of Scientific and Technical Information of China (English)

    董天崴; 王爽; 杨军; 张志国

    2014-01-01

    CYP2D6 genetic polymorphism results in individual difference of therapeutic effect and adverse reaction of related drugs this article made an overview for that.%CYP2D6基因多态性导致有关药物疗效及不良反应的个体差异,本文就此进行综述。

  1. Lack of influence of CYP2D6 genotype on the clearance of (R)-, (S)- and racemic-methadone

    DEFF Research Database (Denmark)

    Coller, J K; Joergensen, C; Foster, D J R;

    2007-01-01

    OBJECTIVE: To investigate the influence of CYP2D6 genotype on the oral clearance of (R)-, (S)- and rac-methadone. METHODS: In this retrospective study, CYP2D6 genotypes were identified in 56 methadone maintained subjects. Plasma concentrations of (R)-, (S)- and rac-methadone were determined by...... stereoselective HPLC and sufficient data were available to estimate the apparent oral clearances of (R)-, (S)- and rac-methadone using a population kinetic model in 37 of the genotyped subjects. RESULTS: The CYP2D6 allele frequencies were similar to those previously reported in Caucasians, the most common being......: CYP2D6*1 (35.2%), CYP2D6*2 (12.0%) and CYP2D6*4 (22.2%). Three unknown SNPs were found in four subjects: 1811G > A (n = 1), 1834C > T (n = 1) and 2720G > C (n = 2). The oral clearances of (R)-, (S)- and rac-methadone varied 5.4-, 6.8- and 6.1-fold, respectively. No significant differences in methadone...

  2. Machine Learning Energies of 2 M Elpasolite (ABC$_2$D$_6$) Crystals

    CERN Document Server

    Faber, Felix; von Lilienfeld, O Anatole; Armiento, Rickard

    2015-01-01

    Elpasolite is the predominant quaternary crystal structure (AlNaK$_2$F$_6$ prototype) reported in the Inorganic Crystal Structure Database. We have developed a machine learning model to calculate density functional theory quality formation energies of all the 2 M pristine ABC$_2$D$_6$ elpasolite crystals which can be made up from main-group elements (up to bismuth). Our model's accuracy can be improved systematically, reaching 0.1 eV/atom for a training set consisting of 10 k crystals. Important bonding trends are revealed, fluoride is best suited to fit the coordination of the D site which lowers the formation energy whereas the opposite is found for carbon. The bonding contribution of elements A and B is very small on average. Low formation energies result from A and B being late elements from group (II), C being a late (I) element, and D being fluoride. Out of 2 M crystals, the three degenerate pairs CaSrCs$_2$F$_6$/SrCaCs$_2$F$_6$, CaSrRb$_2$F$_6$/SrCaRb$_2$F$_6$ and CaBaCs$_2$F$_6$/BaCaCs$_2$F$_6$ yield ...

  3. Machine Learning Energies of 2 Million Elpasolite (A B C2D6) Crystals

    Science.gov (United States)

    Faber, Felix A.; Lindmaa, Alexander; von Lilienfeld, O. Anatole; Armiento, Rickard

    2016-09-01

    Elpasolite is the predominant quaternary crystal structure (AlNaK2F6 prototype) reported in the Inorganic Crystal Structure Database. We develop a machine learning model to calculate density functional theory quality formation energies of all ˜2 ×106 pristine A B C2D6 elpasolite crystals that can be made up from main-group elements (up to bismuth). Our model's accuracy can be improved systematically, reaching a mean absolute error of 0.1 eV /atom for a training set consisting of 10 ×103 crystals. Important bonding trends are revealed: fluoride is best suited to fit the coordination of the D site, which lowers the formation energy whereas the opposite is found for carbon. The bonding contribution of the elements A and B is very small on average. Low formation energies result from A and B being late elements from group II, C being a late (group I) element, and D being fluoride. Out of 2 ×106 crystals, 90 unique structures are predicted to be on the convex hull—among which is NFAl2Ca6, with a peculiar stoichiometry and a negative atomic oxidation state for Al.

  4. 人CYP2D6基因体外表达体系和功能研究方法的建立%Expressing in Vitro and Functional Study of Human CYP2D6 Gene

    Institute of Scientific and Technical Information of China (English)

    吴振强; 秦胜营

    2013-01-01

    根据G eneBank数据库中人CYP2D6基因构建表达载体pMA91-CYP2D6,转化酵母细胞AH22在体外进行表达,抽提所表达的CYP2D6微粒体蛋白进行Western Blot验证表明表达成功.该微粒体蛋白与探针药物异喹胍反应,利用HPLC检测生成产物4-羟基异喹胍,通过分析其得到酶动力学参数Km=10.14±0.94 μmol/L,最终建立起完整的人CYP2D6表达体系和功能研究方法,为未来测定CYP2D6各等位基因对应酶的活性,实现临床个性化用药奠定基础.

  5. CYP2D6基因克隆及在自身免疫性肝炎中的应用%CLONING OF CYP2D6 AND ITS APPLICATION IN AUTOIMMUNE HEPATITIS

    Institute of Scientific and Technical Information of China (English)

    王达; 仲人前; 于嘉屏; 孔宪涛

    2000-01-01

    采用基因克隆与表达技术制备重组人CYP2D6抗原,建立免疫印迹法,检测几组肝炎患者中的抗CYP2D6抗体.605例ALT升高的成人肝炎患者组内CYP2D6自身抗体阳性检出率为3.97%(24/605),50例ALT升高的小儿肝炎患者组内阳性检出率为12%(6/50). 两组比较, 经统计学处理差异有显著性意义(P<0.01).50名正常人及40例HCV RNA阳性的肝炎患者中无一例发现该自身抗体阳性.检出的30例CYP2D6自身抗体阳性患者,30%合并有HBV感染.结果提示:CYP2D6自身抗体检测可作为自身免疫性肝炎诊断的一项重要指标.

  6. CYP2D6*10B基因型对中国人普罗帕酮对映体药动学的影响%Influence of CYP2D6*10B genotype on pharmacokinetics of propafenone enantiomers in Chinese subjects

    Institute of Scientific and Technical Information of China (English)

    陈冰; 蔡卫民

    2003-01-01

    AIM: To study the relationship between genotype of CYP2D6*10B and pharmacokinetics of propafenone enantiomers. METHODS: Genotype of 17 healthy Chinese HAN subjects was determined by an allele specific amplification method. The blood samples (0-15 h) of the subjects were taken after oral administration of a single dose (400 mg) of propafenone hydrochloride. Concentrations of propafenone enantiomers in plasma were mea sured by a reverse-phase HPLC with precolumn derivatization. RESULTS: Seventeen subjects characterized for CYP2D6* 1 0B genotype included (* 1/* 1) (n = 4), (* 1/* 10) (n = 5) and (* 10/* 10) (n = 8). The metabolic ratios (lg MR) of the three genotypes were -2.68+0.23, -2.2+0.7, and -1.1 +0.5, respectively. The AUC of the three groups that of *1/*10 group or *1/*1 group, and the CL of both enantiomers in *10/*10 is only half of that of *1/*10 group or * 1/* 1 group (P<0.05). CONCLUSION: CYP2D6* 10B alleles induce the declined activity of CYP2D6 and impair the metabolism of propafenone.

  7. Systematic functional study of cytochrome P450 2D6 promoter polymorphisms in the Chinese Han population.

    Directory of Open Access Journals (Sweden)

    Xueli Gong

    Full Text Available The promoter polymorphisms of drug-metabolizing genes can lead to interindividual differences in gene expression, which may result in adverse drug effects and therapeutic failure. Based on the database of CYP2D6 gene polymorphisms in the Chinese Han population established by our group, we functionally characterized the single nucleotide polymorphisms (SNPs of the promoter region and corresponding haplotypes in this population. Using site-directed mutagenesis, all the five SNPs identified and ten haplotypes with a frequency equal to or greater than 0.01 in the population were constructed on a luciferase reporter system. Dual luciferase reporter systems were used to analyze regulatory activity. The activity produced by Haplo3(-2183G>A, -1775A>G, -1589G>C, -1431C>T, -1000G>A, -678A>G, Haplo8(-2065G>A, -2058T>G, -1775A>G, -1589G>C, -1235G>A, -678A>G and MU3(-498C>A was 0.7-, 0.7-, 1.2- times respectively compared with the wild type in human hepatoma cell lines(p<0.05. These findings might be useful for optimizing pharmacotherapy and the design of personalized medicine.

  8. Association of CYP2D6*10 (c.100C>T) polymorphisms with clinical outcome of breast cancer after tamoxifen adjuvant endocrine therapy in Chinese population.

    Science.gov (United States)

    Lei, Lei; Wang, Xian; Wu, Xiao-Dan; Wang, Zeng; Chen, Zhan-Hong; Zheng, Ya-Bin; Wang, Xiao-Jia

    2016-01-01

    Tamoxifen is the most widely used adjuvant endocrine therapy for breast cancer. However, the pharmacogenetic effect of CYP2D6 on its efficacy remains unclear. Therefore, this study aimed to evaluate the association of CYP2D6*10 (c.100C>T) polymorphisms with clinical outcome in Chinese breast cancer patients. A total of 72 tamoxifen-treated early breast cancer patients were included in this study. CYP2D6*10 (c.100C>T) polymorphisms (C/C: wild type; T/T: homozygous mutant genotype T; C/T: heterozygote genotype C) were detected by pyrosequencing. The plasma concentrations of tamoxifen and its two major active metabolites were determined by liquid chromatography tandem mass spectrometry (LC-MS). Disease-free survival (DFS) and overall survival (OS) were assessed by Kaplan-Meier analysis, while the Cox proportional hazards model was used in multivariate tests for prognostic significance. We found that T/T carrier showed the lowest serum concentration of endoxifen as compared to C/C and C/T carriers (p2 cm) and grades were independent prognostic factors for DFS but not OS (tumor size >2 cm: HR: 3.870, 95% CI: 1.045-14.330, P = 0.043; tumor grades: HR: 2.230, 95% CI: 1.090-4.562, P = 0.028). In conclusion, the T/T genotype is a negative prognostic factor in young breast cancer patients using tamoxifen. Tumor size (>2 cm) and grades are independent prognostic factors for DFS, when genotype of CYP2D6*10 (c.100C>T) is adjusted. PMID:27648149

  9. Variantes alélicas de CYP2D6: *4, *6 y *10 en una muestra de residentes del estado Aragua, Venezuela

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    Carlos Flores-Angulo

    2015-12-01

    Full Text Available El objetivo del estudio fue determinar la frecuencia de las variantes del gen CYP2D6: *4, *6 y *10 y predecir el fenotipo metabolizador en una muestra de 145 individuos no consanguíneos, aparentemente sanos, residentes del estado Aragua, Venezuela. Los genotipos fueron determinados mediante ensayos de reacción en cadena de la polimerasa seguidos de digestión con endonucleasas de restricción. La predicción del fenotipo metabolizador se realizó con base al sistema Activity score. Las frecuencias de CYP2D6 *4, *6 y *10 fueron de 14,5%, 0,3% y 1%, respectivamente; un porcentaje significativo de individuos fueron categorizados como metabolizador rápido heterocigoto/metabolizador intermedio (23,5% y metabolizador lento (4,1%. Esta información tiene impacto clínico potencial, porque CYP2D6 interviene en el metabolismo de fármacos de prescripción frecuente como: carvedilol, captopril, cloroquina, codeína, fluoxetina, fluvastatina, haloperidol, idarrubicina, indinavir, imatinib, loperamida, nifedipina, ondansetrón y tamoxifeno

  10. Variantes alélicas de CYP2D6: *4, *6 y *10 en una muestra de residentes del estado Aragua, Venezuela

    Directory of Open Access Journals (Sweden)

    Carlos Flores-Angulo

    2015-10-01

    Full Text Available El objetivo del estudio fue determinar la frecuencia de las variantes del gen CYP2D6: *4, *6 y *10 y predecir el fenotipo metabolizador en una muestra de 145 individuos no consanguíneos, aparentemente sanos, residentes del estado Aragua, Venezuela. Los genotipos fueron determinados mediante ensayos de reacción en cadena de la polimerasa seguidos de digestión con endonucleasas de restricción. La predicción del fenotipo metabolizador se realizó con base al sistema Activity score. Las frecuencias de CYP2D6 *4, *6 y *10 fueron de 14,5%, 0,3% y 1%, respectivamente; un porcentaje significativo de individuos fueron categorizados como metabolizador rápido heterocigoto/metabolizador intermedio (23,5% y metabolizador lento (4,1%. Esta información tiene impacto clínico potencial, porque CYP2D6 interviene en el metabolismo de fármacos de prescripción frecuente como: carvedilol, captopril, cloroquina, codeína, fluoxetina, fluvastatina, haloperidol, idarrubicina, indinavir, imatinib, loperamida, nifedipina, ondansetrón y tamoxifeno

  11. Advances in correlation between CYP2D6 and tamoxifen therapy%CYP2D6与他莫昔芬疗效相关性的研究进展

    Institute of Scientific and Technical Information of China (English)

    雷蕾; 王晓稼

    2009-01-01

    CYP2D6是一种重要的P450系氧化代谢酶,是他莫昔芬在体内代谢成更强抗雌激素作用代谢产物endoxifen的重要代谢酶,因此,强代谢乳腺癌患者服用他莫昔芬后引起明显的潮热症状,而潮热症状的发生与他莫昔芬疗效正相关.除了CYP2D6基因多态性可能影响他莫昔芬体内的代谢外,帕罗西汀(paroxetine)可竞争性抑制CYP2D6对他莫昔芬的代谢,使乳腺癌患者对他莫昔芬疗效明显降低.

  12. CYP2 D6的基因多态性与药物临床应用

    Institute of Scientific and Technical Information of China (English)

    刘周杰

    2016-01-01

    CYP2D6是CYP酶系中重要的一种氧化代谢酶,参与多种药物的代谢。 CYP2D6具有基因多态性,这是构成药物代谢个体差异和种族差异的基础,它主要参与心血管类、抗精神病类、镇痛药、以及一些抗癌药物等的代谢。研究 CYP2D6基因多态性与药物代谢个体差异的相关性,有助于减轻药物不良反应,提高治疗效果,实施个体化给药。

  13. Stimulus control by 5methoxy-N,N-dimethyltryptamine in wild-type and CYP2D6-humanized mice

    Science.gov (United States)

    Winter, J. C.; Amorosi, D. J.; Rice, Kenner C.; Cheng, Kejun; Yu, Ai-Ming

    2011-01-01

    In previous studies we have observed that, in comparison with wild type mice, Tg-CYP2D6 mice have increased serum levels of bufotenine [5-hydroxy-N,N-dimethyltryptamine] following the administration of 5-MeO-DMT. Furthermore, following the injection of 5-MeO-DMT, harmaline was observed to increase serum levels of bufotenine and 5-MeO-DMT in both wild-type and Tg-CYP2D6 mice. In the present investigation, 5-MeO-DMT-induced stimulus control was established in wild-type and Tg-CYP2D6 mice. The two groups did not differ in their rate of acquisition of stimulus control. When tested with bufotenine, no 5-MeO-DMT-appropriate responding was observed. In contrast, the more lipid soluble analog of bufotenine, acetylbufotenine, was followed by an intermediate level of responding. The combination of harmaline with 5-MeO-DMT yielded a statistically significant increase in 5-MeO-DMT-appropriate responding in Tg-CYP2D6 mice; a comparable increase occurred in wild-type mice. In addition, it was noted that harmaline alone was followed by a significant degree of 5-MeO-DMT-appropriate responding in Tg-CYP2D6 mice. It is concluded that wild-type and Tg-CYPD2D6 mice do not differ in terms of acquisition of stimulus control by 5-MeO-DMT or in their response to bufotenine and acetylbufotenine. In both groups of mice, harmaline was found to enhance the stimulus effects of 5-MeO-DMT. PMID:21624387

  14. Stimulus control by 5-methoxy-N,N-dimethyltryptamine in wild-type and CYP2D6-humanized mice.

    Science.gov (United States)

    Winter, J C; Amorosi, D J; Rice, Kenner C; Cheng, Kejun; Yu, Ai-Ming

    2011-09-01

    In previous studies we have observed that, in comparison with wild type mice, Tg-CYP2D6 mice have increased serum levels of bufotenine [5-hydroxy-N,N-dimethyltryptamine] following the administration of 5-MeO-DMT. Furthermore, following the injection of 5-MeO-DMT, harmaline was observed to increase serum levels of bufotenine and 5-MeO-DMT in both wild-type and Tg-CYP2D6 mice. In the present investigation, 5-MeO-DMT-induced stimulus control was established in wild-type and Tg-CYP2D6 mice. The two groups did not differ in their rate of acquisition of stimulus control. When tested with bufotenine, no 5-MeO-DMT-appropriate responding was observed. In contrast, the more lipid soluble analog of bufotenine, acetylbufotenine, was followed by an intermediate level of responding. The combination of harmaline with 5-MeO-DMT yielded a statistically significant increase in 5-MeO-DMT-appropriate responding in Tg-CYP2D6 mice; a comparable increase occurred in wild-type mice. In addition, it was noted that harmaline alone was followed by a significant degree of 5-MeO-DMT-appropriate responding in Tg-CYP2D6 mice. It is concluded that wild-type and Tg-CYPD2D6 mice do not differ in terms of acquisition of stimulus control by 5-MeO-DMT or in their response to bufotenine and acetylbufotenine. In both groups of mice, harmaline was found to enhance the stimulus effects of 5-MeO-DMT. PMID:21624387

  15. 厚朴提取物对大鼠CYP2D6亚型酶的影响%Influence of magnolia bark extract on CYP2D6 subtype enzyme in rats

    Institute of Scientific and Technical Information of China (English)

    于卫江; 张斌; 张文周

    2013-01-01

    目的 观察厚朴提取物对大鼠CYP2D6亚型酶的影响.方法 将16只成年雄性Wistar大鼠随机分为对照组和实验组,2组分别经口给予生理盐水和厚朴提取物1周,采用高效液相色谱法(HPLC)测定大鼠尿样及肝微粒体中CYP2D6的探针药物右美沙芬(DM)的代谢率,观察厚朴提取物对CYP2D6亚型酶活性的影响,并通过特异性抑制剂确定肝微粒体重组系统中厚朴提取物对CYP2D6亚型酶活性的影响.结果 实验组大鼠尿样及体外肝微粒体中DM代谢率均明显低于对照组,差异有统计学意义;厚朴提取物组肝微粒体中DM代谢率显著低于西咪替丁组和对照组,差异有统计学意义,而西咪替丁组和对照组比较,差异无统计学意义.结论 厚朴提取物可有效抑制CYP2D6亚型酶的活性,且抑制能力优于西咪替丁.

  16. CYP2D6和GST在白种人晚期肾病中的遗传变异%Genetic Variation of CYP2D6 and GST in Caucasian ESRD Patients

    Institute of Scientific and Technical Information of China (English)

    严奉祥; WedlundPJ; 等

    2002-01-01

    目的:生物转化酶细胞色素P4502D6(CYP2D6)和谷胱苷肽转移酶-M1(GST-M1)、谷胱苷肽转移酶-T1(GST-T1)共同代谢内源性和外源性毒素,一部分人群由于相应基因变异导致这些酶缺乏表达,我们检测白种人群中晚期肾病(ESRD)病人这些酶的基因多态性是否比健康者有较高的频率.方法:从列克星顿及周围地区征募330名晚期肾病病人和303名健康者,均为白种人,给予他们进行CYP2D6和GST-M1和T1基因分型.结果:在ESRD病人中CYP2D6和GST-M1和GST-T1以及CYP2D6和GST-M1或GST-T1都缺乏分别为2.1%和4.2%;而在健康者中均为0.3%(P<0.01).结论:CYP2D6和GST-M1和/或GST-T1酶缺乏在ESRD病人中有较高的频率,提示这些酶缺乏可以预计慢性肾病进展的可能性.

  17. Cost-effectiveness of Cyp2d6 genotyping in older depressed patients, starting with nortriptyline therapy

    NARCIS (Netherlands)

    Berm, E.J.; Gout-Zwart, J.J.; Luttjeboer, J.; Maring, J.G.; Wilffert, B.; Postma, M.J.

    2015-01-01

    Objectives: Genotyping for the cytochrome P450-2D6 has the potency to predict differences in metabolism of nortriptyline. This information could optimize treatment. We explored if possible benefits could outweigh genotyping costs for Dutch depressed patients in clinical psychiatry. Methods: First, a

  18. Risperidone-associated adverse drug reactions and CYP2D6 polymorphisms in a South African cohort

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    Tyren M. Dodgen

    2015-06-01

    Conclusion: CYP2D6 variation appeared not to be a good pharmacogenetic marker for predicting risperidone-related ADRs in this naturalistic South African cohort. Evaluation of a larger cohort would be needed to confirm these observations, including an examination of the role of potential intermediaries between the hypothesised genetic and clinical phenotypes.

  19. 宁夏回族人群CYP2D6*10基因多态性及功能分析%Analysis on polymorphism function of CYP2D6 * 10 in Ningxia Hui

    Institute of Scientific and Technical Information of China (English)

    李居怡; 王健; 高鹏; 杜娟; 李宗吉

    2010-01-01

    目的 探讨基因突变对人CYP2D6蛋白结构与功能的影响.方法 采用等位基因特异扩增(ASA-PCR)及DNA测序技术分析宁夏网族人群CYP2D6*10(C188T)基因多态性,以生物信息学方法对突变造成的肝药酶活性的下降做出合理的解释.结果 蛋白质基本性质分析工具(ProtParam)分析显示,在溶液中CYP2D6*10突变型蛋白的不稳定指数高于野生型,都高于阈值40;二级结构预测软件(DNAStar/Protean)分析显示,突变型蛋白的二级结构在第33位多了一个转角(Gamier-Robson Turn);功能佗点预测程序(Motif Scan)对蛋白功能位点进行预测,结果显示CYP2D6*10野生型蛋白有2个P450酶激活位点.而突变型没有;信号肽预测程序(Signal P)分析显示.神经网络模型(NN)C-score计算结果为突变型蛋白没有信号肽,而野牛型有.结论 基因突变可引起CYP2D6蛋白结构与功能的改变;应用生物信息学方法对CYP2D6基因突变致使的酶活性的下降做出一些可能的解释是可行的.

  20. 氧化苦参碱对大鼠CYP2D6酶的影响

    Institute of Scientific and Technical Information of China (English)

    张斌; 于卫江

    2008-01-01

    目的 通过氧化苦参碱的大鼠体内、外实验,观察氧化苦参碱对大鼠CYP2D6 亚型酶的影响.方法 HPLC法测定大鼠尿液及肝微粒体中探针药物右美沙芬(DM)、代谢物去甲右美沙芬(DT)的含量.对照组和氧化苦参碱组大鼠分别经口给予生理盐水和氧化苦参碱两周,HPLC法测定大鼠尿样及肝微粒体中CYP2D6的探针药物右美沙芬的代谢率,观察氧化苦参碱对CYP2D6活性的影响.并且通过特异性抑制剂确定在肝微粒体重组系统中氧化苦参碱对CYP2D6亚型的影响.结果 实验组大鼠给予氧化苦参碱(100mg/kg),其尿样中右美沙芬的代谢率与对照组相比没有明显差别(P>0.05);实验组大鼠肝微粒体中加入右美沙芬(0.324mmol/L),其右美沙芬的代谢率与对照组相比没有明显差别(P>0.05);氧化苦参碱没有明显降低右美沙芬的代谢率(P>0.05),而CYP2D6特异性抑制剂西米替丁却明显降低右美沙芬的代谢率(P<0.01).结论 氧化苦参碱对CYP2D6酶无明显影响.

  1. Effect of CYP2D6*10 genotype on propafenone pharmacodynamics in Chinese patients with ventricular arrhythmia%CYP2D6*10基因型对中国室性心律失常病人普罗帕酮药效学的影响

    Institute of Scientific and Technical Information of China (English)

    蔡卫民; 徐军; 陈冰; 张馥敏; 黄元铸; 张银娣

    2002-01-01

    important role in plasma levelsand effects of propafenone. In 450 mg/d group, patients with homozygous mutant of CYP2D6* 10 not only had aCmax of propafenone two times as high as those of wild-type genotype, but also showed a two fold higher inhibitoryrate of VPC compared with those with homozygous CYP2D6* 1 (P<0.05). CONCLUSION: CYP2D6* 10 geno-type is relevant to decreased activity of CYP2D6 enzyme in Chinese patients. Elevated plasma concentration isconsistent with better efficacy of propafenone in patients with ventricular arrhythmia.

  2. 细胞色素氧化酶CYP2D6的研究进展

    Institute of Scientific and Technical Information of China (English)

    张泓波; 李宝群; 王瑞婷; 梅爱敏

    2005-01-01

    细胞色素氧化酶CYP450是药物代谢中的一个重要酶系。近年来,对CYP450与药物代谢多态性的关系进行了诸多方面的研究。现已明确CYP2C9、CYP2C19、CYP2D6在表型和基因型水平上均存在遗传多态性,且对其分子机制有了较为深入的了解;而CYPlA2等其他酶可能存在多态性,但各人群研究结果不甚一致。本文着重综述CYP2D6的研究进展情况。

  3. Association of CYP2D6 and CYP1A2 gene polymorphism with tardive dyskinesia in Chinese schizophrenic patients

    Institute of Scientific and Technical Information of China (English)

    Yan FU; Chang-he FAN; He-huang DENG; San-hong HU; De-peng LV; Li-hua LI; Jun-jie WANG; Xin-qiao LU

    2006-01-01

    Aim:To investigate the possible association of the CYP2D6 gene C100T polymorphism and the CYP1A2 gene C163A polymorphism with tardive dyskinesia (TD) in Chinese patients with schizophrenia.Methods:The recruited schizophrenic patients were assessed with the Abnormal Involuntary Movement Scale (AIMS),and divided into groups with TD(n=91)and without TD(n=91)according to the AIMS score.Polymorphisms of the CYP2D6 and CYP1A2 genes were determined by polymerase chain reaction(PER)-restriction fragment length polymorphism(RFLP).Results:No allele frequencies deviated from Hardy-Weinberg equilibrium.No significant differences in genotypes frequencies of the CYP2D C100T polymorphism were observed between patients with TD and without TD (x2=4.078,P>0.05),but patients with TD had a significant excess of the T allele compared with those without TD(x2=4.28,P<0.05).Moreover,the frequency of the CYP1A2 C allele in patients with TD was significantly higher than that in those without TD(x2=6.38,P<0.05).An association between TD and the CyP2D6 100T and CYP1A2 163C alleles was observed.Additionally,there were no differences in the mean AIMS scores among different genotypes in TD patients as a group or in smokers.The results of logistic regression anatysls demonstrated that mean age and duration of illness were risk factors for TD,but not sex,cumulative exposure to neuroleptic drugs in years,CYP2D6 or CYP1A2 genotype.Conclusion:The C100T polymorphism of the CYP2D6 gene and the C163A polymorphism of the CYP1A2 gene may be associated with neuroleptic drug-induced tardive dyskinesia in Chinese patients with schizophrenia.However,genetic factors have a weaker association with susceptibility to TD compared with mean age and duration of illness.

  4. Impact of Cytochrome P450 2D6 Function on the Chiral Blood Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine (MDMA and Its Phase I and II Metabolites in Humans.

    Directory of Open Access Journals (Sweden)

    Andrea E Steuer

    Full Text Available 3,4-methylenedioxymethamphetamine (MDMA; ecstasy metabolism is known to be stereoselective, with preference for S-stereoisomers. Its major metabolic step involves CYP2D6-catalyzed demethylenation to 3,4-dihydroxymethamphetamine (DHMA, followed by methylation and conjugation. Alterations in CYP2D6 genotype and/or phenotype have been associated with higher toxicity. Therefore, the impact of CYP2D6 function on the plasma pharmacokinetics of MDMA and its phase I and II metabolites was tested by comparing extensive metabolizers (EMs, intermediate metabolizers (IMs, and EMs that were pretreated with bupropion as a metabolic inhibitor in a controlled MDMA administration study. Blood plasma samples were collected from 16 healthy participants (13 EMs and three IMs up to 24 h after MDMA administration in a double-blind, placebo-controlled, four-period, cross-over design, with subjects receiving 1 week placebo or bupropion pretreatment followed by a single placebo or MDMA (125 mg dose. Bupropion pretreatment increased the maximum plasma concentration (Cmax and area under the plasma concentration-time curve from 0 to 24 h (AUC24 of R-MDMA (9% and 25%, respectively and S-MDMA (16% and 38%, respectively. Bupropion reduced the Cmax and AUC24 of the CYP2D6-dependently formed metabolite stereoisomers of DHMA 3-sulfate, DHMA 4-sulfate, and 4-hydroxy-3-methoxymethamphetamine (HMMA sulfate and HMMA glucuronide by approximately 40%. The changes that were observed in IMs were generally comparable to bupropion-pretreated EMs. Although changes in stereoselectivity based on CYP2D6 activity were observed, these likely have low clinical relevance. Bupropion and hydroxybupropion stereoisomer pharmacokinetics were unaltered by MDMA co-administration. The present data might aid further interpretations of toxicity based on CYP2D6-dependent MDMA metabolism.

  5. Impact of Cytochrome P450 2D6 Function on the Chiral Blood Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine (MDMA) and Its Phase I and II Metabolites in Humans.

    Science.gov (United States)

    Steuer, Andrea E; Schmidhauser, Corina; Tingelhoff, Eva H; Schmid, Yasmin; Rickli, Anna; Kraemer, Thomas; Liechti, Matthias E

    2016-01-01

    3,4-methylenedioxymethamphetamine (MDMA; ecstasy) metabolism is known to be stereoselective, with preference for S-stereoisomers. Its major metabolic step involves CYP2D6-catalyzed demethylenation to 3,4-dihydroxymethamphetamine (DHMA), followed by methylation and conjugation. Alterations in CYP2D6 genotype and/or phenotype have been associated with higher toxicity. Therefore, the impact of CYP2D6 function on the plasma pharmacokinetics of MDMA and its phase I and II metabolites was tested by comparing extensive metabolizers (EMs), intermediate metabolizers (IMs), and EMs that were pretreated with bupropion as a metabolic inhibitor in a controlled MDMA administration study. Blood plasma samples were collected from 16 healthy participants (13 EMs and three IMs) up to 24 h after MDMA administration in a double-blind, placebo-controlled, four-period, cross-over design, with subjects receiving 1 week placebo or bupropion pretreatment followed by a single placebo or MDMA (125 mg) dose. Bupropion pretreatment increased the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from 0 to 24 h (AUC24) of R-MDMA (9% and 25%, respectively) and S-MDMA (16% and 38%, respectively). Bupropion reduced the Cmax and AUC24 of the CYP2D6-dependently formed metabolite stereoisomers of DHMA 3-sulfate, DHMA 4-sulfate, and 4-hydroxy-3-methoxymethamphetamine (HMMA sulfate and HMMA glucuronide) by approximately 40%. The changes that were observed in IMs were generally comparable to bupropion-pretreated EMs. Although changes in stereoselectivity based on CYP2D6 activity were observed, these likely have low clinical relevance. Bupropion and hydroxybupropion stereoisomer pharmacokinetics were unaltered by MDMA co-administration. The present data might aid further interpretations of toxicity based on CYP2D6-dependent MDMA metabolism. PMID:26967321

  6. Rough Set Theory as an Interpretable Method for Predicting the Inhibition of Cytochrome P450 1A2 and 2D6.

    Science.gov (United States)

    Burton, Julien; Petit, Joachim; Danloy, Emeric; Maggiora, Gerald M; Vercauteren, Daniel P

    2013-07-01

    Early prediction of ADME properties such as the cytochrome P450 (CYP) mediated drug-drug interactions is an important challenge in the drug discovery area. In this study, we propose to couple an original data mining approach based on Rough Set Theory (RST) to a structural description of molecules. The latter was achieved by using two types of structural keys: (1) the MACCS keys and (2) a set of five in-house fingerprints based on properties of the electron density distributions of chemical groups. The compounds considered are involved in the inhibition of CYP1A2 and CYP2D6. RST allowed the extraction of rules further used as classifiers to predict the inhibitory profile of an independent set of molecules. The results reached prediction accuracies of 90.6 and 88.2 % for CYP1A2 and CYP2D6, respectively. In addition, these classifiers were analyzed to determine which structural fragments were most used for building the rules, revealing relationships between the occurrence of particular molecular fragments and CYP inhibition. The results assessed RST as a suitable tool to build strongly predictive models and infer structure-activity rules associated with potency.

  7. Polymorphisms in the genes of citohrom oxidase P450 2D6 (CYP2D6, paraoxonase 1 (PON1 and apolipoproteine E (APOE as risk factors for Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Đurić Gordana

    2007-01-01

    Full Text Available Background/Aim. The presence of Parkinson's disease (PD among the members of a family is a clear indication of the significance of genetics in its development. In spite of that, the majority of patients with PD shows a sporadic form of the disease induced as a result of interaction of both environmental and genetic factors. The aim of this study was to examine the effects of polymorphisms in the genes of cytohrome P450 2D6(CYP2D6, paraoxonase 1 (PON 1 and apolipoprotein E (APOE, as risk factors for PD. Methods. We examined 106 patients with PD (65 men and 41 women and 75 ethnically matched control subjects. The mean age at onset of PD in the patients was 46.9±9.4 years (ranging from 30 to 70 years. Genotyping was performed using standard PCR amplification and restriction endonuclease digestion protocols described for known polymorphism in the candidate genes under study. Results. The genotype A/A polymorphisms 2D6* gene of CYP2D6 and genotype M/M polymorphisms L54M gene of PON1 were significantly more frequent in the patients with PD than in the control group. The patients with genotypes A/A and M/M had 3.4 and 3.2 higher risk of PD, respectively than the control group (p = 0.01. The relation between genotypes A/A gene of CYP2D6 and M/M gene of PON1 was modified by the age at onset. The genotypes were associated with early onset of PD (p = 0.001, p = 0.004. The carriers of the A and M alleles in homozygote had 2.4 and 4.2 years respectively earlier onset of PD than carriers of other genotypes with these polymorphisms. The frequency allele ε4 gene of APOE was higher in the PD patients with early onset (20% than in PD with later onset (7.4%, while the genotype ε3/ε3 was associated with PD late onset (p = 0.024. Combined genotype I (carriers of the two risk allels in homozygote and one alleles risk in heterozygote and combined genotype II (carriers of the three alleles risk in homozygote caused early PD. Combined genotype II was detected in 12

  8. Genotypes for the cytochrome P450 enzymes CYP2D6 and CYP2C19 in human longevitY

    DEFF Research Database (Denmark)

    Bathum, L; Andersen-Ranberg, K; Boldsen, J;

    1998-01-01

    OBJECTIVE: To test whether some genotypes for CYP2D6 or CYP2C19 could contribute to longevity, we genotyped 241 Danish nonagenarians and centenarians for CYP2D6 and CYP2C19. METHODS: For CYP2D6 we identified the alleles CYP2D6*1, CYP2D6*3 and CYP2D6*4 with allele-specific polymerase chain reaction...... (PCR). The CYP2D6*5 alleles were identified with a long PCR method. For CYP2C19 we identified the alleles CYP2C19*1, CYP2C19*2 and CYP2C19*3 with an oligonucleotide ligation assay. RESULTS: The four alleles for CYP2D6 did not occur in Hardy-Weinberg proportions. The frequency of poor metabolism was...... slightly higher (10.2%) than expected [7.7%; odds ratio (OR) = 1.36 (0.75-2.40)]. The genotypes for CYP2C19 occur in Hardy-Weinberg proportions. The frequency of poor metabolism (3.8%) was not significantly different from a young control group [3.1%; OR = 1.21 (0.26-5.75)]. CONCLUSION: CYP2D6 could play a...

  9. Substrate-induced DNA polymerase β activation.

    Science.gov (United States)

    Beard, William A; Shock, David D; Batra, Vinod K; Prasad, Rajendra; Wilson, Samuel H

    2014-11-01

    DNA polymerases and substrates undergo conformational changes upon forming protein-ligand complexes. These conformational adjustments can hasten or deter DNA synthesis and influence substrate discrimination. From structural comparison of binary DNA and ternary DNA-dNTP complexes of DNA polymerase β, several side chains have been implicated in facilitating formation of an active ternary complex poised for chemistry. Site-directed mutagenesis of these highly conserved residues (Asp-192, Arg-258, Phe-272, Glu-295, and Tyr-296) and kinetic characterization provides insight into the role these residues play during correct and incorrect insertion as well as their role in conformational activation. The catalytic efficiencies for correct nucleotide insertion for alanine mutants were wild type ∼ R258A > F272A ∼ Y296A > E295A > D192A. Because the efficiencies for incorrect insertion were affected to about the same extent for each mutant, the effects on fidelity were modest (chain generates a population of non-productive ternary complexes. Structures of binary and ternary substrate complexes of the R258A mutant and a mutant associated with gastric carcinomas, E295K, provide molecular insight into intermediate structural conformations not appreciated previously. Although the R258A mutant crystal structures were similar to wild-type enzyme, the open ternary complex structure of E295K indicates that Arg-258 stabilizes a non-productive conformation of the primer terminus that would decrease catalysis. Significantly, the open E295K ternary complex binds two metal ions indicating that metal binding cannot overcome the modified interactions that have interrupted the closure of the N-subdomain. PMID:25261471

  10. Effects of β1-adrenergic receptor and CYP2D6 genetic polymorphism on metoprolol pharmacokinetics and pharmacodynamics in antihypertension therapy%β1肾上腺素受体与CYP2D6基因多态性对美托洛尔抗高血压治疗的药代动力学和药效学影响

    Institute of Scientific and Technical Information of China (English)

    刘洁; 刘昭前; 刘英姿; 谭志荣; 胡冬莉; 李智; 王丹; 张伟; 周宏灏

    2007-01-01

    BACKGROUND: Metoprolol is a selective β1-Blocker commonly used in essential hypertension. It is metabolized by CYP2D6. CYP2D6*10, which was identified to decrease activity of CYP2D6, is the main variance in Chinese population. β1-adrenergic receptor, with Ser49Gly and Gly389Arg polymorphisms, is the target of metoprolol. It was still unknown that whether the CYP2D6 and β1-adrenergic receptor had a synergic effect on metoprolol antihypertension therapy. AIM: To clarify the genetic polymorphism associated with metoprolol pharmacokinetics and pharmacodynamics in antihypertension therapy. METHODS: 125 mild-to-med essential hypertension patients were enrolled in this study. Patients were mono-therapied with metoprolol for 12 weeks. Blood pressure was monitored every 4 weeks. PCR-RFLP method was use to identify CYP2D6*10 and β1-adrenergic receptor Ser49Gly and Gly389Arg polymorphisms. Plasma metoprolol concentration was measured by HPLC- fluorescence detection. RESULTS: Trough blood level (C0) of metoprolol was associated with CYP2D6*10 variance in a gene-dose-effect manner, whereas the extent of blood pressure decrease was not significant different in CYP2D6*1*1, *1*10 and CYP2D6*10*10 patients. After 12 weeks metoprolol therapy, Gly49 carriers had stronger decrease in systolic and diastolic blood pressure than that of Ser49 homozygotes. Similarly, subjects homozygous for Arg389 had stronger decrease in blood pressure than that of Gly389 carriers. CONCLUSION: CYP2D6*10 variance significantly change the pharmacokinetics of metoprolol, and the genetic polymorphisms of β1-adrenergic receptor were associated with the pharmacodynamics of metopolol in antihypertension therapy.%背景: 美托洛尔是临床常用的抗高血压药物,它经由CYP2D6代谢.CYP2D6*10降低CYP2D6活性,是中国人群中最为常见的多态性.β1肾上腺素受体为美托洛尔的作用靶标,Ser49Gly与Gly389Arg多态性显著改变受体功能.CYP2D6与β1肾上腺素受体遗传多态

  11. Utility and adoption of CYP2D6 and CYP2C19 genotyping and its translation into psychiatric clinical practice

    DEFF Research Database (Denmark)

    Jürgens, G; Jacobsen, C B; Rasmussen, H B;

    2012-01-01

    To describe clinical utility and adoption of routinely offered CYP2D6 and CYP2C19 genotyping (CYP test) in daily clinical practice of a psychiatric centre.......To describe clinical utility and adoption of routinely offered CYP2D6 and CYP2C19 genotyping (CYP test) in daily clinical practice of a psychiatric centre....

  12. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satyender [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Kumar, Vivek [Environmental Biochemistry and Molecular Biology laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Dilshad Garden, Delhi-110095 (India); Vashisht, Kapil; Singh, Priyanka [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Banerjee, Basu Dev, E-mail: banerjeebd@hotmail.com [Environmental Biochemistry and Molecular Biology laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Dilshad Garden, Delhi-110095 (India); Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Jain, Sudhir Kumar [Centre for Epidemiology and Parasitic Diseases, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Rai, Arvind [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India)

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p < 0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37 {+-} 2.15 vs. 6.24 {+-} 1.37 tail% DNA, p < 0.001). Further, the workers with CYP2D6*3 PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p < 0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. -- Highlights: Black-Right-Pointing-Pointer Role of CYP1A1, CYP3A5, CYP2C, CYP2D6 and PON1 genotypes on DNA damage. Black-Right-Pointing-Pointer Workers exposed to some OPs demonstrated increased DNA damage. Black-Right-Pointing-Pointer CYP2D6 *3 PM and PON1 (Q192R and L55M) genotypes are associated with DNA damage. Black-Right-Pointing-Pointer Concomitant presence of certain CYP2D6 and PON1 genotypes can increase DNA damage.

  13. Identifying a selective substrate and inhibitor pair for the evaluation of CYP2J2 activity.

    Science.gov (United States)

    Lee, Caroline A; Jones, J P; Katayama, Jonathan; Kaspera, Rüdiger; Jiang, Ying; Freiwald, Sascha; Smith, Evan; Walker, Gregory S; Totah, Rheem A

    2012-05-01

    CYP2J2, an arachidonic acid epoxygenase, is recognized for its role in the first-pass metabolism of astemizole and ebastine. To fully assess the role of CYP2J2 in drug metabolism, a selective substrate and potent specific chemical inhibitor are essential. In this study, we report amiodarone 4-hydoxylation as a specific CYP2J2-catalyzed reaction with no CYP3A4, or other drug-metabolizing enzyme, involvement. Amiodarone 4-hydroxylation enabled the determination of liver relative activity factor and intersystem extrapolation factor for CYP2J2. Amiodarone 4-hydroxylation correlated with astemizole O-demethylation but not with CYP2J2 protein content in a sample of human liver microsomes. To identify a specific CYP2J2 inhibitor, 138 drugs were screened using terfenadine and astemizole as probe substrates with recombinant CYP2J2. Forty-two drugs inhibited CYP2J2 activity by ≥50% at 30 μM, but inhibition was substrate-dependent. Of these, danazol was a potent inhibitor of both hydroxylation of terfenadine (IC(50) = 77 nM) and O-demethylation of astemizole (K(i) = 20 nM), and inhibition was mostly competitive. Danazol inhibited CYP2C9, CYP2C8, and CYP2D6 with IC(50) values of 1.44, 1.95, and 2.74 μM, respectively. Amiodarone or astemizole were included in a seven-probe cocktail for cytochrome P450 (P450) drug-interaction screening potential, and astemizole demonstrated a better profile because it did not appreciably interact with other P450 probes. Thus, danazol, amiodarone, and astemizole will facilitate the ability to determine the metabolic role of CYP2J2 in hepatic and extrahepatic tissues. PMID:22328583

  14. Mutation frequencies of the cytochrome CYP2D6 gene in Parkinson disease patients and in families

    Energy Technology Data Exchange (ETDEWEB)

    Lucotte, G.; Turpin, J.C. [CHR, Reims (France); Gerard, N. [INSERM, Paris (France)] [and others

    1996-07-26

    The frequencies of five mutations of the debrisoquine 4-hydroxylase (CYP2D6) gene (mutations D6-A, B, C, D, and T), corresponding to poor metabolizer (PM) phenotypes, were determined by restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) in 47 patients with Parkinson disease, and compared with the findings in 47 healthy controls. These mutant alleles were about twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.12 (95% confidence interval, 1.41-2.62). There seem to be no significant differences in frequencies of mutant genotypes in patients among gender and modalities of response with levodopa therapy; but frequency of the mutations was slightly enhanced after age-at-onset of 60 years. Mutations D6-B, D, and T were detected in 7 patients belonging to 10 Parkinson pedigrees. 25 refs., 1 fig., 2 tabs.

  15. CYP2D6 genotype predicts antipsychotic side effects in schizophrenia inpatients: a retrospective matched case-control study

    DEFF Research Database (Denmark)

    Kobylecki, Camilla J; Jakobsen, Klaus D; Hansen, Thomas;

    2009-01-01

    -state plasma concentrations at a given dose, thus increasing the risk of toxic effects from medication. METHODS: We identified 18 PM patients with a schizophrenia spectrum diagnosis from a clinical database covering all patients who have been analyzed in an ongoing standardized CYP2D6 screening program. Each...... PM patient was carefully matched on age, gender and diagnosis with an intermediate metabolizer (IM) and an extensive metabolizer (EM) from the same database to generate 18 triplets. Clinical data, primarily on side effects of treatment, were obtained from medical records by an experienced research...... and consultant psychiatrist, who was blinded to the results of the genotyping. RESULTS: We found that extrapyramidal syndrome or tardive dyskinesia (EPS/TD) was significantly more frequent among PM patients than among the matched IM and EM control subjects. This finding was further supported by the significantly...

  16. No influence of the polymorphisms CYP2C19 and CYP2D6 on the efficacy of cyclophosphamide, thalidomide, and bortezomib in patients with Multiple Myeloma

    DEFF Research Database (Denmark)

    Vangsted, A. J.; Soeby, K.; Klausen, T.W.;

    2010-01-01

    patients were genotyped for the non-functional alleles CYP2C19*2 and CYP2D6*3, *4, *5 (gene deletion), *6, and CYP2D6 gene duplication. Results: In patients who were treated with bortezomib and were carriers of one or two defective CYP2D6 alleles there was a trend towards a better time-to-next treatment....... We found no association between the number of functional CYP2C19 and CYP2D6 alleles and outcome of treatment with cyclophosphamide or thalidomide. Neither was the number of functional CYP2C19 and CYP2D6 alleles associated with neurological adverse reactions to thalidomide and bortezomib. Conclusion......: There was no association between functional CYP2C19 and CYP2D6 alleles and treatment outcome in multiple myeloma patients treated with cyclophosphamide, thalidomide or bortezomib. A larger number of patients treated with bortezomib are needed to determine the role of CYP2D6 alleles in treatment outcome....

  17. No influence of the polymorphisms CYP2C19 and CYP2D6 on the efficacy of cyclophosphamide, thalidomide, and bortezomib in patients with Multiple Myeloma

    International Nuclear Information System (INIS)

    The response to treatment varies among patients with multiple myeloma and markers for prediction of treatment outcome are highly needed. Bioactivation of cyclophosphamide and thalidomide, and biodegradation of bortezomib, is dependent on cytochrome P450 metabolism. We explored the potential influence of different polymorphisms in the CYP enzymes on the outcome of treatment. Data was analyzed from 348 patients undergoing high-dose treatment and stem cell support in Denmark in 1994 to 2004. Clinical information on relapse treatment in 243 individual patients was collected. The patients were genotyped for the non-functional alleles CYP2C19*2 and CYP2D6*3, *4, *5 (gene deletion), *6, and CYP2D6 gene duplication. In patients who were treated with bortezomib and were carriers of one or two defective CYP2D6 alleles there was a trend towards a better time-to-next treatment. We found no association between the number of functional CYP2C19 and CYP2D6 alleles and outcome of treatment with cyclophosphamide or thalidomide. Neither was the number of functional CYP2C19 and CYP2D6 alleles associated with neurological adverse reactions to thalidomide and bortezomib. There was no association between functional CYP2C19 and CYP2D6 alleles and treatment outcome in multiple myeloma patients treated with cyclophosphamide, thalidomide or bortezomib. A larger number of patients treated with bortezomib are needed to determine the role of CYP2D6 alleles in treatment outcome

  18. 基于CYP2D6代谢性相互作用的儿童用药安全提示

    Institute of Scientific and Technical Information of China (English)

    李娟; 李毅; 郭兴蕾

    2015-01-01

    CYP2D6是一种重要的药物代谢酶,研究基于CYP2D6的代谢性相互作用具有重要的临床意义.本文综述了关于儿科常用的各类有关于CYP2D6的药物可能产生的代谢性相互作用,旨在为临床医生合理用药提供参考.

  19. Correlation between CYP2D6 * 10 gene polymorphism and prognosis of breast cancer patients treated with tamoxifen%CYP2D6*10基因多态性与服用他莫昔芬乳腺癌患者预后的相关性

    Institute of Scientific and Technical Information of China (English)

    田超; 杨义; 李卉

    2013-01-01

    目的 探讨CYP2D6 * 10基因多态性与服用他莫昔芬(TAM)乳腺癌患者预后的相关性.方法 收集四川省肿瘤医院2008年1月至2010年10月期间200例服用TAM的乳腺癌患者的口腔黏膜,采用实时RT-PCR法检测CYP2D6 * 10基因多态性,并分为CYP2D6突变组(CYP2D6 * 10/ * 10)和CYP2D6正常组(CYP2D6 wt/ * 10和CYP2D6 wt/wt).采用卡方检验及秩和检验分析CYP2D6 * 10基因多态性与临床病理特征的关系,采用Cox比例风险回归模型分析其与预后的关系.结果 在200例乳腺癌中,CYP2D6 * 10/ * 10纯合子94例(47%),CYP2D6 wt/wt野生型48例(24%),CYP2D6 wt/ * 10杂合型58例(29%).CYP2D6 * 10基因多态性与患者的组织学分级、TNM分期、HER-2表达、肿瘤类型无关(Z=-0.444,P=0.674;Z=-0.716,P=0.500;χ2=0.066,P=0.797;χ2=0.694,P=0.405).Log-rank检验分析显示CYP2D6 * 10突变组患者平均无瘤生存时间明显短于CYP2D6 * 10正常组患者(47.2个月比51.2个月,χ2=5.554,P=0.018).Cox比例风险回归模型显示,CYP2D6 * 10基因型与患者无瘤生存时间明显相关(HR=2.755,95%CI:1.230~6.173,P=0.014).结论 CYP2D6 * 10/ * 10基因型乳腺癌患者服用他莫昔芬预后较差.

  20. CYP2D6基因多态性对帕罗西汀在中国健康人药动学影响%Influence of CYP2D6 genetic polymorphism on pharmacokinetics of paroxetine in Chinese healthy people

    Institute of Scientific and Technical Information of China (English)

    王蒙; 周文佳; 肖莉; 张全英

    2012-01-01

    AIM To investigate the influence of CYP2D6 genetic polymorphism on pharmacokinetics of paroxetine in Chinese healthy people. METHODS Twenty-three Chinese volunteers genotyped for CYP2D6 were separated into three groups by PCR-RFLP: CYP2D6*1/*1 group (rc = 5), CYP2D6*l/*10 group (n = 7), and CYP2D6*10/*10 group ( n - 11). After administration of a single oral dose of paroxetine hydrochloride tablet 20 mg, blood samples were collected at various time points until 96 h. The plasma concentrations of paroxetine were measured by LC-MS/MS method and the pharmacokinetics disposition of them was analyzed. RESULTS Compared with CYP2D6*1/*1 group, the tmax and t1/2l in CYP2D6*l/*10 group and tmax in CYP2D6*10/*10 group had no significant differences (P>0.05); ρmax, AUC0-96h, AUC0_∞ CL (F) and Vd of paroxetine in CYP2D6*l/*10 group and CYP2D6*10/*10 group, and t1/2 in CYP2D6*10/*10 group all had significant differences (P < 0.05 and P < 0.01). CONCLUSION The allelic gene mutations of CYP2D6*10 can cause the changes of metabolic phenotype and have effects on the metabolism of paroxetine in healthy human body.%目的 研究中国健康人CYP2D6基因多态性对帕罗西汀药动学的影响.方法 使用PCR-RFLP方法将23位志愿者分为3组:CYP2D6*1/*1组(n=5),CYP2D6* 1/* 10组(n=7),CY P2D6*10/*10组(n=11).给予帕罗西汀20 mg单剂量口服,收集给药后96 h内的一系列血样,用LC-MS/MS法测定帕罗西汀的血药浓度并做药动学分析.结果 与CYP2D6*1/*1组药动学参数相比,CYP2D6*1/*10组tmax、t1/2和CYP2D6* 10/* 10组tmax无显著差异(P>0.05);CYP2D6*1/*10、CY P2D6*1 0/*10组的ρmax、AUC0-96h、AUC0-x、CL (F)、Vd和CYP2D6*10/*10组t1/2均有显著差异(P<0.05或P<0.01).结论 CY P2D6*1D等位基因突变能引起代谢表型的改变,影响帕罗西汀在健康人的体内代谢.

  1. No influence of the polymorphisms CYP2C19 and CYP2D6 on the efficacy of cyclophosphamide, thalidomide, and bortezomib in patients with Multiple Myeloma

    DEFF Research Database (Denmark)

    Vangsted, A. J.; Soeby, K.; Klausen, T.W.;

    2010-01-01

    Background: The response to treatment varies among patients with multiple myeloma and markers for prediction of treatment outcome are highly needed. Bioactivation of cyclophosphamide and thalidomide, and biodegradation of bortezomib, is dependent on cytochrome P450 metabolism. We explored....... We found no association between the number of functional CYP2C19 and CYP2D6 alleles and outcome of treatment with cyclophosphamide or thalidomide. Neither was the number of functional CYP2C19 and CYP2D6 alleles associated with neurological adverse reactions to thalidomide and bortezomib. Conclusion......: There was no association between functional CYP2C19 and CYP2D6 alleles and treatment outcome in multiple myeloma patients treated with cyclophosphamide, thalidomide or bortezomib. A larger number of patients treated with bortezomib are needed to determine the role of CYP2D6 alleles in treatment outcome....

  2. 中国人群细胞色素P4502D6基因多态性对曲马多药代动力学的影响%Influence of CYP2D6 genetic polymorphism on pharmacokinetics of tramadol in Chinese population

    Institute of Scientific and Technical Information of China (English)

    李芹; 王睿; 郭雅; 裴斐

    2009-01-01

    目的 研究中国人群CYP2D6基因多态性对曲马多(镇痛药)药代动力学的影响.方法 不同基因型中国健康志愿者随机分为4组:第1组CYP2D6*2W*10W,第2组:CYP2D6*2M*10W,第3组:CYP2D6*2M*10H,第4组:CYP2D6*2M*10M.各组单次口服曲马多100 mg后,用高效液相色荧光检测法测定血和尿中曲马多及其M1代谢产物O-去甲基曲马多(M1)的浓度,研究不同基因型对曲马多药代动力学的影响.结果 第2组曲马多及其M1的主要药代动力学参数与第1组相比没有显著性差异;第3组与第1组、第4组与第1组、第4组与第3组比较,主要药代动力学参数均有显著性差异(P<0.05),且呈基因剂量效应.结论 CYP2D6*2对于曲马多的药代动力学过程没有影响;但CYP2D6*10可降低酶活性,且CYP2D6*10纯合子变异较杂合子变异对曲马多药代动力学的影响更大,呈基因剂量效应.%Objective To investigate on influence of CYP2D6 genetic polymorphism on pharmacokinetics of tramadol in Chinese volunteers.Methods Adult healthy Chinese volunteers with different CYP2D6 genotypes were categorized into the following four groups: group 1:CYP2D6 * 2W * 10W, group 2:CYP2D6 * 2M * 10W, group 3:CYP2D6 * 2M * 10H, group 4 : CYP2D6 * 2M * 10M. After oral ad-ministration of 100 mg tramadol, plasma and urine samples were col-lected from each subject at different time within 32 h. The plasma and urine concentrations of tramadol and its metabolite O - desmethyltramad-ol (M1) were determined by HPLC with fluorescence detection. Re-suits The main pharmacokinetic parameters of tramadol and M, in group 2 were not significantly different from those in group 1. There are significant difference for the main pharmacokinetic parameters of tram-adol and M1 between group 3 and group 1, group 4 and group 1, group 4 and group 3, respectively (P<0.05 ). Conclusion The present re-sults shown that CYP2D6 * 2 has no influence on the pharmacokinetics of tramadol, but CYP2D6 * 10 reduces CYP2

  3. Comparison of CYP2D6 genotyping by allele-specific PCR with DXT phe-notype and gene chip testing%CYP2D6 PCR基因型与DXT表型和基因芯片检测的比较

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    目的:为了评价CYP2D6的基因型和表型的联系以及基因芯片在CYP2D6多基因分析中的应用.方法:242健康志愿者,口服dextromethorphan后收集尿液测定其代谢率,收集20ml血提取DNA,并通过基因特异性PCR和/(或)基因芯片分析CYP2D6*2--*11,*17和多拷贝CYP2D6基因,其中5个基因(*3、*4、*6、*7和*9)用PCR和CYD450基因芯片同时分析.结果:CYP2D6基因型比表型更富有信息和更能反映CYP2D6酶的表达.CYP2D6*3、*4、*6、*7和*9的基因检测在CYP450基因芯片和基因特异性PCR中显示高度的一致性.结论:基因芯片在检测基因多位点的多基因中是一个有发展前途和可靠的方法.%To evaluate association of genotype and phenotype of CYP2D6 and the application of oligonucleotide microarray hybridization genetic testing in CYP2D6 multiple alleles analyses. METHODS: Two hundred forty-two healthy volunteers were recruited, and a 60 mg oral dose of dextromethorphan (DXT) was administered to each for assessment of the DXT metabolic ratio [ MR]. A 20 ml blood sample was also collected for DNA isolation and testing. CYP2D6 alleles * 2-*11; * 17 and multiple CYP2D6 gene copies were tested by allele-specific PCR and/or the affymetrix CYP450 gene chip assay. Five of the CYP2D6 alleles ( * 3, * 4, *6, * 7, and * 9) were evaluated by both PCR and the CYP450 gene chip assay. RESULTS: The CYP2D6genotype was more informative and reflective in CYP2D6 enzyme expression than a phenotype. Genetic tests for the CYP2D6 * 3, * 4, * 6, * 7 and * 9 alleles showed a high degree of concordance between the CYP450 gene chip and AS-PCR methods. CONCLUSION: Oligonucleotide microarray hybridization is a promising and reliable approach for detecting multiple alleles at gene loci.

  4. Influence of the CYP2D6 isoenzyme in patients treated with venlafaxine for major depressive disorder: clinical and economic consequences.

    Directory of Open Access Journals (Sweden)

    Antoni Sicras-Mainar

    Full Text Available Antidepressant drugs are the mainstay of drug therapy for sustained remission of symptoms. However, the clinical results are not encouraging. This lack of response could be due, among other causes, to factors that alter the metabolism of the antidepressant drug.to evaluate the impact of concomitant administration of CYP2D6 inhibitors or substrates on the efficacy, tolerability and costs of patients treated with venlafaxine for major depressive disorder in clinical practice.We designed an observational study using the medical records of outpatients. Subjects aged ≥ 18 years who started taking venlafaxine during 2008-2010 were included. Three study groups were considered: no combinations (reference, venlafaxine-substrate, and venlafaxine-inhibitor. The follow-up period was 12 months. The main variables were: demographic data, comorbidity, remission (Hamilton <7, response to treatment, adverse events and costs. The statistical analysis included logistic regression models and ANCOVA, with p values <0.05 considered significant.A total of 1,115 subjects were recruited. The mean age was 61.7 years and 75.1% were female. Approximately 33.3% (95% CI: 30.5 to 36.1 were receiving some kind of drug combination (venlafaxine-substrate: 23.0%, and venlafaxine-inhibitor: 10.3%. Compared with the venlafaxine-substrate and venlafaxine-inhibitor groups, patients not taking concomitant drugs had a better response to therapy (49.1% vs. 39.9% and 34.3%, p<0.01, greater remission of symptoms (59.9% vs. 50.2% and 43.8%, p<0.001, fewer adverse events (1.9% vs. 7.0% and 6.1%, p<0.05 and a lower mean adjusted cost (€2,881.7 vs. €4,963.3 and €7,389.1, p<0.001, respectively. All cost components showed these differences.The patients treated with venlafaxine alone showed a better response to anti-depressant treatment, greater remission of symptoms, a lower incidence of adverse events and lower healthcare costs.

  5. CYP2D6*10基因型与接受他莫昔芬治疗乳腺癌患者的生存率的相关性研究%Association between CYP2 D6*10 genotype and survival of breast cancer patients receiving tamoxifen treatment

    Institute of Scientific and Technical Information of China (English)

    魏影; 徐喆

    2014-01-01

    Objective To explore the association between between CYP 2D6*10 genotype and survival of breast cancer patients receiv-ing tamoxifen(TAM) treatment.Methods Basic clinical feature,survival state and blood samples,paraffin sections were collected from 257 breast cancer patients receiving TAM treatment .CYP2D6*10 allele of breast cancer patients were checked by means of Polymerase Chain Reaction ( PCR) .We observed the association between CYP 2D6*10 genotype and survival of breast cancer patients receiving tamoxifen(TAM) treatment.Results Fifteen percent (38/257) of the patients carried the CYP2D6*10/*10 genotype,41%(105/257) the CYP2D6 wild-type (Wt)/*10 genotype and 44%(114/257) the CYP2D6 wt/wt genotype.There were no discernible cor-relations between clinicopathologic parameters and the CYP 2D6*10 genotype.We determined whether there was a correlation between the CYP2D6*10 genotype and survival and found out that the clinical outcome for patients carrying the CYP 2D6*10/*10 genotype was similar to those with other genotypes .Conclusions Our results suggest that the CYP 2D6*10 genotype is unlikely to have any clinical significance for prognosis of breast cancer patients receiving adjuvant TAM treatment .%目的:研究CYP2D6*10基因型对接受他莫昔芬(tamoxifen,TAM)治疗乳腺癌患者的生存率相关性的影响。方法选择该院乳腺外科2008-2003年收治的257名接受TAM治疗乳腺癌患者。调查TAM使用情况和生存状态等相关资料;采集患者外周静脉血5 mL或石蜡切片用于DNA提取;用PCR技术检测CYP2D6*10基因多态性;查明CYP2D6*10基因多态性与患者的生存率相关性的关系。结果该次研究中,携带CYP2D6*10/*10患者占15%(38/257),CYP2D6野生型(Wt)/*10患者占41%(105/257)和CYP2D6Wt/Wt占44%(114/257)。各CYP2D6*10基因型的临床病理参数之间没有相关性差异。在中国CYP2D6*10/*10基因型对接受TAM治疗乳

  6. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides.

    Science.gov (United States)

    Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions.

  7. No influence of the polymorphisms CYP2C19 and CYP2D6 on the efficacy of cyclophosphamide, thalidomide, and bortezomib in patients with Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Vogel Ulla

    2010-08-01

    Full Text Available Abstract Background The response to treatment varies among patients with multiple myeloma and markers for prediction of treatment outcome are highly needed. Bioactivation of cyclophosphamide and thalidomide, and biodegradation of bortezomib, is dependent on cytochrome P450 metabolism. We explored the potential influence of different polymorphisms in the CYP enzymes on the outcome of treatment. Methods Data was analyzed from 348 patients undergoing high-dose treatment and stem cell support in Denmark in 1994 to 2004. Clinical information on relapse treatment in 243 individual patients was collected. The patients were genotyped for the non-functional alleles CYP2C19*2 and CYP2D6*3, *4, *5 (gene deletion, *6, and CYP2D6 gene duplication. Results In patients who were treated with bortezomib and were carriers of one or two defective CYP2D6 alleles there was a trend towards a better time-to-next treatment. We found no association between the number of functional CYP2C19 and CYP2D6 alleles and outcome of treatment with cyclophosphamide or thalidomide. Neither was the number of functional CYP2C19 and CYP2D6 alleles associated with neurological adverse reactions to thalidomide and bortezomib. Conclusion There was no association between functional CYP2C19 and CYP2D6 alleles and treatment outcome in multiple myeloma patients treated with cyclophosphamide, thalidomide or bortezomib. A larger number of patients treated with bortezomib are needed to determine the role of CYP2D6 alleles in treatment outcome.

  8. No association between cytochrome P450 2D6 gene polymorphism and risk of acute leukemia: evidence based on a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    RUAN Xiao-lan; LI Sheng; ZENG Xian-tao; XIA Ling-hui; HU Yu

    2013-01-01

    Background Many studies indicated the human cytochrome P450 2D6 (CYP2D6) gene polymorphism was associated with acute leukemia (AL) susceptibility,however,the results were inconsistent.So we performed this meta-analysis to evaluate the relationship between CYP2D6*3 or CYP2D6*4 polymorphism and AL susceptibility.Methods We searched PubMed database up to February 20,2013,and finally yielded 9 case-control studies including 1343 cases and 1843 controls which tested the association between CYP2D6*3 or *4 polymorphism and AL.After data extraction,we conducted a meta-analysis using the Comprehensive Meta Analysis software.Results Overall,no significant association between CYP2D6*3 or *4 polymorphism and AL risk was found in this metaanalysis (+ vs.-:OR=1.13,95% CI=0.79-1.63; +/+ vs.-/-:OR=1.73,95% C/=0.99-3.02;-/+ vs.-/-:OR=1.03,95% C/=0.68-1.56; (-/+ and +/+) vs.-/-:OR=1.08,95% C/=0.72-1.63; +/+ vs.(-/+ and-/-):OR=1.76,95% C/=0.98-3.17).Similar results were also been found in stratified subgroup analysis.There was no publication bias.Conclusion CYP2D6*3 or *4 polymorphism might not be associated with AL susceptibility.However,the results need to be further confirmed by well-designed and high quality randomized controlled trials with larger sample sizes.

  9. Secretory Phospholipase A(2) Activity toward Diverse Substrates

    DEFF Research Database (Denmark)

    Madsen, Jesper Jonasson; Linderoth, Lars; Subramanian, Arun Kumar;

    2011-01-01

    We have studied secretory phospholipase A(2)-IIA (sPLA(2)) activity toward different phospholipid analogues by performing biophysical 1 characterizations and molecular dynamics simulations. The phospholipids were natural substrates, triple alkyl phospholipids, a prodrug anticancer etherlipid, and...... charged residues, but relatively large fluctuations are observed, suggesting that these interactions are not necessarily important for stabilizing substrate binding to the enzyme....

  10. Physical Properties and Microbial Activity in Forest Residual Substrate

    Science.gov (United States)

    Many growers in the horticulture industry have expressed concern that switching from a pine bark-based substrate to one with a significant wood content will increase microbial activity, resulting in nitrogen (N) immobilization. This study evaluated four growth substrates (pine bark, peat moss and tw...

  11. CYP2D6*10等位基因特性对临床用药安全性和有效性的影响

    Institute of Scientific and Technical Information of China (English)

    谭蓉; 郑志昌; 杨继红; 孙为民

    2009-01-01

    目的:促进CYP2D6底物药物临床合理用药.方法:从CYP2D6*10等位基因对底物药物的代谢特性角度,阐述应重视该等位基因携带者用药安全有效问题.结果:CYP2D6*10等位基因表达酶蛋白的活性及稳定性的特性,可影响其对底物药物的代谢,进而影响临床用药的安全性和有效性.结论:鉴于中国人CYP2D6*10等位基因携带频率高,为了该基因携带者用药安全和有效,应重新审视CYP2D6底物药物的使用模式.

  12. The Effect of CYP2B6, CYP2D6, and CYP3A4 Alleles on Methadone Binding: A Molecular Docking Study

    Directory of Open Access Journals (Sweden)

    Nik Nur Syazana Bt Nik Mohamed Kamal

    2013-01-01

    Full Text Available Current methadone maintenance therapy (MMT is yet to ensure 100% successful treatment as the optimum dosage has yet to be determined. Overdose leads to death while lower dose causes the opioid withdrawal effect. Single-nucleotide polymorphisms (SNP in cytochrome P450s (CYPs, the methadone metabolizers, have been showen to be the main factor for the interindividual variability of methadone clinical effects. In this study, we investigated the effect of SNPs in three major methadone metabolizers (CYP2B6, CYP2D6, and CYP3A4 on methadone binding affinity. Results showed that CYP2B6*11, CYP2B6*12, CYP2B6*18, and CYP3A4*12 have significantly higher binding affinity to R-methadone compared to wild type. S-methadone has higher binding affinity in CYP3A4*3, CYP3A4*11, and CYP3A4*12 compared to wild type. R-methadone was shown to be the active form of methadone; thus individuals with CYP alleles that binds better to R-methadone will have higher methadone metabolism rate. Therefore, a higher dosage of methadone is necessary to obtain the opiate effect compared to a normal individual and vice versa. These results provide an initial prediction on methadone metabolism rate for individuals with mutant type CYP which enables prescription of optimum methadone dosage for individuals with CYP alleles.

  13. Successful treatment of schizophrenia with melperone augmentation in a patient with phenotypic CYP2D6 ultrarapid metabolization: a case report

    Directory of Open Access Journals (Sweden)

    Gahr Maximilian

    2012-02-01

    Full Text Available Abstract Introduction There are limited treatment options for people with schizophrenia with cytochrome P450 2D6 ultrarapid metabolizer status who do not respond to amisulpride. Furthermore, the literature does not provide evidence-based guidelines for this particular constellation. Case presentation We report the case of a 50-year-old Caucasian female patient with schizophrenia and cytochrome P450 2D6 ultrarapid metabolizer status who experienced an insufficient antipsychotic effect with amisulpride. She was successfully treated with melperone-augmented haloperidol. Conclusion This report yields melperone-augmented haloperidol as a possible pharmacological strategy in the described situation. In addition, our observations support the available evidence for the potential of melperone to act as an inhibitor of cytochrome P450 2D6.

  14. The impact of CYP2D6 and CYP2C19 polymorphisms on suicidal behavior and substance abuse disorder among patients with schizophrenia: a retrospective study

    DEFF Research Database (Denmark)

    Kobylecki, Camilla J; Hansen, Thomas Folkmann; Timm, Sally;

    2008-01-01

    Suicidal behavior and substance abuse are frequent phenomena among patients with schizophrenia and may be attributable in part to antipsychotic treatment failure. Individuals who carry functional variants of the CYP2D6 and CYP2C19 genes, shown to cause altered drug metabolism of psychoactive drugs......, are at risk of toxic accumulation or rapid elimination of these drugs, leading to treatment failure. We tested whether substance abuse disorder and suicidal behavior were associated with the CYP2D6 and CYP2C19 genotypes among patients with schizophrenia. Three hundred sixty-two patients with schizophrenia...... spectrum disorders (International Classification of Diseases, 10th Revision) were genotyped for functional CYP2D6 and CYP2C19 polymorphisms. Based on available medical records and clinical interviews, their suicidal behavior and substance abuse disorder were evaluated. No significant associations between...

  15. CYP1A2 and CYP2D6 Gene Polymorphisms in Schizophrenic Patients with Neuroleptic Drug-Induced Side Effects.

    Science.gov (United States)

    Ivanova, S A; Filipenko, M L; Vyalova, N M; Voronina, E N; Pozhidaev, I V; Osmanova, D Z; Ivanov, M V; Fedorenko, O Yu; Semke, A V; Bokhan, N A

    2016-03-01

    Polymorphic variants of CYP1A2 and CYP2D6 genes of the cytochrome P450 system were studied in patients with schizophrenia with drug-induced motor disorders and hyperprolactinemia against the background of long-term neuroleptic therapy. We revealed an association of polymorphic variant C-163A CYP1A2*1F of CYP1A2 gene with tardive dyskinesia and association of polymorphic variant 1846G>A CY2D6*4 and genotype A/A of CYP2D6 gene (responsible for debrisoquin-4-hydroxylase synthesis) with limbotruncal tardive dyskinesia in patients with schizophrenia receiving neuroleptics for a long time. PMID:27021090

  16. Distribution of CYP2D6 gene copy number variation in chinese littoral han population of zhejiang%浙江沿海地区汉族人群CYP2D6基因拷贝数多态性研究

    Institute of Scientific and Technical Information of China (English)

    周仁芳; 曾爱平

    2008-01-01

    目的 了解浙江沿海地区汉族人群中CYP2D6基因拷贝数多态性分布.方法 使用改良的长模板PCR技术对浙江沿海地区汉族人群中的285例健康人群,进行CYP2D6基因拷贝数多态性进行检测.结果 CYP2D6*5缺失型和CYP2D6*×N重复基因在总样本中的发生频率分别为5.09%(n=29)和0.70%(n=4),在4个重复等位的基因中,其中3个为CYP2D6*1×2,另外1个为CYP2D6*10×2.结论 实验表明本地区CYP2D6基因拷贝数多态性分布不同于其他地区,不同地区呈现出不同的特点,表现出中华民族的遗传多样性.

  17. Substrate utilization and VSS relations in activated sludge processes

    Energy Technology Data Exchange (ETDEWEB)

    Droste, R.L.; Fernandes, L.; Sun, X. [Ottawa Univ., ON (Canada). Dept. of Civil Engineering

    1993-12-31

    A new empirical substrate removal model for activated sludge in continuous flow stirred tank reactor (CFSTR) and sequencing batch reactor (SBR) was developed in this study. This model includes an exponential function of volatile suspended solids to express the active biomass which is actually involved in substrate utilization. Results indicate that the proposed exponential models predict more accurately effluent COD in CFSTR and SBR systems than the first or zero order models. (author). 7 refs., 1 fig., 4 tabs.

  18. CYP2D6遗传多态性对临床个体化给药的影响

    Institute of Scientific and Technical Information of China (English)

    杨勇; 王友群

    2006-01-01

    本文总结了经CYP2D6代谢的临床常用药物,并对此类药物实现临床个体化给药的方法进行了探讨.同时介绍了CYP2D6的各种表型及其在不同种族之间的分布情况,以及该分布对制定临床给药方案的影响.

  19. Does Pharmacogenetic Testing for CYP450 2D6 and 2C19 among Patients with Diagnoses within the Schizophrenic Spectrum Reduce Treatment Costs?

    DEFF Research Database (Denmark)

    Herbild, Louise; Andersen, Stig Ejdrup; Werge, Thomas;

    2013-01-01

    The effect of pharmacogenetic testing for CYP450 2D6 and 2C19 on treatment costs have not yet been documented. This study used Danish patient registers to calculate health care costs of treating patients with diagnoses within the schizophrenic spectrum for one year with or without pharmacogenetic...... testing for polymorphisms in the genes for the CYP2D6 and CYP2C19 enzymes. In a randomized, controlled trial, stratified with respect to metabolizer genotype, 104 patients were assigned to treatment based on pharmacogenetic testing and 103 patients to treatment as usual. Random exclusion of extensive and...

  20. The impact of CYP2D6 and CYP2C19 polymorphisms on suicidal behavior and substance abuse disorder among patients with schizophrenia: a retrospective study

    DEFF Research Database (Denmark)

    Kobylecki, C.J.; Hansen, T.; Timm, S.;

    2008-01-01

    Suicidal behavior and substance abuse are frequent phenomena among patients with schizophrenia and may be attributable in part to antipsychotic treatment failure. Individuals who carry functional variants of the CYP2D6 and CYP2C19 genes, shown to cause altered drug metabolism of psychoactive drugs......, are at risk of toxic accumulation or rapid elimination of these drugs, leading to treatment failure. We tested whether substance abuse disorder and suicidal behavior were associated with the CYP2D6 and CYP2C19 genotypes among patients with schizophrenia. Three hundred sixty-two patients with schizophrenia...

  1. Lipid metabolizing enzyme activities modulated by phospholipid substrate lateral distribution.

    Science.gov (United States)

    Salinas, Dino G; Reyes, Juan G; De la Fuente, Milton

    2011-09-01

    Biological membranes contain many domains enriched in phospholipid lipids and there is not yet clear explanation about how these domains can control the activity of phospholipid metabolizing enzymes. Here we used the surface dilution kinetic theory to derive general equations describing how complex substrate distributions affect the activity of enzymes following either the phospholipid binding kinetic model (which assumes that the enzyme molecules directly bind the phospholipid substrate molecules), or the surface-binding kinetic model (which assumes that the enzyme molecules bind to the membrane before binding the phospholipid substrate). Our results strongly suggest that, if the enzyme follows the phospholipid binding kinetic model, any substrate redistribution would increase the enzyme activity over than observed for a homogeneous distribution of substrate. Besides, enzymes following the surface-binding model would be independent of the substrate distribution. Given that the distribution of substrate in a population of micelles (each of them a lipid domain) should follow a Poisson law, we demonstrate that the general equations give an excellent fit to experimental data of lipases acting on micelles, providing reasonable values for kinetic parameters--without invoking special effects such as cooperative phenomena. Our theory will allow a better understanding of the cellular-metabolism control in membranes, as well as a more simple analysis of the mechanisms of membrane acting enzymes. PMID:21108012

  2. Substrate stiffness regulates filopodial activities in lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Yu-Ren Liou

    Full Text Available Microenvironment stiffening plays a crucial role in tumorigenesis. While filopodia are generally thought to be one of the cellular mechanosensors for probing environmental stiffness, the effects of environmental stiffness on filopodial activities of cancer cells remain unclear. In this work, we investigated the filopodial activities of human lung adenocarcinoma cells CL1-5 cultured on substrates of tunable stiffness using a novel platform. The platform consists of an optical system called structured illumination nano-profilometry, which allows time-lapsed visualization of filopodial activities without fluorescence labeling. The culturing substrates were composed of polyvinyl chloride mixed with an environmentally friendly plasticizer to yield Young's modulus ranging from 20 to 60 kPa. Cell viability studies showed that the viability of cells cultured on the substrates was similar to those cultured on commonly used elastomers such as polydimethylsiloxane. Time-lapsed live cell images were acquired and the filopodial activities in response to substrates with varying degrees of stiffness were analyzed. Statistical analyses revealed that lung cancer cells cultured on softer substrates appeared to have longer filopodia, higher filopodial densities with respect to the cellular perimeter, and slower filopodial retraction rates. Nonetheless, the temporal analysis of filopodial activities revealed that whether a filopodium decides to extend or retract is purely a stochastic process without dependency on substrate stiffness. The discrepancy of the filopodial activities between lung cancer cells cultured on substrates with different degrees of stiffness vanished when the myosin II activities were inhibited by treating the cells with blebbistatin, which suggests that the filopodial activities are closely modulated by the adhesion strength of the cells. Our data quantitatively relate filopodial activities of lung cancer cells with environmental stiffness and

  3. Structure-activity relationship and substrate-dependent phenomena in effects of ginsenosides on activities of drug-metabolizing P450 enzymes.

    Directory of Open Access Journals (Sweden)

    Miao Hao

    Full Text Available Ginseng, a traditional herbal medicine, may interact with several co-administered drugs in clinical settings, and ginsenosides, the major active components of ginseng, may be responsible for these ginseng-drug interactions (GDIs. Results from previous studies on ginsenosides' effects on human drug-metabolizing P450 enzymes are inconsistent and confusing. Herein, we first evaluated the inhibitory effects of fifteen ginsenosides and sapogenins on human CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 enzymes by using commercially available fluorescent probes. The structure-activity relationship of their effects on the P450s was also explored and a pharmacophore model was established for CYP3A4. Moreover, substrate-dependent phenomena were found in ginsenosides' effects on CYP3A4 when another fluorescent probe was used, and were further confirmed in tests with conventional drug probes and human liver microsomes. These substrate-dependent effects of the ginsenosides may provide an explanation for the inconsistent results obtained in previous GDI reports.

  4. Effects and cost-effectiveness of pharmacogenetic screening for CYP2D6 among older adults starting therapy with nortriptyline or venlafaxine : study protocol for a pragmatic randomized controlled trial (CYSCEtrial)

    NARCIS (Netherlands)

    Berm, Elizabeth J. J.; Hak, Eelko; Postma, Maarten; Boshuisen, Marjolein; Breuning, Laura; Brouwers, Jacobus R. B. J.; Dhondt, Ton; Jansen, Paul A. F.; Kok, Rob M.; Maring, Jan G.; van Marum, Rob; Mulder, Hans; Oude Voshaar, Richard; Risselada, Arne J.; Venema, Harry; Vleugel, Liesbeth; Wilffert, Bob

    2015-01-01

    Background: Nortriptyline and venlafaxine are commonly used antidepressants for treatment of depression in older patients. Both drugs are metabolized by the polymorphic cytochrome P450-2D6 (CYP2D6) enzyme and guidelines for dose adaptations based on the CYP2D6 genotype have been developed. The CYP2D

  5. Enumeration and activity of nitrifying bacteria in zeoponic substrates

    Science.gov (United States)

    McGilloway, Robyn Leigh

    Regenerative life-support systems are needed for long-term space missions. One component of a proposed life-support system is the use of zeoponic growth substrates, which slowly release NH4 into 'soil' solution for the production of plants. Nitrifying bacteria that convert NH4 to NO3 are among the important microbial components of these systems. Some evidence suggests that a balance between NH4 and NO3 is desirable in promoting plant growth and seed development. Therefore, enumeration of nitrifying bacteria and evaluation of the kinetics of nitrification in zeoponic substrates warrants investigation. A method for rapid detection and enumeration of a commercial inoculum of nitrifying bacteria in a zeoponic substrate was developed using a most probable number (MPN)-polymerase chain reaction (PCR) approach, and a TaqMan probe-based assay. The detection limit of the MPN-PCR methodology was 2,000 cells per assay. Detection sensitivity for the TaqMan assay was determined to be 60 cells. The quantitative assay demonstrated that the zeoponic substrate was capable of supporting 105 to 107 Nitrobacter cells g-1 substrate. The MPN-PCR method and TaqMan probe-based assay can be effective and rapid approaches to enumerate nitrifying bacteria in zeoponic substrates. Column studies and a growth chamber study were conducted to evaluate the production of NO2 and NO3, and nitrifier populations in zeoponic substrates. The zeoponic substrate provided a readily available source of NH4, and nitrifying bacteria were active in the substrate. Quantities of NH4 oxidized, 10 mug N g-1 h-1, to NO2 and NO3 in inoculated zeoponic substrate were in excess of plant uptake. Acidification as a result of NH4 oxidation resulted in decline of pH to 5.5. The zeoponic substrate showed limited pH buffering capacity. Survival of nitrifying bacteria during periods of desiccation was evaluated, as the zeoponic substrate would likely be stored in an air-dry state between croppings. Substrate was enriched for

  6. Effect of the CYP2D6*10 allele on postoperative tramadol analgesia in patients after gastric cancer surgery%CYP2D6*10等位基因多态性对胃癌术后曲马多镇痛效果的影响

    Institute of Scientific and Technical Information of China (English)

    汪国香; 黄丽霞; 张相彩; 陶凡

    2011-01-01

    目的:探讨中国人群CYP2D6*10等位基因对胃癌术后曲马多镇痛效果的影响.方法:70例胃癌根治术患者,手术结束前30 min静脉注入负荷剂量曲马多100 mg,随后采用持续背景剂量-PCA量的给药模式(曲马多10 mg/mL、甲氧氯普胺0.3 mg/mL)进行术后镇痛.全麻诱导后抽取血样,采用聚合酶链反应-限制性片断长度多态性方法分析患者CYP2D6*10基因多态性,根据不同CYP2D6基因型分为3组,比较不同基因组患者之间曲马多的用量.结果:CYP2D6*10等位基因频率为52.4%,不携带CYP2D6*10(I组)17例,CYP2D6*10杂合子(II组)26例,CYP2D6*10纯合子(III组)20例.48 h曲马多用量,III组明显高于I组和II组,I组和II组之间差异无统计学意义.结论:在中国人群中,CYP2D6*10等位基因对曲马多镇痛效果有显著影响.%Objective To investigate whether the CYP2D6*10 allele has an impact on the postoperative analgesia effect of tramadol in Chinese patients suffering from gastric cancer surgery. Methods Seventy gastric cancer patients suffering from gastrectomy were enrolled. After receiving a loading dose of 100 mg tramadol intravenously, patients could self-administer doses of 10 mg/mL tramadol plus 0.3 mg/mL metoclopramide via patient-controlled analgesia (PCA). Blood samples were collected after induction of anesthesia. The CYP2D6*10 polymorphism was analyzed by means of polymerase chain reaction-based restriction fragment length polymor-phism(PCR-RFLP). Demographic data among groups with different genotypes were analyzed using analysis of variance. The total consumption of tramadol between the three genotype groups for 48 h was compared. Results The allele frequency of CYP2D6*10 is 52.4%: Patients were categorized into three groups according to the CYP2D6 genotype: patients without CYP2D6*10 (group I,n=17), patients with heterozygote for CYP2D6*10 (group Ⅱ, n=26), and patients with homozygote for CYP2D6*10 (group Ⅲ, n=20). The demographic data among

  7. 细胞色素CYP2D6基因多态性与急性髓系白血病的关系研究

    Institute of Scientific and Technical Information of China (English)

    里杨; 许俊锋; 王皓; 郭权; 曹楷翔

    2013-01-01

    目的:探讨细胞色素CYP2D6基因多态性与急性髓系白血病(AML)易感性的关系。方法:采用病例对照研究方法,应用聚合酶链反应-限制性片段长度多态性技术,对114例AML患者及180例健康对照者的CYP2D6(C188T)基因的多态分布进行分析。结果:AML 患者组CYP2D6各基因型频率分布与对照组之间无显著性差异;携带CYP2D6188T突变基因型的个体患AML的风险与野生型携带者相比无显著性差异。结论:CYP2D6基因多态性可能与AML遗传易感性不相关。

  8. CYP2D6基因多态性与他莫昔芬及4-羟基他莫昔芬血清浓度的相关性研究%Clinical analysis of CYP2D6 gene polymorphism with serum concentration of tamoxifen and 4-Hydroxytamoxifen

    Institute of Scientific and Technical Information of China (English)

    田超; 杨义; 李卉

    2014-01-01

    目的 探讨CYP2D6基因多态性与乳腺癌患者他莫昔芬(TAM)及其活性代谢产物4-羟基他莫昔芬(4-OH-TAM)血清浓度的相关性.方法 收集2008年1月~2010年10月期间200例服用TAM的乳腺癌患者的口腔粘膜及血清,采用Real-time RT-PC法检测CYP2D6*10基因多态性,采用液相色谱-质谱方法 (LC-MS)测定患者体内TAM及其活性代谢物4-OH-TAM的的血清浓度.结果 200例乳腺癌中检测到CYP2D6*10/*10纯合子94例(47%),CYP2D6 wt/wt野生型48例(24%),CYP2D6 wt/*10杂合型58例(29%).CYP2D6 wt/wt野生型和wt/*10杂合型两组4-OH-TAM的血清浓度都明显高于*10/*10纯合型(P0.05).结论 乳腺癌患者CYP2D6*10/*10基因型影响他莫昔芬的体内代谢过程,与疗效相关,服用TAM前均应推荐检测CYP2D6*10/*10基因型.

  9. Clinical pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy": the influence of gender and genetics (CYP2D6, COMT, 5-HTT.

    Directory of Open Access Journals (Sweden)

    Ricardo Pardo-Lozano

    Full Text Available The synthetic psychostimulant MDMA (± 3,4-methylenedioxymethamphetamine, ecstasy acts as an indirect serotonin, dopamine, and norepinephrine agonist and as a mechanism-based inhibitor of the cytochrome P-450 2D6 (CYP2D6. It has been suggested that women are more sensitive to MDMA effects than men but no clinical experimental studies have satisfactorily evaluated the factors contributing to such observations. There are no studies evaluating the influence of genetic polymorphism on the pharmacokinetics (CYP2D6; catechol-O-methyltransferase, COMT and pharmacological effects of MDMA (serotonin transporter, 5-HTT; COMT. This clinical study was designed to evaluate the pharmacokinetics and physiological and subjective effects of MDMA considering gender and the genetic polymorphisms of CYP2D6, COMT, and 5-HTT. A total of 27 (12 women healthy, recreational users of ecstasy were included (all extensive metabolizers for CYP2D6. A single oral weight-adjusted dose of MDMA was administered (1.4 mg/kg, range 75-100 mg which was similar to recreational doses. None of the women were taking oral contraceptives and the experimental session was performed during the early follicular phase of their menstrual cycle. Principal findings show that subjects reached similar MDMA plasma concentrations, and experienced similar positive effects, irrespective of gender or CYP2D6 (not taking into consideration poor or ultra-rapid metabolizers or COMT genotypes. However, HMMA plasma concentrations were linked to CYP2D6 genotype (higher with two functional alleles. Female subjects displayed more intense physiological (heart rate, and oral temperature and negative effects (dizziness, sedation, depression, and psychotic symptoms. Genotypes of COMT val158met or 5-HTTLPR with high functionality (val/val or l/* determined greater cardiovascular effects, and with low functionality (met/* or s/s negative subjective effects (dizziness, anxiety, sedation. In conclusion, the contribution

  10. Development of a fluorescent substrate to measure hyaluronidase activity

    OpenAIRE

    Zhang, Li-Shu; Mummert, Mark E.

    2008-01-01

    A novel fluorescent substrate (termed FRET-HA) to quantitatively assess hyaluronidase activity was developed. Hyaluronan (HA), the major substrate for hyaluronidase, was dual labeled with fluorescein amine and rhodamine B amine. The fluorescein amine fluorescence signal was significantly quenched while the rhodamine B amine signal was significantly enhanced due to fluorescence resonance energy transfer (FRET). In the presence of bovine testes hyaluronidase, cleavage of HA disrupted FRET resul...

  11. The Allele and Genotype Frequences of CYP2D6*10 in Ningxia Hui Population%宁夏回族人群CYP2D6*10等位基因及基因型分布频率

    Institute of Scientific and Technical Information of China (English)

    李宗吉; 王健; 王惠成; 葛立军

    2009-01-01

    目的 了解宁夏回族人群CYP2D6*10等位基因及基因型分布频率,为临床使用CYP2D6底物药物提供依据.方法 采用等位基因特异扩增(ASA-PCR)技术,分析了180例回族体检者的CYP2D6基因型.结果 CYP2D6*10基因点突变结果中野生型纯合子频率为32.3%,杂合子频率为38.3%,突变型纯合子频率为29.4%,突变型等位基因频率为48.6%.结论 宁夏回族人群CYP2D6*10突变基因频率与国内外其他民族有一定差异,在临床应用经CYP2D6代谢的药物时应考虑个体间的代谢速率差异,确保用药安全有效.

  12. Determination of CYP2D6*10 and*14 genotypes by amplification refractory mutation methods in Chinese subjects%突变阻断扩增法检测中国人CYP2D6*10、*14等位基因

    Institute of Scientific and Technical Information of China (English)

    陈冰; 马涛; 蔡卫民

    2009-01-01

    目的 根据突变阻断扩增原理,建立用于检测中国人CYP2D6*10及*14等位基因的方法.方法 采用单管四引物法检测CYP2D6*10等位基因,建立等位基因特异扩增法检测CYP2D6*14等位基因,检测295名健康中国汉族人CYP2D6*10等位基因.结果 CYP2D6*10及*14等位基因基因频率分别为55.8%和1.8%,295位受试者中包括1位*14/*14、6位*1/*14、3位*10/*14,基因型分布符合Hardy-Weinberg平衡(x2=2.15,df=5,P>0.82).结论 本室建立的CYP2D6*10、*14等位基因分析法具有方便快捷、结果准确可靠的特点.

  13. Substrate-dependent modulation of the catalytic activity of CYP3A by erlotinib

    Institute of Scientific and Technical Information of China (English)

    Pei-pei DONG; Chang-xiao LIU; Ling YANG; Zhong-ze FANG; Yan-yan ZHANG; Guang-bo GE; Yu-xi MAO; Liang-liang ZHU; Yan-qing QU; Wei Li; Li-ming WANG

    2011-01-01

    Aim: To ascertain the effects of erlotinib on CYP3A, to investigate the amplitude and kinetics of erlotinib-mediated inhibition of seven major CYP isoforms in human liver microsomes (HLMs) for evaluating the magnitude of erlotinib in drug-drug interaction in vivo.Methods:The activities of 7 major CYP isoforms (CYP1A2, CYP2A6, CYP3A, CYP2C9, CYP2D6, CYP2C8, and CYP2E1) were assessed in HLMs using HPLC or UFLC analysis. A two-step incubation method was used to examine the time-dependent inhibition of erlotinib on CYP3A.Results: The activity of CYP2C8 was inhibited with an IC50 value of 6.17±2.0μmol/L. Erlotinib stimulated the midazolam 1'-hydroxy reaction, but inhibited the formation of 6β-hydroxytestosterone and oxidized nifedipine. Inhibition of CYP3A by erlotinib was substratedependent: the IC50 values for inhibiting testosterone 6β-hydroxylation and nifedipine metabolism were 31.3±8.0 and 20.5±5.3μmol/L, respectively. Erlotinib also exhibited the time-dependent inhibition on CYP3A, regardless of the probe substrate used: the value of K1 and k1nack were 6.3μmol/L and 0.035 min-1 for midazolam; 9.0μmol/L and 0.045 min-1 for testosterone; and 10.1μmol/L and 0.058 min-1 for nifedipine.Conclusion: The inhibition of CYP3A by erlotinib was substrate-dependent, while its time-dependent inhibition on CYP3A was substrateindependent. The time-dependent inhibition of CYP3A may be a possible cause of drug-drug interaction, suggesting that attention should be paid to the evaluation of erlotinib's safety, especially in the context of combination therapy.

  14. Fibrinogen patterns and activity on substrates with tailored hydroxy density.

    Science.gov (United States)

    Rodríguez Hernández, José Carlos; Rico, Patricia; Moratal, David; Monleón Pradas, Manuel; Salmerón-Sánchez, Manuel

    2009-08-11

    The influence of the surface fraction of OH groups on fibrinogen (FG) adsorption is investigated in copolymers of ethyl acrylate and hydroxy ethylacrylate. The amount of adsorbed FG, quantified by western-blotting combined with image analysis of the corresponding bands, decreases as the hydrophilicity of the substrate increases. The influence of substrate wettability on FG conformation and distribution is observed by atomic force microscopy (AFM). The most hydrophobic substrate promotes FG fibrillogenesis, which leads to a fibrin-like appearance in the absence of any thrombin. The degree of FG interconnection was quantified by calculating the fractal dimension of the adsorbed protein from image analysis of the AFM results. The biological activity of the adsorbed FG is correlated to cell adhesion on FG-coated substrates.

  15. CYP2 D6基因多态性对帕罗西汀在河南汉族健康受试者体内药代动力学的影响%Influence of CYP2 D6 genetic polymorphism on pharmacokinetics of par-oxetine in Henan Han healthy subjects

    Institute of Scientific and Technical Information of China (English)

    周霖; 薛文华; 张海朋; 刘克锋; 赵杰

    2014-01-01

    目的:研究CYP2D6基因多态性对帕罗西汀在河南汉族健康受试者体内药代动力学的影响。方法:河南汉族健康受试者48人,使用PCR-RFLP技术对其进行CYP2D6基因型检测。受试者单剂量(7.5 mg)口服甲磺酸帕罗西汀胶囊后,收集120 h内的系列血样,用建立的LC-MS/MS法测定血浆帕罗西汀浓度,绘制药-时曲线,进行药代动力学分析。结果:男性CYP2D6*1/*1型受试者9人,CYP2D6*1/*10型21人;女性CYP2D6*1/*1型受试者5人,CYP2D6*1/*10型13人;未检测到CYP2D6*10/*10型;男、女CYP2D6基因型分布差异无统计学意义(χ2=0.027,P>0.999)。与CYP2D6*1/*1型男性受试者比较,CYP2D6*1/*10型男性受试者tmax、t1/2无明显变化(Z=1.145,t=1.400,P>0.05),CL(F)、Vd 降低(Z=2.557,t=2.104,P<0.05),ρmax、AUC0-120和AUC0-∞增加(Z=2.421、2.512、2.557,P<0.05)。与CYP2D6*1/*1型女性受试者比较,CYP2D6*1/*10型女性受试者ρmax、tmax、t1/2及Vd 无明显变化(Z=1.992、1.921,t=2.117、1.905,P>0.05),但 CL(F)降低(Z=2.021,P<0.05), AUC0-120和AUC0-∞增加(Z=2.021、2.021,P<0.05)。结论:CYP2D6*10突变等位基因可影响甲磺酸帕罗西汀在河南汉族健康人群体内的代谢。%Aim:To investigate the influence of CYP2D6 genetic polymorphism on pharmacokinetics of paroxetine in Henan Han healthy people .Methods:A total of 48 Han healthy volunteers from Henan Province were subjected to detect genetic polymorphied by PCR R-FLP method .The volunteers were given a single oral dose of paroxetine mesylate capsule (7.5 mg), and blood samples were collected at different time points until 120 h.The concentrations of paroxetine in plas-ma were measured by LC-MS/MS method, and the pharmacokinetics was analyzed .Results: There were 9 males with CYP2D6*1/*1, 21 with CYP2D6

  16. 等位基因特异扩增法研究中国人CYP2D6中速代谢的相关基因%ALLELE SPECIFIC AMPLIFICATON FOR CYP2D6 GENE RELATED TO INTERMEDIATE METABOLIZER IN CHINESE SUBJECTS

    Institute of Scientific and Technical Information of China (English)

    陈冰; 蔡卫民; 凌树森

    2001-01-01

    AIM To establish an allele specific PCR amplification (ASA-PCR) for determination of the genotype of CYP2D6*10B polymorphism in Chinese subjects. METHODS CYP2D6*10B alleles of 65 healthy Chinese subjects were analyzed by a two-step PCR assay and the correlation of genotype and phenotype was studied. RESULTS There were 20 CYP2D6*10B heterozygous genotypes subjects (wt/m) in 35 very extensive metabolizers (VEMs), which consisted the major part of VEM subjects (57%). Meanwhile, 20 subjects consisting 69% of 29 intermediate metabolizers were CYP2D6*10B homozygous mutant genotypes (m/m). The poor metabolizer was also m/m. The metabolic ratio of CYP2D6*10B m/m subjects were larger than wt/m and wild type, the values were -1.49±0.54, -2.20±0.49 and -2.47±0.61 (P<0.01). CONCLUSION PCR-ASA was shown to be a rapid and specific method. It can be used to study the genetic polymorphism, especially CYP2D6 intermediate metabolism.%目的 建立CYP2D6*10B的等位基因特异扩增法(ASA-PCR),以探讨中国人CYP2D6中速代谢的基因分型。方法 采用两步扩增法得到CYP2D6*10B等位基因特异片段,分析健康中国汉族人CYP2D6*10B等位基因,并探讨基因分型结果与右美沙芬表型分型结果的相关性。结果 35名表型为极快代谢受试者(VEMs)中,CYP2D6*10B以杂合子(wt/m)为主占57%;29名中速代谢受试者(IMs)以突变型纯合子(m/m)为主占69%;慢代谢受试者(PM)基因型为m/m。CYP2D6*10B m/m组的MR明显大于wt/m组和野生型组(wt/wt)。结论 ASA-PCR法有快速、准确的优点,可用于CYP2D6中速代谢的检测与研究。

  17. No association between schizophrenia and polymorphisms within the genes for debrisoquine 4-hydroxylase (CYP2D6) and the dopamine transporter (DAT)

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.; Williams, J.; Asherson, P.; McGuffin, P.; Owen, M. [Univ of Wales College of Medicine, Cardiff (United Kingdom)

    1995-02-27

    It has been suggested that the cytochrome P450 mono-oxygenase, debrisoquine 4-hydroxylase, is involved in the catabolism and processing of neurotransmitters subsequent to their reuptake into target cells. It is also thought to be related to the dopamine transporter that acts to take released dopamine back up into presynaptic terminals. The present study used the association approach to test the hypothesis that mutations in the genes for debrisoquine 4-hydroxylase (CYP2D6) and the dopamine transporter (DAT) confer susceptibility to schizophrenia. There were no differences in allele or genotype frequencies between patients and controls in the mutations causing the poor metaboliser phenotype in CYP2D6. In addition there was no association found between schizophrenia and a 48 bp repeat within the 3{prime} untranslated region of DAT. 18 refs., 2 tabs.

  18. Paroxetine, a cytochrome P450 2D6 inhibitor, diminishes the stereoselective O-demethylation and reduces the hypoalgesic effect of tramadol

    DEFF Research Database (Denmark)

    Laugesen, S; Enggaard, T P; Pedersen, R S;

    2005-01-01

    OBJECTIVE: Tramadol hydrochloride (INN, tramadol) exerts its antinociceptive action through a monoaminergic effect mediated by the parent compound and an opioid effect mediated mainly by the O-demethylated metabolite (+)-M1. O-demethylation is catalyzed by cytochrome P450 (CYP) 2D6. Paroxetine...... is a very potent inhibitor of CYP2D6. The objective of this study was to investigate the influence of paroxetine pretreatment on the biotransformation and the hypoalgesic effect of tramadol. METHODS: With and without paroxetine pretreatment (20 mg daily for 3 consecutive days), the formation of M1...... and the analgesic effect of 150 mg of tramadol were studied in 16 healthy extensive metabolizers of sparteine in a randomized, double-blind, placebo-controlled, 4-way crossover study by use of experimental pain models. RESULTS: With paroxetine pretreatment, the area under the plasma concentration-time curve (AUC...

  19. Genetic polymorphism of cytochrome P450 2D6 in Chinese population detected by gene chips%基因芯片法测定中国人群细胞色素P450 2D6的基因多态性

    Institute of Scientific and Technical Information of China (English)

    李芹; 王睿; 许力; 文思远; 王升启

    2006-01-01

    目的:根据细胞色素P450 2D6基因序列的多态性分布特点,针对在中国人群药物代谢中具有潜在作用的突变位点C188T和G4268C,设计寡核苷酸探针,制备寡核苷酸芯片,探讨基因芯片技术应用于CYP2D6基因分型的可行性,观察中国人群细胞色素P450 2D6的基因多态性.方法:实验于2005-02/08进行.以克隆并已测序的细胞色素P450 2D6基因重组质粒作为标准样品,扩增产物与芯片进行杂交,制备基因芯片,测定312名中国健康志愿者(已签署知情同意书)细胞色素P4502D6基因分型,并使用直接测序法对结果进行验证.结果:312名全部进入结果分析.①312名中国健康志愿者中CYP2D6*2和CYP2D6*10的变异频率分别为CYP2D6*2W*10W 8.3%,*2H*10W 13.5%,*2M*10W 10.6%,*2M*10H 17.0%,*2M*10M 34.6%,*2H*10H 9.6%,*2H*10M 64%.②对部分样本采用直接测序的方法进行进一步确证,结果完全吻合.结论:①CYP2D6*2和CYP2D6*10突变型等位基因在中国人群中出现的频率较高.②基因芯片法简便、快捷,适用于中国人群细胞色素P4502D6基因分型研究.

  20. CYP2D6*10等位基因多态性对文拉法辛血药浓度的影响%Effect of CYP2D6*10 gene polymorphism on blood concentration of venlafaxine

    Institute of Scientific and Technical Information of China (English)

    杨丽蓉; 刘天龙; 刘小雷

    2013-01-01

    目的 旨在研究细胞色素P450酶2D6*10(CYP2D6* 10)基因多态性对文拉法辛血药浓度的影响.方法 随机选择65例抑郁症患者为研究对象,提取其外周血中的DNA并利用特异性的引物对其进行扩增,对得到的扩增产物进行酶切,通过电泳表征酶切结果并分析65例抑郁患者CYP2D6*10基因的基因类型.根据所选择患者基因类型的不同,将其分为3组,即A组:纯合突变(CYP2D6*10/*14),B组:杂合体[CYP2D6*1(*2)/*14]及C组:野生型纯合体[CYP2D6*1(*2)/*5];各组患者口服文拉法辛225mg后,使用高效液相色谱仪测定患者文拉法辛(VL)和O-去甲文拉法辛(ODVL)的血药浓度以研究文拉法辛在不同基因携带者体内的代谢情况.通过汉密尔顿抑郁量表(HAMD)和药物不良反应量表(TESS)来明确文拉法辛对不同CYP2D6*10基因携带者的治疗效果和产生不良反应情况.结果 电泳结果显示,在65名患者中,纯合突变(CYP2D6*10/*14)为29例(44.6%),杂合体([CYP2D6*1(*2)/*14]为17例(26.1%),野生型纯合体[CYP2D6*1(*2)/*5]为19例(29.3%);3组间CvL CODVL及CODVL/CVL比较均具有显著地差异(P<0.05);根据CODVI/CVL值可知,A组、B组及C组对文拉法辛的代谢类型分别为快型(EM)、中型(IM)及慢型(PM).各组间TESS评分和HAMD评分差异具有统计学意义(P< 0.05).结论 不同CYP2D6* 10基因是通过决定抑郁症患者对文拉法辛的代谢类型而影响其血药浓度.%Objective To determine the effect of CYP2D6*10 gene polymorphism on blood concentration of venlafaxine. Methods A total of 65 patients with dysthymia disorders were selected as the case group and DNA extracted from their peripheral blood was amplified by PCR. The PCR products were digested by restriction endonuclease (HphI) and their CYP2D6*10 genotypes were determined by electrophoresis. According to different genotypes, 65 patients were divided into 3 groups: group A: CYP2D6*l0 /*14, group B: [ CYP2D6*1 (*2 ) /*14 ], and

  1. Tailoring adjuvant endocrine therapy for postmenopausal breast cancer: a CYP2D6 multiple-genotype-based modeling analysis and validation.

    Directory of Open Access Journals (Sweden)

    Ke-Da Yu

    Full Text Available PURPOSE: Previous studies have suggested that postmenopausal women with breast cancer who present with wild-type CYP2D6 may actually have similar or superior recurrence-free survival outcomes when given tamoxifen in place of aromatase inhibitors (AIs. The present study established a CYP2D6 multiple-genotype-based model to determine the optimal endocrine therapy for patients harboring wild-type CYP2D6. METHODS: We created a Markov model to determine whether tamoxifen or AIs maximized 5-year disease-free survival (DFS for extensive metabolizer (EM patients using annual hazard ratio (HR data from the BIG 1-98 trial. We then replicated the model by evaluating 9-year event-free survival (EFS using HR data from the ATAC trial. In addition, we employed two-way sensitivity analyses to explore the impact of HR of decreased-metabolizer (DM and its frequency on survival by studying a range of estimates. RESULTS: The 5-year DFS of tamoxifen-treated EM patients was 83.3%, which is similar to that of genotypically unselected patients who received an AI (83.7%. In the validation study, we further demonstrated that the 9-year EFS of tamoxifen-treated EM patients was 81.4%, which is higher than that of genotypically unselected patients receiving tamoxifen (78.4% and similar to that of patients receiving an AI (83.2%. Two-way sensitivity analyses demonstrated the robustness of the results. CONCLUSIONS: Our modeling analyses indicate that, among EM patients, the DFS/EFS outcome of patients receiving tamoxifen is similar to that of patients receiving an AI. Further prospective clinical trials are needed to evaluate the value of the CYP2D6 genotype in the selection of endocrine therapy.

  2. A Physiologically Based Pharmacokinetic Model to Predict Disposition of CYP2D6 and CYP1A2 Metabolized Drugs in Pregnant Women

    OpenAIRE

    Ke, Alice Ban; Nallani, Srikanth C.; Zhao, Ping; Rostami-Hodjegan, Amin; Isoherranen, Nina; Unadkat, Jashvant D.

    2013-01-01

    Conducting pharmacokinetic (PK) studies in pregnant women is challenging. Therefore, we asked if a physiologically based pharmacokinetic (PBPK) model could be used to evaluate different dosing regimens for pregnant women. We refined and verified our previously published pregnancy PBPK model by incorporating cytochrome P450 CYP1A2 suppression (based on caffeine PK) and CYP2D6 induction (based on metoprolol PK) into the model. This model accounts for gestational age–dependent changes in materna...

  3. Genetic polymorphisms of CYP2D6*10 and the effectiveness of combined tamoxifen citrate and testosterone undecanoate treatment in infertile men with idiopathic oligozoospermia*

    OpenAIRE

    Tang, Kai-Fa; Zhao, Yi-li; Ding, Shang-shu; Wu, Qi-Fei; Wang, Xing-yang; Shi, Jia-qi; SUN, FA; Xing, Jun-Ping

    2015-01-01

    Tamoxifen citrate, as the first line of treatment for infertile men with idiopathic oligozoospermia, was proposed by the World Health Organization (WHO), and testosterone undecanoate has shown benefits in semen values. Our objective was to assess the effectiveness of treatment with tamoxifen citrate and testosterone undecanoate in infertile men with idiopathic oligozoospermia, and whether the results would be affected by polymorphisms of CYP2D6*10. A total of 230 infertile men and 147 control...

  4. Genetic polymorphisms of CYP2D6*10 and the effectiveness of combined tamoxifen citrate and testosterone undecanoate treatment in infertile men with idiopathic oligozoospermia

    Institute of Scientific and Technical Information of China (English)

    Kai-fa TANG; Yi-li ZHAO; Shang-shu DING; Qi-fei WU; Xing-yang WANG; Jia-qi SHI; Fa SUN; Jun-ping XING

    2015-01-01

      结论:CYP2D6*10基因突变型特发性少精男性不育患者接受他莫昔芬联合十一酸睾酮疗效较基因野生型组差。%Tamoxifen citrate, as the first line of treatment for infertile men with idiopathic oligozoospermia, was proposed by the World Health Organization (WHO), and testosterone undecanoate has shown benefits in semen values. Our objective was to assess the effectiveness of treatment with tamoxifen citrate and testosterone un-decanoate in infertile men with idiopathic oligozoospermia, and whether the results would be affected by polymor-phisms of CYP2D6*10. A total of 230 infertile men and 147 controls were included in the study. Patients were treated with tamoxifen citrate and testosterone undecanoate. Sex hormone, sperm parameters, and incidence of spontaneous pregnancy were detected. There were no significant differences between the control and patient groups with respect to CYP2D6*10 genotype frequencies (P>0.05). The follicle-stimulation hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were raised, and sperm concentration and motility were increased at 3 months and became significant at 6 months, and they were higher in the wild-type al ele (C/C) than in the heterozygous variant al ele (C/T) or homozygous variant allele (T/T) subgroups (P<0.05). In addition, the percentage of normal morphology was raised at 6 months, and represented the highest percentage in the C/C subgroup (P<0.05). The incidence of spontaneous pregnancy in the C/C subgroup was higher than that in the C/T or T/T subgroups (P<0.01). This study showed that the CYP2D6*10 variant genotype demonstrated worse clinical effects in infertile men with idiopathic oligozoospermia.

  5. 用回归分割法预测4味中药对CYP2D6代谢的抑制作用

    Institute of Scientific and Technical Information of China (English)

    郑春松; 陈立武; 杜建; 叶蕻芝

    2007-01-01

    细胞色素P4502D6(CYP2D6)是人体中重要的药物代谢酶,参与临床近百种药物的代谢,包括多种抗心律失常药、β受体阻滞剂、抗高血压药、抗抑郁药以及抗肿瘤药等。某些毒性或致癌物也可被CYP2D6代谢解毒或激活。除影响外源性化学物质的代谢外,CYP2D6还与某些疾病呈相关性。黄芪、女贞子、山药、白花蛇舌草有很好的抗肿瘤作用.目前研究很多,

  6. Association of polymorphism of CYP2D6 and CYP2C9 genes encoding P-450 proteins of cytochrome with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Saratsev A.V.

    2012-12-01

    Full Text Available Gene polymorphisms of cytochrome P-450 CYP2 encoding proteins of cytochrome P-450 are essential forantihy-pertensive drugs metabolism. Purpose: We study the associations of functionally defective allele variants of CYP2D6 gene and CYP2C9 gene with the degree of arterial hypertension (AH. Materials and methods: Samples of DNA of leukocytes of blood of 150 patients with AH without the associated clinical conditions (56% of women at the age of 20-59 years have been investigated. For the study of polymorphism of genes the pharmacogenetic biochip developed in the Institute of Molecular Biology n.a. V. A. Engelgardt has been used. Comparison of frequencies of occurrence of signs has been carried out on the basis of chi-square criterion. Results: It has been revealed that homozygotes by mutant A1075C, C430T alleles of CYP2C9gene and G1934A of CYP2D6 gene have been significantly more common among patients with hypertension III (p=0.01. Conclusion: The research works on genes of system of P-450 cytochrome have important clinical value for rationalization of pharmacotherapy of hypertension. The increased frequency of occurrence of mutant allele of CYP2D6 and CYP2C9 genes in patients with hypertension III requires special attention to the problem of efficiency and safety of application of hypotensive drugs for the patients.

  7. Substrate independent ATPase activity may complicate high throughput screening.

    Science.gov (United States)

    Tuntland, Micheal L; Fung, L W-M

    2016-10-01

    Inorganic phosphate release, [Pi], is often measured in an enzymatic reaction in a high throughput setting. Based on the published mechanism, we designed a protocol for our screening for inhibitors of SAICAR synthetase (PurC), and we found a gradual increase in [Pi] in positive control samples over the course of the day. Further investigation indicated that hydrolysis of ATP catalyzed by PurC, rather than substrate-related phosphate release, was responsible for a partial contribution to the signals in the control samples. Thus substrate-independent ATPase activity may complicate high throughput screening. PMID:27430931

  8. Comparison of Streptokinase Activity from Streptococcus mutans using Different Substrates

    OpenAIRE

    Muhammad Anjum Zia*, Rana Faisal, Rao Zahid Abbas1, Gull-e-Faran, Muhammad Kashif Saleemi2 and Junaid Ali Khan3

    2013-01-01

    Streptokinase is a novel bacterial fibrinolytic enzyme that binds and activates plasminogen and is produced by several species of Streptococci. Streptococcus mutans was selected for optimum production of streptokinase using corn steep liquor, molasses, rice polishing and sugarcane bagass in liquid state fermentation. Substrates were applied in different concentrations ranging from 0.1-0.8%. Maximum fibrinolytic activity was observed by 0.3% corn steep liquor, 0.5% molasses and rice polishing ...

  9. 细胞色素P450 2D6酶基因多态性与氟西汀临床效应的相关性研究%Correlation between polymorphism of cytochrome P450 2D6 gene and clinical response to fluoxetine

    Institute of Scientific and Technical Information of China (English)

    侯静; 林建荣; 郑东; 何凤贞; 谭静卿; 陆欣乔; 黄煜坤; 李洁仪; 庞振泰; 林振强

    2002-01-01

    目的研究中国人P450 2D6酶(CYP2D6)基因多态性与氟西汀临床效应之间的关系.方法用氟西汀对108例抑郁患者(抑郁症89例,精神分裂症后抑郁7例,分裂情感性精神病抑郁型4例,强迫性神经症2例,焦虑性神经症1例,抑郁性神经症4例,分裂样精神病(伴抑郁症状)1例)进行治疗,用汉密尔顿抑郁量表(HAMD)和治疗中需处理的副反应症状量表(TESS)评定疗效和副反应,用聚合酶链反应-限制性片段长度多态性分析法(PCR-RFLP)分析患者CYP2D6基因型.结果 (1)PCR-RFLP分析表明,在108例抑郁患者中,CYP2D6基因型为 wt/wt者26例,wt/Ch者55例,Ch/Ch者26例, wt/A者1例,未发现B等位基因.CYP2D6等位基因频率分别为CYP2D6wt(50%),CYP2D6Ch(49.5%), CYP2D6A(0.5%). (2)入组时,不同基因型的患者之间HAMD基础评分的差异无显著性(P>0.05).经氟西汀治疗4周和8周后,不同CYP2D6基因型患者的HAMD量表评分比治疗前降低,差异均有非常显著性(P=0.000);8周后减分率达80%左右,而TESS评分较低.在不同基因型的患者之间,治疗后的HAMD评分、HAMD减分率及TESS评分的差异均无显著性(P>0.05).患者治疗前后的HAMD评分及HAMD减分率、TESS评分等与CYP2D6基因型及CYP2D6突变等位基因数目的相关关系均无显著性(P>0.05).结论未发现中国人CYP2D6基因多态性与氟西汀临床效应之间有关联.

  10. CYP2D6 Genetic Polymorphisms in Chinese Healthy and Schizophrenia Populations%中国健康人群与精神分裂症患者CYP2D6(C100T)遗传多态性的相关研究

    Institute of Scientific and Technical Information of China (English)

    周健; 李虓; 王刚; 陈雪彦; 康熙雄

    2008-01-01

    目的 探讨中国健康人群与精神分裂症患者细胞色素P450 2D6(CYP2D6)遗传多态性的相关性.方法 应用PCR与DNA测序相结合的方法对88名精神分裂症患者(男40例,女48例;平均年龄40.38±13.45岁)与93名健康志愿者(男40例,女53例,平均年龄43.60±12.05岁)进行了CYP2D6的基因多态性分析,根据CYP2D6(C100T)将精神分裂症患者和健康志愿者基因型分为三组(C/C,C/T,T/T).结果 在CYP2D6(C100T)的基因型和等位基因型检测中,精神分裂症患者和健康志愿者组间的基因型和等位基因没有显著性差异(X2=0.202,P>0.05;X2=0.066,P>0.05).结论 CYP2D6(C100T)可能不是中国精神分裂症患者的一个易感因素.

  11. 他汀类药物降脂治疗的CYP2D6基因多态性及其与高脂血症的关系%Statins therapy in CYP2D6 gene polymorphism and hyperlipidemia

    Institute of Scientific and Technical Information of China (English)

    李居怡; 王健; 王奕; 甘利明; 黄文静; 邓艾平

    2016-01-01

    目的:观察他汀类药物降脂治疗相关的基因多态性位点CYP4502D6* 10(CYP2D6*10)在宁夏地区的分布和对辛伐他汀降脂疗效的影响及其与高脂血症的关系.方法:采用等位基因特异扩增技术,测定150例健康回族人和200例高脂血症患者CYP2D6基因型并分析基因型与血脂水平、辛伐他汀调脂疗效的关系.结果:CYP2D6* 10基因在宁夏地区的突变频率为47.6%,CYP2D6*10等位基因与高脂血症无显著相关性,服用辛伐他汀8周后CC基因型较CT及TT基因型个体总胆固醇(TC)水平明显降低,差异有统计学意义.结论:CYP2D6* 10基因多态性存在种族和地域的差异,CYP2D6* 10基因多态性对TC水平有显著影响,该基因多态性可能成为辛伐他汀调脂疗效的预测因子.

  12. 利培酮治疗与细胞色素P4502D6/C188T酶基因多态性的关联分析%Genetic analysis of the cytochrome P450-2D6(CYP2D6)locus:screening influence of risperidone on clinical outcomes in schizophrenia

    Institute of Scientific and Technical Information of China (English)

    王飚; 杨晓敏; 江三多; 钱伊萍; 汪栋祥; 江开达

    2004-01-01

    目的研究利培酮临床效应的个体差异与其代谢酶细胞色素P450 2D6(cytochrome P450 2D6, CYP2D6)酶基因多态性的相关性.方法对88例符合CCMD-3精神分裂症诊断标准的患者和96例健康对照者作病例-对照分析.精神分裂症患者给予利培酮治疗8周,用阳性和阴性症状量表(positive and negative symptom scale, PANSS)评分评价利培酮疗效.采用聚合酶链反应扩增及限制性片段长度多态性(PCR-RFLP)技术对CYP2D6 exon Ⅰ的C188T位点突变进行检测,分析利培酮临床效应与其主要代谢酶CYP2D6/C188T酶基因多态性的相关性. 结果中国上海地区人群的CYP2D6/C188T突变率(弱代谢型)为36.3%,病例组和正常对照组间基因型频率总体分布比较无显著差异(χ2=1.15, df=2, P>0.05),两组间的等位基因频率之间比较也无显著性差异(χ2=0.78, df=1, P>0.05).进行性别及有否家族史分组后分析,亦无差异存在,且CYP2D6/C188T突变与利培酮临床效应之间并无相关性(χ2=1.12, df=2; χ2=0.03, df=1, P>0.05). 结论未发现中国人CYP2D6/C188T多态性与利培酮临床效应的个体差异有相关性.

  13. CYP2D6和UGT1A6基因多态性与慢性苯中毒的危险性%Association of Genetic Polymorphism of CYP2D6 and UGT1A6 with Risks of Chronic Benzene Poisoning

    Institute of Scientific and Technical Information of China (English)

    顾寿永; 张忠彬; 曹多志; 万俊香; 高晓玲; 金锡鹏; 夏昭林

    2005-01-01

    目的探讨CYP2D6基因和UGT1A6基因多态性与慢性苯中毒易感性的关系.方法采用病例一对照研究,选择152名苯中毒工人为病例组,152名接触苯而无中毒表现的工人为对照组.采用PCR-RFLP技术检测CYP2D6第9外显子g.4268位点和UGT1A6第1外显子t.181位点的多态性.结果携带CYP2D6 g.4268 C/C基因型的个体较携带有CYP2D6 g.4268 G/G或G/C基因型的个体发生苯中毒的危险性高1.72倍(95%CI:1.8~2.78,P=0.03);在不吸烟的人群中,携带CYP2D6 g.4268 C/C基因型的个体比携带G/G或G/C基因型的个体发生苯中毒的风险性高1.75倍(95%CI:1.03~2.94,P=0.04);在不饮酒的人群中,携带CYP2D6 g.4268 C/C基因型个体比携带CYP2D6 g.4268 G/G和G/C基因型的个体发生苯中毒的危险性高1.82倍(95%CI:1.09~3.03,P=0.02).UGT1A6 t.181的各基因型在病例组和对照组的分布频率差异无显著性(P>0.05).结论携带CYP2D6 g.4268 C/C基因型的个体对苯中毒可能易感.

  14. Large area flexible SERS active substrates using engineered nanostructures

    Science.gov (United States)

    Chung, Aram J.; Huh, Yun Suk; Erickson, David

    2011-07-01

    Surface enhanced Raman scattering (SERS) is an analytical sensing method that provides label-free detection, molecularly specific information, and extremely high sensitivity. The Raman enhancement that makes this method attractive is mainly attributed to the local amplification of the incident electromagnetic field that occurs when a surface plasmon mode is excited at a metallic nanostructure. Here, we present a simple, cost effective method for creating flexible, large area SERS-active substrates using a new technique we call shadow mask assisted evaporation (SMAE). The advantage of large, flexible SERS substrates such as these is they have more area for multiplexing and can be incorporated into irregular surfaces such as clothing. We demonstrate the formation of four different types of nanostructure arrays (pillar, nib, ellipsoidal cylinder, and triangular tip) by controlling the evaporation angle, substrate rotation, and deposition rate of metals onto anodized alumina nanoporous membranes as large as 27 mm. In addition, we present experimental results showing how a hybrid structure comprising of gold nanospheres embedded in a silver nano-pillar structure can be used to obtain a 50× SERS enhancement over the raw nanoparticles themselves.Surface enhanced Raman scattering (SERS) is an analytical sensing method that provides label-free detection, molecularly specific information, and extremely high sensitivity. The Raman enhancement that makes this method attractive is mainly attributed to the local amplification of the incident electromagnetic field that occurs when a surface plasmon mode is excited at a metallic nanostructure. Here, we present a simple, cost effective method for creating flexible, large area SERS-active substrates using a new technique we call shadow mask assisted evaporation (SMAE). The advantage of large, flexible SERS substrates such as these is they have more area for multiplexing and can be incorporated into irregular surfaces such as

  15. Substrate modulation of enzyme activity in the herpesvirus protease family

    OpenAIRE

    Lazic, Ana; Goetz, David H.; Nomura, Anson M.; Marnett, Alan B.; Craik, Charles S.

    2007-01-01

    The herpesvirus proteases are an example in which allosteric regulation of an enzyme activity is achieved through the formation of quaternary structure. Here, we report a 1.7 Å resolution structure of Kaposi’s Sarcoma herpesvirus protease in complex with a hexapeptide transition state analogue that stabilizes the dimeric state of the enzyme. Extended substrate binding sites are induced upon peptide binding. In particular, 104 Å2 of surface are buried in the newly formed S4 pocket when tyrosin...

  16. Genetic polymorphisms of CYP2D6*10 and the effectiveness of combined tamoxifen citrate and testosterone undecanoate treatment in infertile men with idiopathic oligozoospermia*

    Science.gov (United States)

    Tang, Kai-fa; Zhao, Yi-li; Ding, Shang-shu; Wu, Qi-fei; Wang, Xing-yang; Shi, Jia-qi; Sun, Fa; Xing, Jun-ping

    2015-01-01

    Tamoxifen citrate, as the first line of treatment for infertile men with idiopathic oligozoospermia, was proposed by the World Health Organization (WHO), and testosterone undecanoate has shown benefits in semen values. Our objective was to assess the effectiveness of treatment with tamoxifen citrate and testosterone undecanoate in infertile men with idiopathic oligozoospermia, and whether the results would be affected by polymorphisms of CYP2D6*10. A total of 230 infertile men and 147 controls were included in the study. Patients were treated with tamoxifen citrate and testosterone undecanoate. Sex hormone, sperm parameters, and incidence of spontaneous pregnancy were detected. There were no significant differences between the control and patient groups with respect to CYP2D6*10 genotype frequencies (P>0.05). The follicle-stimulation hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were raised, and sperm concentration and motility were increased at 3 months and became significant at 6 months, and they were higher in the wild-type allele (C/C) than in the heterozygous variant allele (C/T) or homozygous variant allele (T/T) subgroups (P<0.05). In addition, the percentage of normal morphology was raised at 6 months, and represented the highest percentage in the C/C subgroup (P<0.05). The incidence of spontaneous pregnancy in the C/C subgroup was higher than that in the C/T or T/T subgroups (P<0.01). This study showed that the CYP2D6*10 variant genotype demonstrated worse clinical effects in infertile men with idiopathic oligozoospermia. PMID:25743120

  17. Genetic polymorphisms of CYP2D6*10 and the effectiveness of combined tamoxifen citrate and testosterone undecanoate treatment in infertile men with idiopathic oligozoospermia.

    Science.gov (United States)

    Tang, Kai-fa; Zhao, Yi-li; Ding, Shang-shu; Wu, Qi-fei; Wang, Xing-yang; Shi, Jia-qi; Sun, Fa; Xing, Jun-ping

    2015-03-01

    Tamoxifen citrate, as the first line of treatment for infertile men with idiopathic oligozoospermia, was proposed by the World Health Organization (WHO), and testosterone undecanoate has shown benefits in semen values. Our objective was to assess the effectiveness of treatment with tamoxifen citrate and testosterone undecanoate in infertile men with idiopathic oligozoospermia, and whether the results would be affected by polymorphisms of CYP2D6*10. A total of 230 infertile men and 147 controls were included in the study. Patients were treated with tamoxifen citrate and testosterone undecanoate. Sex hormone, sperm parameters, and incidence of spontaneous pregnancy were detected. There were no significant differences between the control and patient groups with respect to CYP2D6*10 genotype frequencies (P>0.05). The follicle-stimulation hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were raised, and sperm concentration and motility were increased at 3 months and became significant at 6 months, and they were higher in the wild-type allele (C/C) than in the heterozygous variant allele (C/T) or homozygous variant allele (T/T) subgroups (P<0.05). In addition, the percentage of normal morphology was raised at 6 months, and represented the highest percentage in the C/C subgroup (P<0.05). The incidence of spontaneous pregnancy in the C/C subgroup was higher than that in the C/T or T/T subgroups (P<0.01). This study showed that the CYP2D6*10 variant genotype demonstrated worse clinical effects in infertile men with idiopathic oligozoospermia. PMID:25743120

  18. Implication of Xenobiotic Metabolizing Enzyme gene (CYP2E1, CYP2C19, CYP2D6, mEH and NAT2 Polymorphisms in Breast Carcinoma

    Directory of Open Access Journals (Sweden)

    Gabbouj Sallouha

    2008-04-01

    Full Text Available Abstract Background Xenobiotic Metabolizing Enzymes (XMEs contribute to the detoxification of numerous cancer therapy-induced products. This study investigated the susceptibility and prognostic implications of the CYP2E1, CYP2C19, CYP2D6, mEH and NAT2 gene polymorphisms in breast carcinoma patients. Methods The authors used polymerase chain reaction and restriction enzyme digestion to characterize the variation of the CYP2E1, CYP2C19, CYP2D6, mEH and NAT2 gene in a total of 560 unrelated subjects (246 controls and 314 patients. Results The mEH (C/C mutant and the NAT2 slow acetylator genotypes were significantly associated with breast carcinoma risk (p = 0.02; p = 0.01, respectively. For NAT2 the association was more pronounced among postmenopausal patients (p = 0.006. A significant association was found between CYP2D6 (G/G wild type and breast carcinoma risk only in postmenopausal patients (p = 0.04. Association studies of genetic markers with the rates of breast carcinoma specific overall survival (OVS and the disease-free survival (DFS revealed among all breast carcinoma patients no association to DFS but significant differences in OVS only with the mEH gene polymorphisms (p = 0.02. In addition, the mEH wild genotype showed a significant association with decreased OVS in patients with axillary lymph node-negative patients (p = 0.03 and with decreasesd DFS in patients with axillary lymph node-positive patients (p = 0.001. However, the NAT2 intermediate acetylator genotype was associated with decreased DFS in axillary lymph node-negative patients. Conclusion The present study may prove that polymorphisms of some XME genes may predict the onset of breast carcinoma as well as survival after treatment.

  19. 26种中药提取物对CYP3A4和CYP2D6代谢的抑制作用

    Institute of Scientific and Technical Information of China (English)

    Iwata; H; 郑晓燕(摘译); 阴赪宏(校)

    2005-01-01

    研究认为,细胞色素P450(CYP)酶与药物相互作用。本次在NADPH-生成体系存在的情况下,以单味中药甲醇提取物对人肝细胞微粒体进行预培养,检测26种中药对CYP3A4和CYP2D6的抑制作用。

  20. 氨苄西林与双黄连注射液单用及配伍时对大鼠CYP2D6的影响%Effects on CYP2D6 by the Single Use of Ampicillin and Shuanghuanglian or Combination of Both

    Institute of Scientific and Technical Information of China (English)

    王欢; 吴东媛; 杜智敏

    2008-01-01

    目的 通过氨苄西林和双黄连注射液的大鼠体内、外实验,观察两种药物分别给药及合用时对大鼠CYP2D6的影响.方法 对照组和实验组大鼠分别经尾静脉注射给予0.9%氯化钠溶液、双黄连注射液、氨苄西林、双黄连注射液联合氨苄西林,均给药1周.高效液相色谱法测定大鼠尿样及肝微粒体中CYP2D6探针药物右美沙芬的代谢率,观察氨苄西林、双黄连注射液分别单用及合用时对大鼠CYP2D6活性的影响.通过Western blot法测定其对大鼠肝微粒体CYP2D6蛋白表达的调控.结果 实验组大鼠分别给予双黄连注射液、氨苄西林及双黄连注射液配伍氨苄西林时,尿样中右美沙芬代谢率与对照组差异无显著性(P>0.05);实验组大鼠肝微粒体中加入右美沙芬(0.324 mmol·L-1),右美沙芬代谢率与对照组差异无显著性(P>0.05);各实验组与对照组CYP2D6蛋白表达差异无显著性.结论 双黄连注射液、氨苄西林单用和两药配伍使用均不影响CYP2D6酶的活性,与同时使用经CYP2D6代谢的其他药物不会产生相互作用.

  1. CYP2D6*10 polymorphism and response to donepezil in patients with Alzheimer's disease%阿尔茨海默病CYP2D6*10基因多态性与多奈哌齐疗效

    Institute of Scientific and Technical Information of China (English)

    郑雪丽; 苗雅; 钟远; 万丽丽

    2012-01-01

    目的 研究阿尔茨海默病(AD)患者CYP2D6* 10基因多态性对多奈哌齐疗效的影响.方法 筛选AD患者110例(AD组)和健康体检者124例(对照组),应用限制性片段长度多态性-聚合酶链反应(RFLP-PCR)方法对两组患者进行CYP2D6*10基因多态性测定.AD组给予多奈哌齐治疗6个月,于服药前后,应用简易精神状态量表( MMSE)和阿尔茨海默病评定量表认知分量表(ADAS-Cog)进行认知功能测定;应用高效液相色谱-质谱法测定患者血浆中多奈哌齐的稳态血药浓度.结果 AD组与对照组CYP2D6*10的基因型和等位基因频率分布差异无统计学意义(P>0.05);AD组CYP2D6*10基因突变型(T/T型与C/T型)的血药浓度、MMSE和ADAS-Cog评分与野生型(C/C型)相比,差异均有统计学意义(P< 0.05).结论 多奈哌齐对阿尔茨海默病CYP2D6* 10基因突变型患者的疗效优于野生型患者.%Objective To analyze the relation of CYP2D6* 10 polymorphism with response to donepezil in patients with Alzheimer's disease(AD). Methods A total of 110 AD patients (AD group) and 124 healthy individuals (control group) were recruited for the study. RFLP-PCR was applied to analyze the CYP2D6*10 gene polymorphisms. Besides, the AD patients were administrated with donepezil 5-10 mg/d for 6 months and evaluated by cognition scales (MMSE and ADAS-Cog) before and after therapy. The steady plasma concentration (Cp) of donepezil was measured by HPLC-MS. Results There was no statistical difference in genotypes and allele frequency of CYP2D6* 10 between AD group and control group. However, significant differences were found in AD patients on steady concentration of donepezil and cognition scores (MMSE and ADAS-Cog) between CYP2D6*10 mutant genotypes (T/T and C/T group) and wild type (C/C group) (P < 0.05). Conclusions Donepezil is more effective for AD patients carrying CYP2D6*10 mutants than those carrying wild type.

  2. Influence of CYP2D6 genetic polymorphism on pharmacokinetics of metoprolol in Chinese population%中国人群CYP2D6基因多态性对美托洛尔药代动力学的影响

    Institute of Scientific and Technical Information of China (English)

    李芹; 王睿; 郭雅; 裴斐

    2008-01-01

    目的:研究中国人群CYP2D6基因多态性对美托洛尔药代动力学的影响.方法:使用基因芯片技术测定中国健康志愿者CYP2D6的基因型,按照分型结果将志愿者分为四组,第1组:CYP2D6*2W*10W,第2组:CYP2D6*2H*10W或CYP2D6*2M*10W,第3组:CYP2D6*2M*10H,第4组:CYP2D6*2M*10M,每组筛选10人,共40人.各组志愿者单次口服 100 mg 美托洛尔后,使用HPLC方法测定血和尿中美托洛尔及其代谢产物α-羟基美托洛尔(HM)的浓度,研究其在不同基因型志愿者体内的药代过程.结果:第2组美托洛尔及其HM的主要药动学参数与第1组相比均没有统计学差异.第3组美托洛尔的t1/2、AUC、Cmax显著高于第1组(P<0.05);而HM的t1/2延长 47.3%,AUC降低 56.0%(P<0.05).第4组美托洛尔的t1/2、AUC、Cmax均显著高于第1组(P<0.05)和第3组(P<0.05);HM的t1/2、AUC、Cmax与第1组和第3组相比均有统计学差异(P<0.05),且呈现基因剂量效应.第3组和第4组的口服清除率和肾清除率均低于第1组,而0~24 h 代谢比率分别为第1组的 1.82 倍和 3.96 倍.结论:CYP2D6*2对于美托洛尔的药代动力学过程没有影响;但CYP2D6*10可降低酶活性,且CYP2D6*10纯合子变异比杂合子变异对美托洛尔药代动力学的影响更大,呈现基因剂量效应.

  3. Interaction of drug metabolizing cytochrome P450 2D6 poor metabolizers with cytochrome P450 2C9 and 2C19 genotypes modify the susceptibility to head and neck cancer and treatment response

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Sunishtha S.; Ruwali, Munindra [Developmental Toxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Council CSIR, P.O. Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India); Pant, Mohan C.; Shukla, Pragya [Department of Radiotherapy, C.S.M. Medical University, Shahmina Road, Lucknow 226 001 (India); Singh, Ram L. [Department of Biochemistry, Dr. R.M.L. Awadh University, Faizabad 224 001, U.P. (India); Parmar, Devendra, E-mail: parmar_devendra@hotmail.com [Developmental Toxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Council CSIR, P.O. Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India)

    2010-02-03

    The present case-control study attempted to investigate the association of poor metabolizer (PM) genotypes of cytochrome P450 2D6 (CYP2D6*4 and CYP2D6*10) with squamous cell carcinoma of head and neck (HNSCC) and treatment response in patients receiving chemotherapy or combination of chemo- and radiotherapy. Cases with the PM genotypes of CYP2D6 displayed a significantly increased risk for HNSCC as compared to wild type genotypes. The risk was found to further increase in cases (up to 4.8) carrying combination of PM genotypes of CYP2D6, CYP2C9 (CYP2C9*2) or CYP2C19 (CYP2C19*2), suggesting that synergism amongst the PM genotypes of drug metabolizing CYPs leads to impairment in the detoxification of the tobacco carcinogens. A small increase in the risk in tobacco (chewers or smokers) or alcohol users in cases with CYP2D6*4 allele while no change or even a small decrease in risk in cases with CYP2D6*10 allele when compared to non-tobacco or alcohol users have suggested that CYP2D6 genotypes alone do not appear to interact significantly with environmental risk factors in modifying the susceptibility to HNSCC. Furthermore, most of the cases carrying PM genotypes of CYP2D6 did not respond to the treatment. Moreover, higher prevalence of non-responders among cases carrying combination of CYP2D6*4 or CYP2D6*4, CYP2C9*2 and CYP2C19*2 have demonstrated that interaction of PM genotypes may not only significantly modify the susceptibility to HNSCC but also the treatment response.

  4. CYP1A1和CYP2D6基因多态性对白血病发生的影响%Genetic polymorphisms of CYP1A1 and CYP2D6 and their impact on leukemia morbidity

    Institute of Scientific and Technical Information of China (English)

    李文凯; 刘清霞; 陈放知; 骆亚萍; 陈慧娟; 夏嘉志; 陈汉春

    2008-01-01

    目的 分析细胞色素P450 CYP1A1和CYP2D6的多态性基因型在湖南地区白血病患者和健康人群中的分布及其对白血病发生的影响.方法 采用PCR及PCR-RFLP技术分析多态性基因型频率.结果 CYP1A1和CYP2D6基因的野生型、杂合突变型及纯合突变型的分布频率在急性淋巴细胞性白血病、急性非淋巴细胞性白血病、慢性粒细胞性白血病患者组与健康对照组之间无显著性差异;携带一个突变等位基因型的个体患白血病的风险与相应野生型携带者比较均无显著性差异;急性非淋巴细胞性白血病患者组的CYP1A1杂合突变型与CYP2D6杂合突变型的联合基因型频率高于健康对照组.结论 单独的CYP1A1或CYP2D6基因的多态性变异与白血病易感性不相关;CYP1A1杂合突变与CYP2D6杂合突变的联合基因型增加患急性非淋巴细胞性白血病的风险.

  5. The correlation between ACE and CYP2D6 polymorphism and the effect of perindopril%心衰患者 ACE 及 CYP2 D6遗传多态性与培哚普利疗效的关联性研究

    Institute of Scientific and Technical Information of China (English)

    彭俊; 黄自明; 郭观华

    2015-01-01

    Objective To investigate the correlation between ACE and CYP 2D6 polymorphism and the effect of perindopril.Methods The genotype was determined by PCR in 158 patients.The differences of left ventricular end-diastolic diameters ( LVDD) , left ventricular ejection fractions ( LVEF) and AngⅡlevel before and after perindo-pril treatment were detected .Results The patients with DD/CC, DD/CT and DD/TT phenotype had a great de-crease in LVDD and AngⅡ after perindopril treatment .Conclusion ACE polymorphisms correlates to the effect of perindopril treatment .CYPD2D6 polymorphism does not correlate to the perindopril treatment .%目的:探讨心衰患者ACE及CYP2D6遗传多态性与培哚普利疗效的关联性。方法选取158例心衰患者,应用PCR方法检测其ACE及CYP2D6多态性,给予培哚普利治疗,对治疗前后的左室舒张末期内径( LVDD)、左室射血分数( LVEF)和血浆血管紧张素Ⅱ( AngⅡ)进行检测。结果 DD/CC、DD/CT和DD/TT型患者经治疗后,LVDD明显缩小,且血浆AngⅡ水平下降的幅度最大。结论 ACE基因的多态性与培哚普利的治疗效果有关联性,CYP2D6基因多态性对培哚普利的疗效无明显影响。

  6. Escitalopram er en svag hæmmer af CYP2D6-katalyserede O-demetylering af (+)-tramadol, men ikke mindsker hypoalgesic virkning i eksperimentelle smerter

    DEFF Research Database (Denmark)

    Noehr-Jensen, L; Zwisler, S T; Larsen, F;

    2009-01-01

    Tramadol er O-demethylerede til den aktive metabolit (+)-O-desmethyltramadol ((+)- M1) via CYP2D6, et enzym, der er svagt hæmmes af escitalopram. Vi har undersøgt muligheden for en farmakokinetisk (PK) og farmakodynamiske (PD) virkningen af escitalopram på tramadol metabolisme. Femten raske...... forsøgspersoner afsluttet denne randomiseret, dobbeltblindt, trefaset, crossover forsøg. Kombinationer af escitalopram 20 mg / dag eller placebo sammen med tramadol 150 mg eller placebo blev anvendt. Blodprøver til farmakokinetik blev trukket på 0-24 timer efter medicinering. Den analgetiske virkning af (+)-M...... 1,95 mikromol / LH efter escitalopram (P = 0,0027). Den gennemsnitlige ÄúÊÇ (1-12) af CPT var 4.140 og 4.388 cm.s efter placebo og escitalopram (p = 0,71). Selvom escitalopram er en svag hæmmer af CYP2D6, er det ikke forringer den analgetiske virkning af tramadol....

  7. 细胞色素P4502D6基因多态性和药物相互作用%Genetic polymorghism of CYP2D6 and drug interactions

    Institute of Scientific and Technical Information of China (English)

    李芹; 王睿

    2006-01-01

    细胞色素P4502D6(CYP2D6)是一种重要的P450系氧化代谢酶,参与多种重要药物的代谢.CYP2D6具有基因多态性,对药物的代谢呈现明显的个体差异.而且CYP2D6能被多种药物竞争性抑制和诱导,药物联用时易产生相互作用.本文从CYP2D6的基因多态性与代谢表型、底物竞争作用、代谢酶的诱导和抑制等方面,探讨CYP2D6基因多态性与药物相互作用的关系.

  8. 乳腺癌患者CYP2D6多态性与Endoxifen血药浓度的相关性分析%Association between CYP2D6 polymorphism and plasma concentration of Endoxifen in breast cancer patients

    Institute of Scientific and Technical Information of China (English)

    杨汐; 罗波; 吴斌

    2013-01-01

    目的:研究乳腺癌术后服用他莫昔芬(TAM)辅助治疗绝经前、雌激素受体(ER)阳性患者CYP2D6基因多态性与TAM活性代谢产物Endoxifen血药浓度的相关性,及其与TAM不良反应发生的相关性.方法:57例乳腺癌术后经TAM辅助治疗的患者(绝经前、ER阳性),采用Tetra-primer ARMS PCR检测其CYP2D6基因型,采用LC-MS/MS测定所有患者体内TAM及其活性代谢产物Endoxifen的血药浓度;根据患者自述标记存在治疗不良反应的个体.结果:CYP2D6* 10/* 10型和*1/* 10型受试者体内Endoxifen的血药浓度值分别为(23.55±4.01)和(25.90±3.93) ng/mL,均显著低于*1/*1型受试者(34.82±5.95) ng/mL,差异有统计学意义,P<0.01;但*10/* 10型和*1/* 10型之间Endoxifen的浓度值差异无统计学意义,P>0.05.CYP2D6* 1/*1型组自述无任何不良反应的比例(22.2%)低于突变组(62.5%),且差异有统计学意义,P<0.05.结论:CYP2D6基因多态性与Endoxifen血药浓度的差异及TAM治疗不良反应的发生有关;根据CYP2D6基因型,可指导绝经前、ER阳性乳腺癌患者术后的TAM个体化用药.

  9. β1肾上腺素受体与CYP2D6基因多态性对美托洛尔抗高血压治疗的影响%Effectes of β1-adrenergic receptor and CYP2D6 gene polymorphism on metoprolol antihypertension therapy

    Institute of Scientific and Technical Information of China (English)

    徐承华; 杨玉雯; 曹蘅

    2011-01-01

    AIM: To investigate effects of β1-adrenergic receptor and CYP2D6 gene polymorphism on metoprolol antihypertension therapy. METHODS: 120 cases of patients with essential hypertension were detected by β1 -adrenergic receptor and CYP2D6 gene polymorphism, 118 patients with Arg 389 allele in β1- adrenergic re-ceptor gene chosen from 120 essential hypertension patients were divided into three phenotype groups according to CYP2D6 gene mutations: the poor metabolism group(PM, 55 cases), intermediate metabolism group (IM, 36 cases)and extensive metabolism group(EM, 27 cases). The subjects of PM, IM and EM were administratedwith metoprolol for the same doseQOO mg/d), taking orally twice a day. Blood pressures, heart rates and side effects were observed during 4-week following-up. RESULTS: Blood pressure and heart rate in group PM, IM and EM were decreased, especially, obviously decreased in group PM, however, the incidence of side effect was significantly increased in group PM. CONCLUSION: The genetic polymorphism of β1- ad-renergic receptor and CYP2D6 was associated with the efficiency of metoprolol antihyperten-sion therapy.%目的:探讨β1肾上腺素受体与CYP2D6基因多态性对美托洛尔抗高血压治疗的影响.方法:将2008年10月至2009年10月在安徽省皖南地区收集的120例原发性高血压患者进行岛肾上腺素能受体(β1-AR)和代谢酶细胞色素2136(CYP2D6)基因多态性检测,将β1-AR 389位携带Arg的118例患者按照CYP2D6基因表型分为弱代谢组(PM组,55例)、中等代谢组(IM组,36例)和强代谢组(EM组,27例),给予相同剂量(100 mg/d)美托洛尔,均分2次口服降压治疗,共随访4周,观察血压、心率和不良反应等指标.结果:PM、IM、EM组血压和心率均下降,尤以PM组血压和心率降幅最大,但不良反应发生率明显增加.结论:β1肾上腺素受体和CYP2D6基因多态性与美托洛尔降压疗效有一定相关性.

  10. Genetic polymorphism analysis of cytochromeP450 CYP2D6 and CYP2C19 in Han and Uyghur breast cancer patients in Xinjiang%新疆汉族与维吾尔族乳腺癌CYP2D6和CYP2C19基因多态性差异研究

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    目的 探讨新疆汉族与维吾尔族绝经前乳腺癌患者CYP2D6和CYP2C19基因频率分布及他莫昔芬代谢类型以指导临床合理用药.方法 选取2011-06-01-2013-12-01新疆医科大学附属肿瘤医院绝经前激素受体阳性乳腺癌患者中汉族125例和维吾尔族121例,对CYP450中常见突变位点利用TaqMan(R)-MGB技术进行基因检测并确定他莫昔芬代谢类型.结果 CYP2D6(* 1/* 10)、CYP2D6(* 10/* 10)及CYP2C19(* 1/*1)基因型在汉族、维吾尔族两组患者中表达差异有统计学意义,x2值分别为1.123、9.746和5.935,P值分别为0.029、0.002和0.015;而CYP2D6(* 1/*5)、CYP2D6(* 5/*5)、CYP2D6(* 5/* 10)、CYP2C19(* 3/*3)基因型在两组患者中均无表达,差异无统计学意义,P>0.05.两组中CYP2D6(* 1/*1)、CYP2C19(* 1/*2)、CYP2C19(* 2/*2)、CYP2C19(* 1/*3)和CYP2C19(* 2/*3)基因型差异无统计学意义,P>0.05.汉族患者他莫昔芬快、中、慢代谢型者比例分别为72.0%、24.0%和4.0%,维吾尔族分别为76.9%、17.4%和5.7%,P>0.05.结论 汉族、维吾尔族乳腺癌患者中CYP2C19*2、CYP2C19*3基因频率均差异无统计学意义;而CYP2D6* 10等位基因的频率差异有统计学意义;他莫昔芬的代谢类型均以快代谢类型为主,两组之间差异无统计学意义.

  11. Genetic polymorphism of CYP2D6 in Karnataka and AndhraPradesh population in India%CYP2D6在印度卡纳塔克邦和安得拉邦人群中的遗传多态性

    Institute of Scientific and Technical Information of China (English)

    Benny K ABRAHAM, C ADITHAN; P USHA KIRAN; Mohammed ASAD; K KOUMARAVELOU

    2000-01-01

    AIM: To study the prevalence of cytochrome P-450 2D6 (CYP2D6) polymorphism in Karnataka ( KA ) and Andhra Pradesh (AP) population. METHODS: Two hundred and eleven healthy human volunteers participated in the study (100 from KA and 111 from AP). At bed time, after voiding their bladder, the volunteers ingested 30 mg of dextromethorphan hydrobromide (DM). Urine samples were collected for 8 h. DM and its metabolite dextrorphan (DT) were estimated in the urine using HPLC. The metabolic ratio (DM/DT) was used for phenotyping. RESULTS: The prevalence of poor metabolisers (PM) in KA is 4 % and AP is 1.8 %.CONCLUSION: The frequency of PM phenotype in South Indian population is in between the Western and Oriental population.

  12. Effects of CYP2D6*10 genetic polymorphism on the protection of metoprolol for the elder during perioperative period%CYP2D6*10遗传基因多态性对美托洛尔在围术期保护老年患者心脏功能的影响

    Institute of Scientific and Technical Information of China (English)

    刘芳; 张燕; 先小纲

    2014-01-01

    目的:探讨CYP2D6*10等位基因C188T单核苷酸多态性与美托洛尔(metoprolol,METO)在老年患者围术期心脏保护疗效的关系.方法:筛选323名应用METO预防围术期心血管风险的老年患者,采用PCR-RFLP法分析CYP2D6*10基因C188>T位点的单核苷酸多态性.患者用药后进行围术期临床跟踪,观测并评价METO治疗围术期血流动力学紊乱发生事件及个体服药后3h肌钙蛋白的变化.结果:本研究人群中CYP2D6* 10外显子C188>T位点的C、T等位基因频率分别为48.76%和51.24%,CYP2D6* 10基因野生型纯合子C/C、杂合子C/T、突变型纯合子T/T基因型人群分布分别为24.76%、47.98%和27.24%,其频率分布均符合Hardy-Weinberg平衡定律.统计结果显示基因型与心血管术后均有中等强度关联.对心肌梗死风险因子的散点图按照基因多态性分布情况进行分组后分析发现,其心血管风险增高与CYP2D6* 10遗传多态性存在相关的基因剂量效应.结论:CYP2D6* 10基因多态性(C188>T)可能导致METO在老年患者围术期中的心脏保护功能增强,同时还可能带来心动过缓的副作用.CYP2D6* 10突变与METO疗效密切相关,可致患者用药后收缩压显著改变,临床应关注CYP2D6遗传多态性对METO疗效的影响.

  13. Transient Response of Aerobic and Anoxic Activated Sludge Activities to Sudden Substrate Concentration Changes

    DEFF Research Database (Denmark)

    Sin, G.; Vanrolleghem, P.A.; Gernaey, Krist

    2004-01-01

    The state-of-the-art understanding of activated sludge processes as summarized in activated sludge models (ASMs) predicts an instantaneous increase in the biomass activity (which is measured, e.g., by the corresponding respiration rate OUR, NUR, etc.) under sudden substrate concentration changes...... process. That transient phenomenon exhibits itself immediately upon addition of a substrate source to an endogenously respiring activated sludge sample and it usually takes a few minutes until the activated sludge reaches its maximum possible rate under given environmental conditions. This discrepancy...... response of the activated sludge most likely results from the sequence of intracellular reactions involved in substrate degradation by the activated sludge. Results from studies performed elsewhere with pure cultures (S. cerevisae and E. coli) support the hypothesis. The transient phenomenon can...

  14. An Experimental and Theoretical Study on the Kinetic Isotope Effect of C2H6 and C2D6 Reaction with OH

    KAUST Repository

    Khaled, Fethi

    2015-10-30

    We report experimental and theoretical results for the deuterated kinetic isotope effect (DKIE) of the reaction of OH with ethane (C2H6) and deuterated ethane (C2D6). The reactions were investigated behind reflected shock waves over 800–1350 K by monitoring OH radicals near 306.69 nm using laser absorption. In addition, high level CCSD(T)/cc-pV(T,Q)Z//MP2/cc-pVTZ quantum chemical and statistical rate theory calculations were performed which agreed very well with the experimental findings. The results reported herein provide the first experimental evidence that DKIE for alkanes asymptotes to a value of 1.4 at high temperatures.

  15. 基因芯片技术对中国人群细胞色素P450 2D6基因多态性的研究

    Institute of Scientific and Technical Information of China (English)

    李芹; 王睿

    2005-01-01

    目的:探讨基因芯片技术在细胞色素P450 2D6基因分型中应用的可行性,研究中国人群CYP2D6的基因多态性。方法建立寡核苷酸芯片测定CYP2D6基因型的方法,测定288例中国健康志愿者CYP2D6基因分型,并使用直接测序法对结果进行验证。结果:288例中国健康志愿者中CYP2D6*2和CYP2D6*10的变异频率分别高达52.8%和53.5%。对部分样本采用直接测序的方法进行进一步确证,结果完全吻合。结论:基因芯片法适用于中国人群CYP2D6基因分型研究。

  16. Study on association of polymorphism of CYP450 2D6 with head and neck cancer and treatment response in patients receiving neoadjuvant chemotherapy paclitaxel, cisplatin, 5fu (TPF followed by chemoradiation

    Directory of Open Access Journals (Sweden)

    Divyesh Kumar

    2014-04-01

    Results: Patients with CYP 2D6 1 showed good response to the therapy given, while CYP 2D6 4 and 10 were poor responders. Conclusion: There is a strong association of polymorphs of CYP 2D6 with occurrence of head and neck cancer. Response to treatment (TPF--CT-RT is polymorph graded. Our study thus provides an insight in to the concept of and ldquo;Right therapy to the right patient and rdquo;. [Int J Res Med Sci 2014; 2(2.000: 585-591

  17. Substrate integrated ferrite phase shifters and active frequency selective surfaces

    CERN Document Server

    Cahill, B M

    2002-01-01

    There are two distinct parts to this thesis; the first investigates the use of ferrite tiles in the construction of printed phase shifting transmission lines, culminating in the design of two compact electromagnetic controlled beam steered patch and slot antenna arrays. The second part investigates the use of active frequency selective surfaces (AFSS), which are later used to cover a uPVC constructed enclosure. Field intensity measurements are taken from within the enclosure to determine the dynamic screening effectiveness. Trans Tech G-350 Ferrite is investigated to determine its application in printed microstrip and stripline phase shifting transmission lines. 50-Ohm transmission lines are constructed using the ferrite tile and interfaced to Rogers RT Duroid 5870 substrate. Scattering parameter measurements are made under the application of variable magnetic fields to the ferrite. Later, two types of planar microwave beam steering antennas are constructed. The first uses the ferrites integrated into the Dur...

  18. Substrate regulation of ascorbate transport activity in astrocytes

    International Nuclear Information System (INIS)

    Astrocytes possess a concentrative L-ascorbate (vitamin C) uptake mechanism involving a Na(+)-dependent L-ascorbate transporter located in the plasma membrane. The present experiments examined the effects of deprivation and supplementation of extracellular L-ascorbate on the activity of this transport system. Initial rates of L-ascorbate uptake were measured by incubating primary cultures of rat astrocytes with L-[14C]ascorbate for 1 min at 37 degrees C. We observed that the apparent maximal rate of uptake (Vmax) increased rapidly (less than 1 h) when cultured cells were deprived of L-ascorbate. In contrast, there was no change in the apparent affinity of the transport system for L-[14C]ascorbate. The increase in Vmax was reversed by addition of L-ascorbate, but not D-isoascorbate, to the medium. The effects of external ascorbate on ascorbate transport activity were specific in that preincubation of cultures with L-ascorbate did not affect uptake of 2-deoxy-D-[3H(G)]glucose. We conclude that the astroglial ascorbate transport system is modulated by changes in substrate availability. Regulation of transport activity may play a role in intracellular ascorbate homeostasis by compensating for regional differences and temporal fluctuations in external ascorbate levels

  19. Substrate integrated ferrite phase shifters and active frequency selective surfaces

    International Nuclear Information System (INIS)

    There are two distinct parts to this thesis; the first investigates the use of ferrite tiles in the construction of printed phase shifting transmission lines, culminating in the design of two compact electromagnetic controlled beam steered patch and slot antenna arrays. The second part investigates the use of active frequency selective surfaces (AFSS), which are later used to cover a uPVC constructed enclosure. Field intensity measurements are taken from within the enclosure to determine the dynamic screening effectiveness. Trans Tech G-350 Ferrite is investigated to determine its application in printed microstrip and stripline phase shifting transmission lines. 50-Ohm transmission lines are constructed using the ferrite tile and interfaced to Rogers RT Duroid 5870 substrate. Scattering parameter measurements are made under the application of variable magnetic fields to the ferrite. Later, two types of planar microwave beam steering antennas are constructed. The first uses the ferrites integrated into the Duroid as microstrip lines with 3 patch antennas as the radiating elements. The second uses stripline transmission lines, with slot antennas as the radiating sources etched into the ground plane of the triplate. Beam steering is achieved by the application of an external electromagnet. An AFSS is constructed by the interposition of PIN diodes into a dipole FSS array. Transmission response measurements are then made for various angles of electromagnetic wave incidence. Two states of operation exist: when a current is passed through the diodes and when the diodes are switched off. These two states form a high pass and band stop space filter respectively. An enclosure covered with the AFSS is constructed and externally illuminated in the range 2.0 - 2.8GHz. A probe antenna inside the enclosure positioned at various locations through out the volume is used to establish the effective screening action of the AFSS in 3 dimensional space. (author)

  20. Effect of low-dose ritonavir (100 mg twice daily) on the activity of cytochrome P450 2D6 in healthy volunteers

    NARCIS (Netherlands)

    Aarnoutse, Rob E; Kleinnijenhuis, Johanneke; Koopmans, Peter P; Touw, Daan J; Wieling, Jaap; Hekster, Yechiel A; Burger, David M

    2005-01-01

    OBJECTIVE: In the treatment of human immunodeficiency virus infection, the protease inhibitor ritonavir is used in a low dose (100 mg twice daily) to inhibit cytochrome P450 (CYP) 3A4 and thereby increase plasma concentrations of coadministered protease inhibitors. When applied in a therapeutic dose

  1. Analysis of SNP genetic polymorphism in CYP3A4 and CYP2D6 in Chinese Han population%中国汉族人群CYP2D6、CYP3A4 SNP位点基因多态性分析

    Institute of Scientific and Technical Information of China (English)

    杨栋; 万立华; 涂政; 石屹; 胡兰

    2014-01-01

    目的:通过对药物代谢酶CYP2D6和CYP3A4的相关单核苷酸多态性(single nucleotide polymorphism,SNP)筛选检测,获得其在中国汉族人群中遗传多态性分布的相关数据.方法:筛选11个关于CYP2D6、CYP3A4基因的SNP位点,取192份中国汉族无关个体健康自愿者的血液样本获得基因组DNA,根据单碱基延伸技术通过GenomeLabTM SNPstream(R)基因分型系统进行SNP分型.结果:本次检测的11个SNP位点在研究人群中全部具有多态性(最小等位基因频率>0.01),其中7个SNP(RS28624811、RS28670611、RS9623531、RS5758589、RS3735451、RS2246709、RS2404955、RS4646440)位点的等位基因频率在此人群与白种人相比差异具有统计学意义(P<0.01).结论:汉族人群可能有继承特定的遗传信息,导致与其他人群具有不同药物代谢率.

  2. 闽南地区抑郁症患者CYP1A2和CYP2D6基因多态性与度洛西汀疗效的关联研究%Association of CYP1A2 and CYP2D6 gene polymorphism with therapeutic efficacy of duloxetine on depression in southern region of Fujian

    Institute of Scientific and Technical Information of China (English)

    陈进东; 徐象珍; 陈彬彬

    2015-01-01

    Objective To explore the influence of CYP1A2 and CYP2D6 gene polymorphism on blood concentration,therapeutic efficacy and adverse effects of anti-depression drug duloxetine on depression patients in southern region of Fujian.Methods 82 patients with depression were selected from southern region of FuJian, China,and all participates received duloxetine for two weeks.Blood concentrations of duloxetine were detected by HPLC-MS,and CYP1A2 and CYP2D6 genotypes were determined by sequencing with the amplified PCR products from peripheral blood DNA.The therapeutic efficacy and adverse effects of duloxetine were evaluated by Hamilton depression scale (HAMD) and treatment emergent symptom scale (TESS) respectively.Results Subjects were divided into GG,GA and AA three groups based on CYP1A2 * 1C genotyping.There was no significant difference in blood concentrations of duloxetine, dose-corrected blood concentrations, the reduction rate of HAMD and the reduction rate of TESS among the three groups.Results were the same with CYP1A2 * 1F,which were divided into CC, CA and AA three groups.Subjects was divided into CC, CT,TT three groups based on CYP2D6 * 10 locus genotyping.Blood concentrations of duloxetine were (13.89±3.22) ng · ml-1 , (16.08±4.24) ng · ml-1 , (17.25±4.62) ng · ml-1 respectively and there was significant difference(F=3.21, P<0.05).CC group was significantly lower than TT group(P<0.05) , and CT group was lower than TT group but without significant difference (P>0.05).Dose-corrected blood concentrations were (304.84± 103.76), (368.13± 143.49), (444.50± 195.58) respectively and there was significant difference(F=4.19, P<0.05), and CC group was significantly lower than TT group (P<0.05).The reduction rate of HAMD were 0.42±0.11,0.46±0.11,0.52±0.09 respectively and there was significant difference (F =6.29, P<0.05), and CC and CT group was significantly lower than TT group(P<0.05).The reduction rate of TESS were 1.14±0.66,1.48±0.69, 1.69

  3. Substrate-dependent modulation of CYP3A4 catalytic activity: analysis of 27 test compounds with four fluorometric substrates.

    Science.gov (United States)

    Stresser, D M; Blanchard, A P; Turner, S D; Erve, J C; Dandeneau, A A; Miller, V P; Crespi, C L

    2000-12-01

    Inhibition of cytochrome P450 catalytic activity is a principal mechanism for pharmacokinetic drug-drug interactions. Rapid, in vitro testing for cytochrome P450 inhibition potential is part of the current paradigm for identifying drug candidates likely to give such interactions. We have explored the extent that qualitative and quantitative inhibition parameters are dependent on the cytochrome P450 (CYP) 3A4 probe substrate. Inhibition potential (e.g., IC(50) values from 8-point inhibition curves) or activation potential for most compounds varied dramatically depending on the fluorometric probe substrates for CYP3A4 [benzyloxyresorufin (BzRes), 7-benzyloxy-4-trifluoromethylcoumarin (BFC), 7-benzyloxyquinoline (BQ), and dibenzylfluorescein (DBF)]. For 21 compounds that were primarily inhibitors, the range of IC(50) values for the four substrates varied from 2.1- to 195-fold with an average of 29-fold. While the rank order of sensitivity among the fluorometric substrates varied among the individual inhibitors, on average, BFC dealkylation was the most sensitive to inhibition, while BQ dealkylation was least sensitive. Partial inhibition was observed with BzRes and BQ but not for BFC and DBF. BzRes was more prone to activation, whereas dramatic changes in IC(50) values were observed when the BQ concentration was below the S(50). Three different correlation analyses indicated that IC(50) values with BFC, BQ, and DBF correlated well with each other, whereas the response with BzRes correlated more weakly with the other substrates. One of these correlation analyses was extended to the percent inhibition of 10 microM inhibitor with the standard CYP3A4 probe substrates testosterone, midazolam, and nifedipine. In this analysis the responses with BQ, BFC and DBF correlated well with testosterone and midazolam but more poorly with nifedipine. In the aggregate, BFC and DBF appear more suitable as an initial screen for CYP3A4 inhibition. However, the substrate-dependent effects

  4. Proteolytic activity of prostate-specific antigen (PSA towards protein substrates and effect of peptides stimulating PSA activity.

    Directory of Open Access Journals (Sweden)

    Johanna M Mattsson

    Full Text Available Prostate-specific antigen (PSA or kallikrein-related peptidase-3, KLK3 exerts chymotrypsin-like proteolytic activity. The main biological function of PSA is the liquefaction of the clot formed after ejaculation by cleavage of semenogelins I and II in seminal fluid. PSA also cleaves several other substrates, which may explain its putative functions in prostate cancer and its antiangiogenic activity. We compared the proteolytic efficiency of PSA towards several protein and peptide substrates and studied the effect of peptides stimulating the activity of PSA with these substrates. An endothelial cell tube formation model was used to analyze the effect of PSA-degraded protein fragments on angiogenesis. We showed that PSA degrades semenogelins I and II much more efficiently than other previously identified protein substrates, e.g., fibronectin, galectin-3 and IGFBP-3. We identified nidogen-1 as a new substrate for PSA. Peptides B2 and C4 that stimulate the activity of PSA towards small peptide substrates also enhanced the proteolytic activity of PSA towards protein substrates. Nidogen-1, galectin-3 or their fragments produced by PSA did not have any effect on endothelial cell tube formation. Although PSA cleaves several other protein substrates, in addition to semenogelins, the physiological importance of this activity remains speculative. The PSA levels in prostate are very high, but several other highly active proteases, such as hK2 and trypsin, are also expressed in the prostate and may cleave protein substrates that are weakly cleaved by PSA.

  5. Effect of an antiretroviral regimen containing ritonavir boosted lopinavir on intestinal and hepatic CYP3A, CYP2D6 and P-glycoprotein in HIV-infected patients.

    NARCIS (Netherlands)

    Wyen, C.; Fuhr, U.; Frank, D.; Aarnoutse, R.E.; Klaassen, T.; Lazar, A.; Seeringer, A.; Doroshyenko, O.; Kirchheiner, J.C.; Abdulrazik, F.; Schmeisser, N.; Lehmann, C.; Hein, W.; Schomig, E.; Burger, D.M.; Fatkenheuer, G.; Jetter, A.

    2008-01-01

    This study aimed to quantify the inhibition of cytochrome P450 (CYP3A), CYP2D6, and P-glycoprotein in human immunodeficiency virus (HIV)-infected patients receiving an antiretroviral therapy (ART) containing ritonavir boosted lopinavir, and to identify factors influencing ritonavir and lopinavir pha

  6. Modeling of organic substrate transformation in the high-rate activated sludge process.

    Science.gov (United States)

    Nogaj, Thomas; Randall, Andrew; Jimenez, Jose; Takacs, Imre; Bott, Charles; Miller, Mark; Murthy, Sudhir; Wett, Bernhard

    2015-01-01

    This study describes the development of a modified activated sludge model No.1 framework to describe the organic substrate transformation in the high-rate activated sludge (HRAS) process. New process mechanisms for dual soluble substrate utilization, production of extracellular polymeric substances (EPS), absorption of soluble substrate (storage), and adsorption of colloidal substrate were included in the modified model. Data from two HRAS pilot plants were investigated to calibrate and to validate the proposed model for HRAS systems. A subdivision of readily biodegradable soluble substrate into a slow and fast fraction were included to allow accurate description of effluent soluble chemical oxygen demand (COD) in HRAS versus longer solids retention time (SRT) systems. The modified model incorporates production of EPS and storage polymers as part of the aerobic growth transformation process on the soluble substrate and transformation processes for flocculation of colloidal COD to particulate COD. The adsorbed organics are then converted through hydrolysis to the slowly biodegradable soluble fraction. Two soluble substrate models were evaluated during this study, i.e., the dual substrate and the diauxic models. Both models used two state variables for biodegradable soluble substrate (SBf and SBs) and a single biomass population. The A-stage pilot typically removed 63% of the soluble substrate (SB) at an SRT <0.13 d and 79% at SRT of 0.23 d. In comparison, the dual substrate model predicted 58% removal at the lower SRT and 78% at the higher SRT, with the diauxic model predicting 32% and 70% removals, respectively. Overall, the dual substrate model provided better results than the diauxic model and therefore it was adopted during this study. The dual substrate model successfully described the higher effluent soluble COD observed in the HRAS systems due to the partial removal of SBs, which is almost completely removed in higher SRT systems.

  7. Do CVD grown graphene films have antibacterial activity on metallic substrates?

    CERN Document Server

    Dellieu, Louis; Reckinger, Nicolas; Didembourg, Christian; Letesson, Jean-Jacques; Sarrazin, Michael; Deparis, Olivier; Matroule, Jean-Yves; Colomer, Jean-François

    2014-01-01

    Accurate assessment of the antibacterial activity of graphene requires consideration of both the graphene fabrication method and, for supported films, the properties of the substrate. Large-area graphene films produced by chemical vapor deposition were grown directly on copper substrates or transferred on a gold substrate and their effect on the viability and proliferation of the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli were assessed. The viability and the proliferation of both bacterial species were not affected when they were grown on a graphene film entirely covering the gold substrate, indicating that conductivity plays no role on bacterial viability and graphene has no antibacterial activity against S. aureus and E. coli. On the other hand, antibacterial activity was observed when graphene coated the copper substrates, resulting from the release of bactericidal cupric ions in inverse proportion to the graphene surface coverage.

  8. Association of CYP2D6 and CYP2C19 polymorphisms and disease-free survival of Thai post-menopausal breast cancer patients who received adjuvant tamoxifen

    Directory of Open Access Journals (Sweden)

    Chamnanphon M

    2013-05-01

    Full Text Available Montri Chamnanphon,1 Khunthong Pechatanan,2 Ekapob Sirachainan,3 Narumol Trachu,4 Wasun Chantratita,5 Ekawat Pasomsub,5 Wilai Noonpakdee,6 Insee Sensorn,1,7 Chonlaphat Sukasem11Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 2Department of Medicine, Phramongkutklao College of Medicine, 3Division of Medical Oncology, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 4Research Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 5Division of Virology, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 6Department of Biochemistry, Faculty of Science, Mahidol University, 7Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok, ThailandPurpose: To investigate the impact of CYP2D6 and CYP2C19 polymorphisms in predicting tamoxifen efficacy and clinical outcomes in Thai breast cancer patients.Methods: Polymorphisms of CYP2D6 and CYP2C19 were genotyped by the AmpliChip™ CYP450 Test (Roche Molecular Diagnostics, Branchburg, NJ, USA for 57 patients, who were matched as recurrent versus nonrecurrent breast cancers (n = 33 versus n = 24, respectively, with a 5-year follow-up.Results: Based on the genotype data, five CYP2D6 predicted phenotype groups were identified in this study including homozygous extensive metabolizer (13 of 57, 22.80%, extensive/intermediate metabolizer (23 of 57, 40.40%, extensive/poor metabolizer (3 of 57, 5.30%, homozygous intermediate metabolizer (14 of 57, 24.50%, and intermediate/poor metabolizer (4 of 57, 7.00%, and three CYP2C19 genotype groups including homozygous extensive metabolizer (27 of 57, 47.40%, extensive/intermediate metabolizer (27 of 57, 47.40%, and homozygous poor metabolizer (3 of 57, 5.30%. The CYP2D6 variant alleles were *10 (52 of 114, 45.60%, *5 (5 of 114, 4.40%, *41 (2 of 114, 1.80%, *4 (1 of 114, 0

  9. 浙南地区女性人群CYP2D6及MDR1基因多态性对曲马多镇痛效果的影响

    Institute of Scientific and Technical Information of China (English)

    马光泛; 陈千煌

    2013-01-01

      目的探讨CYP2D6*10等位基因及MDR1 C3435T基因多态性对浙南地区女性人群术后曲马多镇痛效果的影响.方法收集行子宫肌瘤剥除手术患者194例,手术结束前30 min肌肉注射曲马多,采用患者自控镇痛(PCA)模式进行术后镇痛.抽取外周血,采用聚合酶链反应-限制性条带长度多态性方法(PCR-RFLP),分析患者CYP2D6*10等位基因及MDR1 C3435T基因多态性,比较不同基因型患者之间曲马多的累积量,记录镇痛起效时间、持续时间、VAS及不良反应.结果 CYP2D6*10等位基因频率为52.84%,术后2、6、12h曲马多累积量及术后2、6hVAS的比较,m/m型明显高于w/w型和m/w型,差异有统计学意义(P0.05).结论在浙南地区女性人群中,CYP2D6*10等位基因对曲马多镇痛效果有显著影响,MDR1 C3435T等位基因对曲马多镇痛效果无显著影响.%Objective To investigate the association of CYP2D6*10 and MDR1 C3435T polymorphisms with analgesic ef-ficacy of tramadol in woman patients of Southern Zhejiang province. Methods One hundred and ninety four patients with hys-termyoma undergoing uterine myomatectomy from August 2010 to March 2012. Patients were given with loading dose of tramadol intramuscularly 30 minutes before the ending of surgery and received the postoperative patient-control ed analgesia (PCA). Samples of peripheral blood were col ected for DNA isolation. Polymorphisms of CYP2D6*10 and MDR1 C3435T were detected with PCR-RFLP analysis. The differences of tramadol consumption in the genotype groups were monitored and the starting time and duration of analgesia, VAS scores and adverse reaction were observed. Results The al elic frequency of CYP2D6 was 52.84%. The tramadol consumption at 2、6h and 12h after surgery and VAS at 2h and 6h after surgery in m/m type (n=50) were higher than those in w/w (n=39) and m/w (n=105) type (P<0.05). Variant al eles C3435T in MDR1 gene was seen in frequency of 38.14%. There were no significant

  10. Polymorphisms in NAT2, CYP2D6, CYP2C19 and GSTP1 and their association with prostate cancer

    DEFF Research Database (Denmark)

    Wadelius, Mia; Autrup, Judith; Stubbins, Michael J.;

    1999-01-01

    . An association between CYP2D6 poor metabolism and prostate cancer was seen among smoking Danes; odds ratio 3.10 (95% confidence interval 1.07; 8.93), P = 0.03, but not among smoking Swedes; odds ratio 1.19 (95% confidence interval 0.41; 3.42), P = 0.75. Smoking is not a known risk factor for prostate cancer...

  11. A substrate-driven allosteric switch that enhances PDI catalytic activity

    Science.gov (United States)

    Bekendam, Roelof H.; Bendapudi, Pavan K.; Lin, Lin; Nag, Partha P.; Pu, Jun; Kennedy, Daniel R.; Feldenzer, Alexandra; Chiu, Joyce; Cook, Kristina M.; Furie, Bruce; Huang, Mingdong; Hogg, Philip J.; Flaumenhaft, Robert

    2016-01-01

    Protein disulfide isomerase (PDI) is an oxidoreductase essential for folding proteins in the endoplasmic reticulum. The domain structure of PDI is a–b–b′–x–a′, wherein the thioredoxin-like a and a′ domains mediate disulfide bond shuffling and b and b′ domains are substrate binding. The b′ and a′ domains are connected via the x-linker, a 19-amino-acid flexible peptide. Here we identify a class of compounds, termed bepristats, that target the substrate-binding pocket of b′. Bepristats reversibly block substrate binding and inhibit platelet aggregation and thrombus formation in vivo. Ligation of the substrate-binding pocket by bepristats paradoxically enhances catalytic activity of a and a′ by displacing the x-linker, which acts as an allosteric switch to augment reductase activity in the catalytic domains. This substrate-driven allosteric switch is also activated by peptides and proteins and is present in other thiol isomerases. Our results demonstrate a mechanism whereby binding of a substrate to thiol isomerases enhances catalytic activity of remote domains. PMID:27573496

  12. Electrocatalytic Oxygen Evolution on Iridium Oxide: Uncovering Catalyst-Substrate Interactions and Active Iridium Oxide Species

    OpenAIRE

    Reier, T.; Teschner, D; Lunkenbein, T.; Bergmann, A; Selve, S.; Kraehnert, R.; R. Schlögl; Strasser, P.

    2014-01-01

    The morphology, crystallinity, and chemical state of well-defined Ir oxide nanoscale thin-film catalysts prepared on Ti substrates at various calcination temperatures were investigated. Special emphasis was placed on the calcination temperature-dependent interaction between Ir oxide film and Ti substrate and its impact on the electrocatalytic oxygen evolution reaction (OER) activity. The Ir oxide films were characterized by scanning electron microscopy, transmission electron microscopy, scann...

  13. Substrate Stiffness Regulates Proinflammatory Mediator Production through TLR4 Activity in Macrophages

    Science.gov (United States)

    Previtera, Michelle L.; Sengupta, Amitabha

    2015-01-01

    Clinical data show that disease adversely affects tissue elasticity or stiffness. While macrophage activity plays a critical role in driving disease pathology, there are limited data available on the effects of tissue stiffness on macrophage activity. In this study, the effects of substrate stiffness on inflammatory mediator production by macrophages were investigated. Bone marrow–derived macrophages were grown on polyacrylamide gels that mimicked the stiffness of a variety of soft biological tissues. Overall, macrophages grown on soft substrates produced less proinflammatory mediators than macrophages grown on stiff substrates when the endotoxin LPS was added to media. In addition, the pathways involved in stiffness–regulated proinflammation were investigated. The TLR4 signaling pathway was examined by evaluating TLR4, p–NF–κB p65, MyD88, and p–IκBα expression as well as p–NF–κB p65 translocation. Expression and translocation of the various signaling molecules were higher in macrophages grown on stiff substrates than on soft substrates. Furthermore, TLR4 knockout experiments showed that TLR4 activity enhanced proinflammation on stiff substrates. In conclusion, these results suggest that proinflammatory mediator production initiated by TLR4 is mechanically regulated in macrophages. PMID:26710072

  14. VPO catalysts synthesized on substrates with modified activated carbons

    International Nuclear Information System (INIS)

    VPO catalysts were prepared on oxidized and unoxidized activated carbons differing in initial porous structure. Carbons were oxidized under relatively soft (30% H2O2, 200 deg. C) and hard (50% H2O2, 350 deg. C) conditions. Carbon modification was carried out hydrothermally in a traditional autoclave (HTT) or a microwave reactor (MWT). The synthesis was also carried out under hydrothermal (HTS or MWS) conditions. V2O5 and NH4VO3 were used as precursors. The samples are characterized by diversified porous structure at SBET = 732-1617 m2/g and Vpor = 0.44-0.90 cm3/g, as well as various degree of VPO crystallinity. Possibility of preparation of the VPO catalysts under ecologically appropriate conditions, i.e. in aqueous solutions, was shown.

  15. Substrate-induced activation of a trapped IMC-mediated protein folding intermediate.

    Science.gov (United States)

    Inouye, M; Fu, X; Shinde, U

    2001-04-01

    While several unfolded proteins acquire native structures through distinct folding intermediates, the physiological relevance and importance of such states in the folding kinetics remain controversial. The intramolecular chaperone (IMC) of subtilisin was used to trap a partially folded, stable crosslinked intermediate conformer (CLIC) through a disulfide bond between mutated IMC and subtilisin. The trapped CLIC contains non-native interactions. Here we show that CLIC can be induced into a catalytically active form by incubating it with small peptide substrates. The structure and catalytic properties of the activated crosslinked intermediate conformer (A-CLIC) differ from those of the fully folded enzyme in that A-CLIC lacks any endopeptidase activity toward a large protein substrate. Our results show that a disulfide-linked partially folded protein can be induced to acquire catalytic activity with a substrate specificity that is different from completely folded subtilisin. These results also suggest that protein folding intermediates may also participate in catalytic reactions.

  16. Hydrolysis of particulate substrate by activated sludge under aerobic, anoxic and anaerobic conditions

    DEFF Research Database (Denmark)

    Henze, Mogens; Mladenovski, C.

    1991-01-01

    An investigation of hydrolysis of particulate organic substrate by activated sludge has been made. Raw municipal wastewater was used as substrate. It was mixed with activated sludge from a high loaded activated sludge plant with pure oxygen aeration. During 4 days batch experiments under aerobic......, anoxic and anaerobic conditions, the hydrolysis was following through the production of ammonia. The hydrolysis rate of nitrogeneous compounds is significantly affected by the electron donor available. The rate is high under aerobic conditions, medium under anaerobic conditions and low under anoxic...... conditions. The ratio between the hydrolysis rates under aerobic and under anoxic conditions are very similar to the respiration rates measured as electron equivalents....

  17. Pharmacokinetic Interactions between Monoamine Oxidase A Inhibitor Harmaline and 5-Methoxy-N,N-Dimethyltryptamine, and the Impact of CYP2D6 Status

    OpenAIRE

    Jiang, Xi-Ling; Shen, Hong-Wu; Mager, Donald E.; Yu, Ai-Ming

    2013-01-01

    5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT or street name “5-MEO”) is a newer designer drug belonging to a group of naturally occurring indolealkylamines. Our recent study has demonstrated that coadministration of monoamine oxidase A (MAO-A) inhibitor harmaline (5 mg/kg) increases systemic exposure to 5-MeO-DMT (2 mg/kg) and active metabolite bufotenine. This study is aimed at delineating harmaline and 5-MeO-DMT pharmacokinetic (PK) interactions at multiple dose levels, as well as the impact...

  18. Active-matrix organic light-emitting diode displays on flexible metal foil substrates

    Science.gov (United States)

    Chuang, Ta-Ko

    This dissertation presents the research efforts that deal with the development of polysilicon thin film transistors (TFTs) on stainless-steel-foil substrates, the implementation of high-resolution flexible active-matrix backplanes, and the integration of the flexible polysilicon TFT backplanes with polymer light-emitting diodes. This research investigated the preparation of the steel foil substrates, the fabrication of flexible polysilicon TFT backplanes and polymer light emitting diodes (PLEDs), and the encapsulation of the flexible Active Matrix Polymer Light Emitting Diode displays. The first successful integration of polysilicon TFT backplane with PLEDs onto light-weight, robust, and flexible stainless-steel-foil substrates is presented. A top-emitting, monochrome active-matrix polymer light-emitting diode (AM-PLED) display, having the VGA (640x480) format and a 230 dpi resolution, is demonstrated for the first time on flexible stainless-steel-foil substrates. This work validates the compatibility of the polysilicon technology for high-resolution flexible AM-PLED displays. Furthermore, this work shows that a variety of other large-area microelectronics could also be implemented onto flexible metal foils, benefiting by the metal oil dimensional stability and ability to withstand high process temperature. In conclusion, the polysilicon TFT technology combining with metal-foil substrates opens up a new road for flexible displays as well as large-area flexible electronic applications.

  19. An improved fluorescent substrate for assaying soluble and membrane-associated ADAM family member activities.

    Science.gov (United States)

    Moss, Marcia L; Minond, Dmitriy; Yoneyama, Toshie; Hansen, Hinrich P; Vujanovic, Nikola; Rasmussen, Fred H

    2016-08-15

    A fluorescent resonance energy transfer substrate with improved sensitivity for ADAM17, -10, and -9 (where ADAM represents a disintegrin and metalloproteinase) has been designed. The new substrate, Dabcyl-Pro-Arg-Ala-Ala-Ala-Homophe-Thr-Ser-Pro-Lys(FAM)-NH2, has specificity constants of 6.3 (±0.3) × 10(4) M(-1) s(-1) and 2.4 (±0.3) × 10(3) M(-1) s(-1) for ADAM17 and ADAM10, respectively. The substrate is more sensitive than widely used peptides based on the precursor tumor necrosis factor-alpha (TNF-alpha) cleavage site, PEPDAB010 or Dabcyl-Ser-Pro-Leu-Ala-Gln-Ala-Val-Arg-Ser-Ser-Lys(FAM)-NH2 and Mca-Pro-Leu-Ala-Gln-Ala-Val-Dpa-Arg-Ser-Ser-Arg-NH2. ADAM9 also processes the new peptide more than 18-fold better than the TNF-alpha-based substrates. The new substrate has a unique selectivity profile because it is processed less efficiently by ADAM8 and MMP1, -2, -3, -8, -9, -12, and -14. This substrate provides a unique tool in which to assess ADAM17, -10, and -9 activities. PMID:27177841

  20. Early activation of caspases during T lymphocyte stimulation results in selective substrate cleavage in nonapoptotic cells.

    Science.gov (United States)

    Alam, A; Cohen, L Y; Aouad, S; Sékaly, R P

    1999-12-20

    Apoptosis induced by T cell receptor (TCR) triggering in T lymphocytes involves activation of cysteine proteases of the caspase family through their proteolytic processing. Caspase-3 cleavage was also reported during T cell stimulation in the absence of apoptosis, although the physiological relevance of this response remains unclear. We show here that the caspase inhibitor benzyloxycarbonyl (Cbz)-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD) blocks proliferation, major histocompatibility complex class II expression, and blastic transformation during stimulation of peripheral blood lymphocytes. Moreover, T cell activation triggers the selective processing and activation of downstream caspases (caspase-3, -6, and -7), but not caspase-1, -2, or -4, as demonstrated even in intact cells using a cell-permeable fluorescent substrate. Caspase-3 processing occurs in different T cell subsets (CD4(+), CD8(+), CD45RA(+), and CD45RO(+)), and in activated B lymphocytes. The pathway leading to caspase activation involves death receptors and caspase-8, which is also processed after TCR triggering, but not caspase-9, which remains as a proenzyme. Most importantly, caspase activity results in a selective substrate specificity, since poly(ADP-ribose) polymerase (PARP), lamin B, and Wee1 kinase, but not DNA fragmentation factor (DFF45) or replication factor C (RFC140), are processed. Caspase and substrate processing occur in nonapoptotic lymphocytes. Thus, caspase activation is an early and physiological response in viable, stimulated lymphocytes, and appears to be involved in early steps of lymphocyte activation. PMID:10601362

  1. Unnatural amino acids increase activity and specificity of synthetic substrates for human and malarial cathepsin C.

    Science.gov (United States)

    Poreba, Marcin; Mihelic, Marko; Krai, Priscilla; Rajkovic, Jelena; Krezel, Artur; Pawelczak, Malgorzata; Klemba, Michael; Turk, Dusan; Turk, Boris; Latajka, Rafal; Drag, Marcin

    2014-04-01

    Mammalian cathepsin C is primarily responsible for the removal of N-terminal dipeptides and activation of several serine proteases in inflammatory or immune cells, while its malarial parasite ortholog dipeptidyl aminopeptidase 1 plays a crucial role in catabolizing the hemoglobin of its host erythrocyte. In this report, we describe the systematic substrate specificity analysis of three cathepsin C orthologs from Homo sapiens (human), Bos taurus (bovine) and Plasmodium falciparum (malaria parasite). Here, we present a new approach with a tailored fluorogenic substrate library designed and synthesized to probe the S1 and S2 pocket preferences of these enzymes with both natural and a broad range of unnatural amino acids. Our approach identified very efficiently hydrolyzed substrates containing unnatural amino acids, which resulted in the design of significantly better substrates than those previously known. Additionally, in this study significant differences in terms of the structures of optimal substrates for human and malarial orthologs are important from the therapeutic point of view. These data can be also used for the design of specific inhibitors or activity-based probes.

  2. Mutants of Micromonospora viridifaciens sialidase have highly variable activities on natural and non-natural substrates

    DEFF Research Database (Denmark)

    Jers, Carsten; Guo, Yao; Kepp, Kasper Planeta;

    2015-01-01

    This study aimed to improve the hydrolase activity of the well-characterised bacterial sialidase from Micromonospora viridifaciens. The enzyme and its mutated versions were produced in Bacillus subtilis and secreted to the growth medium. Twenty amino acid positions in or near the active site were...... by natural evolution, major changes in chemical properties are advantageous, and these changes tend to correlate with decreased stability, partly explaining commonly observed trade-offs between stability and proficiency....... subjected to site-saturation mutagenesis and evaluated on the artificial sialidase substrate 2-O-(p-nitrophenyl)-α-d-N-acetylneuraminic acid and on the natural substrate casein glycomacropeptide. A considerably higher fraction of the mutants exhibited increased activity on the artificial substrate compared...... with the natural one, with the most proficient mutant showing a 13-fold improvement in kcat/Km. In contrast, no mutants displayed more than a 2-fold increase in activity on the natural substrate. To gain further insight into this important discrepancy, we analysed the stability of mutants using the Po...

  3. Activated carbon addition affects substrate pH and germination of six plant species

    NARCIS (Netherlands)

    Kabouw, P.; Nab, M.; Dam, van M.

    2010-01-01

    Activated carbon (AC) is widely used in ecological studies for neutralizing allelopathic compounds. However, it has been suggested that AC has direct effects on plants because it alters substrate parameters such as nutrient availability and pH. These side-effects of AC addition may interfere with al

  4. Spatiotemporal stability of neonatal rat cardiomyocyte monolayers spontaneous activity is dependent on the culture substrate.

    Directory of Open Access Journals (Sweden)

    Jonathan Boudreau-Béland

    Full Text Available In native conditions, cardiac cells must continuously comply with diverse stimuli necessitating a perpetual adaptation. Polydimethylsiloxane (PDMS is commonly used in cell culture to study cellular response to changes in the mechanical environment. The aim of this study was to evaluate the impact of using PDMS substrates on the properties of spontaneous activity of cardiomyocyte monolayer cultures. We compared PDMS to the gold standard normally used in culture: a glass substrate. Although mean frequency of spontaneous activity remained unaltered, incidence of reentrant activity was significantly higher in samples cultured on glass compared to PDMS substrates. Higher spatial and temporal instability of the spontaneous rate activation was found when cardiomyocytes were cultured on PDMS, and correlated with decreased connexin-43 and increased CaV3.1 and HCN2 mRNA levels. Compared to cultures on glass, cultures on PDMS were associated with the strongest response to isoproterenol and acetylcholine. These results reveal the importance of carefully selecting the culture substrate for studies involving mechanical stimulation, especially for tissue engineering or pharmacological high-throughput screening of cardiac tissue analog.

  5. The design and manufacturing development of an active silicon substrate MCM

    Science.gov (United States)

    Roughton, M. G.; Waite, L.

    1994-10-01

    The demand for engine control systems with reduced weight, size and cost, increased integration, improved reliability and higher temperature operation drives the system designer to the use of advanced hybrid assembly technologies. This paper describes the design and manufacturing development of a silicon based 'D' type multichip module, MCM, containing an active substrate of memory. This CPU module is one of the building blocks for a range of generic engine control systems. The active substrate approach potentially gives higher packing density than wafer scale due to its 3D configuration. The active substrate comprises 12 SRAM 128K x 8 bit of diffused memory arranged in groups of three. The design is organized so that a 'memory manager' ASIC selects pages of good memory from the substrate die thus obtaining the best possible yield. A single wafer contains 4 silicon hybrid substrates, each approximately 40mm sq, which will be processed before separating into discrete circuits. The MCM structure is comprised of four aluminium metallization layers with benzocyclobutene, BCB, as the dielectric. Approximately 16 other devices including a processor, the 'memory manager' ASIC, a Processor Support ASIC and EDPROM, plus resistor network chips and decoupling capacitors will be added to the silicon substrate using adhesive and wire bond interconnection. The 'memory manager' ASIC tests the RAM on power-up, reject areas of bad memory and configures the good areas such that a continuous block of functional RAM is available to the processor. The RAM is configured as a 16 bit wide with both 16 bit and 8 bit read/write accesses being supported. The total module is to be assembled in a high temperature co-fired ceramic package with 200 I/O. After test and any rework that may be necessary the package will be sealed with a Kovar lid ready for final test.

  6. Characterization of 107 genomic DNA reference materials for CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1: a GeT-RM and Association for Molecular Pathology collaborative project.

    Science.gov (United States)

    Pratt, Victoria M; Zehnbauer, Barbara; Wilson, Jean Amos; Baak, Ruth; Babic, Nikolina; Bettinotti, Maria; Buller, Arlene; Butz, Ken; Campbell, Matthew; Civalier, Chris; El-Badry, Abdalla; Farkas, Daniel H; Lyon, Elaine; Mandal, Saptarshi; McKinney, Jason; Muralidharan, Kasinathan; Noll, LeAnne; Sander, Tara; Shabbeer, Junaid; Smith, Chingying; Telatar, Milhan; Toji, Lorraine; Vairavan, Anand; Vance, Carlos; Weck, Karen E; Wu, Alan H B; Yeo, Kiang-Teck J; Zeller, Markus; Kalman, Lisa

    2010-11-01

    Pharmacogenetic testing is becoming more common; however, very few quality control and other reference materials that cover alleles commonly included in such assays are currently available. To address these needs, the Centers for Disease Control and Prevention's Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing community and the Coriell Cell Repositories, have characterized a panel of 107 genomic DNA reference materials for five loci (CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1) that are commonly included in pharmacogenetic testing panels and proficiency testing surveys. Genomic DNA from publicly available cell lines was sent to volunteer laboratories for genotyping. Each sample was tested in three to six laboratories using a variety of commercially available or laboratory-developed platforms. The results were consistent among laboratories, with differences in allele assignments largely related to the manufacturer's assay design and variable nomenclature, especially for CYP2D6. The alleles included in the assay platforms varied, but most were identified in the set of 107 DNA samples. Nine additional pharmacogenetic loci (CYP4F2, EPHX1, ABCB1, HLAB, KIF6, CYP3A4, CYP3A5, TPMT, and DPD) were also tested. These samples are publicly available from Coriell and will be useful for quality assurance, proficiency testing, test development, and research.

  7. 细胞色素CYP2D6基因多态性与海洛因海绵状白质脑病易感性的关系%Association of cytochrome P4502D6 gene polymorphism with the susceptibility of heroin spongiform leucoencephalopathy

    Institute of Scientific and Technical Information of China (English)

    周亮; 陆兵勋; 尹恝

    2010-01-01

    目的 探讨细胞色素CYP2D6基因多态性与海洛因海绵状白质脑病(HSLE)易感性的关系.方法 通过PCR-RFLP技术.分析HSLE患者与吸毒及正常对照基因多态性.结果 HSLE病人CYP2D6/C188、CYP2D6/L2938、CYP2D6/G4268基因突变率均高于正常人.结论 解毒酶CYP2D6基因缺陷与HSLE发病有一定的关系.

  8. Paraoxonase-1 activity determination via paraoxon substrate yields no significant difference in mild hyperhomocysteinemia.

    Science.gov (United States)

    Türkeli, Hatice; Caycı, Tuncer; Akgül, Emin Özgür; Macit, Enis; Yaman, Halil; Aydın, Ibrahim; Demirin, Hilmi; Alacam, Hasan; Ozkan, Esin; Cakır, Erdinç; Deren, Ozgür; Erbil, Mehmet Kemal; Kunak, Z Ilker; Burat, Kutlay; Akman, Serif

    2010-11-01

    Elevated plasma homocystein (Hcy) level has been recognized as an important risk factor for a number of cardiovascular diseases, peripheral arterial occlusive disease and venous thrombosis. A part of Hcy in the organism is turned to homocysteine thiolactone (HcyT) via a ring closure reaction, which gains rate in hyperhomocysteinemia, and in turn undergoes a hydrolytic reaction back to Hcy by paraoxonase enzyme (PON). Since this is a protective reflex action enzyme against hyperhomocysteinemia, we investigated how a mild hyperhomocysteinemic nutritional habit affected serum PON activity in a population-based study. The difference detected via enzymatic activity using the paraoxon substrate was statistically non-significant (p=0.19), suggesting a defective performance to reflect the expected significance. Determination of serum PON activity via substrate paraoxon yielded no significant difference in an acute mild hyperhomocysteinemic diet model in humans. PMID:19419786

  9. Investigation of the Photocatalytic Activity of ZnO Nanowires: Substrate Effect and Kinetics Analysis

    Directory of Open Access Journals (Sweden)

    Jan-Hau Chang

    2014-01-01

    Full Text Available The photocatalytic activity of substrate-supported ZnO nanowires is investigated with a focus on the substrate effect and the photodegradation kinetics. The employed NWs are grown on various substrates by thermal evaporation and a 50 μM rhodamine B solution is used as the target solution. It is found that the photocatalytic activity is facilitated by using a conductive substrate and such a result can be reasonably attributed to the improvement of charge separation. The photodegradation is found to follow a zeroth-order kinetics at high concentrations and a first-order kinetics at low concentrations with a transition at around 10 μM. The present observation is opposed to the commonly accepted first-order kinetics. Degradation constants of 0.58 μM·min−1 for the zeroth-order and 0.028 min−1 for the first-order have been achieved. The first-order constant also compares favorably with reported values.

  10. Gold Incorporated Mesoporous Silica Thin Film Model Surface as a Robust SERS and Catalytically Active Substrate

    Directory of Open Access Journals (Sweden)

    Anandakumari Chandrasekharan Sunil Sekhar

    2016-05-01

    Full Text Available Ultra-small gold nanoparticles incorporated in mesoporous silica thin films with accessible pore channels perpendicular to the substrate are prepared by a modified sol-gel method. The simple and easy spin coating technique is applied here to make homogeneous thin films. The surface characterization using FESEM shows crack-free films with a perpendicular pore arrangement. The applicability of these thin films as catalysts as well as a robust SERS active substrate for model catalysis study is tested. Compared to bare silica film our gold incorporated silica, GSM-23F gave an enhancement factor of 103 for RhB with a laser source 633 nm. The reduction reaction of p-nitrophenol with sodium borohydride from our thin films shows a decrease in peak intensity corresponding to –NO2 group as time proceeds, confirming the catalytic activity. Such model surfaces can potentially bridge the material gap between a real catalytic system and surface science studies.

  11. Substrates and enzyme activities related to biotransformation of resveratrol from phenylalanine by Alternaria sp. MG1.

    Science.gov (United States)

    Zhang, Jinhua; Shi, Junling; Liu, Yanlin

    2013-12-01

    To identify the substrates and enzymes related to resveratrol biosynthesis in Alternaria sp. MG1, different substrates were used to produce resveratrol, and their influence on resveratrol production was analyzed using high performance liquid chromatography (HPLC). Formation of resveratrol and related intermediates was identified using mass spectrum. During the biotransformation, activities of related enzymes, including phenylalanine ammonia-lyase (PAL), trans-cinnamate 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL), were analyzed and tracked. The reaction system contained 100 mL 0.2 mol/L phosphate buffer (pH 6.5), 120 g/L Alternaria sp. MG1 cells, 0.1 g/L MgSO₄, and 0.2 g/L CaSO₄ and different substrates according to the experimental design. The biotransformation was carried out for 21 h at 28 °C and 120 rpm. Resveratrol formation was identified when phenylalanine, tyrosine, cinnamic acid, and p-coumaric acid were separately used as the only substrate. Accumulation of cinnamic acid, p-coumaric acid, and resveratrol and the activities of PAL, C4H, and 4CL were identified and changed in different trends during transformation with phenylalanine as the only substrate. The addition of carbohydrates and the increase of phenylalanine concentration promoted resveratrol production and yielded the highest value (4.57 μg/L) when 2 g/L glucose, 1 g/L cyclodextrin, and phenylalanine (4.7 mmol/L) were used simultaneously.

  12. Purifying capability, enzyme activity, and nitrification potentials in December in integrated vertical flow constructed wetland with earthworms and different substrates.

    Science.gov (United States)

    Xu, Defu; Gu, Jiaru; Li, Yingxue; Zhang, Yu; Howard, Alan; Guan, Yidong; Li, Jiuhai; Xu, Hui

    2016-01-01

    The response of purifying capability, enzyme activity, nitrification potentials, and total number of bacteria in the rhizosphere in December to wetland plants, substrates, and earthworms was investigated in integrated vertical flow constructed wetlands (IVFCW). The removal efficiency of total nitrogen (TN), NH4-N, chemical oxygen demand (COD), and total phosphorus (TP) was increased when earthworms were added into IVFCW. A significantly average removal efficiency of N in IVFCW that employed river sand as substrate and in IVFCW that employed a mixture of river sand and Qing sand as substrate was not found. However, the average removal efficiency of P was higher in IVFCW with a mixture of river sand and Qing sand as substrate than in IVFCW with river sand as substrate. Invertase activity in December was higher in IVFCW that used a mixture of river sand and Qing sand as substrate than in IVFCW which used only river sand as substrate. However, urease activity, nitrification potential, and total number of bacteria in December was higher in IVFCW that employed river sand as substrate than in IVFCW with a mixture of river sand and Qing sand as substrate. The addition of earthworms into the integrated vertical flow constructed wetland increased the above-ground biomass, enzyme activity (catalase, urease, and invertase), nitrification potentials, and total number of bacteria in December. The above-ground biomass of wetland plants was significantly positively correlated with urease and nitrification potentials (p activity and nitrification potentials in December, which resulted in improving purifying capability. PMID:26573309

  13. Dual fluorescent molecular substrates selectively report the activation, sustainability and reversibility of cellular PKB/Akt activity

    Science.gov (United States)

    Shen, Duanwen; Bai, Mingfeng; Tang, Rui; Xu, Baogang; Ju, Xiaoming; Pestell, Richard G.; Achilefu, Samuel

    2013-04-01

    Using a newly developed near-infrared (NIR) dye that fluoresces at two different wavelengths (dichromic fluorescence, DCF), we discovered a new fluorescent substrate for Akt, also known as protein kinase B, and a method to quantitatively report this enzyme's activity in real time. Upon insulin activation of cellular Akt, the enzyme multi-phosphorylated a single serine residue of a diserine DCF substrate in a time-dependent manner, culminating in monophospho- to triphospho-serine products. The NIR DCF probe was highly selective for the Akt1 isoform, which was demonstrated using Akt1 knockout cells derived from MMTV-ErbB2 transgenic mice. The DCF mechanism provides unparalleled potential to assess the stimulation, sustainability, and reversibility of Akt activation longitudinally. Importantly, NIR fluorescence provides a pathway to translate findings from cells to living organisms, a condition that could eventually facilitate the use of these probes in humans.

  14. 2,4-Dichlorophenol hydroxylase for chlorophenol removal: Substrate specificity and catalytic activity.

    Science.gov (United States)

    Ren, Hejun; Li, Qingchao; Zhan, Yang; Fang, Xuexun; Yu, Dahai

    2016-01-01

    Chlorophenols (CPs) are common environmental pollutants. As such, different treatments have been assessed to facilitate their removal. In this study, 2,4-dichlorophenol (2,4-DCP) hydroxylase was used to systematically investigate the activity and removal ability of 19CP congeners at 25 and 0 °C. Results demonstrated that 2,4-DCP hydroxylase exhibited a broad substrate specificity to CPs. The activities of 2,4-DCP hydroxylase against specific CP congeners, including 3-CP, 2,3,6-trichlorophenol, 2-CP, and 2,3-DCP, were higher than those against 2,4-DCP, which is the preferred substrate of previously reported 2,4-DCP hydroxylase. To verify whether cofactors are necessary to promote hydroxylase activity against CP congeners, we added FAD and found that the added FAD induced a 1.33-fold to 5.13-fold significant increase in hydroxylase activity against different CP congeners. The metabolic pathways of the CP degradation in the enzymatic hydroxylation step were preliminarily proposed on the basis of the analyses of the enzymatic activities against 19CP congeners. We found that the high activity and removal rate of 2,4-DCP hydroxylase against CPs at 0 °C enhance the low-temperature-adaptability of this enzyme to the CP congeners; as such, the proposed removal process may be applied to biochemical, bioremediation, and industrial processes, particularly in cold environments. PMID:26672451

  15. Substrate sources regulate spatial variation of metabolically active methanogens from two contrasting freshwater wetlands.

    Science.gov (United States)

    Lin, Yongxin; Liu, Deyan; Ding, Weixin; Kang, Hojeong; Freeman, Chris; Yuan, Junji; Xiang, Jian

    2015-12-01

    There is ample evidence that methane (CH4) emissions from natural wetlands exhibit large spatial variations at a field scale. However, little is known about the metabolically active methanogens mediating these differences. We explored the spatial patterns in active methanogens of summer inundated Calamagrostis angustifolia marsh with low CH4 emissions and permanently inundated Carex lasiocarpa marsh with high CH4 emissions in Sanjiang Plain, China. In C. angustifolia marsh, the addition of (13)C-acetate significantly increased the CH4 production rate, and Methanosarcinaceae methanogens were found to participate in the consumption of acetate. In C. lasiocarpa marsh, there was no apparent increase in the CH4 production rate and no methanogen species were labeled with (13)C. When (13)CO2-H2 was added, however, CH4 production was found to be due to Fen Cluster (Methanomicrobiales) in C. angustifolia marsh and Methanobacterium Cluster B (Methanobacteriaceae) together with Fen Cluster in C. lasiocarpa marsh. These results suggested that CH4 was produced primarily by hydrogenotrophic methanogens using substrates mainly derived from plant litter in C. lasiocarpa marsh and by both hydrogenotrophic and acetoclastic methanogens using substrates mainly derived from root exudate in C. angustifolia marsh. The significantly lower CH4 emissions measured in situ in C. angustifolia marsh was primarily due to a deficiency of substrates compared to C. lasiocarpa marsh. Therefore, we speculate that the substrate source regulates both the type of active methanogens and the CH4 production pathway and consequently contributes to the spatial variations in CH4 productions observed in these freshwater marshes. PMID:26286511

  16. Multi-substrate-activity space and quasi-species in enzyme evolution: Ohno's dilemma, promiscuity and functional orthogonality.

    Science.gov (United States)

    Mannervik, Bengt; Runarsdottir, Arna; Kurtovic, Sanela

    2009-08-01

    A functional enzyme displays activity with at least one substrate and can be represented by a vector in substrate-activity space. Many enzymes, including GSTs (glutathione transferases), are promiscuous in the sense that they act on alternative substrates, and the corresponding vectors operate in multidimensional space. The direction of the vector is governed by the relative activities of the diverse substrates. Stochastic mutations of already existing enzymes generate populations of variants, and clusters of functionally similar mutants can serve as parents for subsequent generations of enzymes. The proper evolving unit is a functional quasi-species, which may not be identical with the 'best' variant in its generation. The manifestation of the quasi-species is dependent on the substrate matrix used to explore catalytic activities. Multivariate analysis is an approach to identifying quasi-species and to investigate evolutionary trajectories in the directed evolution of enzymes for novel functions.

  17. Improved sensitivity of an acid sphingomyelinase activity assay using a C6:0 sphingomyelin substrate

    OpenAIRE

    Wei-Lien Chuang; Joshua Pacheco; Samantha Cooper; Kingsbury, Jonathan S.; John Hinds; Pavlina Wolf; Petra Oliva; Joan Keutzer; Cox, Gerald F.; Kate Zhang

    2015-01-01

    Short-chain C6-sphingomyelin is an artificial substrate that was used in an acid sphingomyelinase activity assay for a pilot screening study of patients with Niemann–Pick disease types A and B. Using previously published multiplex and single assay conditions, normal acid sphingomyelinase activity levels (i.e. false negative results) were observed in two sisters with Niemann–Pick B who were compound heterozygotes for two missense mutations, p.C92W and p.P184L, in the SMPD1 gene. Increasing the...

  18. Danazol Inhibits Cytochrome P450 2J2 Activity in a Substrate-independent Manner.

    Science.gov (United States)

    Lee, Eunyoung; Wu, Zhexue; Shon, Jong Cheol; Liu, Kwang-Hyeon

    2015-08-01

    Cytochrome P450 2J2 (CYP2J2) is an enzyme responsible for the metabolism of endogenous substrates including arachidonic acid, as well as therapeutic drugs such as albendazole, astemizole, ebastine, and terfenadine. Selective inhibitors of CYP2J2 are essential for P450 reaction phenotyping studies. To find representative CYP2J2 index inhibitors, we evaluated the inhibitory potential of danazol, hydroxyebastine, telmisartan, and terfenadone against CYP2J2 activity for four representative CYP2J2 substrates (albendazole, astemizole, ebastine, and terfenadine) using recombinant CYP2J2. Of these four CYP2J2 inhibitors, danazol strongly inhibited CYP2J2-mediated albendazole, astemizole, ebastine, and terfenadine metabolism in a substrate-independent manner, with IC50 values of 0.05, 0.07, 0.18, and 0.34 μM, respectively. Danazol noncompetitively inhibited CYP2J2-mediated astemizole O-demethylation activities with a Ki value of 0.06 μM. Terfenadone strongly inhibited CYP2J2-mediated albendazole, astemizole, and terfenadine metabolism (IC50 20 μM). Taken together, these data suggest that danazol may be used as a CYP2J2 index inhibitor in reaction phenotyping studies. PMID:26048912

  19. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine 200.

    Science.gov (United States)

    Kovaleva, Elena G; Rogers, Melanie S; Lipscomb, John D

    2015-09-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady-state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homoprotocatechuate, 4-sulfonylcatechol, and 4-nitrocatechol) possessing substituents with different inductive capacity. Structures determined at 1.35-1.75 Å resolution show that there is essentially no change in overall active site architecture or substrate binding mode for these variants when compared to the structures of the wild-type enzyme and its analogous complexes. This shows that the maximal 50-fold decrease in kcat for ring cleavage, the dramatic changes in pH dependence, and the switch from ring cleavage to ring oxidation of 4-nitrocatechol by the FeHPCD variants can be attributed specifically to the properties of the altered second-sphere residue and the substrate. The results suggest that proton transfer is necessary for catalysis, and that it occurs most efficiently when the substrate provides the proton and His200 serves as a catalyst. However, in the absence of an available substrate proton, a defined proton-transfer pathway in the protein can be utilized. Changes in the steric bulk and charge of the residue at position 200 appear to be capable of altering the rate-limiting step in catalysis and, perhaps, the nature of the reactive species. PMID:26267790

  20. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine-200

    Science.gov (United States)

    Kovaleva, Elena G.; Rogers, Melanie S.; Lipscomb, John D.

    2015-01-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homoprotocatechuate, 4-sulfonylcatechol, and 4-nitrocatechol) possessing substituents with different inductive capacity. Structures solved at 1.35 –1.75 Å resolution show that there is essentially no change in overall active site architecture or substrate binding mode for these variants when compared to the structures of the wild type enzyme and its analogous complexes. This shows that the maximal 50-fold decrease in kcat for ring cleavage, the dramatic changes in pH dependence, and the switch from ring cleavage to ring oxidation of 4-nitrocatechol by the FeHPCD variants can be attributed specifically to the properties of the altered second sphere residue and the substrate. The results suggest that proton transfer is necessary for catalysis, and that it occurs most efficiently when the substrate provides the proton and His200 serves as a catalyst. However, in the absence of an available substrate proton, a defined proton-transfer pathway in the protein can be utilized. Changes in steric bulk and charge of the residue at position 200 appear capable of altering the rate-limiting step in catalysis, and perhaps, the nature of the reactive species. PMID:26267790

  1. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine 200.

    Science.gov (United States)

    Kovaleva, Elena G; Rogers, Melanie S; Lipscomb, John D

    2015-09-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady-state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homoprotocatechuate, 4-sulfonylcatechol, and 4-nitrocatechol) possessing substituents with different inductive capacity. Structures determined at 1.35-1.75 Å resolution show that there is essentially no change in overall active site architecture or substrate binding mode for these variants when compared to the structures of the wild-type enzyme and its analogous complexes. This shows that the maximal 50-fold decrease in kcat for ring cleavage, the dramatic changes in pH dependence, and the switch from ring cleavage to ring oxidation of 4-nitrocatechol by the FeHPCD variants can be attributed specifically to the properties of the altered second-sphere residue and the substrate. The results suggest that proton transfer is necessary for catalysis, and that it occurs most efficiently when the substrate provides the proton and His200 serves as a catalyst. However, in the absence of an available substrate proton, a defined proton-transfer pathway in the protein can be utilized. Changes in the steric bulk and charge of the residue at position 200 appear to be capable of altering the rate-limiting step in catalysis and, perhaps, the nature of the reactive species.

  2. Substrate activation of brewers' yeast pyruvate decarboxylase is abolished by mutation of cysteine 221 to serine.

    Science.gov (United States)

    Baburina, I; Gao, Y; Hu, Z; Jordan, F; Hohmann, S; Furey, W

    1994-05-10

    Brewers' yeast pyruvate decarboxylase (EC 4.1.1.1), a thiamin diphosphate and Mg(II)-dependent enzyme, isolated from Saccharomyces cerevisiae possesses four cysteines/subunit at positions 69, 152, 221, and 222. Earlier studies conducted on a variant of the enzyme with a single Cys at position 221 (derived from a gene that was the product of spontaneous fusion) showed that this enzyme is still subject to substrate activation [Zeng, X., Farrenkopf, B., Hohmann, S., Jordan, F., Dyda, F., & Furey, W. (1993) Biochemistry 32, 2704-2709], indicating that if Cys was responsible for this activation, it had to be C221. To further test the hypothesis, the C221S and C222S single and the C221S-C222S double mutants were constructed. It is clearly shown that the mutation at C221, but not at C222, leads to abolished substrate activation according to a number of kinetic criteria, both steady state and pre steady state. On the basis of the three-dimensional structure of the enzyme [Dyda, F., Furey, W., Swaminathan, S., Sax, M., Farrenkopf, B., Jordan, F. (1993) Biochemistry 32, 6165-6170], it is obvious that while C221 is located on the beta domain, whereas thiamin diphosphate is wedged at the interface of the alpha and gamma domains, addition of pyruvate or pyruvamide as a hemiketal adduct to the sulfur of C221 can easily bridge the gap between the beta and alpha domains. In fact, residues in one or both domains must be dislocated by this adduct formation. It is very likely that regulation as expressed in substrate activation is transmitted via this direct contact made between the two domains in the presence of the activator.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Catalytic irreversible inhibition of bacterial and plant arginine decarboxylase activities by novel substrate and product analogues.

    Science.gov (United States)

    Bitonti, A J; Casara, P J; McCann, P P; Bey, P

    1987-02-15

    Arginine decarboxylase (ADC) activity from Escherichia coli and two plant species (oats and barley) was inhibited by five new substrate (arginine) and product (agmatine) analogues. The five compounds, (E)-alpha-monofluoromethyldehydroarginine (delta-MFMA), alpha-monofluoromethylarginine (MFMA), alpha-monofluoromethylagatine (FMA), alpha-ethynylagmatine (EA) and alpha-allenylagmatine (AA), were all more potent inhibitors of ADC activity than was alpha-difluoromethylarginine (DFMA), the only irreversible inhibitor of this enzyme described previously. The inhibition caused by the five compounds was apparently enzyme-activated and irreversible, since the loss of enzyme activity followed pseudo-first-order kinetics, was time-dependent, the natural substrate of ADC (arginine) blocked the effects of the inhibitors, and the inhibition remained after chromatography of inhibited ADC on Sephadex G-25 or on overnight dialysis of the enzyme. DFMA, FMA, delta-MFMA and MFMA were effective at very low concentrations (10 nM-10 microM) at inhibiting ADC activity in growing E. coli. FMA was also shown to deplete putrescine effectively in E. coli, particularly when combined with an inhibitor of ornithine decarboxylase, alpha-monofluoromethyl-putrescine. The potential uses of the compounds for the study of the role of polyamine biosynthesis in bacteria and plants is discussed.

  4. High performance organic transistor active-matrix driver developed on paper substrate

    Science.gov (United States)

    Peng, Boyu; Ren, Xiaochen; Wang, Zongrong; Wang, Xinyu; Roberts, Robert C.; Chan, Paddy K. L.

    2014-09-01

    The fabrication of electronic circuits on unconventional substrates largely broadens their application areas. For example, green electronics achieved through utilization of biodegradable or recyclable substrates, can mitigate the solid waste problems that arise at the end of their lifespan. Here, we combine screen-printing, high precision laser drilling and thermal evaporation, to fabricate organic field effect transistor (OFET) active-matrix (AM) arrays onto standard printer paper. The devices show a mobility and on/off ratio as high as 0.56 cm2V-1s-1 and 109 respectively. Small electrode overlap gives rise to a cut-off frequency of 39 kHz, which supports that our AM array is suitable for novel practical applications. We demonstrate an 8 × 8 AM light emitting diode (LED) driver with programmable scanning and information display functions. The AM array structure has excellent potential for scaling up.

  5. Magnetic activity of surface plasmon resonance using dielectric magnetic materials fabricated on quartz glass substrate

    Science.gov (United States)

    Narushima, Kazuki; Ashizawa, Yoshito; Brachwitz, Kerstin; Hochmuth, Holger; Lorenz, Michael; Grundmann, Marius; Nakagawa, Katsuji

    2016-07-01

    The magnetic activity of surface plasmons in Au/MFe2O4 (M = Ni, Co, and Zn) polycrystalline bilayer films fabricated on a quartz glass substrate was studied for future magnetic sensor applications using surface plasmon resonance. The excitation of surface plasmons and their magnetic activity were observed in all investigated Au/MFe2O4 films. The magnetic activity of surface plasmons of the polycrystalline Au/NiFe2O4 film was larger than those of the other polycrystalline Au/MFe2O4 films, the epitaxial NiFe2O4 film, and metallic films. The large magnetic activity of surface plasmons of the polycrystalline film is controlled by manipulating surface plasmon excitation conditions and magnetic properties.

  6. Changes in enzymes activity, substrate utilization pattern and diversity of soil microbial communities under cadmium pollution

    Institute of Scientific and Technical Information of China (English)

    Muhammad Akmal; WANG Hai-zhen; WU Jian-jun; XU Jian-ming; XU De-fu

    2005-01-01

    Heavy metal pollution has received increasing attention in recent years mainly because of the public awareness of environmental issues. In this study we have evaluated the effect of cadmium(Cd) on enzymes activity, substrate utilization pattern and diversity of microbial communities in soil spiked with 0, 20, 40, 60, 80, and 100 mg/kg Cd, during 60 d of incubation at 25℃. Enzyme activities determined at 0, 15, 30, 45, and 60 d after heavy metal application(DAA) showed marked declines for various Cd treatments, and up to 60 DAA, 100 mg/kg Cd resulted in 50.1%, 47.4%, and 39.8 % decreases in soil urease, acid phosphatase and dehydrogenase activities,respectively to control. At 60 DAA, substrate utilization pattern of soil microbial communities determined by inoculating Biolog ECO plates indicated that Cd addition had markedly inhibited the functional activity of soil microbial communities and multivariate analysis of sole carbon source utilization showed significantly different utilization patterns for 80 and 100 mg/kg Cd treatments. The structural diversity of soil microbial communities assessed by PCR-DGGE method at 60 DAA, illustrated that DGGE patterns in soil simplified with increasing Cd concentration, and clustering of DGGE profiles for various Cd treatments revealed that they had more than 50% difference with that of control.

  7. Improvement of thermostability and activity of Trichoderma reesei endo-xylanase Xyn III on insoluble substrates.

    Science.gov (United States)

    Matsuzawa, Tomohiko; Kaneko, Satoshi; Yaoi, Katsuro

    2016-09-01

    Trichoderma reesei Xyn III, an endo-β-1,4-xylanase belonging to glycoside hydrolase family 10 (GH10), is vital for the saccharification of xylans in plant biomass. However, its enzymatic thermostability and hydrolytic activity on insoluble substrates are low. To overcome these difficulties, the thermostability of Xyn III was improved using random mutagenesis and directed evolution, and its hydrolytic activity on insoluble substrates was improved by creating a chimeric protein. In the screening of thermostable Xyn III mutants from a random mutagenesis library, we identified two amino acid residues, Gln286 and Asn340, which are important for the thermostability of Xyn III. The Xyn III Gln286Ala/Asn340Tyr mutant showed xylanase activity even after heat treatment at 60 °C for 30 min or 50 °C for 96 h, indicating a dramatic enhancement in thermostability. In addition, we found that the addition of a xylan-binding domain (XBD) to the C-terminal of Xyn III improved its hydrolytic activity on insoluble xylan. PMID:27138202

  8. Characterization of phytase activity from cultivated edible mushrooms and their production substrates.

    Science.gov (United States)

    Collopy, Patrick D; Royse, Daniel J

    2004-12-15

    Phytase is used commercially to maximize phytic acid degradation and to decrease phosphorus levels in poultry and swine manure. To determine phytase content in edible mushrooms, basidiomata of Agaricus bisporus and three specialty mushrooms (Grifola frondosa, Lentinula edodes, and Pleurotus cornucopiae) and spent mushroom substrate (SMS) were surveyed. Enzyme activity ranged from 0.046 to 0.074 unit/g of tissue for four A. bisporus types (closed and open whites and closed and open browns) grown at The Pennsylvania State University's Mushroom Test Demonstration Facility (MTDF). The addition of various nutrient supplements to phase II mushroom production substrate did not alter phytase activity in A. bisporus. Portabella mushrooms (open brown) obtained from a commercial farm had significantly higher levels of phytase activity (0.211 unit/g of tissue) compared to A. bisporus grown at the MTDF. Of the specialty mushrooms surveyed, maitake (G. frondosa) had 20% higher phytase activity (0.287 unit/g of tissue) than commercial portabella mushrooms. The yellow oyster mushroom (P. cornucopiae) ranked second in level of phytase activity (0.213 unit/g of tissue). Shiitake (L. edodes) contained the least amount of phytase in basidiomata (0.107 unit/g of tissue). Post-crop steam treatment (60 degrees C, 24 h) of SMS reduced phytase activity from 0.074 to 0.018 unit/g. Phytase was partially purified from commercially grown portabella basidiomata 314-fold with an estimated molecular mass of 531 kDa by gel filtration chromatography. The optimum pH for activity was 5.5, but appreciable phytase activity was observed over the range of pH 5.0-8.0. Partially purified A. bisporus phytase was inactivated following a 10-min incubation at > or =60 degrees C.

  9. Profiling of Substrates for Zinc‐dependent Lysine Deacylase Enzymes: HDAC3 Exhibits Decrotonylase Activity In Vitro

    DEFF Research Database (Denmark)

    Madsen, Andreas Stahl; Olsen, Christian Adam

    2012-01-01

    Systematic screening of the activities of the eleven human zinc-dependent lysine deacylases against a series of fluorogenic substrates (see scheme) as well as kinetic evaluation revealed substrates for screenings of histone deacetylases HDAC10 and HDAC11 at reasonably low enzyme concentrations...

  10. Active vacuum brazing of CNT films to metal substrates for superior electron field emission performance

    Science.gov (United States)

    Longtin, Rémi; Sanchez-Valencia, Juan Ramon; Shorubalko, Ivan; Furrer, Roman; Hack, Erwin; Elsener, Hansrudolf; Gröning, Oliver; Greenwood, Paul; Rupesinghe, Nalin; Teo, Kenneth; Leinenbach, Christian; Gröning, Pierangelo

    2015-02-01

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active vacuum brazing at 820 °C with a Ag-Cu-Ti alloy and at 880 °C with a Cu-Sn-Ti-Zr alloy. The brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron field-emission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm-1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expected.

  11. Chitosan based substrates for wound infection detection based on increased lysozyme activity.

    Science.gov (United States)

    Tegl, Gregor; Rollett, Alexandra; Dopplinger, Jasmin; Gamerith, Clemens; Guebitz, Georg M

    2016-10-20

    There is a strong need of point-of-care diagnostics for early detection of wound infection. In this study, substrates based on functionalized chitosan were developed for visual detection of elevated lysozyme activity, an infection biomarker in wound fluids. For efficient hydrolysis by lysozyme, N-acetyl chitosan with a final degree of acetylation of around 50% was synthesized. N-acetylated chitosan and a chitosan-starch composite were labeled with structurally different dyes resulting in lysozyme-responsive biomaterials. Incubation with lysozyme in buffer and artificial wound fluid lead to a release of colored hydrolysis products already after 2h incubation. Tests in human wound fluid from infected wounds indicated a clear visual color change after 2.5h compared to control samples. A higher degree of swelling of the chitosan/starch containing substrate led to faster hydrolysis by lysozyme. This study demonstrates the potential of the lysozyme-responsive materials for diagnosis of wound infection and provides different diagnostic substrates for potential incorporation in point-of-care devices. PMID:27474566

  12. Unraveling Kinase Activation Dynamics Using Kinase-Substrate Relationships from Temporal Large-Scale Phosphoproteomics Studies.

    Directory of Open Access Journals (Sweden)

    Westa Domanova

    Full Text Available In response to stimuli, biological processes are tightly controlled by dynamic cellular signaling mechanisms. Reversible protein phosphorylation occurs on rapid time-scales (milliseconds to seconds, making it an ideal carrier of these signals. Advances in mass spectrometry-based proteomics have led to the identification of many tens of thousands of phosphorylation sites, yet for the majority of these the kinase is unknown and the underlying network topology of signaling networks therefore remains obscured. Identifying kinase substrate relationships (KSRs is therefore an important goal in cell signaling research. Existing consensus sequence motif based prediction algorithms do not consider the biological context of KSRs, and are therefore insensitive to many other mechanisms guiding kinase-substrate recognition in cellular contexts. Here, we use temporal information to identify biologically relevant KSRs from Large-scale In Vivo Experiments (KSR-LIVE in a data-dependent and automated fashion. First, we used available phosphorylation databases to construct a repository of existing experimentally-predicted KSRs. For each kinase in this database, we used time-resolved phosphoproteomics data to examine how its substrates changed in phosphorylation over time. Although substrates for a particular kinase clustered together, they often exhibited a different temporal pattern to the phosphorylation of the kinase. Therefore, although phosphorylation regulates kinase activity, our findings imply that substrate phosphorylation likely serve as a better proxy for kinase activity than kinase phosphorylation. KSR-LIVE can thereby infer which kinases are regulated within a biological context. Moreover, KSR-LIVE can also be used to automatically generate positive training sets for the subsequent prediction of novel KSRs using machine learning approaches. We demonstrate that this approach can distinguish between Akt and Rps6kb1, two kinases that share the same

  13. Unraveling Kinase Activation Dynamics Using Kinase-Substrate Relationships from Temporal Large-Scale Phosphoproteomics Studies

    Science.gov (United States)

    Chaudhuri, Rima; Yang, Pengyi; Vafaee, Fatemeh; Fazakerley, Daniel; Humphrey, Sean; James, David; Kuncic, Zdenka

    2016-01-01

    In response to stimuli, biological processes are tightly controlled by dynamic cellular signaling mechanisms. Reversible protein phosphorylation occurs on rapid time-scales (milliseconds to seconds), making it an ideal carrier of these signals. Advances in mass spectrometry-based proteomics have led to the identification of many tens of thousands of phosphorylation sites, yet for the majority of these the kinase is unknown and the underlying network topology of signaling networks therefore remains obscured. Identifying kinase substrate relationships (KSRs) is therefore an important goal in cell signaling research. Existing consensus sequence motif based prediction algorithms do not consider the biological context of KSRs, and are therefore insensitive to many other mechanisms guiding kinase-substrate recognition in cellular contexts. Here, we use temporal information to identify biologically relevant KSRs from Large-scale In Vivo Experiments (KSR-LIVE) in a data-dependent and automated fashion. First, we used available phosphorylation databases to construct a repository of existing experimentally-predicted KSRs. For each kinase in this database, we used time-resolved phosphoproteomics data to examine how its substrates changed in phosphorylation over time. Although substrates for a particular kinase clustered together, they often exhibited a different temporal pattern to the phosphorylation of the kinase. Therefore, although phosphorylation regulates kinase activity, our findings imply that substrate phosphorylation likely serve as a better proxy for kinase activity than kinase phosphorylation. KSR-LIVE can thereby infer which kinases are regulated within a biological context. Moreover, KSR-LIVE can also be used to automatically generate positive training sets for the subsequent prediction of novel KSRs using machine learning approaches. We demonstrate that this approach can distinguish between Akt and Rps6kb1, two kinases that share the same linear consensus motif

  14. Unraveling Kinase Activation Dynamics Using Kinase-Substrate Relationships from Temporal Large-Scale Phosphoproteomics Studies.

    Science.gov (United States)

    Domanova, Westa; Krycer, James; Chaudhuri, Rima; Yang, Pengyi; Vafaee, Fatemeh; Fazakerley, Daniel; Humphrey, Sean; James, David; Kuncic, Zdenka

    2016-01-01

    In response to stimuli, biological processes are tightly controlled by dynamic cellular signaling mechanisms. Reversible protein phosphorylation occurs on rapid time-scales (milliseconds to seconds), making it an ideal carrier of these signals. Advances in mass spectrometry-based proteomics have led to the identification of many tens of thousands of phosphorylation sites, yet for the majority of these the kinase is unknown and the underlying network topology of signaling networks therefore remains obscured. Identifying kinase substrate relationships (KSRs) is therefore an important goal in cell signaling research. Existing consensus sequence motif based prediction algorithms do not consider the biological context of KSRs, and are therefore insensitive to many other mechanisms guiding kinase-substrate recognition in cellular contexts. Here, we use temporal information to identify biologically relevant KSRs from Large-scale In Vivo Experiments (KSR-LIVE) in a data-dependent and automated fashion. First, we used available phosphorylation databases to construct a repository of existing experimentally-predicted KSRs. For each kinase in this database, we used time-resolved phosphoproteomics data to examine how its substrates changed in phosphorylation over time. Although substrates for a particular kinase clustered together, they often exhibited a different temporal pattern to the phosphorylation of the kinase. Therefore, although phosphorylation regulates kinase activity, our findings imply that substrate phosphorylation likely serve as a better proxy for kinase activity than kinase phosphorylation. KSR-LIVE can thereby infer which kinases are regulated within a biological context. Moreover, KSR-LIVE can also be used to automatically generate positive training sets for the subsequent prediction of novel KSRs using machine learning approaches. We demonstrate that this approach can distinguish between Akt and Rps6kb1, two kinases that share the same linear consensus motif

  15. Silver nanoparticles deposited on porous silicon as a surface-enhanced Raman scattering (SERS) active substrate.

    Science.gov (United States)

    Zeiri, Leila; Rechav, Katya; Porat, Ze'ev; Zeiri, Yehuda

    2012-03-01

    Silver nanoparticles were deposited spontaneously from their aqueous solution on a porous silicon (PS) layer. The PS acts both as a reducing agent and as the substrate on which the nanoparticles nucleate. At higher silver ion concentrations, layers of nanoparticle aggregates were formed on the PS surface. The morphology of the metallic layers and their SERS activity were influenced by the concentrations of the silver ion solutions used for deposition. Raman measurements of rhodamine 6G (R6G) and crystal violet (CV) adsorbed on these surfaces showed remarkable enhancement of up to about 10 orders of magnitude.

  16. Improved sensitivity of an acid sphingomyelinase activity assay using a C6:0 sphingomyelin substrate.

    Science.gov (United States)

    Chuang, Wei-Lien; Pacheco, Joshua; Cooper, Samantha; Kingsbury, Jonathan S; Hinds, John; Wolf, Pavlina; Oliva, Petra; Keutzer, Joan; Cox, Gerald F; Zhang, Kate

    2015-06-01

    Short-chain C6-sphingomyelin is an artificial substrate that was used in an acid sphingomyelinase activity assay for a pilot screening study of patients with Niemann-Pick disease types A and B. Using previously published multiplex and single assay conditions, normal acid sphingomyelinase activity levels (i.e. false negative results) were observed in two sisters with Niemann-Pick B who were compound heterozygotes for two missense mutations, p.C92W and p.P184L, in the SMPD1 gene. Increasing the sodium taurocholate detergent concentration in the assay buffer lowered the activity levels of these two patients into the range observed with other patients with clear separation from normal controls. PMID:26937397

  17. Long read nanopore sequencing for detection of HLA and CYP2D6 variants and haplotypes [v1; ref status: indexed, http://f1000r.es/4zj

    Directory of Open Access Journals (Sweden)

    Ron Ammar

    2015-01-01

    Full Text Available Haplotypes are often critical for the interpretation of genetic laboratory observations into medically actionable findings. Current massively parallel DNA sequencing technologies produce short sequence reads that are often unable to resolve haplotype information. Phasing short read data typically requires supplemental statistical phasing based on known haplotype structure in the population or parental genotypic data. Here we demonstrate that the MinION nanopore sequencer is capable of producing very long reads to resolve both variants and haplotypes of HLA-A, HLA-B and CYP2D6 genes important in determining patient drug response in sample NA12878 of CEPH/UTAH pedigree 1463, without the need for statistical phasing. Long read data from a single 24-hour nanopore sequencing run was used to reconstruct haplotypes, which were confirmed by HapMap data and statistically phased Complete Genomics and Sequenom genotypes. Our results demonstrate that nanopore sequencing is an emerging standalone technology with potential utility in a clinical environment to aid in medical decision-making.

  18. Long read nanopore sequencing for detection of HLA and CYP2D6 variants and haplotypes [v2; ref status: indexed, http://f1000r.es/5ev

    Directory of Open Access Journals (Sweden)

    Ron Ammar

    2015-05-01

    Full Text Available Haplotypes are often critical for the interpretation of genetic laboratory observations into medically actionable findings. Current massively parallel DNA sequencing technologies produce short sequence reads that are often unable to resolve haplotype information. Phasing short read data typically requires supplemental statistical phasing based on known haplotype structure in the population or parental genotypic data. Here we demonstrate that the MinION nanopore sequencer is capable of producing very long reads to resolve both variants and haplotypes of HLA-A, HLA-B and CYP2D6 genes important in determining patient drug response in sample NA12878 of CEPH/UTAH pedigree 1463, without the need for statistical phasing. Long read data from a single 24-hour nanopore sequencing run was used to reconstruct haplotypes, which were confirmed by HapMap data and statistically phased Complete Genomics and Sequenom genotypes. Our results demonstrate that nanopore sequencing is an emerging standalone technology with potential utility in a clinical environment to aid in medical decision-making.

  19. Effect of cytochrome P450 2D6*10 polymorphism on the pharmacokinetics of oral nebivolol after single and multiple doses%细胞色素 P4502 D6*10基因多态性对单次及多次口服奈必洛尔药代动力学的影响

    Institute of Scientific and Technical Information of China (English)

    蔡凝芳; 程泽能; 李碧峰; 黄小红; 许可珍; 蔡梦云; 冯惠平; 何丽华; 余敏; 郭歆

    2015-01-01

    目的:评价细胞色素P4502D6*10( CYP2D6*10)基因多态性对单次及多次口服奈必洛尔药代动力学的影响。方法根据CYP2D6*10基因型选择入选15名中国健康受试者,其中CYP2D6*1携带者8名,CYP2D6*10/*10基因型7名。所有受试者单次口服奈必洛尔5 mg和多次口服奈必洛尔5 mg・ d-1,qd,连续7 d。用LC-MS/MS法测定奈必洛尔血药浓度,用WinNonlin软件计算主要的药代动力学参数。结果单次口服奈必洛尔后 CYP2D6*1携带者和CYP2D6*10/*10基因型个体中奈必洛尔的主要药代动力学参数:t1/2分别为(9.88±5.47),(12.29±6.19) h; AUCinf分别为(7.26±5.88),(8.56±5.20)μg・ L-1・ h;Cmax分别为(1.11±0.53),(1.42±0.75)μg・ L-1。多次口服奈必洛尔后CYP2D6*1携带者和CYP2D6*10/*10基因型个体中奈必洛尔的主要药代动力学参数:t1/2分别为(8.56±2.38),(7.67±4.75) h; AUCinf分别为(10.62±5.62),(12.74±7.40)μg・ L-1・ h;Cmax分别为(2.05±0.83),(2.02±0.75)μg・ L-1。奈必洛尔主要药代动力学参数在不同基因型组间比较差异无统计学意义( P>0.05)。多次给药的清除率在不同基因型中均显著低于单次给药(P<0.05)。结论 CYP2D6*10基因多态性对单次及多次口服奈必洛尔药代动力学无显著影响。多次给药后奈必洛尔体内消除减慢,且不受CYP2D6*10基因多态性影响。%Objective To evaluate the effect of cytochrome P450 2 D6*10 ( CYP2 D6*10 ) polymorphism on the pharmacokinetics of oral nebivolol after single and multiple doses. Methods Fifteen healthy volunteers which were selected according to their CYP2D6*10 genotype, consisted of 8 of CYP2D6*1 carriers and 7 of CYP2D6*10/*10 geno-types.All subjects received a single dose of 5 mg and multiple doses (5 mg・ d-1 , qd, for 7 days) .Nebivolol in plasma

  20. Directed enzyme evolution guided by multidimensional analysis of substrate-activity space.

    Science.gov (United States)

    Larsson, Anna-Karin; Emrén, Lars O; Bardsley, William G; Mannervik, Bengt

    2004-01-01

    The directed evolution of protein function frequently involves identification of mutants with improved properties from a population of variants obtained by mutagenesis. The selection of clones to parent the subsequent generation is crucial to the continued creation of superior progeny. In the present study, multivariate analysis guided the evolution of human glutathione transferase (GST) T1-1 to 65-fold enhanced alkyltransferase activity. Six alternative substrates monitored the substrate-activity space that characterized a mutant library of enzymes, obtained by recombination of DNA and heterologous expression in Escherichia coli. A subset of mutants was identified by their proximity in the targeted region of six-dimensional factor space. DNA from these mutants was recombined to create a new generation of GST variants from which an improved enzyme was isolated. The multidimensional cluster analysis is applicable to quantitative properties in any population of molecules undergoing evolution and can guide the tailoring of proteins, nucleic acids and other chemical structures to novel and improved functions.

  1. Structure-activity relationships in the hydrolysis of substrates by the phosphotriesterase from Pseudomonas diminuta

    International Nuclear Information System (INIS)

    The mechanism and substrate specificity of the phosphotriesterase from Pseudomonas diminuta have been examined. The enzyme hydrolyzes a large number of phosphotriester substrates in addition to paraoxon (diethyl p-nitrophenyl phosphate) and its thiophosphate analogue, parathion. The two ethyl groups in paraoxon can be changed to propyl and butyl groups, but the maximal velocity and Km values decrease substantially. The enzyme will not hydrolyze phosphomonoesters or -diesters. There is a linear correlation between enzymatic activity and the pKa of the phenolic leaving group for 16 paraoxon analogues. The beta value in the corresponding Bronsted plot is -0.8. No effect on either Vmax or Vmax/Km is observed when sucrose is used to increase the relative solvent viscosity by 3-fold. These results are consistent with rate-limiting phosphorus-oxygen bond cleavage. A plot of log V versus pH for the hydrolysis of paraoxon shows one enzymatic group that must be unprotonated for activity with a pKa of 6.1. The deuterium isotope effect by D2O on Vmax and Vmax/Km is 2.4 and 1.2, respectively, and the proton inventory is linear, which indicates that only one proton is in flight during the transition state. The inhibition patterns by the products are consistent with a random kinetic mechanism

  2. Evaluation of Proposed In Vivo Probe Substrates and Inhibitors for Phenotyping Transporter Activity in Humans.

    Science.gov (United States)

    Momper, Jeremiah D; Tsunoda, Shirley M; Ma, Joseph D

    2016-07-01

    Drug transporters are present in various tissues and have a significant role in drug absorption, distribution, and elimination. The International Transporter Consortium has identified 7 transporters of increasing importance from evidence of clinically significant transporter-mediated drug-drug interactions. The transporters are P-glycoprotein, breast cancer resistance protein, organic anion transporting polypeptide (OATP) 1B1, OATP1B3, organic cation transporter 2, organic anion transporters (OAT) 1, and OAT3. Decision trees were created based on in vitro experiments to determine whether an in vivo transporter-mediated drug-drug interaction study is needed. Phenotyping is a methodology that evaluates real-time in vivo transporter activity, whereby changes in a probe substrate or probe inhibitor reflect alternations in the activity of the specified transporter. In vivo probe substrates and/or probe inhibitors have been proposed for each aforementioned transporter. In vitro findings and animal models provide the strongest evidence regarding probe specificity. However, such findings have not conclusively correlated with human phenotyping studies. Furthermore, the extent of contribution from multiple transporters in probe disposition complicates the ability to discern if study findings are the result of a specific transporter and thus provide a recommendation for a preferred probe for a drug transporter. PMID:27385182

  3. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine-200

    OpenAIRE

    Kovaleva, Elena G.; Rogers, Melanie S.; Lipscomb, John D.

    2015-01-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homo...

  4. Targeted reengineering of protein geranylgeranyltransferase type I selectivity functionally implicates active-site residues in protein-substrate recognition.

    Science.gov (United States)

    Gangopadhyay, Soumyashree A; Losito, Erica L; Hougland, James L

    2014-01-21

    Posttranslational modifications are vital for the function of many proteins. Prenylation is one such modification, wherein protein geranylgeranyltransferase type I (GGTase-I) or protein farnesyltransferase (FTase) modify proteins by attaching a 20- or 15-carbon isoprenoid group, respectively, to a cysteine residue near the C-terminus of a target protein. These enzymes require a C-terminal Ca1a2X sequence on their substrates, with the a1, a2, and X residues serving as substrate-recognition elements for FTase and/or GGTase-I. While crystallographic structures of rat GGTase-I show a tightly packed and hydrophobic a2 residue binding pocket, consistent with a preference for moderately sized a2 residues in GGTase-I substrates, the functional impact of enzyme-substrate contacts within this active site remains to be determined. Using site-directed mutagenesis and peptide substrate structure-activity studies, we have identified specific active-site residues within rat GGTase-I involved in substrate recognition and developed novel GGTase-I variants with expanded/altered substrate selectivity. The ability to drastically alter GGTase-I selectivity mirrors similar behavior observed in FTase but employs mutation of a distinct set of structurally homologous active-site residues. Our work demonstrates that tunable selectivity may be a general phenomenon among multispecific enzymes involved in posttranslational modification and raises the possibility of variable substrate selectivity among GGTase-I orthologues from different organisms. Furthermore, the GGTase-I variants developed herein can serve as tools for studying GGTase-I substrate selectivity and the effects of prenylation pathway modifications on specific proteins. PMID:24344934

  5. Imaging of enzyme activity by scanning electrochemical microscope equipped with a feedback control for substrate-probe distance.

    Science.gov (United States)

    Oyamatsu, Daisuke; Hirano, Yu; Kanaya, Norihiro; Mase, Yoshiaki; Nishizawa, Matsuhiko; Matsue, Tomokazu

    2003-08-01

    The enzymatic activity of diaphorase (Dp) immobilized on a solid substrate was characterized using a scanning electrochemical microscope (SECM) with shear force feedback to control the substrate-probe distance. The shear force between the substrate and the probe was monitored with a tuning fork-type quartz crystal and used as the feedback control to set the microelectrode probe close to the substrate surface. The sensitivity and the contrast of the SECM image were improved in the constant distance mode (distance, 50 nm) with the shear force feedback compared to the image in the constant height mode without the feedback. By using this system, the SECM and topographic images of the immobilized diaphorase were simultaneously measured. The microelectrode tip used in this study was ground aslant like a syringe needle in order to obtain the shaper topographic images. This shape was also effective for avoiding the interference during the diffusion of the enzyme substrates. PMID:12893317

  6. Development of a protease activity assay using heat-sensitive Tus-GFP fusion protein substrates.

    Science.gov (United States)

    Askin, Samuel P; Morin, Isabelle; Schaeffer, Patrick M

    2011-08-15

    Proteases are implicated in various diseases and several have been identified as potential drug targets or biomarkers. As a result, protease activity assays that can be performed in high throughput are essential for the screening of inhibitors in drug discovery programs. Here we describe the development of a simple, general method for the characterization of protease activity and its use for inhibitor screening. GFP was genetically fused to a comparatively unstable Tus protein through an interdomain linker containing a specially designed protease site, which can be proteolyzed. When this Tus-GFP fusion protein substrate is proteolyzed it releases GFP, which remains in solution after a short heat denaturation and centrifugation step used to eliminate uncleaved Tus-GFP. Thus, the increase in GFP fluorescence is directly proportional to protease activity. We validated the protease activity assay with three different proteases, i.e., trypsin, caspase 3, and neutrophil elastase, and demonstrated that it can be used to determine protease activity and the effect of inhibitors with small sample volumes in just a few simple steps using a fluorescence plate reader.

  7. Electrodeposition of metallic tungsten coating from binary oxide molten salt on low activation steel substrate

    International Nuclear Information System (INIS)

    Tungsten is considered a promising plasma facing armor material for future fusion devices. An electrodeposited metallic tungsten coating from Na2WO4–WO3 binary oxide molten salt on low activation steel (LAS) substrate was investigated in this paper. Tungsten coatings were deposited under various pulsed currents conditions at 1173 K in atmosphere. Cathodic current density and pulsed duty cycle were investigated for pulsed current electrolysis. The crystal structure and microstructure of tungsten coatings were characterized by X-ray diffractometry, scanning electron microscopy, and energy X-ray dispersive analysis techniques. The results indicated that pulsed current density and duty cycle significantly influence tungsten nucleation and electro-crystallization phenomena. The average grain size of the coating becomes much larger with increasing cathodic current density, which demonstrates that appropriate high cathodic current density can accelerate the growth of grains on the surface of the substrate. The micro-hardness of tungsten coatings increases with the increasing thickness of coatings; the maximum micro-hardness is 482 HV. The prepared tungsten coatings have a smooth surface, a porosity of less than 1%, and an oxygen content of 0.024 wt%

  8. A Camelid-derived Antibody Fragment Targeting the Active Site of a Serine Protease Balances between Inhibitor and Substrate Behavior.

    Science.gov (United States)

    Kromann-Hansen, Tobias; Oldenburg, Emil; Yung, Kristen Wing Yu; Ghassabeh, Gholamreza H; Muyldermans, Serge; Declerck, Paul J; Huang, Mingdong; Andreasen, Peter A; Ngo, Jacky Chi Ki

    2016-07-15

    A peptide segment that binds the active site of a serine protease in a substrate-like manner may behave like an inhibitor or a substrate. However, there is sparse information on which factors determine the behavior a particular peptide segment will exhibit. Here, we describe the first x-ray crystal structure of a nanobody in complex with a serine protease. The nanobody displays a new type of interaction between an antibody and a serine protease as it inserts its complementary determining region-H3 loop into the active site of the protease in a substrate-like manner. The unique binding mechanism causes the nanobody to behave as a strong inhibitor as well as a poor substrate. Intriguingly, its substrate behavior is incomplete, as 30-40% of the nanobody remained intact and inhibitory after prolonged incubation with the protease. Biochemical analysis reveals that an intra-loop interaction network within the complementary determining region-H3 of the nanobody balances its inhibitor versus substrate behavior. Collectively, our results unveil molecular factors, which may be a general mechanism to determine the substrate versus inhibitor behavior of other protease inhibitors. PMID:27226628

  9. Proteinase K activity determination with β-galactosidase as sensitive macromolecular substrate.

    Science.gov (United States)

    Ghéczy, Nicolas; Küchler, Andreas; Walde, Peter

    2016-11-15

    Proteinase K from Engyodontium album (proK) is a relatively unspecific serine endopeptidase which is known to attack proteins yet in their native states. If the attacked protein is an enzyme, even a partial hydrolysis by proK may lead to an inactivation of the enzyme, which can be monitored by measuring the loss of catalytic activity of the attacked enzyme. E. coli β-galactosidase (β-Gal) was used in this work as such enzyme. It was found to be a convenient and sensitive macromolecular model substrate for comparing the "native protein-attacking ability" of free and immobilized proK at pH = 7.0 and 23 °C. The β-Gal activity was measured spectrophotometrically with o-nitrophenyl-β-galactopyranoside. Reproducible proK determinations were possible for as little as 4.3 ng proK by using a proK analyte solution of 10 nM. Compared to free proK, immobilized proK was much less efficient in inactivating β-Gal, most likely due to a decreased mobility of immobilized proK and a restricted accessibility of β-Gal to the active site of proK. Worth noting is, that under conditions at which β-Gal was completely inactivated by proK, the activity of hen egg lysozyme, horseradish peroxidase, or Aspergillus sp. glucose oxidase remained unaltered. PMID:27594349

  10. Proteinase K activity determination with β-galactosidase as sensitive macromolecular substrate.

    Science.gov (United States)

    Ghéczy, Nicolas; Küchler, Andreas; Walde, Peter

    2016-11-15

    Proteinase K from Engyodontium album (proK) is a relatively unspecific serine endopeptidase which is known to attack proteins yet in their native states. If the attacked protein is an enzyme, even a partial hydrolysis by proK may lead to an inactivation of the enzyme, which can be monitored by measuring the loss of catalytic activity of the attacked enzyme. E. coli β-galactosidase (β-Gal) was used in this work as such enzyme. It was found to be a convenient and sensitive macromolecular model substrate for comparing the "native protein-attacking ability" of free and immobilized proK at pH = 7.0 and 23 °C. The β-Gal activity was measured spectrophotometrically with o-nitrophenyl-β-galactopyranoside. Reproducible proK determinations were possible for as little as 4.3 ng proK by using a proK analyte solution of 10 nM. Compared to free proK, immobilized proK was much less efficient in inactivating β-Gal, most likely due to a decreased mobility of immobilized proK and a restricted accessibility of β-Gal to the active site of proK. Worth noting is, that under conditions at which β-Gal was completely inactivated by proK, the activity of hen egg lysozyme, horseradish peroxidase, or Aspergillus sp. glucose oxidase remained unaltered.

  11. Probing substrate interactions in the active tunnel of a catalytically deficient cellobiohydrolase (Cel7)

    DEFF Research Database (Denmark)

    Westh, Peter; Colussi, Francieli; Sørensen, Trine Holst;

    2015-01-01

    Cellobiohydrolases (CBHs) break down cellulose sequentially by sliding along the crystal surface with a single cellulose strand threaded through the catalytic tunnel of the enzyme. This so-called processive mechanism relies on a complex pattern of enzyme-substrate interactions, which need to be...... sites in the catalytic tunnel, and using COS ligands with a degree of polymerization (DP) from 2 to 8, different regions of the tunnel could be probed. For COS ligands with DP of 2-3 the binding constants were around 105 M-1, and for longer ligands (DP 5-8) this value was about 107 M-1. Within each of......) decreased monotonously with both temperature and DP. Combined interpretation of these thermodynamic results and previously published structural data allowed assessment of an affinity profile along the length axis of the active tunnel...

  12. Amorphous silicon thin film transistor active-matrix organic light-emitting diode displays fabricated on flexible substrates

    Science.gov (United States)

    Nichols, Jonathan A.

    Organic light-emitting diode (OLED) displays are of immense interest because they have several advantages over liquid crystal displays, the current dominant flat panel display technology. OLED displays are emissive and therefore are brighter, have a larger viewing angle, and do not require backlights and filters, allowing thinner, lighter, and more power efficient displays. The goal of this work was to advance the state-of-the-art in active-matrix OLED display technology. First, hydrogenated amorphous silicon (a-Si:H) thin film transistor (TFT) active-matrix OLED pixels and arrays were designed and fabricated on glass substrates. The devices operated at low voltages and demonstrated that lower performance TFTs could be utilized in active-matrix OLED displays, possibly allowing lower cost processing and the use of polymeric substrates. Attempts at designing more control into the display at the pixel level were also made. Bistable (one bit gray scale) active-matrix OLED pixels and arrays were designed and fabricated. Such pixels could be used in novel applications and eventually help reduce the bandwidth requirements in high-resolution and large-area displays. Finally, a-Si:H TFT active-matrix OLED pixels and arrays were fabricated on a polymeric substrate. Displays fabricated on a polymeric substrates would be lightweight; flexible, more rugged, and potentially less expensive to fabricate. Many of the difficulties associated with fabricating active-matrix backplanes on flexible substrates were studied and addressed.

  13. SUBSTRATE UTILIZATION IS INFLUENCED BY ACUTE DIETARY CARBOHYDRATE INTAKE IN ACTIVE, HEALTHY FEMALES

    Directory of Open Access Journals (Sweden)

    Sara Gregory

    2011-03-01

    Full Text Available The present study compared the metabolic responses between a single low-carbohydrate (LC and low-fat (LF meal followed by an aerobic exercise bout in females. Subjects included 8 active, premenopausal females. Subjects completed a LC and LF testing session. Respiratory gas exchange (RER measurements were taken for 20 min fasted, for 55 min postprandial (PP, and during 30 min of exercise. Blood was collected for assessment of glucose (G, insulin (IN, triglycerides (TG, and free fatty acids (FFA during the final 10 min of each time period. The LF meal provided 396 kcal (78% carbohydrate, 7% fat, and 15% protein. The LC meal provided 392 kcal (15% carbohydrate, 68% fat, and 18% protein. No significant differences existed between test meals for fasting blood measurements. PP IN (µU·mL-1 levels were significantly lower following LC compared to LF [10.7 (6.1 vs. 26.0 (21.0]. Postexercise (PE FFA (mEq·L-1 levels were significantly greater following LC [1.1 (0.3 vs. 0.5 (0.3]. PE TG (mg·dL-1 levels were significantly greater following LC [152.0 (53.1 vs. 114.4 (40.9]. RER was significantly lower at all time points following LC compared to LF. In moderately active adult females, ingestion of a single LC meal resulted in greater lipid oxidation at rest and during exercise as compared to a single LF meal. Although macronutrient distribution appears to have dictated substrate utilization in the present study, more research is needed regarding the long-term effects of macronutrient redistribution with and without exercise on substrate utilization.

  14. Bacillus subtilis BY-kinase PtkA controls enzyme activity and localization of its protein substrates

    DEFF Research Database (Denmark)

    Jers, Carsten; Pedersen, Malene Mejer; Paspaliari, Dafni Katerina;

    2010-01-01

    P>Bacillus subtilis BY-kinase PtkA was previously shown to phosphorylate, and thereby regulate the activity of two classes of protein substrates: UDP-glucose dehydrogenases and single-stranded DNA-binding proteins. Our recent phosphoproteome study identified nine new tyrosine-phosphorylated prote......A was dramatically altered in Delta ptkA background. Our results confirm that PtkA can control enzyme activity of its substrates in some cases, but also reveal a new mode of action for PtkA, namely ensuring correct cellular localization of its targets.......-phosphorylated proteins in B. subtilis. We found that the majority of these proteins could be phosphorylated by PtkA in vitro. Among these new substrates, single-stranded DNA exonuclease YorK, and aspartate semialdehyde dehydrogenase Asd were activated by PtkA-dependent phosphorylation. Because enzyme activity...

  15. Myoglobin inhibition of most protease activities measured with fluorescent substrates is an artifact!

    Science.gov (United States)

    Volle, B; Dutaud, D; Ouali, A

    1999-05-01

    Myoglobin has been suggested to be a potential inhibitor of endogenous muscle proteases as different as cathepsin B, cathepsin L, cathepsin H and calpains all being supposed to be important in post-mortem muscle. The present work aimed at verifying the ability of myoglobin and its prosthetic group, hemin, to inhibit a series of endopeptidases including papain, cathepsin B, trypsin, calpains as well as two activities of the 20S proteasome. The conclusion of the present work was that inhibition of proteolytic activities of endopeptidases by myoglobin is an artifact. This was based on the following evidences: (1) a similar extent of inhibition was observed for all proteases tested whether myoglobin or hemin were added before starting the reaction or after having stopped it; (2) a quenching of the probes fluorescence by myoglobin and hemin; (3) no inhibition of calpains were found when assayed with non labeled casein as substrate and the activity expressed as the increase in the absorbency at 280 nm of the TCA soluble protein fragments.(1). PMID:22062146

  16. Calcite precipitation on glass substrates and active stalagmites in Katerloch Cave (Austria): Constraints from environmental monitoring

    Science.gov (United States)

    Sakoparnig, Marlene; Boch, Ronny; Wang, Xianfeng; Lin, Ke; Spötl, Christoph; Leis, Albrecht; Gollowitsch, Anna; Dietzel, Martin

    2016-04-01

    Located near Graz at the SE-rim of the Alps Katerloch is well-known for its impressive dripstone decoration, e.g. several metres tall and relatively fast growing (0.2-0.7 mm/yr on average) candle-stick-type stalagmites. In the course of an ongoing multi-annual and partially high-resolution cave monitoring program we study modern (active) sites of carbonate deposition focusing on the site-specific growth dynamics and connection of modern regional and cave environmental conditions with petrographic, chemical and stable isotopic information captured in the speleothems. Fresh calcite precipitates on artificial (glass) substrates underneath active drip sites were collected continuously from 2006 to 2014 (eight years!). The samples (up to 7 mm thick) represent cave sections of different temperature and drip sites of partially different characteristics (e.g. drip rate). We also recovered short drill cores (up to 3 cm length, 1 cm diameter) from the top of active stalagmites probably representing the last decades to centuries of calcite crystallization. Moreover, an actively growing stalagmite (K10) comprising both modern and past calcite deposition was collected. 238U-234U-230Th dating using MC-ICP-MS of K10 (71 cm long) revealed several distinct growth intervals (separated by growth interruptions) starting at 129.1 ±1.2 kyr BP (Last Interglacial) up to now, mostly reflecting warm and humid climate intervals. High-resolution (100 μm) isotope profiles micromilled from the multi-annual modern calcite precipitates on artificial substrates revealed low δ13C values of -12.8 to -8.3 ‰ (VPDB) and relatively high δ18O of -6.9 to -4.9 ‰Ṫhe δ18O curves from all collection sites (different growth rate) record a pronounced decrease during their most recent growth period most likely corresponding to a significant decrease towards lower oxygen isotope values observed in drip waters collected in the year 2014 compared with samples from 2005 to 2007. Drip water δ2H /δ18O

  17. A microarray of ubiquitylated proteins for profiling deubiquitylase activity reveals the critical roles of both chain and substrate.

    Science.gov (United States)

    Loch, Christian M; Strickler, James E

    2012-11-01

    Substrate ubiquitylation is a reversible process critical to cellular homeostasis that is often dysregulated in many human pathologies including cancer and neurodegeneration. Elucidating the mechanistic details of this pathway could unlock a large store of information useful to the design of diagnostic and therapeutic interventions. Proteomic approaches to the questions at hand have generally utilized mass spectrometry (MS), which has been successful in identifying both ubiquitylation substrates and profiling pan-cellular chain linkages, but is generally unable to connect the two. Interacting partners of the deubiquitylating enzymes (DUBs) have also been reported by MS, although substrates of catalytically competent DUBs generally cannot be. Where they have been used towards the study of ubiquitylation, protein microarrays have usually functioned as platforms for the identification of substrates for specific E3 ubiquitin ligases. Here, we report on the first use of protein microarrays to identify substrates of DUBs, and in so doing demonstrate the first example of microarray proteomics involving multiple (i.e., distinct, sequential and opposing) enzymatic activities. This technique demonstrates the selectivity of DUBs for both substrate and type (mono- versus poly-) of ubiquitylation. This work shows that the vast majority of DUBs are monoubiquitylated in vitro, and are incapable of removing this modification from themselves. This work also underscores the critical role of utilizing both ubiquitin chains and substrates when attempting to characterize DUBs. This article is part of a Special Issue entitled: Ubiquitin Drug Discovery and Diagnostics.

  18. Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease N{sup pro}

    Energy Technology Data Exchange (ETDEWEB)

    Gottipati, Keerthi; Acholi, Sudheer [Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647 (United States); Ruggli, Nicolas [Institute of Virology and Immunology, CH-3147 Mittelhäusern (Switzerland); Choi, Kyung H., E-mail: kychoi@utmb.edu [Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647 (United States)

    2014-03-15

    Pestivirus N{sup pro} is the first protein translated in the viral polypeptide, and cleaves itself off co-translationally generating the N-terminus of the core protein. Once released, N{sup pro} blocks the host's interferon response by inducing degradation of interferon regulatory factor-3. N{sup pro'}s intracellular autocatalytic activity and lack of trans-activity have hampered in vitro cleavage studies to establish its substrate specificity and the roles of individual residues. We constructed N{sup pro}-GFP fusion proteins that carry the authentic cleavage site and determined the autoproteolytic activities of N{sup pro} proteins containing substitutions at the predicted catalytic sites Glu22 and Cys69, at Arg100 that forms a salt bridge with Glu22, and at the cleavage site Cys168. Contrary to previous reports, we show that N{sup pro'}s catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, N{sup pro} does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. - Highlights: • N{sup pro'}s autoproteolysis is studied using N{sup pro}-GFP fusion proteins. • N-terminal 17 amino acids are dispensable without loss of protease activity. • The putative catalytic residue Glu22 is not involved in protease catalysis. • No specificity for Cys168 at the cleavage site despite evolutionary conservation. • N{sup pro} prefers small amino acids with non-branched beta carbons at the P1 position.

  19. Temperature and substrate chemistry as major drivers of interregional variability of leaf microbial decomposition and cellulolytic activity in headwater streams.

    Science.gov (United States)

    Fenoy, Encarnación; Casas, J Jesús; Díaz-López, Manuel; Rubio, Juan; Guil-Guerrero, J Luís; Moyano-López, Francisco J

    2016-11-01

    Abiotic factors, substrate chemistry and decomposers community composition are primary drivers of leaf litter decomposition. In soil, much of the variation in litter decomposition is explained by climate and substrate chemistry, but with a significant contribution of the specialisation of decomposer communities to degrade specific substrates (home-field advantage, HFA). In streams, however, HFA effects on litter decomposition have not been explicitly tested. We evaluated responses of microbial decomposition and β-glucosidase activity to abiotic factors, substrate and decomposer assemblages, using a reciprocal litter transplant experiment: 'ecosystem type' (mountain vs lowland streams) × 'litter chemistry' (alder vs reed). Temperature, pH and ionic concentration were higher in lowland streams. Decomposition for both species was faster in lowland streams. Decomposition of reed was more accelerated in lowland compared with mountain streams than that of alder, suggesting higher temperature sensitivity of decomposition in reed. Q10 (5°C-15°C) values of β-glucosidase activity were over 2. The alkaline pH and high ionic concentration of lowland streams depleted enzyme activity. We found similar relationships of decomposition or enzyme activity with abiotic factors for both species, suggesting limited support to the HFA hypothesis. Overall, our results suggest a prime role of temperature interacting with substrate chemistry on litter decomposition. PMID:27515735

  20. A Rational Design Strategy for the Selective Activity Enhancement of a Molecular Chaperone toward a Target Substrate.

    Science.gov (United States)

    Aprile, Francesco A; Sormanni, Pietro; Vendruscolo, Michele

    2015-08-18

    Molecular chaperones facilitate the folding and assembly of proteins and inhibit their aberrant aggregation. They thus offer several opportunities for biomedical and biotechnological applications, as for example they can often prevent protein aggregation more effectively than other therapeutic molecules, including small molecules and antibodies. Here we present a method of designing molecular chaperones with enhanced activity against specific amyloidogenic substrates while leaving unaltered their functions toward other substrates. The method consists of grafting onto a molecular chaperone a peptide designed to bind specifically an epitope in the target substrate. We illustrate this strategy by describing Hsp70 variants with increased affinities for α-synuclein and Aβ42 but otherwise unaltered affinities for other substrates. These designed variants inhibit protein aggregation and disaggregate preformed fibrils significantly more effectively than wild-type Hsp70 indicating that the strategy presented here provides a possible route for tailoring rationally molecular chaperones for specific purposes.

  1. Enzyme Activities and Substrate Degradation by Fungal Isolates on Cassava Waste During Solid State Fermentation

    OpenAIRE

    Pothiraj, C.; Eyini, M.

    2007-01-01

    The growth and bioconversion potential of selected strains growing on cassava waste substrate during solid state fermentation were assessed. Rhizopus stolonifer showed the highest and the fastest utilization of starch and cellulose in the cassava waste substrate. It showed 70% starch utilization and 81% cellulose utilization within eight days. The release of reducing sugars indicating the substrate saccharification or degradation potential of the organisms reached the highest value of 406.5 m...

  2. Evaluation of organic substrates to enhance the sulfate-reducing activity in phosphogypsum.

    Science.gov (United States)

    Castillo, Julio; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José M

    2012-11-15

    Several experiments were conducted to evaluate the activity and growth of sulfate-reducing bacteria (SRB) in a metal-rich culture medium (approx. 250 mg/L Fe, 75 mg/L Zn and Cu, 10mg/L Cd) with phosphogypsum as bacterial inoculum. Phosphogypsum was collected from the stack covering the salt-marshes of the Tinto river (SW Spain). Three organic amendments were used as carbon sources, two low-cost wastes (horse manure and legume compost) and one sample of natural soil (vegetal cover). In the experiments, sulfate was reduced to sulfide during the growth of SRB populations, and concentrations were decreased in the solution. Metal concentrations also decreased to values below the detection limit. Metal removal took place by precipitation of newly-formed sulfides. Pyrite-S was the main sulfide component (approx. 200 μmol/g and 80% of pyritization) and occurred mainly as framboidal grains and rarely as isolated polyhedral crystals. Horse manure was the most successful organic substrate to promote SRB activity (sulfate removal of 61%), followed by vegetal cover (49%) and legume compost (31%). These findings propose the possibility of using naturally-occurring SRB in the phosphogypsum for bioremediation strategies based on natural soil covers with organic amendments.

  3. Study of the activity of DNA polymerases β and λ using 5-formyluridine containing DNA substrates

    Directory of Open Access Journals (Sweden)

    Lavrik O. I.

    2012-06-01

    Full Text Available Aim. To investigate the TLS-activity of human DNA polymerases β and λ (pols β and λ using 5-formyluridine (5-foU containing DNA duplexes which are imitating the intermediates during replication of the leading DNA strand, and to study the influence of replication factors hRPA and hPCNA on this activity. Methods. The EMSA and the methods of enzyme’s kinetics were used. Results. The capability of pols β and λ to catalyze DNA synthesis across 5-foU was investigated and the kinetic characteristics of this process in the presence and in the absence of protein factors hRPA and hPCNA were evaluated. Conclusions. It was shown that: (i both proteins are able to catalyze TLS on used DNA substrates regardless of the reaction conditions, however, pol λ was more accurate enzyme; (ii hRPA can stimulate the efficacy of the nonmutagenic TLS catalyzed by pol at the nucleotide incorporation directly opposite of 5-foU, at the same time it doesn’t influence the incorporation efficacy if the damage displaced into the duplex; (iii hPCNA doesn’t influence the efficacy of TLS catalyzed by both enzymes.

  4. Active-site models for complexes of quinolinate synthase with substrates and intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Erika V.; Zhang, Yang; Colabroy, Keri L.; Sanders, Jennie M.; Settembre, Ethan C.; Dorrestein, Pieter C.; Begley, Tadhg P.; Ealick, Steven E., E-mail: see3@cornell.edu [Cornell University, Ithaca, NY 14853-1301 (United States)

    2013-09-01

    Structural studies of quinolinate synthase suggest a model for the enzyme–substrate complex and an enzyme–intermediate complex with a [4Fe–4S] cluster. Quinolinate synthase (QS) catalyzes the condensation of iminoaspartate and dihydroxyacetone phosphate to form quinolinate, the universal precursor for the de novo biosynthesis of nicotinamide adenine dinucleotide. QS has been difficult to characterize owing either to instability or lack of activity when it is overexpressed and purified. Here, the structure of QS from Pyrococcus furiosus has been determined at 2.8 Å resolution. The structure is a homodimer consisting of three domains per protomer. Each domain shows the same topology with a four-stranded parallel β-sheet flanked by four α-helices, suggesting that the domains are the result of gene triplication. Biochemical studies of QS indicate that the enzyme requires a [4Fe–4S] cluster, which is lacking in this crystal structure, for full activity. The organization of domains in the protomer is distinctly different from that of a monomeric structure of QS from P. horikoshii [Sakuraba et al. (2005 ▶), J. Biol. Chem.280, 26645–26648]. The domain arrangement in P. furiosus QS may be related to protection of cysteine side chains, which are required to chelate the [4Fe–4S] cluster, prior to cluster assembly.

  5. Programmable SERS active substrates for chemical and biosensing applications using amorphous/crystalline hybrid silicon nanomaterial

    Science.gov (United States)

    Powell, Jeffery Alexander; Venkatakrishnan, Krishnan; Tan, Bo

    2016-01-01

    We present the creation of a unique nanostructured amorphous/crystalline hybrid silicon material that exhibits surface enhanced Raman scattering (SERS) activity. This nanomaterial is an interconnected network of amorphous/crystalline nanospheroids which form a nanoweb structure; to our knowledge this material has not been previously observed nor has it been applied for use as a SERS sensing material. This material is formed using a femtosecond synthesis technique which facilitates a laser plume ion condensation formation mechanism. By fine-tuning the laser plume temperature and ion interaction mechanisms within the plume, we are able to precisely program the relative proportion of crystalline Si to amorphous Si content in the nanospheroids as well as the size distribution of individual nanospheroids and the size of Raman hotspot nanogaps. With the use of Rhodamine 6G (R6G) and Crystal Violet (CV) chemical dyes, we have been able to observe a maximum enhancement factor of 5.38 × 106 and 3.72 × 106 respectively, for the hybrid nanomaterial compared to a bulk Si wafer substrate. With the creation of a silicon-based nanomaterial capable of SERS detection of analytes, this work demonstrates a redefinition of the role of nanostructured Si from an inactive to SERS active role in nano-Raman sensing applications.

  6. Rapid Functional Definition of Extended Spectrum β-Lactamase Activity in Bacterial Cultures via Competitive Inhibition of Fluorescent Substrate Cleavage

    OpenAIRE

    Sallum, Ulysses W; Zheng, Xiang; Verma, Sarika; Hasan, Tayyaba

    2010-01-01

    The functional definition of extended-spectrum β-lactamase (ESBL) activity is a clinical challenge. Here we report a rapid and convenient assay of β-lactamase activity through the competitive inhibition of fluorescent substrate hydrolysis that provides a read-out nearly 40x more rapidly than conventional techniques for functional definition. A panel of β-lactam antibiotics was used for competition against β-lactamase enzyme activated photosensitizer (β-LEAP) yielding a competitive index (Ci) ...

  7. Interfacial Structure and Photocatalytic Activity of Magnetron Sputtered TiO2 on Conducting Metal Substrates

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Petit, Jean-Pierre; Mermoux, Michel;

    2014-01-01

    The photocatalytic behavior of magnetron sputtered anatase TiO2 coatings on copper, nickel, and gold was investigated with the aim of understanding the effect of the metallic substrate and coating-substrate interface structure. Stoichiometry and nanoscale structure of the coating were investigated...... measurements. The nature of the metal substrate and coating-substrate interface had profound influence on the photocatalytic behavior. Less photon energy was required for TiO2 excitation on a nickel substrate, whereas TiO2 coating on copper showed a higher band gap attributed to quantum confinement. However......, the TiO2 coating on gold exhibited behavior typical of facile transfer of electrons to and from the CB, therefore requiring only a small amount of photon energy to make the TiO2 coating conductive....

  8. Neuronal Activity Stimulated by Liquid Substrates Injection at Zusanli (ST36 Acupoint: The Possible Mechanism of Aquapuncture

    Directory of Open Access Journals (Sweden)

    Chun-Yen Chen

    2014-01-01

    Full Text Available Aquapuncture is a modified acupuncture technique and it is generally accepted that it has a greater therapeutic effect than acupuncture because of the combination of the acupoint stimulation and the pharmacological effect of the drugs. However, to date, the mechanisms underlying the effects of aquapuncture remain unclear. We hypothesized that both the change in the local spatial configuration and the substrate stimulation of aquapuncture would activate neuronal signaling. Thus, bee venom, normal saline, and vitamins B1 and B12 were injected into a Zusanli (ST36 acupoint as substrate of aquapuncture, whereas a dry needle was inserted into ST36 as a control. After aquapuncture, activated neurons expressing Fos protein were mainly observed in the dorsal horn of the spinal cord in lumbar segments L3–5, with the distribution nearly identical among all groups. However, the bee venom injection induced significantly more Fos-expressing neurons than the other substrates. Based on these data, we suggest that changes in the spatial configuration of the acupoint activate neuronal signaling and that bee venom may further strengthen this neuronal activity. In conclusion, the mechanisms for the effects of aquapuncture appear to be the spatial configuration changes occurring within the acupoint and the ability of injected substrates to stimulate neuronal activity.

  9. Deubiquitylase, deSUMOylase, and deISGylase activity microarrays for assay of substrate preference and functional modifiers.

    Science.gov (United States)

    Loch, Christian M; Cuccherini, Charles L; Leach, Craig A; Strickler, James E

    2011-01-01

    Microarray-based proteomics expanded the information potential of DNA arrays to the level of protein translation and interaction, but so far, not much beyond. Although enzymatic activity from immobilized proteins has been reliably studied using surface plasmon resonance, a microarray of catalytically competent enzymes would facilitate high throughput, parallel study of their function. The ability to localize activity from soluble substrates has frustrated development of such an array. Here, we report the novel use of previously developed, highly specific suicide substrates for three families of enzymes: deubiquitylases, deSUMOylases, and deISGylases. We show specificity of each family to its cognate substrate, and demonstrate utility of the array in a secondary screen of small molecule inhibitors.

  10. Effect of substrate (ZnO morphology on enzyme immobilization and its catalytic activity

    Directory of Open Access Journals (Sweden)

    Huang Xuelei

    2011-01-01

    Full Text Available Abstract In this study, zinc oxide (ZnO nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. The effects of morphology of ZnO nanocrystals on enzyme immobilization and their catalytic activities were investigated. The ZnO nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system. The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay. Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker. The results showed that three-dimensional nanomultipod is more appropriate for the immobilization of enzyme used further in catalytic reaction.

  11. Effect of substrate (ZnO) morphology on enzyme immobilization and its catalytic activity

    Science.gov (United States)

    Zhang, Yan; Wu, Haixia; Huang, Xuelei; Zhang, Jingyan; Guo, Shouwu

    2011-07-01

    In this study, zinc oxide (ZnO) nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. The effects of morphology of ZnO nanocrystals on enzyme immobilization and their catalytic activities were investigated. The ZnO nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system. The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay. Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker. The results showed that three-dimensional nanomultipod is more appropriate for the immobilization of enzyme used further in catalytic reaction.

  12. Synthesis of carbon nanofibers on impregnated powdered activated carbon as cheap substrate

    Directory of Open Access Journals (Sweden)

    A.A. Mamun

    2016-07-01

    Full Text Available The catalysis and characterization of carbon nanofibers (CNFs composite are reported in this work. Carbon nanofibers were produced on oil palm shell powdered activated carbon (PAC, which was impregnated with nickel. Chemical Vapor Deposition (CVD of C2H2 was used in the presence of hydrogen at ∼650 °C. The flow rates of carbon source and hydrogen were fixed. The CNFs formed directly on the surface of the impregnated PAC. Variable weight percentages (1%, 3%, 5%, 7% and 9% of the catalyst salt (Ni+2 were used for the impregnation. However, the best catalysis was observed on the substrate with 3% Ni+2. The product displayed a relatively high surface area, essentially constituted by the external surface. New functional groups also appeared compared to those in the PAC. Field Emission Scanning Microscopy (FESEM, Transmission Electron Microscopy (TEM, Fourier Transform Infrared (FTIR, BET surface area analysis and energy dispersive X-ray (EDX were used for the characterization of the new carbon nano product, which was produced through a clean novel process.

  13. Posttranslational ruling of xanthine oxidase activity in bovine milk by its substrates

    International Nuclear Information System (INIS)

    The aims of this study were to test the hypothesis that the substrates of xanthine oxidase (XO), xanthine and hypoxanthine, are consumed while the milk is stored in the gland between milkings, and to explore how XO activity responds to bacteria commonly associated with subclinical infections in the mammary gland. Freshly secreted milk was obtained following complete evacuation of the gland and induction of milk ejection with oxytocin. In bacteria-free fresh milk xanthine and hypoxanthine were converted to uric acid within 30 min (T1/2 ∼ 10 min), which in turn provides electrons for formation of hydrogen peroxide and endows the alveolar lumen with passive protection against invading bacteria. On the other hand, the longer residence time of milk in the cistern compartment was not associated with oxidative stress as a result of XO idleness caused by exhaustion of its physiological fuels. The specific response of XO to bacteria species and the resulting bacteria-dependent nitrosative stress further demonstrates that it is part of the gland immune system

  14. Memory characteristics of poly-Si using MIC as an active layer on glass substrates

    International Nuclear Information System (INIS)

    In this paper the electrical properties of nonvolatile memory (NVM) using multi-stack gate insulators of oxide-nitride-oxynitride (ONOn) and an active layer of low temperature polycrystalline silicon (LTPS) were investigated. From hydrogenated amorphous silicon (a-Si : H), the LTPS thin film with a high crystalline fraction of 96% and a low surface roughness of 1.28 nm was fabricated by metal induced crystallization (MIC) with annealing conditions of 650 0C for 5 h on glass substrates. The LTPS thin film transistor or the NVM had a field effect mobility of (μFE) 10 cm2 V-1 s-1 and a threshold voltage (VTH) of -3.5 V. The results demonstrated that the NVM had a memory window of 1.6 V with a programming and erasing (P/E) voltage of -14 V and 14 V in 1 ms. Moreover, retention properties of the memory were shown to exceed 80% after 10 years. Therefore, the LTPS fabricated by MIC has become a potential material for NVM application which is employed for the system integration of panel displays.

  15. Memory characteristics of poly-Si using MIC as an active layer on glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanh Nga; Jung, Sungwook; Nguyen, Van Duy; Yi, Junsin, E-mail: yi@yurim.skku.ac.k [School of Information and Communication Engineering, Sungkyunkwan University, Suwon, Kyouggi 440-746 (Korea, Republic of)

    2010-03-17

    In this paper the electrical properties of nonvolatile memory (NVM) using multi-stack gate insulators of oxide-nitride-oxynitride (ONOn) and an active layer of low temperature polycrystalline silicon (LTPS) were investigated. From hydrogenated amorphous silicon (a-Si : H), the LTPS thin film with a high crystalline fraction of 96% and a low surface roughness of 1.28 nm was fabricated by metal induced crystallization (MIC) with annealing conditions of 650 {sup 0}C for 5 h on glass substrates. The LTPS thin film transistor or the NVM had a field effect mobility of ({mu}{sub FE}) 10 cm{sup 2} V{sup -1} s{sup -1} and a threshold voltage (V{sub TH}) of -3.5 V. The results demonstrated that the NVM had a memory window of 1.6 V with a programming and erasing (P/E) voltage of -14 V and 14 V in 1 ms. Moreover, retention properties of the memory were shown to exceed 80% after 10 years. Therefore, the LTPS fabricated by MIC has become a potential material for NVM application which is employed for the system integration of panel displays.

  16. 褪黑素对大鼠肝微粒体细胞色素P450酶亚型CYP2C9、CYP2D6、CYP3A4活性的影响

    Institute of Scientific and Technical Information of China (English)

    刘明远; 杨光远; 王跃新; 张春斌; 白雪; 张建华

    2011-01-01

    目的 观察褪黑素对大鼠肝微粒体内细胞色素P450 (CYP450) 酶亚型CYP2C9、CYP2D6、CYP3A4活性的影响.方法 以生理盐水为对照,大鼠灌胃0.54 mg·kg-1·d-1的褪黑素,连续7 d,然后测定其肝微体中CYP2C9、CYP2D6、CYP3A4活性.结果 与对照组比较,褪黑素组CYP2C9、CYP2D6、CYP3A4的活性无变化(P>0.05).结论 褪黑素对CYP450酶 CYP2C9、CYP2D6、CYP3A4活性无影响.

  17. A Camelid-derived Antibody Fragment Targeting the Active Site of a Serine Protease Balances between Inhibitor and Substrate Behavior

    DEFF Research Database (Denmark)

    Kromann-Hansen, Tobias; Oldenburg, Emil; Yung, Kristen Wing Yu;

    2016-01-01

    -ray crystal structure of a nanobody in complex with a serine protease. The nanobody displays a new type of interaction between an antibody and a serine protease as it inserts its CDR-H3 loop into the active site of the protease in a substrate-like manner. The unique binding mechanism causes the nanobody to...

  18. Ligninolytic enzymes activities of Oyster mushrooms cultivated on OMW (olive mill waste) supplemented media, spawn and substrates

    NARCIS (Netherlands)

    Ruiz-Rodrigues, A.; Polonia, I.; Soler-Rivas, C.; Wichers, H.J.

    2011-01-01

    Ligninolytic enzymes activities (laccases, peroxidases (total, MnP and MiP) and aryl-alcohol oxidase (AAO)) were measured during the cultivation of six commercial Pleurotus sp. strains on MMP media, on cereal grains (spawn) and on straw substrates (the three commonly utilized cultivation steps to ob

  19. Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

    DEFF Research Database (Denmark)

    Kooij, P W; Schiøtt, M; Boomsma, J J;

    2011-01-01

    Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix......, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking...... from the rice diet, relative to the leaf diet controls. Enzyme activity in the older, bottom sections of fungus gardens decreased, indicating a faster processing of the rice substrate compared to the leaf diet. These results suggest that leaf-cutting ant fungus gardens can rapidly adjust enzyme...

  20. Pt monolayer coating on complex network substrate with high catalytic activity for the hydrogen evolution reaction

    OpenAIRE

    Li, Man; Ma, Qiang; Zi, Wei; Liu, Xiaojing; Zhu, Xuejie; Liu, Shengzhong (Frank)

    2015-01-01

    A deposition process has been developed to fabricate a complete-monolayer Pt coating on a large-surface-area three-dimensional (3D) Ni foam substrate using a buffer layer (Ag or Au) strategy. The quartz crystal microbalance, current density analysis, cyclic voltammetry integration, and X-ray photoelectron spectroscopy results show that the monolayer deposition process accomplishes full coverage on the substrate and the deposition can be controlled to a single atomic layer thickness. To our kn...

  1. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates

    Directory of Open Access Journals (Sweden)

    Namratha Pai Kotebagilu

    2015-01-01

    Full Text Available Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol of four medicinal plants, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, against Fenton reaction-mediated oxidation of three biological lipid substrates; cholesterol, low-density lipoprotein, and brain homogenate. The antioxidant activity of the extracts was measured by thiobarbituric acid reactive substances method. Also, the correlation between the polyphenol, flavonoid content, and the antioxidant activity in biological substrates was analyzed. Results indicated highest antioxidant potential by 80% methanol extract of Canthium parviflorum (97.55%, methanol extract of Andrographis paniculata (72.15%, and methanol extract of Canthium parviflorum (49.55% in cholesterol, low-density lipoprotein, and brain, respectively. The polyphenol and flavonoid contents of methanol extract of Andrographis paniculata in cholesterol (r=0.816 and low-density lipoprotein (r=0.948 and Costus speciosus in brain (r=0.977, polyphenols, and r=0.949, flavonoids correlated well with the antioxidant activity. The findings prove the antioxidant potential of the selected medicinal plants against Fenton reaction in biological lipid substrates.

  2. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates.

    Science.gov (United States)

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha; Urooj, Asna

    2015-01-01

    Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol) of four medicinal plants, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, against Fenton reaction-mediated oxidation of three biological lipid substrates; cholesterol, low-density lipoprotein, and brain homogenate. The antioxidant activity of the extracts was measured by thiobarbituric acid reactive substances method. Also, the correlation between the polyphenol, flavonoid content, and the antioxidant activity in biological substrates was analyzed. Results indicated highest antioxidant potential by 80% methanol extract of Canthium parviflorum (97.55%), methanol extract of Andrographis paniculata (72.15%), and methanol extract of Canthium parviflorum (49.55%) in cholesterol, low-density lipoprotein, and brain, respectively. The polyphenol and flavonoid contents of methanol extract of Andrographis paniculata in cholesterol (r = 0.816) and low-density lipoprotein (r = 0.948) and Costus speciosus in brain (r = 0.977, polyphenols, and r = 0.949, flavonoids) correlated well with the antioxidant activity. The findings prove the antioxidant potential of the selected medicinal plants against Fenton reaction in biological lipid substrates. PMID:26933511

  3. Fabrication of highly active and cost effective SERS plasmonic substrates by electrophoretic deposition of gold nanoparticles on a DVD template

    International Nuclear Information System (INIS)

    Highlights: • Simple and cost effective electrophoretic method to fabricate plasmonic substrates. • SERS performance at three different excitation laser lines. • Promising applicability in SERS based biosensing. - Abstract: In this work we present a simple, rapid and cost effective method to fabricate highly active SERS substrates. This method consists in an electrophoretic deposition of gold nanoparticles on a metallic nanostructured template of a commercial digital versatile disk (DVD). The negatively charged gold nanoparticles self-assemble on the positively charged DVD metallic film connected to a positive terminal of a battery, due to the influence of the electric field. When gold nanoparticles self-assembled on DVD metallic film, a 10-fold additional enhancement of Raman signal was observed when compared with the case of GNPs self-assembled on a polycarbonate DVD substrate only. Finite-difference time-domain simulations demonstrated that the additional electromagnetic field arising in the hot-spots created between gold nanoparticles and DVD metallic film induces an additional enhancement of the Raman signal. SERS efficiency of the fabricated plasmonic substrate was successfully demonstrated through detection of para-aminothiophenol molecule with three different excitation laser lines (532, 633 and 785 nm). The enhancement factor was calculated to be 106 and indicates that plasmonic substrates fabricated through this method could be a promising platform for future SERS based sensors

  4. Fabrication of highly active and cost effective SERS plasmonic substrates by electrophoretic deposition of gold nanoparticles on a DVD template

    Energy Technology Data Exchange (ETDEWEB)

    Leordean, Cosmin; Marta, Bogdan; Gabudean, Ana-Maria; Focsan, Monica; Botiz, Ioan; Astilean, Simion, E-mail: simion.astilean@phys.ubbcluj.ro

    2015-09-15

    Highlights: • Simple and cost effective electrophoretic method to fabricate plasmonic substrates. • SERS performance at three different excitation laser lines. • Promising applicability in SERS based biosensing. - Abstract: In this work we present a simple, rapid and cost effective method to fabricate highly active SERS substrates. This method consists in an electrophoretic deposition of gold nanoparticles on a metallic nanostructured template of a commercial digital versatile disk (DVD). The negatively charged gold nanoparticles self-assemble on the positively charged DVD metallic film connected to a positive terminal of a battery, due to the influence of the electric field. When gold nanoparticles self-assembled on DVD metallic film, a 10-fold additional enhancement of Raman signal was observed when compared with the case of GNPs self-assembled on a polycarbonate DVD substrate only. Finite-difference time-domain simulations demonstrated that the additional electromagnetic field arising in the hot-spots created between gold nanoparticles and DVD metallic film induces an additional enhancement of the Raman signal. SERS efficiency of the fabricated plasmonic substrate was successfully demonstrated through detection of para-aminothiophenol molecule with three different excitation laser lines (532, 633 and 785 nm). The enhancement factor was calculated to be 10{sup 6} and indicates that plasmonic substrates fabricated through this method could be a promising platform for future SERS based sensors.

  5. Role of the conducting layer substrate on TiO2 nucleation when using microwave activated chemical bath deposition

    Science.gov (United States)

    Zumeta, I.; Espinosa, R.; Ayllón, J. A.; Vigil, E.

    2002-12-01

    Nanostructured TiO2 is used in novel dye sensitized solar cells. Because of their interaction with light, thin TiO2 films are also used as coatings for self-cleaning glasses and tiles. Microwave activated chemical bath deposition represents a simple and cost-effective way to obtain nanostructured TiO2 films. It is important to study, in this technique, the role of the conducting layer used as the substrate. The influence of microwave-substrate interactions on TiO2 deposition is analysed using different substrate positions, employing substrates with different conductivities, and also using different microwave radiation powers for film deposition. We prove that a common domestic microwave oven with a large cavity and inhomogeneous radiation field can be used with equally satisfactory results. The transmittance spectra of the obtained films were studied and used to analyse film thickness and to obtain gap energy values. The results, regarding different indium-tin oxide resistivities and different substrate positions in the oven cavity, show that the interaction of the microwave field with the conducting layer is determinant in layer deposition. It has also been found that film thickness increases with the power of the applied radiation while the gap energies of the TiO2 films decrease approaching the 3.2 eV value reported for bulk anatase. This indicates that these films are not crystalline and it agrees with x-ray spectra that do not reveal any peak.

  6. 细胞色素P4502D6基因拷贝数多态性与血铅尿铅水平的关系研究%The relationship between copy number polymorphisms of CYP2D6 gene and lead level of blood and urine in workers exposed to lead

    Institute of Scientific and Technical Information of China (English)

    蒋琴琴; 刘斌; 刘移民

    2013-01-01

    目的 探讨铅作业人群细胞色素氧化酶P450酶系中的CYP2D6基因拷贝数多态性与铅毒性引起的血铅、尿铅水平的关系.方法 选择广州市某蓄电池行业233名铅作业工人,按铅尘接触水平分为高浓度组和低浓度组2组,采用统一调查表进行职业性健康问卷调查;采用石墨炉原子吸收光谱法测定现场空气铅尘及铅作业工人血铅、尿铅水平;提取铅作业人群周围血DNA,采用实时荧光定量聚合酶链式反应(PCR)法和△Ct值法检测铅作业工人的CYP2D6基因拷贝数,分析不同铅尘作业环境下作业人员CYP2D6基因拷贝数多态性与血铅、尿铅水平的关系.结果 铅作业工人CYP2D6基因拷贝数与血铅、尿铅水平有关,2组中拷贝数小于2的作业人员血铅浓度均高于拷贝数为2的人群(P<0.001),低浓度组拷贝数小于2的研究对象尿铅浓度比拷贝数为2的人群高(P=0.03),尚未发现年龄、性别、工龄、学历与血铅水平和尿铅水平的关系差异有统计学意义.结论 CYP2D6基因拷贝数多态性与铅毒性引起的血铅尿铅水平有关,拷贝数少于2的CYP2D6基因可能是铅中毒易感基因型.%OBJECTIVE To probe into the the relationship between blood lead and urine lead level and copy number polymorphisms of CYP2D6 gene in workers exposed to lead. METHODS 233 cases of workers exposed to lead were scheduled for an interview to collect the subjects' data on occupational information. Their blood lead, urine lead and the ambient air lead were tested with graphite furnace atomic absorption spectrometry. CYP2D6 gene copy number of these workers was detected with realtime fluorescence quantitative PCR method and ACt method. Under different concentrations of environmental lead dust, analyze the relationship between CYP2D6 gene copy number polymorphisms and blood lead, urine lead level. RESULTS CYP2D6 gene copy number polymorphisms was relative with blood lead and urine lead level in

  7. APPLICATION OF 6-NITROCOUMARIN AS A SUBSTRATE FOR THE FLUORESCENT DETECTION OF NITROREDUCTASE ACTIVITY IN Sporothrix schenckii

    Directory of Open Access Journals (Sweden)

    Cheila Denise Ottonelli Stopiglia

    2013-09-01

    Full Text Available Introduction Sporothrix schenckii is a thermal dimorphic pathogenic fungus causing a subcutaneous mycosis, sporotrichosis. Nitrocoumarin represents a fluorogenic substrate class where the microbial nitroreductase activity produces several derivatives, already used in several other enzyme assays. The objective of this study was the analysis of 6-nitrocoumarin (6-NC as a substrate to study the nitroreductase activity in Sporothrix schenckii. Methods Thirty-five samples of S. schenckii were cultivated for seven, 14 and 21 days at 35 °C in a microculture containing 6-nitrocoumarin or 6-aminocoumarin (6-AC dissolved in dimethyl sulfoxide or dimethyl sulfoxide as a negative control, for posterior examination under an epifluorescence microscope. The organic layer of the seven, 14 and 21-day cultures was analyzed by means of direct illumination with 365 nm UV light and by means of elution on G silica gel plate with hexane:ethyl acetate 1:4 unveiled with UV light. Results All of the strains showed the presence of 6-AC (yellow fluorescence and 6-hydroxylaminocoumarin (blue fluorescence in thin layer chromatography, which explains the green fluorescence observed in the fungus structure. Conclusion The nitroreductase activity is widely distributed in the S. schenckii complex and 6-NC is a fluorogenic substrate of easy access and applicability for the nitroreductase activity detection.

  8. Investigation of photocatalytic activity of titanium dioxide deposited on metallic substrates by DC magnetron sputtering

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Canulescu, Stela; Dirscherl, Kai;

    2013-01-01

    The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology...

  9. ROS-activated ATM-dependent phosphorylation of cytoplasmic substrates identified by large scale phosphoproteomics screen

    DEFF Research Database (Denmark)

    Kozlov, Sergei V; Waardenberg, Ashley J; Engholm-Keller, Kasper;

    2016-01-01

    substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (OSR1, HDGF and ccdc82) as ATM...

  10. Molecular Modeling of Peroxidase and Polyphenol Oxidase: Substrate Specificity and Active Site Comparison

    Directory of Open Access Journals (Sweden)

    Lalida Shank

    2010-09-01

    Full Text Available Peroxidases (POD and polyphenol oxidase (PPO are enzymes that are well known to be involved in the enzymatic browning reaction of fruits and vegetables with different catalytic mechanisms. Both enzymes have some common substrates, but each also has its specific substrates. In our computational study, the amino acid sequence of grape peroxidase (ABX was used for the construction of models employing homology modeling method based on the X-ray structure of cytosolic ascorbate peroxidase from pea (PDB ID:1APX, whereas the model of grape polyphenol oxidase was obtained directly from the available X-ray structure (PDB ID:2P3X. Molecular docking of common substrates of these two enzymes was subsequently studied. It was found that epicatechin and catechin exhibited high affinity with both enzymes, even though POD and PPO have different binding pockets regarding the size and the key amino acids involved in binding. Predicted binding modes of substrates with both enzymes were also compared. The calculated docking interaction energy of trihydroxybenzoic acid related compounds shows high affinity, suggesting specificity and potential use as common inhibitor to grape ascorbate peroxidase and polyphenol oxidase.

  11. Preparation and characterization of spray deposited Cd1-xZnxS thin films on activated substrate

    Science.gov (United States)

    Sankarasubramanian, Kaliappan; Sethuraman, Kunjithapatham; Babu, Ramraj Ramesh; Ramamurthi, Kandasamy

    2013-10-01

    Cd1-xZnxS thin films were deposited on the glass substrates (GS) and on the potassium permanganate activated substrates (KMAS) at 350 °C using spray pyrolysis technique. X-ray diffraction studies confirmed that the films are polycrystalline and belong to the hexagonal structure. Scanning electron microscopic studies revealed an effective change on the surface morphology of the film due to potassium permanganate activation (KMA). Transmittance spectra of Cd1-xZnxS thin films were recorded in the range of 320-700 nm and the transmittance was found to be high for the film coated on KMAS than GS. Photoluminescence spectra show a strong emission peak at 585 nm for the film coated on the GS and it is shifted to 592 nm for the film coated on KMAS. Thus the results authenticate that KMA influences the structural and optical properties of the deposited films.

  12. Restricted Active Site Docking by Enzyme-bound Substrate Enforces the Ordered Cleavage of Prothrombin by Prothrombinase*

    OpenAIRE

    Hacisalihoglu, Ayse; Panizzi, Peter; Bock, Paul E.; Camire, Rodney M.; Krishnaswamy, Sriram

    2007-01-01

    The preferred pathway for prothrombin activation by prothrombinase involves initial cleavage at Arg320 to produce meizothrombin, which is then cleaved at Arg271 to liberate thrombin. Exosite binding drives substrate affinity and is independent of the bond being cleaved. The pathway for cleavage is determined by large differences in Vmax for cleavage at the two sites within intact prothrombin. By fluorescence binding studies in the absence of catalysis, we have assessed the ability of the indi...

  13. Modulation of γ-secretase activity by multiple enzyme-substrate interactions: implications in pathogenesis of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Zeljko M Svedružić

    Full Text Available BACKGROUND: We describe molecular processes that can facilitate pathogenesis of Alzheimer's disease (AD by analyzing the catalytic cycle of a membrane-imbedded protease γ-secretase, from the initial interaction with its C99 substrate to the final release of toxic Aβ peptides. RESULTS: The C-terminal AICD fragment is cleaved first in a pre-steady-state burst. The lowest Aβ42/Aβ40 ratio is observed in pre-steady-state when Aβ40 is the dominant product. Aβ42 is produced after Aβ40, and therefore Aβ42 is not a precursor for Aβ40. The longer more hydrophobic Aβ products gradually accumulate with multiple catalytic turnovers as a result of interrupted catalytic cycles. Saturation of γ-secretase with its C99 substrate leads to 30% decrease in Aβ40 with concomitant increase in the longer Aβ products and Aβ42/Aβ40 ratio. To different degree the same changes in Aβ products can be observed with two mutations that lead to an early onset of AD, ΔE9 and G384A. Four different lines of evidence show that γ-secretase can bind and cleave multiple substrate molecules in one catalytic turnover. Consequently depending on its concentration, NotchΔE substrate can activate or inhibit γ-secretase activity on C99 substrate. Multiple C99 molecules bound to γ-secretase can affect processive cleavages of the nascent Aβ catalytic intermediates and facilitate their premature release as the toxic membrane-imbedded Aβ-bundles. CONCLUSIONS: Gradual saturation of γ-secretase with its substrate can be the pathogenic process in different alleged causes of AD. Thus, competitive inhibitors of γ-secretase offer the best chance for a successful therapy, while the noncompetitive inhibitors could even facilitate development of the disease by inducing enzyme saturation at otherwise sub-saturating substrate. Membrane-imbedded Aβ-bundles generated by γ-secretase could be neurotoxic and thus crucial for our understanding of the amyloid hypothesis and AD

  14. Activity Based High-Throughput Screening for Novel O-GlcNAc Transferase Substrates Using a Dynamic Peptide Microarray.

    Directory of Open Access Journals (Sweden)

    Jie Shi

    Full Text Available O-GlcNAcylation is a reversible and dynamic protein post-translational modification in mammalian cells. The O-GlcNAc cycle is catalyzed by O-GlcNAc transferase (OGT and O-GlcNAcase (OGA. O-GlcNAcylation plays important role in many vital cellular events including transcription, cell cycle regulation, stress response and protein degradation, and altered O-GlcNAcylation has long been implicated in cancer, diabetes and neurodegenerative diseases. Recently, numerous approaches have been developed to identify OGT substrates and study their function, but there is still a strong demand for highly efficient techniques. Here we demonstrated the utility of the peptide microarray approach to discover novel OGT substrates and study its specificity. Interestingly, the protein RBL-2, which is a key regulator of entry into cell division and may function as a tumor suppressor, was identified as a substrate for three isoforms of OGT. Using peptide Ala scanning, we found Ser 420 is one possible O-GlcNAc site in RBL-2. Moreover, substitution of Ser 420, on its own, inhibited OGT activity, raising the possibility of mechanism-based development for selective OGT inhibitors. This approach will prove useful for both discovery of novel OGT substrates and studying OGT specificity.

  15. Effects of Hard Surface Grinding and Activation on Electroless-Nickel Plating on Cast Aluminium Alloy Substrates

    Directory of Open Access Journals (Sweden)

    Olawale Olarewaju Ajibola

    2014-01-01

    Full Text Available This work examined effects of hard surface polishing grits and activation on electroless-nickel (EN plating on cast aluminium alloy substrates in sodium hypophosphite baths. As-received aluminium alloy sample sourced from automobile hydraulic brake master cylinder piston was melted in electric furnace and sand cast into rod. The cast samples were polished using different grits (60 μm–1200 μm before plating. The effects on adhesion, appearance, and quantity of EN deposits on substrates were studied. Observation shows that the quantity of EN deposit is partly dependent on the alloy type and roughness of the surface of the substrates, whereas the adhesion and brightness are not solely controlled by the degree of surface polishing. The best yield in terms of adhesion and appearance was obtained from the activation in zincate and palladium chloride solutions. Higher plating rates (g/mm2/min of 3.01E-05, 2.41E-05, and 2.90E-05 were obtained from chromate, zincate, and chloride than 8.49E-06, 8.86E-06, and 1.69E-05 as obtained from HCl etched, NaOH, and H2O activated surfaces, respectively.

  16. β1肾上腺素受体与CYP2D6基因多态性对美托洛尔抗高血压治疗的药代动力学和药效学影响

    Institute of Scientific and Technical Information of China (English)

    HU Jie; HU Zhao-qian; HU Ying-zi; TAN Zhi-rong; HU Dong-li; LI Zhi; WANG Dan; ZHANG Wei; ZHOU Hong-hao

    2007-01-01

    背景:美托洛尔是临床常用的抗高血压药物,它经由CYP2D6代谢。CYP2D6*10降低CYP2D6活性,是中国人群中最为常见的多态性。β1肾上腺素受体为美托洛尔的作用靶标,Ser49Gly与Gly389Arg多态性显著改变受体功能。CYP2D6与β1肾上腺素受体遗传多态性对美托洛尔降压疗效的联合影响仍属未知。目的:发现与美托洛尔药代动力学与药效动力学相关的基因多态性位点。为提高高血压病的疗效和减少不良反应提供实验依据。方法:符合WHO/ISH高血压诊断标准的轻、中度高血压患者125例,服用美托洛尔单药治疗12周,每四周检测血压。在临床观察疗效的同时,应用PCR-RFLP方法对患者进行CYP2D6*10与β1肾上腺素受体Ser49Gly和Gly389Arg基因型分析。同时抽取静脉血5mL,高效液相色谱-荧光检测法测定患者美托洛尔谷浓度。结果:美托洛尔谷浓度与CYP2D610基因型显著相关,并呈基因剂量效应。但高血压患者血压降低程度在CYP2D6*1*1、1*10与CYP2D6*10*10组间无差异。Gly49携带者服用美托洛尔后收缩压与舒张压的降低显著大于Ser49Ser纯合子;与Gly389携带者相比,Arg389Arg服用美托洛尔后收缩压与舒张压的降低更为显著,表明Gly49与Arg389型受体对美托洛尔治疗有较好的敏感性。结论:CYP2D6*10突变显著改变美托洛尔的药代动力学,但对美托洛尔的降压效果无显著性影响。β1肾上腺素受体遗传多态性与β受体阻滞药的降压敏感性有一定相关性。

  17. Effects of Macromolecular Crowding on Alcohol Dehydrogenase Activity Are Substrate-Dependent.

    Science.gov (United States)

    Wilcox, A E; LoConte, Micaela A; Slade, Kristin M

    2016-06-28

    Enzymes operate in a densely packed cellular environment that rarely matches the dilute conditions under which they are studied. To better understand the ramifications of this crowding, the Michaelis-Menten kinetics of yeast alcohol dehydrogenase (YADH) were monitored spectrophotometrically in the presence of high concentrations of dextran. Crowding decreased the maximal rate of the reaction by 40% for assays with ethanol, the primary substrate of YADH. This observation was attributed to slowed release of the reduced β-nicotinamide adenine dinucleotide product, which is rate-limiting. In contrast, when larger alcohols were used as the YADH substrate, the rate-limiting step becomes hydride transfer and crowding instead increased the maximal rate of the reaction by 20-40%. This work reveals the importance of considering enzyme mechanism when evaluating the ways in which crowding can alter kinetics.

  18. Investigation of photocatalytic activity of titanium dioxide coating deposited on aluminium alloy substrate by plasma technique

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Soyama, Juliano; Dirscherl, Kai;

    2011-01-01

    . Literature consists of large number of publications on titanium dioxide coating for self-cleaning applications, with glass as the main substrate. Only little work is available on TiO2 coating of metallic alloys used for engineering applications. Engineering materials, such as light-weight aluminium and steel...... have wide spread technological applications, where a combination of self-cleaning properties has a huge business potential. The results presented in this paper demonstrate superior photocatalytic properties of TiO2 coated aluminium compared to nano-scale TiO2 coating on glass substrate. The thickness...... of the crystals. Furthermore, it manifested that the surface area of the coating increased linearly with crystal size. The optical measurements demonstrated that the ability of the coating to absorb light was depended on the thickness of the coating. As the coating became thicker, the absorption increased up...

  19. Modulation of Pantothenate Kinase 3 Activity by Small Molecules that Interact with the Substrate/Allosteric Regulatory Domain

    Energy Technology Data Exchange (ETDEWEB)

    Leonardi, Roberta; Zhang, Yong-Mei; Yun, Mi-Kyung; Zhou, Ruobing; Zeng, Fu-Yue; Lin, Wenwei; Cui, Jimmy; Chen, Taosheng; Rock, Charles O.; White, Stephen W.; Jackowski, Suzanne (SJCH)

    2010-09-27

    Pantothenate kinase (PanK) catalyzes the rate-controlling step in coenzyme A (CoA) biosynthesis. PanK3 is stringently regulated by acetyl-CoA and uses an ordered kinetic mechanism with ATP as the leading substrate. Biochemical analysis of site-directed mutants indicates that pantothenate binds in a tunnel adjacent to the active site that is occupied by the pantothenate moiety of the acetyl-CoA regulator in the PanK3 acetyl-CoA binary complex. A high-throughput screen for PanK3 inhibitors and activators was applied to a bioactive compound library. Thiazolidinediones, sulfonylureas and steroids were inhibitors, and fatty acyl-amides and tamoxifen were activators. The PanK3 activators and inhibitors either stimulated or repressed CoA biosynthesis in HepG2/C3A cells. The flexible allosteric acetyl-CoA regulatory domain of PanK3 also binds the substrates, pantothenate and pantetheine, and small molecule inhibitors and activators to modulate PanK3 activity.

  20. Addition of Aromatic Substrates Restores Trichloroethylene Degradation Activity in Pseudomonas putida F1

    OpenAIRE

    Morono, Yuki; Unno, Hajime; TANJI, Yasunori; Hori, Katsutoshi

    2004-01-01

    The rate of trichloroethylene (TCE) degradation by toluene dioxygenase (TDO) in resting cells of Pseudomonas putida F1 gradually decreased and eventually stopped within 1.5 h, as in previous reports. However, the subsequent addition of toluene, which is the principal substrate of TDO, resulted in its immediate degradation without a lag phase. After the consumption of toluene, degradation of TCE restarted at a rate similar to its initial degradation, suggesting that this degradation was mediat...

  1. Structure of active IspH enzyme from escherichia coli provides mechanistic insights into substrate reduction

    KAUST Repository

    Gräwert, Tobias

    2009-07-20

    The terminal step of the non-mevalonate pathway of terpene biosynthesis is catalyzed by IspH (see scheme). In the crystal structure of IspH from E. coli, a bound inorganic diphosphate ligand occupies the position of the diphosphate residue of the substrate. Together with mutation studies and theoretical calculations, these data support a mechanism which is analogous to the Birch reduction of allylic alcohols. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.

  2. Control of Substrate Access to the Active Site in Methane Monooxygenase

    OpenAIRE

    Lee, Seung Jae; McCormick, Michael S.; Lippard, Stephen J.; Cho, Uhn-Soo

    2013-01-01

    Methanotrophs consume methane as their major carbon source and have an essential role in the global carbon cycle by limiting escape of this greenhouse gas to the atmosphere. These bacteria oxidize methane to methanol by soluble and particulate methane monooxygenases (MMOs). Soluble MMO contains three protein components, a 251-kilodalton hydroxylase (MMOH), a 38.6-kilodalton reductase (MMOR), and a 15.9-kilodalton regulatory protein (MMOB), required to couple electron consumption with substrat...

  3. Acyl-CoA:cholesterol acyltransferases (ACATs/SOATs): Enzymes with multiple sterols as substrates and as activators.

    Science.gov (United States)

    Rogers, Maximillian A; Liu, Jay; Song, Bao-Liang; Li, Bo-Liang; Chang, Catherine C Y; Chang, Ta-Yuan

    2015-07-01

    Cholesterol is essential to the growth and viability of cells. The metabolites of cholesterol include: steroids, oxysterols, and bile acids, all of which play important physiological functions. Cholesterol and its metabolites have been implicated in the pathogenesis of multiple human diseases, including: atherosclerosis, cancer, neurodegenerative diseases, and diabetes. Thus, understanding how cells maintain the homeostasis of cholesterol and its metabolites is an important area of study. Acyl-coenzyme A:cholesterol acyltransferases (ACATs, also abbreviated as SOATs) converts cholesterol to cholesteryl esters and play key roles in the regulation of cellular cholesterol homeostasis. ACATs are most unusual enzymes because (i) they metabolize diverse substrates including both sterols and certain steroids; (ii) they contain two different binding sites for steroidal molecules. In mammals, there are two ACAT genes that encode two different enzymes, ACAT1 and ACAT2. Both are allosteric enzymes that can be activated by a variety of sterols. In addition to cholesterol, other sterols that possess the 3-beta OH at C-3, including PREG, oxysterols (such as 24(S)-hydroxycholesterol and 27-hydroxycholesterol, etc.), and various plant sterols, could all be ACAT substrates. All sterols that possess the iso-octyl side chain including cholesterol, oxysterols, various plant sterols could all be activators of ACAT. PREG can only be an ACAT substrate because it lacks the iso-octyl side chain required to be an ACAT activator. The unnatural cholesterol analogs epi-cholesterol (with 3-alpha OH in steroid ring B) and ent-cholesterol (the mirror image of cholesterol) contain the iso-octyl side chain but do not have the 3-beta OH at C-3. Thus, they can only serve as activators and cannot serve as substrates. Thus, within the ACAT holoenzyme, there are site(s) that bind sterol as substrate and site(s) that bind sterol as activator; these sites are distinct from each other. These features form

  4. Substrate-dependent activation of the Vibrio cholerae vexAB RND efflux system requires vexR.

    Directory of Open Access Journals (Sweden)

    Dawn L Taylor

    Full Text Available Vibrio cholerae encodes six resistance-nodulation-division (RND efflux systems which function in antimicrobial resistance, virulence factor production, and intestinal colonization. Among the six RND efflux systems, VexAB exhibited broad substrate specificity and played a predominant role in intrinsic antimicrobial resistance. The VexAB system was encoded in an apparent three gene operon that included vexR; which encodes an uncharacterized TetR family regulator. In this work we examined the role of vexR in vexRAB expression. We found that VexR bound to the vexRAB promoter and vexR deletion resulted in decreased vexRAB expression and increased susceptibility to VexAB antimicrobial substrates. Substrate-dependent induction of vexRAB was dependent on vexR and episomal vexR expression provided a growth advantage in the presence of the VexAB substrate deoxycholate. The expression of vexRAB increased, in a vexR-dependent manner, in response to the loss of RND efflux activity. This suggested that VexAB may function to export intracellular metabolites. Support for this hypothesis was provided by data showing that vexRAB was upregulated in several metabolic mutants including tryptophan biosynthetic mutants that were predicted to accumulate indole. In addition, vexRAB was found to be upregulated in response to exogenous indole and to contribute to indole resistance. The collective results indicate that vexR is required for vexRAB expression in response to VexAB substrates and that the VexAB RND efflux system modulates the intracellular levels of metabolites that could otherwise accumulate to toxic levels.

  5. Substrate-dependent activation of the Vibrio cholerae vexAB RND efflux system requires vexR.

    Science.gov (United States)

    Taylor, Dawn L; Ante, Vanessa M; Bina, X Renee; Howard, Mondraya F; Bina, James E

    2015-01-01

    Vibrio cholerae encodes six resistance-nodulation-division (RND) efflux systems which function in antimicrobial resistance, virulence factor production, and intestinal colonization. Among the six RND efflux systems, VexAB exhibited broad substrate specificity and played a predominant role in intrinsic antimicrobial resistance. The VexAB system was encoded in an apparent three gene operon that included vexR; which encodes an uncharacterized TetR family regulator. In this work we examined the role of vexR in vexRAB expression. We found that VexR bound to the vexRAB promoter and vexR deletion resulted in decreased vexRAB expression and increased susceptibility to VexAB antimicrobial substrates. Substrate-dependent induction of vexRAB was dependent on vexR and episomal vexR expression provided a growth advantage in the presence of the VexAB substrate deoxycholate. The expression of vexRAB increased, in a vexR-dependent manner, in response to the loss of RND efflux activity. This suggested that VexAB may function to export intracellular metabolites. Support for this hypothesis was provided by data showing that vexRAB was upregulated in several metabolic mutants including tryptophan biosynthetic mutants that were predicted to accumulate indole. In addition, vexRAB was found to be upregulated in response to exogenous indole and to contribute to indole resistance. The collective results indicate that vexR is required for vexRAB expression in response to VexAB substrates and that the VexAB RND efflux system modulates the intracellular levels of metabolites that could otherwise accumulate to toxic levels. PMID:25695834

  6. Multiple transport-active binding sites are available for a single substrate on human P-glycoprotein (ABCB1).

    Science.gov (United States)

    Chufan, Eduardo E; Kapoor, Khyati; Sim, Hong-May; Singh, Satyakam; Talele, Tanaji T; Durell, Stewart R; Ambudkar, Suresh V

    2013-01-01

    P-glycoprotein (Pgp, ABCB1) is an ATP-Binding Cassette (ABC) transporter that is associated with the development of multidrug resistance in cancer cells. Pgp transports a variety of chemically dissimilar amphipathic compounds using the energy from ATP hydrolysis. In the present study, to elucidate the binding sites on Pgp for substrates and modulators, we employed site-directed mutagenesis, cell- and membrane-based assays, molecular modeling and docking. We generated single, double and triple mutants with substitutions of the Y307, F343, Q725, F728, F978 and V982 residues at the proposed drug-binding site with cys in a cysless Pgp, and expressed them in insect and mammalian cells using a baculovirus expression system. All the mutant proteins were expressed at the cell surface to the same extent as the cysless wild-type Pgp. With substitution of three residues of the pocket (Y307, Q725 and V982) with cysteine in a cysless Pgp, QZ59S-SSS, cyclosporine A, tariquidar, valinomycin and FSBA lose the ability to inhibit the labeling of Pgp with a transport substrate, [(125)I]-Iodoarylazidoprazosin, indicating these drugs cannot bind at their primary binding sites. However, the drugs can modulate the ATP hydrolysis of the mutant Pgps, demonstrating that they bind at secondary sites. In addition, the transport of six fluorescent substrates in HeLa cells expressing triple mutant (Y307C/Q725C/V982C) Pgp is also not significantly altered, showing that substrates bound at secondary sites are still transported. The homology modeling of human Pgp and substrate and modulator docking studies support the biochemical and transport data. In aggregate, our results demonstrate that a large flexible pocket in the Pgp transmembrane domains is able to bind chemically diverse compounds. When residues of the primary drug-binding site are mutated, substrates and modulators bind to secondary sites on the transporter and more than one transport-active binding site is available for each

  7. Multiple transport-active binding sites are available for a single substrate on human P-glycoprotein (ABCB1.

    Directory of Open Access Journals (Sweden)

    Eduardo E Chufan

    Full Text Available P-glycoprotein (Pgp, ABCB1 is an ATP-Binding Cassette (ABC transporter that is associated with the development of multidrug resistance in cancer cells. Pgp transports a variety of chemically dissimilar amphipathic compounds using the energy from ATP hydrolysis. In the present study, to elucidate the binding sites on Pgp for substrates and modulators, we employed site-directed mutagenesis, cell- and membrane-based assays, molecular modeling and docking. We generated single, double and triple mutants with substitutions of the Y307, F343, Q725, F728, F978 and V982 residues at the proposed drug-binding site with cys in a cysless Pgp, and expressed them in insect and mammalian cells using a baculovirus expression system. All the mutant proteins were expressed at the cell surface to the same extent as the cysless wild-type Pgp. With substitution of three residues of the pocket (Y307, Q725 and V982 with cysteine in a cysless Pgp, QZ59S-SSS, cyclosporine A, tariquidar, valinomycin and FSBA lose the ability to inhibit the labeling of Pgp with a transport substrate, [(125I]-Iodoarylazidoprazosin, indicating these drugs cannot bind at their primary binding sites. However, the drugs can modulate the ATP hydrolysis of the mutant Pgps, demonstrating that they bind at secondary sites. In addition, the transport of six fluorescent substrates in HeLa cells expressing triple mutant (Y307C/Q725C/V982C Pgp is also not significantly altered, showing that substrates bound at secondary sites are still transported. The homology modeling of human Pgp and substrate and modulator docking studies support the biochemical and transport data. In aggregate, our results demonstrate that a large flexible pocket in the Pgp transmembrane domains is able to bind chemically diverse compounds. When residues of the primary drug-binding site are mutated, substrates and modulators bind to secondary sites on the transporter and more than one transport-active binding site is available

  8. Mitochondrial intermediate peptidase: Expression in Escherichia coli and improvement of its enzymatic activity detection with FRET substrates

    International Nuclear Information System (INIS)

    In the present study, soluble, functionally-active, recombinant human mitochondrial intermediate peptidase (hMIP), a mitochondrial metalloendoprotease, was expressed in a prokaryotic system. The hMIP fusion protein, with a poly-His-tag (6x His), was obtained by cloning the coding region of hMIP cDNA into the pET-28a expression vector, which was then used to transform Escherichia coli BL21 (DE3) pLysS. After isolation and purification of the fusion protein by affinity chromatography using Ni-Sepharose resin, the protein was purified further using ion exchange chromatography with a Hi-trap resource Q column. The recombinant hMIP was characterized by Western blotting using three distinct antibodies, circular dichroism, and enzymatic assays that used the first FRET substrates developed for MIP and a series of protease inhibitors. The successful expression of enzymatically-active hMIP in addition to the FRET substrates will contribute greatly to the determination of substrate specificity of this protease and to the development of specific inhibitors that are essential for a better understanding of the role of this protease in mitochondrial functioning.

  9. Fuel-Stimulated Insulin Secretion Depends upon Mitochondria Activation and the Integration of Mitochondrial and Cytosolic Substrate Cycles

    Directory of Open Access Journals (Sweden)

    Gary W. Cline

    2011-10-01

    Full Text Available The pancreatic islet β-cell is uniquely specialized to couple its metabolism and rates of insulin secretion with the levels of circulating nutrient fuels, with the mitochondrial playing a central regulatory role in this process. In the β-cell, mitochondrial activation generates an integrated signal reflecting rates of oxidativephosphorylation, Kreb's cycle flux, and anaplerosis that ultimately determines the rate of insulin exocytosis. Mitochondrial activation can be regulated by proton leak and mediated by UCP2, and by alkalinization to utilize the pH gradient to drive substrate and ion transport. Converging lines of evidence support the hypothesis that substrate cycles driven by rates of Kreb's cycle flux and by anaplerosis play an integral role in coupling responsive changes in mitochondrial metabolism with insulin secretion. The components and mechanisms that account for the integrated signal of ATP production, substrate cycling, the regulation of cellular redox state, and the production of other secondary signaling intermediates are operative in both rodent and human islet β-cells.

  10. Inhibition of spontaneous network activity in neonatal hippocampal slices by energy substrates is not correlated with intracellular acidification.

    Science.gov (United States)

    Mukhtarov, Marat; Ivanov, Anton; Zilberter, Yuri; Bregestovski, Piotr

    2011-01-01

    Several energy substrates complementary to glucose, including lactate, pyruvate and β-hydroxybutyrate, serve as a fuel for neurons. It was reported recently that these substrates can substantially modulate cortical excitability in neonatal slices. However, complementary energy substrates (CES) can also induce an intracellular acidification when added exogenously. Therefore, action of CES on the neuronal properties governing excitability in neonatal brain slices may be underlain by a change in the cell energy status or by intracellular acidification, or both. Here, we attempt to elucidate these possibilities in neonatal hippocampus by recording neuronal population activity and monitoring intracellular pH. We show that a spontaneous network activity pattern, giant depolarizing potentials (GDPs), characteristic for the neonatal hippocampal slices exposed to artificial cerebrospinal fluid, is strongly inhibited by CES and this effect is unlikely to be caused by a subtle intracellular acidification induced by these compounds. Indeed, a much stronger intracellular acidification in the HCO(3) -free solution inhibited neither the GDP frequency nor the GDP amplitude. Therefore, modulation of neuronal energy homeostasis is the most likely factor underlying the effect of lactate, pyruvate and β-hydroxybutyrate on network excitability in neonatal brain slices.

  11. Fabrication of SERS-active substrates using silver nanofilm-coated porous anodic aluminum oxide for detection of antibiotics.

    Science.gov (United States)

    Chen, Jing; Feng, Shaolong; Gao, Fang; Grant, Edward; Xu, Jie; Wang, Shuo; Huang, Qian; Lu, Xiaonan

    2015-04-01

    We have developed a silver nanofilm-coated porous anodic aluminum oxide (AAO) as a surface-enhanced Raman scattering (SERS)-active substrate for the detection of trace level of chloramphenicol, a representative antibiotic in food systems. The ordered aluminum template generated during the synthesis of AAO serves as a patterned matrix on which a coated silver film replicates the patterned AAO matrix to form a 2-dimensional ordered nanostructure. We used atomic force microscopy and scanning electron microscopy images to determine the morphology of this nanosubstrate, and characterized its localized surface plasmon resonance by ultraviolet-visible reflection. We gauged the SERS effect of this nanosubstrate by confocal micro-Raman spectroscopy (782-nm laser), finding a satisfactory and consistent performance with enhancement factors of approximately 2 × 10(4) and a limit of detection for chloramphenicol of 7.5 ppb. We applied principal component analysis to determine the limit of quantification for chloramphenicol of 10 ppb. Using electromagnetic field theory, we developed a detailed mathematical model to explain the mechanism of Raman signal enhancement of this nanosubstrate. With simple sample pretreatment and separation steps, this silver nanofilm-coated AAO substrate could detect 50 ppb chloramphenicol in milk, indicating good potential as a reliable SERS-active substrate for rapid detection of chemical contaminants in agricultural and food products.

  12. Chemically-modified graphene sheets as an active layer for eco-friendly metal electroplating on plastic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Joon-Suk; Hwang, Taeseon; Nam, Gi-Yong; Hong, Jung-Pyo [Department of Polymer Science and Engineering, Sungkyunkwan University, Chunchun-dong, Jangan-gu, Suwon, 440-746 (Korea, Republic of); Bae, Ah-Hyun; Son, Sang-Ik; Lee, Geun-Ho; Sung, Hak kyung [Manufacturing Tech. Center, Samsung Electronics Co., Ltd., Maetan-dong, Yeongtong-gu, Suwon, 443-742 (Korea, Republic of); Choi, Hyouk Ryeol; Koo, Ja Choon [School of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Nam, Jae-Do, E-mail: jdnam@skku.edu [Department of Polymer Science and Engineering, Sungkyunkwan University, Chunchun-dong, Jangan-gu, Suwon, 440-746 (Korea, Republic of); Department of Energy Science, Sungkyunkwan University, Suwon (Korea, Republic of)

    2012-10-30

    Eco-friendly nickel (Ni) electroplating was carried out on a plastic substrate using chemically modified graphene sheets as an active and conductive layer to initiate electroplating without using conventional pre-treatment or electroless metal-seeding processes. A graphene oxide (GO) solution was self-assembled on a polyethylene terephthalate (PET) film followed by evaporation to give GO layers (thickness around 6.5 {mu}m) on PET (GO/PET) film. Then, the GO/PET film was chemically and thermally reduced to convert the GO layers to reduced graphene oxide (RGO) layers on the PET substrate. The RGO-coated PET (RGO/PET) film showed the sheet resistance of 100 {Omega} per square. On RGO/PET film, Ni electroplating was conducted under the constant-current condition and the entire surface of the PET film was completely metalized with Ni without any voids.

  13. Salinosporamides A and B Inhibit Proteasome Activity and Delay the Degradation of N-end Rule Model Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seungkyun; Bang, Daein; Choi, Wonhoon; Lee, Minjae [Kyung Hee Univ., Yongin (Korea, Republic of); Kim, Seonghwan; Oh, Dongchan [Seoul National Univ., Seoul (Korea, Republic of)

    2013-05-15

    The proteasome, which is highly evolutionarily conserved, is responsible for the degradation of most short-lived proteins in cells. Small-molecule inhibitors targeting the proteasome's degradative activity have been extensively developed as lead compounds for various human diseases. An exemplified molecule is bortezomib, which was approved by FDA in 2003 for the treatment of multiple myeloma. Here, using transiently and stably expressed N-end rule model substrates in mammalian cells, we evaluated and identified that salinosporamide A and salinosporamide B effectively inhibited the proteasomal degradation. Considering that a variety of proteasome substrates are implicated in the pathogenesis of many diseases, they have the potential to be clinically applicable as therapeutic agents.

  14. Azocasein Substrate for Determination of Proteolytic Activity: Reexamining a Traditional Method Using Bromelain Samples

    OpenAIRE

    Coêlho, Diego F.; Thais Peron Saturnino; Fernanda Freitas Fernandes; Priscila Gava Mazzola; Edgar Silveira; Elias Basile Tambourgi

    2016-01-01

    Given the importance of protease’s worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM). We also quantified the limit o...

  15. Azocasein Substrate for Determination of Proteolytic Activity: Reexamining a Traditional Method Using Bromelain Samples.

    Science.gov (United States)

    Coêlho, Diego F; Saturnino, Thais Peron; Fernandes, Fernanda Freitas; Mazzola, Priscila Gava; Silveira, Edgar; Tambourgi, Elias Basile

    2016-01-01

    Given the importance of protease's worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM). We also quantified the limit of detection (LoD) and limit of quantification (LoQ) in the above-mentioned optimum (0.072 and 0.494 mg·mL(-1) of azocasein, resp.) and a calibration curve that correlates optical density with the amount of substrate digested. In all analysed samples, we observed a significant decrease in response after storage (around 17%), which suggests its use must be immediately after preparation. Thus, the protocol presented in this paper offers a significant improvement, given that subjective definitions are commonly used in the literature and this simple mathematical approach makes it clear and concise. PMID:26925415

  16. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    KAUST Repository

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

  17. Azocasein Substrate for Determination of Proteolytic Activity: Reexamining a Traditional Method Using Bromelain Samples

    Directory of Open Access Journals (Sweden)

    Diego F. Coêlho

    2016-01-01

    Full Text Available Given the importance of protease’s worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM. We also quantified the limit of detection (LoD and limit of quantification (LoQ in the above-mentioned optimum (0.072 and 0.494 mg·mL−1 of azocasein, resp. and a calibration curve that correlates optical density with the amount of substrate digested. In all analysed samples, we observed a significant decrease in response after storage (around 17%, which suggests its use must be immediately after preparation. Thus, the protocol presented in this paper offers a significant improvement, given that subjective definitions are commonly used in the literature and this simple mathematical approach makes it clear and concise.

  18. Microbial community dynamics linked to enhanced substrate availability and biogas production of electrokinetically pre-treated waste activated sludge.

    Science.gov (United States)

    Westerholm, Maria; Crauwels, Sam; Houtmeyers, Sofie; Meerbergen, Ken; Van Geel, Maarten; Lievens, Bart; Appels, Lise

    2016-10-01

    The restricted hydrolytic degradation rate of complex organic matter presents a considerable challenge in anaerobic digestion of waste activated sludge (WAS). Within this context, application of pre-treatment of digester substrate has potential for improved waste management and enhanced biogas production. Anaerobic degradation of untreated or electrokinetically pre-treated WAS was performed in two pilot-scale digesters for 132days. WAS electrokinetically pre-treated with energy input 0.066kJ/kg sludge was used in a first phase of operation and WAS pre-treated with energy input 0.091kJ/kg sludge was used in a second phase (each phase lasted at least three hydraulic retention times). Substrate characteristics before and after pre-treatment and effects on biogas digester performance were comprehensively analysed. To gain insights into influences of altered substrate characteristics on microbial communities, the dynamics within the bacterial and archaeal communities in the two digesters were investigated using 16S rRNA gene sequencing (pyrosequencing) and quantitative PCR (qPCR). Specific primers targeting dominant operation taxonomic units (OTUs) and members of the candidate phylum Cloacimonetes were designed to further evaluate their abundance and dynamics in the digesters. Electrokinetic pre-treatment significantly improved chemical oxygen demand (COD) and carbohydrate solubility and increased biogas production by 10-11% compared with untreated sludge. Compositional similarity of the bacterial community during initial operation and diversification during later operation indicated gradual adaptation of the community to the higher solubility of organic material in the pre-treated substrate. Further analyses revealed positive correlations between gene abundance of dominant OTUs related to Clostridia and Cloacimonetes and increased substrate availability and biogas production. Among the methanogens, the genus Methanosaeta dominated in both digesters. Overall, the

  19. Microbial community dynamics linked to enhanced substrate availability and biogas production of electrokinetically pre-treated waste activated sludge.

    Science.gov (United States)

    Westerholm, Maria; Crauwels, Sam; Houtmeyers, Sofie; Meerbergen, Ken; Van Geel, Maarten; Lievens, Bart; Appels, Lise

    2016-10-01

    The restricted hydrolytic degradation rate of complex organic matter presents a considerable challenge in anaerobic digestion of waste activated sludge (WAS). Within this context, application of pre-treatment of digester substrate has potential for improved waste management and enhanced biogas production. Anaerobic degradation of untreated or electrokinetically pre-treated WAS was performed in two pilot-scale digesters for 132days. WAS electrokinetically pre-treated with energy input 0.066kJ/kg sludge was used in a first phase of operation and WAS pre-treated with energy input 0.091kJ/kg sludge was used in a second phase (each phase lasted at least three hydraulic retention times). Substrate characteristics before and after pre-treatment and effects on biogas digester performance were comprehensively analysed. To gain insights into influences of altered substrate characteristics on microbial communities, the dynamics within the bacterial and archaeal communities in the two digesters were investigated using 16S rRNA gene sequencing (pyrosequencing) and quantitative PCR (qPCR). Specific primers targeting dominant operation taxonomic units (OTUs) and members of the candidate phylum Cloacimonetes were designed to further evaluate their abundance and dynamics in the digesters. Electrokinetic pre-treatment significantly improved chemical oxygen demand (COD) and carbohydrate solubility and increased biogas production by 10-11% compared with untreated sludge. Compositional similarity of the bacterial community during initial operation and diversification during later operation indicated gradual adaptation of the community to the higher solubility of organic material in the pre-treated substrate. Further analyses revealed positive correlations between gene abundance of dominant OTUs related to Clostridia and Cloacimonetes and increased substrate availability and biogas production. Among the methanogens, the genus Methanosaeta dominated in both digesters. Overall, the

  20. Control of substrate oxidation in MOD ceramic coating on low-activation ferritic steel with reduced-pressure atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Teruya, E-mail: teru@nifs.ac.jp; Muroga, Takeo

    2014-12-15

    Highlights: • A Cr{sub 2}O{sub 3} layer was produced on a ferritic steel substrate with a reduced-pressure. • The Cr{sub 2}O{sub 3} layer prevents further substrate oxidation in following coating process. • The Cr{sub 2}O{sub 3} layer has a function as a hydrogen permeation barrier. • A smooth MOD Er{sub 2}O{sub 3} coating was successfully made on the Cr{sub 2}O{sub 3} layer by dip coating. • The Cr{sub 2}O{sub 3} layer would enhance flexibility in MOD coating process and performances. - Abstract: An Er{sub 2}O{sub 3} ceramic coating fabricated using the metal–organic decomposition (MOD) method on a Cr{sub 2}O{sub 3}-covered low-activation ferritic steel JLF-1 substrate was examined to improve hydrogen permeation barrier performance of the coating. The Cr{sub 2}O{sub 3} layer was obtained before coating by heat treating the substrate at 700 °C under reduced pressures of <5 × 10{sup −3} Pa and 5 Pa. The Cr{sub 2}O{sub 3} layer was significantly stable even with heat treatment at 700 °C in air. This layer prevented further production of Fe{sub 2}O{sub 3}, which has been considered to degrade coating performance. An MOD Er{sub 2}O{sub 3} coating with a smooth surface was successfully obtained on a Cr{sub 2}O{sub 3}-covered JLF-1 substrate by dip coating followed by drying and baking. Preprocessing to obtain a Cr{sub 2}O{sub 3} layer would provide flexibility in the coating process for blanket components and ducts. Moreover, the Cr{sub 2}O{sub 3} layer suppressed hydrogen permeation through the JLF-1 substrate. While further optimization of the coating fabrication process is required, it would be possible to suppress hydrogen permeation significantly by multilayers of Cr{sub 2}O{sub 3} and MOD oxide ceramic.

  1. Aromatic Amino Acid Mutagenesis at the Substrate Binding Pocket of Yarrowia lipolytica Lipase Lip2 Affects Its Activity and Thermostability

    Directory of Open Access Journals (Sweden)

    Guilong Wang

    2014-01-01

    Full Text Available The lipase2 from Yarrowia lipolytica (YLLip2 is a yeast lipase exhibiting high homologous to filamentous fungal lipase family. Though its crystal structure has been resolved, its structure-function relationship has rarely been reported. By contrast, there are two amino acid residues (V94 and I100 with significant difference in the substrate binding pocket of YLLip2; they were subjected to site-directed mutagenesis (SDM to introduce aromatic amino acid mutations. Two mutants (V94W and I100F were created. The enzymatic properties of the mutant lipases were detected and compared with the wild-type. The activities of mutant enzymes dropped to some extent towards p-nitrophenyl palmitate (pNPC16 and their optimum temperature was 35°C, which was 5°C lower than that of the wild-type. However, the thermostability of I100F increased 22.44% after incubation for 1 h at 40°C and its optimum substrate shifted from p-nitrophenyl laurate (pNPC12 to p-nitrophenyl caprate (pNPC10. The above results demonstrated that the two substituted amino acid residuals have close relationship with such enzymatic properties as thermostability and substrate selectivity.

  2. Activity assays of mammalian thioredoxin and thioredoxin reductase: fluorescent disulfide substrates, mechanisms, and use with tissue samples.

    Science.gov (United States)

    Montano, Sergio J; Lu, Jun; Gustafsson, Tomas N; Holmgren, Arne

    2014-03-15

    Thioredoxin (Trx) is a protein disulfide reductase that, together with nicotinamide adenine dinucleotide phosphate (NADPH) and thioredoxin reductase (TrxR), controls oxidative stress or redox signaling via thiol redox control. Human cytosolic Trx1 has Cys32 and Cys35 as the active site and three additional cysteine residues (Cys62, Cys69, and Cys73), which by oxidation generates inactive Cys62 to Cys69 two-disulfide Trx. This, combined with TrxR with a broad substrate specificity, complicates assays of mammalian Trx and TrxR. We sought to understand the autoregulation of Trx and TrxR and to generate new methods for quantification of Trx and TrxR. We optimized the synthesis of two fluorescent substrates, di-eosin-glutathione disulfide (Di-E-GSSG) and fluorescein isothiocyanate-labeled insulin (FiTC-insulin), which displayed higher fluorescence on disulfide reduction. Di-E-GSSG showed a very large increase in fluorescence quantum yield but had a relatively low affinity for Trx and was also a weak direct substrate for TrxR, in contrast to GSSG. FiTC-insulin was used to develop highly sensitive assays for TrxR and Trx. Reproducible conditions were developed for reactivation of modified Trx, commonly present in frozen or oxidized samples. Trx in cell extracts and tissue samples, including plasma and serum, were subsequently analyzed, showing highly reproducible results and allowing measurement of trace amounts of Trx.

  3. A Substrate-Assisted Mechanism of Nucleophile Activation in a Ser-His-Asp Containing C-C Bond Hydrolase

    Energy Technology Data Exchange (ETDEWEB)

    Ruzzini, Antonio C.; Bhowmik, Shiva; Ghosh, Subhangi; Yam, Katherine C.; Bolin, Jeffrey T.; Eltis, Lindsay D. [Purdue; (UBC)

    2013-11-12

    The meta-cleavage product (MCP) hydrolases utilize a Ser–His–Asp triad to hydrolyze a carbon–carbon bond. Hydrolysis of the MCP substrate has been proposed to proceed via an enol-to-keto tautomerization followed by a nucleophilic mechanism of catalysis. Ketonization involves an intermediate, ESred, which possesses a remarkable bathochromically shifted absorption spectrum. We investigated the catalytic mechanism of the MCP hydrolases using DxnB2 from Sphingomonas wittichii RW1. Pre-steady-state kinetic and LC ESI/MS evaluation of the DxnB2-mediated hydrolysis of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid to 2-hydroxy-2,4-pentadienoic acid and benzoate support a nucleophilic mechanism catalysis. In DxnB2, the rate of ESred decay and product formation showed a solvent kinetic isotope effect of 2.5, indicating that a proton transfer reaction, assigned here to substrate ketonization, limits the rate of acylation. For a series of substituted MCPs, this rate was linearly dependent on MCP pKa2nuc ~ 1). Structural characterization of DxnB2 S105A:MCP complexes revealed that the catalytic histidine is displaced upon substrate-binding. The results provide evidence for enzyme-catalyzed ketonization in which the catalytic His–Asp pair does not play an essential role. The data further suggest that ESred represents a dianionic intermediate that acts as a general base to activate the serine nucleophile. This substrate-assisted mechanism of nucleophilic catalysis distinguishes MCP hydrolases from other serine hydrolases.

  4. Fluorometric assay using naphthylamide substrates for assessing novel venom peptidase activities.

    Science.gov (United States)

    Gasparello-Clemente, Elaine; Silveira, Paulo Flávio

    2002-11-01

    In the present study we examined the feasibility of using the fluorometry of naphthylamine derivatives for revealing peptidase activities in venoms of the snakes Bothrops jararaca, Bothrops alternatus, Bothrops atrox, Bothrops moojeni, Bothrops insularis, Crotalus durissus terrificus and Bitis arietans, of the scorpions Tityus serrulatus and Tityus bahiensis, and of the spiders Phoneutria nigriventer and Loxosceles intermedia. Neutral aminopeptidase (APN) and prolyl-dipeptidyl aminopeptidase IV (DPP IV) activities were presented in all snake venoms, with the highest levels in B. alternatus. Although all examined peptidase activities showed relatively low levels in arthropod venoms, basic aminopeptidase (APB) activity from P. nigriventer venom was the exception. Compared to the other peptidase activities, relatively high levels of acid aminopeptidase (APA) activity were restricted to B. arietans venom. B. arietans also exhibited a prominent content of APB activity which was lower in other venoms. Relatively low prolyl endopeptidase and proline iminopeptidase activities were, respectively, detectable only in T. bahiensis and B. insularis. Pyroglutamate aminopeptidase activity was undetectable in all venoms. All examined peptidase activities were undetectable in T. serrulatus venom. In this study, the specificities of a diverse array of peptidase activities from representative venoms were demonstrated for the first time, with a description of their distribution which may contribute to guiding further investigations. The expressive difference between snake and arthropod venoms was indicated by APN and DPP IV activities while APA and APB activities distinguished the venom of B. arietans from those of Brazilian snakes. The data reflected the relatively uniform qualitative distribution of the peptidase activities investigated, together with their unequal quantitative distribution, indicating the evolutionary divergence in the processing of peptides in these different

  5. ACTIVITIES OF AMMONIA ASSIMILATION ENZYMES AS INDICATORS OF THE RELATIVE SUPPLY OF NITROGEN SUBSTRATES FOR MARINE BACTERIOPLANKTON IN SUB-TROPICAL COASTAL WATER

    Science.gov (United States)

    The supply of nitrogen substrates available for bacterial production in seawater was determined using the activities of ammonia assimilation enzymes, glutamine synthetase (GS) and glutamate dehydrogenase (GDH). Expression of GS and GDH by bacteria in pure culture is generally ind...

  6. Enantiomeric perylene-glycerolipids as fluorogenic substrates for a dual wavelength assay of lipase activity and stereoselectivity.

    Science.gov (United States)

    Zandonella, G; Haalck, L; Spener, F; Faber, K; Paltauf, F; Hermetter, A

    1996-01-01

    A new type of fluorogenic alkyldiacyl glycerols was synthesized and used as fluorogenic substrates for the analysis of lipase activities and stereoselectivities. These compounds contain perylene as a fluorophore and the trinitrophenylamino (TNP) residue as a quencher. Both substituents are covalently bound to the omega-ends of the sn-2 and sn-1 (3) acyl chains, respectively. Upon glycerolipid hydrolysis, the residues are separated from each other thus allowing determination of lipase activity by the continuous increase in fluorescence intensity which is caused by dequenching. Using enantiomeric pairs of these compounds, we were able to analyze lipase stereoselectivity depending on the reaction medium. Mixtures of enantiomeric fluorogenic alkyldiacyl glycerols, selectively labelled with pyrene or perylene as fluorophores, can be used for a dual-wavelength "stereoassay" of lipases. Since absorption and emission maxima of both labels are clearly separated, hydrolysis of the respective enantiomeric substrates can be determined simultaneously, and the difference in the rates of hydrolysis can be taken as a parameter for the stereopreference of a lipase. Hydrolysis rates measured with perylene-substituted lipids are generally lower than those obtained with the pyrene analogs. Thus, with a mixture of perylene and pyrene-substituted lipids, we observe a higher apparent stereoselectivity of lipases since we measure a combination of stereo- and substrate selectivity. In the presence of albumin, all microbial lipases tested so far exhibit stereopreference for the sn-1 glycerol position. In our assay, the apparent stereoselectivities are highest if in the presence of albumin, the sn-1 position carries pyrene and the sn-3 position is substituted with perylene. The lipase stereoselectivity assay described here requires the simultaneous measurement of the fluorescence intensities at two different wavelengths in a single cuvette and can thus be carried out using existing and cheap

  7. A Sensitive Microplate Assay for Lipase Activity Measurement Using Olive Oil Emulsion Substrate: Modification of the Copper Soap Colorimetric Method.

    Science.gov (United States)

    Mustafa, Ahmad; Karmali, Amin; Abdelmoez, Wael

    2016-01-01

    The present work involves a sensitive high-throughput microtiter plate based colorimetric assay for estimating lipase activity using cupric acetate pyridine reagent (CAPR). In the first approach, three factors two levels factorial design methodology was used to evaluate the interactive effect of different parameters on the sensitivity of the assay method. The optimization study revealed that the optimum CAPR concentration was 7.5% w/v, the optimum solvent was heptane and the optimum CAPR pH was 6. In the second approach, the optimized colorimetric microplate assay was used to measure lipase activity based on enzymatic hydrolysis of olive oil emulsion substrate at 37°C and 150 rpm. The emulsion substrates were formulated by using olive oil, triton X-100 (10% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 1:1:1 in the case of Candida sp. lipase. While in the case of immobilized lipozyme RMIM, The emulsion substrates were formulated by using olive oil, triton X-100 (1% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 2:1:1. Absorbance was measured at 655 nm. The stability of this assay (in terms of colored heptane phase absorbance readings) retained more than 92.5% after 24 h at 4°C compared to the absorbance readings measured at zero time. In comparison with other lipase assay methods, beside the developed sensitivity, the reproducibility and the lower limit of detection (LOD) of the proposed method, it permits analyzing of 96 samples at one time in a 96-well microplate. Furthermore, it consumes small quantities of chemicals and unit operations. PMID:27581492

  8. Substrate binding activates the designed triple mutant of the colicin E7 metallonuclease

    DEFF Research Database (Denmark)

    Németh, Eszter; Körtvélyesi, Tamás; Kožíšek, Milan;

    2014-01-01

    The nuclease domain of colicin E7 (NColE7) cleaves DNA nonspecifically. The active center is a Zn(2+)-containing HNH motif at the C-terminus. The N-terminal loop is essential for the catalytic activity providing opportunity for allosteric modulation of the enzyme. To identify the key residues res...

  9. Arrayed SU-8 polymer thermal actuators with inherent real-time feedback for actively modifying MEMS’ substrate warpage

    Science.gov (United States)

    Wang, Xinghua; Xiao, Dingbang; Chen, Zhihua; Wu, Xuezhong

    2016-09-01

    This paper describes the design, fabrication and characterization of a batch-fabricated micro-thermal actuators array with inherent real-time self-feedback, which can be used to actively modify micro-electro-mechanical systems’ (MEMS’) substrate warpage. Arrayed polymer thermal actuators utilize SU-8 polymer (a thick negative photoresist) as a functional material with integrated Ti/Al film-heaters as a microscale heat source. The electro-thermo-mechanical response of a micro-fabricated actuator was measured. The resistance of the Al/Ti film resistor varies obviously with ambient temperature, which can be used as inherent feedback for observing real-time displacement of activated SU-8 bumps (0.43 μm Ω-1). Due to the high thermal expansion coefficient, SU-8 bumps tend to have relatively large deflection at low driving voltage and are very easily integrated with MEMS devices. Experimental results indicated that the proposed SU-8 polymer thermal actuators (array) are able to achieve accurate rectification of MEMS’ substrate warpage, which might find potential applications for solving stress-induced problems in MEMS.

  10. The human DNA-activated protein kinase, DNA-PK: Substrate specificity

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C.W.; Connelly, M.A.; Zhang, H.; Sipley, J.A. [Brookhaven National Lab., Upton, NY (United States). Biology Dept.; Lees-Miller, S.P.; Lintott, L.G. [Univ. of Calgary, Alberta (Canada). Dept. of Biological Sciences; Sakaguchi, Kazuyasu; Appella, E. [National Institutes of Health, Bethesda, MD (United States). Lab. of Cell Biology

    1994-11-05

    Although much has been learned about the structure and function of p53 and the probable sequence of subsequent events that lead to cell cycle arrest, little is known about how DNA damage is detected and the nature of the signal that is generated by DNA damage. Circumstantial evidence suggests that protein kinases may be involved. In vitro, human DNA-PK phosphorylates a variety of nuclear DNA-binding, regulatory proteins including the tumor suppressor protein p53, the single-stranded DNA binding protein RPA, the heat shock protein hsp90, the large tumor antigen (TAg) of simian virus 40, a variety of transcription factors including Fos, Jun, serum response factor (SRF), Myc, Sp1, Oct-1, TFIID, E2F, the estrogen receptor, and the large subunit of RNA polymerase II (reviewed in Anderson, 1993; Jackson et al., 1993). However, for most of these proteins, the sites that are phosphorylated by DNA-PK are not known. To determine if the sites that were phosphorylated in vitro also were phosphorylated in vivo and if DNA-PK recognized a preferred protein sequence, the authors identified the sites phosphorylated by DNA-PK in several substrates by direct protein sequence analysis. Each phosphorylated serine or threonine is followed immediately by glutamine in the polypeptide chain; at no other positions are the amino acid residues obviously constrained.

  11. AKTIVITAS HIALURONIDASE BAKTERI STREPTOKOKUS GRUP B PADA SUBSTRAT ASAM HIALURONAT THE HYALURONIDASE ACTIVITY OF GROUP B STREPTOCOCCUS IN HYALURONIC ACID SUBSTRATE

    Directory of Open Access Journals (Sweden)

    Zinatul Hayati

    2007-06-01

    Full Text Available Streptococcus agalactiae atau yang juga dikenal dengan Streptokokus grup B (SGB telah diketahui sebagai agen penyebab pneumonia, septikemia dan meningitis neonatal pada manusia dan hewan. Hialuronidase merupakan produk ekstraseluler dari SGB yang menentukan virulensinya. Penelitian ini dilakukan untuk menguji akitvitas hialuronidase dari 10 isolat SGB yang diisolasi dari kasus komplikase obstetri, serta memurnikan dan mengkarakterisasi hialuronidase yang diisolasi dari SGB SV-14 pada substrat asam hialuronat.

  12. Intracellular protease activation in apoptosis and cell-mediated cytotoxicity characterized by cell-permeable fluorogenic protease substrates

    Institute of Scientific and Technical Information of China (English)

    Beverly Z Packard; Akira Komoriya

    2008-01-01

    Over the past decade the importance of signaling from reporter molecules inside live cells and tissues has been clearly established. Biochemical events related to inflammation, tumor metastasis and proliferation, and viral infectivity and replication are examples of processes being further defined as more molecular tools for live cell measurements become available. Moreover, in addition to quantitating parameters related to physiologic processes, real-time imaging of molecular interactions that compose basic cellular activities are providing insights into understanding disease mechanisms as well as extending clinical efficacy of therapeutic regimens. In this review the use of highly cell-permeable fluorogenic substrates that report protease activities inside live cells is described; applications to defining the molecular events of two cellular processes, i.e., apoptosis and cell-mediated cytotoxicity, are then illustrated.

  13. Nanostructure, solvation dynamics, and nanotemplating of plasmonically active SERS substrate in reverse vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Ranajay; Rakshit, Surajit [S.N. Bose National Centre for Basic Sciences, Department of Chemical, Biological and Macromolecular Sciences (India); Majumdar, Dipanwita; Singha, Achintya [Bose Institute, Department of Physics (India); Mitra, Rajib Kumar; Pal, Samir Kumar, E-mail: skpal@bose.res.in [S.N. Bose National Centre for Basic Sciences, Department of Chemical, Biological and Macromolecular Sciences (India)

    2013-04-15

    Reverse vesicles (RVs) are the organic counterparts to vesicles and are spherical containers in oils consisting of an oily core surrounded by reverse bilayers with water layers present in between. We present here a facile route for forming stable RV from nontoxic surfactants and oil components. The RV formation is characterized by dynamic light scattering and further confirmed by transmission electron microscopic (TEM) techniques. The water channels present in between the bilayers are found to be a potential template for inorganic nanoparticles' (NPs) synthesis. Both the UV-Vis absorption spectroscopy and the TEM study reveal successful formation of highly clustered silver NPs within the water layers of the RVs. X-ray powder diffraction analyzes the crystalline nature of the NPs. FTIR spectroscopy shows the signature of different kinds of water molecules in between the RV bilayers. The dynamical description of the templating water, dictating the controlled formation of the NPs in the RV, is well revealed in the picosecond-resolved solvation dynamics study of a hydrophilic fluorescence probe 2 Prime -(4-hydroxyphenyl)-5-[5-(4-methylpiperazine-1-yl) -benzimidazo-2-yl-benzimidazole] (H258). The rotational anisotropy study successfully describes geometrical restriction of the probe molecule in the RV. Notably, this study provides the first proof-of-concept data for the ability of the RV to be a template of synthesizing metal NPs. The as-prepared NP clusters are evaluated to be potential surface-enhanced Raman scattering substrate in solution using crystal violet as a model analyte. The present study offers a new RV, which is a prospective nontoxic nanotemplate and is believed to contribute potentially in the emerging NP-vesicle hybrid assembly-based plasmonic applications.Nanotemplating of metal clusters for the efficient SERS detection in liquid phase is reported in a new nontoxic reverse vesicle.

  14. Wetland restoration and methanogenesis: the activity of microbial populations and competition for substrates at different temperatures

    Directory of Open Access Journals (Sweden)

    V. Jerman

    2009-02-01

    Full Text Available Ljubljana marsh in Slovenia is a 16 000 ha area of partly drained fen, intended to be flooded to restore its ecological functions. The resultant water-logging may create anoxic conditions, eventually stimulating production and emission of methane, the most important greenhouse gas next to carbon dioxide. We examined the upper layer (~30 cm of Ljubljana marsh soil for microbial processes that would predominate in water-saturated conditions, focusing on the potential for iron reduction, carbon mineralization (CO2 and CH4 production, and methane emission. Methane emission from water-saturated microcosms was near minimum detectable levels even after extended periods of flooding (>5 months. Methane production in anoxic soil slurries started only after a lag period and was inversely related to iron reduction, which suggested that iron reduction out-competed methanogenesis for electron donors, such as H2 and acetate. Methane production was observed only in samples incubated at 14–38°C. At the beginning of methanogenesis, acetoclastic methanogenesis dominated. In accordance with the preferred substrate, most (91% mcrA (encoding the methyl coenzyme-M reductase, a key gene in methanogenesis clone sequences could be affiliated to the acetoclastic genus Methanosarcina. No methanogens were detected in the original soil. However, a diverse community of iron-reducing Geobacteraceae was found. Our results suggest that methane emission can remain transient and low if water-table fluctuations allow re-oxidation of ferrous iron, sustaining iron reduction as the most important process in terminal carbon mineralization.

  15. Wetland restoration and methanogenesis: the activity of microbial populations and competition for substrates at different temperatures

    Directory of Open Access Journals (Sweden)

    V. Jerman

    2009-06-01

    Full Text Available Ljubljana marsh in Slovenia is a 16 000 ha area of partly drained fen, intended to be flooded to restore its ecological functions. The resultant water-logging may create anoxic conditions, eventually stimulating production and emission of methane, the most important greenhouse gas next to carbon dioxide. We examined the upper layer (~30 cm of Ljubljana marsh soil for microbial processes that would predominate in water-saturated conditions, focusing on the potential for iron reduction, carbon mineralization (CO2 and CH4 production, and methane emission. Methane emission from water-saturated microcosms was near minimum detectable levels even after extended periods of flooding (>5 months. Methane production in anoxic soil slurries started only after a lag period of 84 d at 15°C and a minimum of 7 d at 37°C, the optimum temperature for methanogenesis. This lag was inversely related to iron reduction, which suggested that iron reduction out-competed methanogenesis for electron donors, such as H2 and acetate. Methane production was observed only in samples incubated at 14–38°C. At the beginning of methanogenesis, acetoclastic methanogenesis dominated. In accordance with the preferred substrate, most (91% mcrA (encoding the methyl coenzyme-M reductase, a key gene in methanogenesis clone sequences could be affiliated to the acetoclastic genus Methanosarcina. No methanogens were detected in the original soil. However, a diverse community of iron-reducing Geobacteraceae was found. Our results suggest that methane emission can remain transient and low if water-table fluctuations allow re-oxidation of ferrous iron, sustaining iron reduction as the most important process in terminal carbon mineralization.

  16. Rapid functional definition of extended spectrum β-lactamase activity in bacterial cultures via competitive inhibition of fluorescent substrate cleavage.

    Science.gov (United States)

    Sallum, Ulysses W; Zheng, Xiang; Verma, Sarika; Hasan, Tayyaba

    2010-01-01

    The functional definition of extended-spectrum β-lactamase (ESBL) activity is a clinical challenge. Here we report a rapid and convenient assay of β-lactamase activity through the competitive inhibition of fluorescent substrate hydrolysis that provides a read-out nearly 40× more rapidly than conventional techniques for functional definition. A panel of β-lactam antibiotics was used for competition against β-lactamase enzyme-activated photosensitizer (β-LEAP) yielding a competitive index (C(i)) in 30 min. Significant differences in the relative C(i) values of the panel of β-lactams were determined in vitro for Bacillus cereus penicillinase. Additionally, the relative C(i) values for whole bacterial cell suspensions of B. cereus 5/β were compared with the relative minimal inhibitory concentration (MIC) values and a correlation coefficient of 0.899 was determined. We further demonstrated the ability of β-LEAP to probe the capacity of ceftazidime to inhibit the enzyme activity of a panel of ESBL-producing Escherichia coli. The bacteria were assayed for susceptibility to ceftazidime and the relative MIC values were compared with the relative C(i) values for ceftazidime yielding a correlation coefficient of 0.984. This work demonstrates for the first time the whole cell assay of the competitive inhibition of β-lactamase enzyme activity and derivation of associated constants.

  17. Influence of soil management practices and substrate availability on microbial biomass and its activities in some haplic luvisols

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, Jurgen K. [University Hohenheeim, Stuttgart (Germany)

    1996-07-01

    Soil microbial biomass and activities are sensitive indicators of management effects. Higher contents of microbial biomass and higher activities, for example, are found with crop rotations in contrast to bare fallow and mono culture systems. The main reason for these differences is a higher input of crop and root residues in crop rotation systems, leading to more microbial available substrate. The objectives of this study were to describe indices for microbial available substrate in arable soils depending on management practices, and to relate them with soil microbial biomass and activities. At two locations (Muttergarten and hinger Hof near the University of Hohenheim, Stuttgart, SW-Germany), adenosine triphosphate (ATP) contents and microbial activities were measured in haplic Luviosls. As indices for microbial available substrate, water soluble organic carbon compounds in soils were determined and decomposable young soil organic matter was calculated from organic fertilizers and crop and root residues using empirical decomposition functions. Higher ATP contents and microbial activities were observed along with organic fertilization (liquid cattle manure) than with mineral fertilization. Shallow cultivation with a rotary cultivator led to higher values of microbial properties in the upper part of the Ap horizon than ploughing. Soil microbial parameters were higher in plots under a rape-cereals crop rotation, compared to a legumes-cereals crop rotation. Microbial biomass and its activities were related more closely to decomposable young soil organic matter than to soil humus content or to any other soil property. Water soluble organic carbon compounds did not prove as an indicator of microbial available substrate. [Spanish] La biomasa y la actividad microbianas son indicadores sensibles de los efectos del manejo del suelo. Por ejemplo, con la rotacion de cultivos se obtiene un contenido y una actividad mayores de la biomasa microbiana en contraste con el simple

  18. An EXAFS study of the interaction of substrate with the ferric active site of protocatechuate 3,4-dioxygenase

    Energy Technology Data Exchange (ETDEWEB)

    True, A.E.; Orville, A.M.; Pearce, L.L.; Lipscomb, J.D.; Que, L. Jr. (Univ. of Minnesota, Minneapolis (USA))

    1990-12-01

    X-ray crystallographic studies of the intradiol cleaving protocatechuate 3,4-dioxygenase from Pseudomonas aeruginosa have shown that the enzyme has a trigonal bipyramidal ferric active site with two histidines, two tyrosines, and a solvent molecule as ligands. Fe K-edge EXAFS studies of the spectroscopically similar protocatechuate 3,4-dioxygenase from Brevibacterium fuscum are consistent with a pentacoordinate geometry of the iron active site with 3 O/N ligands at 1.90 {angstrom} and 2 O/N ligands at 2.08 {angstrom}. The 2.08-{angstrom} bonds are assigned to the two histidines, while the 1.90-{angstrom} bonds are associated with the two tyrosines and the coordinated solvent. The short Fe-O distance for the solvent suggests that it coordinates as hydroxide rather than water. When the inhibitor terephthalate is bound to the enzyme, the XANES data indicate that the ferric site becomes 6-coordinate and the EXAFS data show a beat pattern which can only be simulated with an additional Fe-O/N interaction at 2.46 {angstrom}. Together, the data suggest that the oxygens of the carboxylate group in terephthalate displace the hydroxide and chelate to the ferric site but in an asymmetric fashion. In contrast, protocatechuate 3,4-dioxygenase remains 5-coordinate upon the addition of the slow substrate homoprotocatechuic acid (HPCA). Previous EPR data have indicated that HPCA forms an iron chelate via the two hydroxyl functions. For the iron site to remain 5-coordinate and the HPCA to be chelated to the iron, the substrate must displace not only the hydroxide but also a ligand from the protein backbone, probably a histidine. The mechanistic implications of the displacement of hydroxide and a protein ligand in the active site are discussed.

  19. Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases.

    Science.gov (United States)

    Dayalan Naidu, Sharadha; Sutherland, Calum; Zhang, Ying; Risco, Ana; de la Vega, Laureano; Caunt, Christopher J; Hastie, C James; Lamont, Douglas J; Torrente, Laura; Chowdhry, Sudhir; Benjamin, Ivor J; Keyse, Stephen M; Cuenda, Ana; Dinkova-Kostova, Albena T

    2016-09-15

    Heat shock factor 1 (HSF1) monitors the structural integrity of the proteome. Phosphorylation at S326 is a hallmark for HSF1 activation, but the identity of the kinase(s) phosphorylating this site has remained elusive. We show here that the dietary agent phenethyl isothiocyanate (PEITC) inhibits heat shock protein 90 (Hsp90), the main negative regulator of HSF1; activates p38 mitogen-activated protein kinase (MAPK); and increases S326 phosphorylation, trimerization, and nuclear translocation of HSF1, and the transcription of a luciferase reporter, as well as the endogenous prototypic HSF1 target Hsp70. In vitro, all members of the p38 MAPK family rapidly and stoichiometrically catalyze the S326 phosphorylation. The use of stable knockdown cell lines and inhibitors indicated that among the p38 MAPKs, p38γ is the principal isoform responsible for the phosphorylation of HSF1 at S326 in cells. A protease-mass spectrometry approach confirmed S326 phosphorylation and unexpectedly revealed that p38 MAPK also catalyzes the phosphorylation of HSF1 at S303/307, previously known repressive posttranslational modifications. Thus, we have identified p38 MAPKs as highly efficient catalysts for the phosphorylation of HSF1. Furthermore, our findings suggest that the magnitude and persistence of activation of p38 MAPK are important determinants of the extent and duration of the heat shock response. PMID:27354066

  20. Human intestinal P-glycoprotein activity estimated by the model substrate digoxin

    DEFF Research Database (Denmark)

    Larsen, U L; Hyldahl Olesen, L; Nyvold, Charlotte Guldborg;

    2007-01-01

    P-glycoprotein (Pgp) plays a part in the intestinal uptake of xenobiotics and has been associated with susceptibility to ulcerative colitis. The aim of this study was to examine Pgp activity in relation to age, gender, medical treatment (rifampicin or ketoconazole) and the multidrug resistance (M...

  1. B Cell Receptor Activation Predominantly Regulates AKT-mTORC1/2 Substrates Functionally Related to RNA Processing

    Science.gov (United States)

    Mohammad, Dara K.; Ali, Raja H.; Turunen, Janne J.; Nore, Beston F.; Smith, C. I. Edvard

    2016-01-01

    Protein kinase B (AKT) phosphorylates numerous substrates on the consensus motif RXRXXpS/T, a docking site for 14-3-3 interactions. To identify novel AKT-induced phosphorylation events following B cell receptor (BCR) activation, we performed proteomics, biochemical and bioinformatics analyses. Phosphorylated consensus motif-specific antibody enrichment, followed by tandem mass spectrometry, identified 446 proteins, containing 186 novel phosphorylation events. Moreover, we found 85 proteins with up regulated phosphorylation, while in 277 it was down regulated following stimulation. Up regulation was mainly in proteins involved in ribosomal and translational regulation, DNA binding and transcription regulation. Conversely, down regulation was preferentially in RNA binding, mRNA splicing and mRNP export proteins. Immunoblotting of two identified RNA regulatory proteins, RBM25 and MEF-2D, confirmed the proteomics data. Consistent with these findings, the AKT-inhibitor (MK-2206) dramatically reduced, while the mTORC-inhibitor PP242 totally blocked phosphorylation on the RXRXXpS/T motif. This demonstrates that this motif, previously suggested as an AKT target sequence, also is a substrate for mTORC1/2. Proteins with PDZ, PH and/or SH3 domains contained the consensus motif, whereas in those with an HMG-box, H15 domains and/or NF-X1-zinc-fingers, the motif was absent. Proteins carrying the consensus motif were found in all eukaryotic clades indicating that they regulate a phylogenetically conserved set of proteins. PMID:27487157

  2. CYP2D6 genotype determination in the Danish population

    DEFF Research Database (Denmark)

    Brøsen, K; Nielsen, P N; Brusgaard, K;

    1994-01-01

    .741 (0.026) in the Danish population and the second most common allele was the D6-B with an apparent frequency of 0.194 (0.024). The median (range) of the sparteine metabolic ratio (MR) in 47 homozygous D6-wt EM was 0.28 (0.11-4.10) and the corresponding value in heterozygous EM was 0.36 (0...

  3. Thermodynamics of the localized D2-D6 system

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Reino, Marta [Martin Fisher School of Physics, Brandeis University, Waltham, MA 02454 (United States)]. E-mail: marta@brandeis.edu; Naculich, Stephen G. [Department of Physics, Bowdoin College, Brunswick, ME 04011 (United States)]. E-mail: naculich@bowdoin.edu; Schnitzer, Howard J. [Martin Fisher School of Physics, Brandeis University, Waltham, MA 02454 (United States)]. E-mail: schnitzer@brandeis.edu

    2005-05-02

    An exact fully-localized extremal supergravity solution for N{sub 2} D2-branes and N{sub 6} D6-branes, which is dual to 3-dimensional supersymmetric SU(N{sub 2}) gauge theory with N{sub 6} fundamentals, was found by Cherkis and Hashimoto. In order to consider the thermal properties of the gauge theory we present the non-extremal extension of this solution to first order in an expansion near the core of the D6-branes. We compute the Hawking temperature and the black-brane horizon area/entropy. The leading-order entropy, which is proportional to N{sub 2}{sup 3/2}N{sub 6}{sup 1/2}T{sub H}{sup 2}, is not corrected to first order in the expansion. This result is consistent with the analogous weak-coupling result at the correspondence point N{sub 2} similar to N{sub 6}.

  4. Programmable SERS active substrates for chemical and biosensing applications using amorphous/crystalline hybrid silicon nanomaterial

    OpenAIRE

    Jeffery Alexander Powell; Krishnan Venkatakrishnan; Bo Tan

    2016-01-01

    We present the creation of a unique nanostructured amorphous/crystalline hybrid silicon material that exhibits surface enhanced Raman scattering (SERS) activity. This nanomaterial is an interconnected network of amorphous/crystalline nanospheroids which form a nanoweb structure; to our knowledge this material has not been previously observed nor has it been applied for use as a SERS sensing material. This material is formed using a femtosecond synthesis technique which facilitates a laser plu...

  5. CHEMICAL, PHYSICAL AND SENSORY ANALYSIS OF ACTIVITY DIFFERENT YEAST SPECIES ON IDENTICAL SUBSTRATE IN WINE PRODUCTION

    OpenAIRE

    Vladimír Vietoris; Hana Balková,Tatiana Bojňanská; Ľubomír Bennár; Peter Czako

    2013-01-01

    Rizling vlašský is the second most important variety in Slovakia. The science of wine production includes a summary of knowledge and experience in the field of grape growing and wine making, or the production of different types of wines using specific methods of production. Wine quality is the result of the interaction between yeast, bacteria and microscopic funguses. In this research, we studied the effects of active dry wine yeasts on chemical, physical and sensory parameters in wine produc...

  6. Early Activation of Caspases during T Lymphocyte Stimulation Results in Selective Substrate Cleavage in Nonapoptotic Cells

    OpenAIRE

    Alam, Antoine; Cohen, Luchino Y.; Aouad, Salah; Sékaly, Rafick-Pierre

    1999-01-01

    Apoptosis induced by T cell receptor (TCR) triggering in T lymphocytes involves activation of cysteine proteases of the caspase family through their proteolytic processing. Caspase-3 cleavage was also reported during T cell stimulation in the absence of apoptosis, although the physiological relevance of this response remains unclear. We show here that the caspase inhibitor benzyloxycarbonyl (Cbz)-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD) blocks proliferation, major histocompatibility complex...

  7. Structure of Human Acid Sphingomyelinase Reveals the Role of the Saposin Domain in Activating Substrate Hydrolysis.

    Science.gov (United States)

    Xiong, Zi-Jian; Huang, Jingjing; Poda, Gennady; Pomès, Régis; Privé, Gilbert G

    2016-07-31

    Acid sphingomyelinase (ASM) is a lysosomal phosphodiesterase that catalyzes the hydrolysis of sphingomyelin to produce ceramide and phosphocholine. While other lysosomal sphingolipid hydrolases require a saposin activator protein for full activity, the ASM polypeptide incorporates a built-in N-terminal saposin domain and does not require an external activator protein. Here, we report the crystal structure of human ASM and describe the organization of the three main regions of the enzyme: the N-terminal saposin domain, the proline-rich connector, and the catalytic domain. The saposin domain is tightly associated along an edge of the large, bowl-shaped catalytic domain and adopts an open form that exposes a hydrophobic concave surface approximately 30Å from the catalytic center. The calculated electrostatic potential of the enzyme is electropositive at the acidic pH of the lysosome, consistent with the strict requirement for the presence of acidic lipids in target membranes. Docking studies indicate that sphingomyelin binds with the ceramide-phosphate group positioned at the binuclear zinc center and molecular dynamic simulations indicate that the intrinsic flexibility of the saposin domain is important for monomer-dimer exchange and for membrane interactions. Overall, ASM uses a combination of electrostatic and hydrophobic interactions to cause local disruptions of target bilayers in order to bring the lipid headgroup to the catalytic center in a membrane-bound reaction.

  8. Structure of Human Acid Sphingomyelinase Reveals the Role of the Saposin Domain in Activating Substrate Hydrolysis.

    Science.gov (United States)

    Xiong, Zi-Jian; Huang, Jingjing; Poda, Gennady; Pomès, Régis; Privé, Gilbert G

    2016-07-31

    Acid sphingomyelinase (ASM) is a lysosomal phosphodiesterase that catalyzes the hydrolysis of sphingomyelin to produce ceramide and phosphocholine. While other lysosomal sphingolipid hydrolases require a saposin activator protein for full activity, the ASM polypeptide incorporates a built-in N-terminal saposin domain and does not require an external activator protein. Here, we report the crystal structure of human ASM and describe the organization of the three main regions of the enzyme: the N-terminal saposin domain, the proline-rich connector, and the catalytic domain. The saposin domain is tightly associated along an edge of the large, bowl-shaped catalytic domain and adopts an open form that exposes a hydrophobic concave surface approximately 30Å from the catalytic center. The calculated electrostatic potential of the enzyme is electropositive at the acidic pH of the lysosome, consistent with the strict requirement for the presence of acidic lipids in target membranes. Docking studies indicate that sphingomyelin binds with the ceramide-phosphate group positioned at the binuclear zinc center and molecular dynamic simulations indicate that the intrinsic flexibility of the saposin domain is important for monomer-dimer exchange and for membrane interactions. Overall, ASM uses a combination of electrostatic and hydrophobic interactions to cause local disruptions of target bilayers in order to bring the lipid headgroup to the catalytic center in a membrane-bound reaction. PMID:27349982

  9. Carboxy-terminal mutations of bile acid CoA:N-acyltransferase alter activity and substrate specificity.

    Science.gov (United States)

    Styles, Nathan A; Shonsey, Erin M; Falany, Josie L; Guidry, Amber L; Barnes, Stephen; Falany, Charles N

    2016-07-01

    Bile acid CoA:amino acid N-acyltransferase (BAAT) is the terminal enzyme in the synthesis of bile salts from cholesterol and catalyzes the conjugation of taurine or glycine to bile acid CoA thioesters to form bile acid N-acylamidates. BAAT has a dual localization to the cytosol and peroxisomes, possibly due to an inefficient carboxy-terminal peroxisomal targeting signal (PTS), -serine-glutamine-leucine (-SQL). Mutational analysis was used to define the role of the carboxy terminus in peroxisomal localization and kinetic activity. Amidation activity of BAAT and BAAT lacking the final two amino acids (AAs) (BAAT-S) were similar, whereas the activity of BAAT with a canonical PTS sequence (BAAT-SKL) was increased >2.5-fold. Kinetic analysis of BAAT and BAAT-SKL showed that BAAT-SKL had a lower Km for taurine and glycine as well as a greater Vmax There was no difference in the affinity for cholyl-CoA. In contrast to BAAT, BAAT-SKL forms bile acid N-acylamidates with β-alanine. BAAT-S immunoprecipitated when incubated with peroxisomal biogenesis factor 5 (Pex5) and rabbit anti-Pex5 antibodies; however, deleting the final 12 AAs prevented coimmunoprecipitation with Pex5, indicating the Pex5 interaction involves more than the -SQL sequence. These results indicate that even small changes in the carboxy terminus of BAAT can have significant effects on activity and substrate specificity. PMID:27230263

  10. Synthesis of carbon nanofibers on impregnated powdered activated carbon as cheap substrate

    OpenAIRE

    Mamun, A. A.; Y.M. Ahmed; S.A. Muyibi; M.F.R. Al-Khatib; A.T. Jameel; M.A. AlSaadi

    2016-01-01

    The catalysis and characterization of carbon nanofibers (CNFs) composite are reported in this work. Carbon nanofibers were produced on oil palm shell powdered activated carbon (PAC), which was impregnated with nickel. Chemical Vapor Deposition (CVD) of C2H2 was used in the presence of hydrogen at ∼650 °C. The flow rates of carbon source and hydrogen were fixed. The CNFs formed directly on the surface of the impregnated PAC. Variable weight percentages (1%, 3%, 5%, 7% and 9%) of the catalyst s...

  11. Characterization of the Helicase Activity and Substrate Specificity of Mycobacterium tuberculosis UvrD▿

    OpenAIRE

    Curti, Elena; Smerdon, Stephen J; Davis, Elaine O.

    2006-01-01

    UvrD is a helicase that is widely conserved in gram-negative bacteria. A uvrD homologue was identified in Mycobacterium tuberculosis on the basis of the homology of its encoded protein with Escherichia coli UvrD, with which it shares 39% amino acid identity, distributed throughout the protein. The gene was cloned, and a histidine-tagged form of the protein was expressed and purified to homogeneity. The purified protein had in vitro ATPase activity that was dependent upon the presence of DNA. ...

  12. Testing anti-fungal activity of a soil-like substrate for growing plants in bioregenerative life support systems

    Science.gov (United States)

    Nesterenko, E. V.; Kozlov, V. A.; Khizhnyak, S. V.; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.; Liu, Hong; Xing, Yidong; Hu, Enzhu

    2009-10-01

    The object of this research is to study a soil-like substrate (SLS) to grow plants in a Bioregenerative Life Support System (BLSS). Wheat and rice straw were used as raw materials to prepare SLS. Anti-fungal activity of SLS using test cultures of Bipolaris sorokiniana, a plant-pathogenic fungus which causes wheat root rot was studied. Experiments were conducted with SLS samples, using natural soil and sand as controls. Infecting the substrates, was performed at two levels: the first level was done with wheat seeds carrying B. sorokiniana and the second level with seeds and additional conidia of B. sorokiniana from an outside source. We measured wheat disease incidence and severity in two crop plantings. Lowest disease incidence values were obtained from the second planting, SLS: 26% and 41% at the first and the second infection levels, respectively. For soil the values were 60% and 82%, respectively, and for sand they were 67% and 74%, respectively. Wheat root rot in the second crop planting on SLS, at both infection levels was considerably less severe (9% and 13%, respectively) than on natural soil (20% and 33%) and sand (22% and 32%). SLS significantly suppressed the germination of B. sorokiniana conidia. Conidia germination was 5% in aqueous SLS suspension, and 18% in clean water. No significant differences were found regarding the impact on conidia germination between the SLS samples obtained from wheat and rice straw. The anti-fungal activity in SLS increased because of the presence of worms. SLS also contained bacteria stimulating and inhibiting B. sorokiniana growth.

  13. Gamma secretase activating protein is a substrate for caspase-3: implications for Alzheimer’s disease

    Science.gov (United States)

    Chu, Jin; Li, Jian-Guo; Joshi, Yash B.; Giannopoulos, Phillip F.; Hoffman, Nicholas E.; Madesh, Muniswamy; Praticò, Domenico

    2014-01-01

    SUMMARY Background A major hallmark feature of Alzheimer’s disease (AD) is the accumulation of amyloid β (Aβ), whose formation is regulated by the γ-secretase complex and its activating protein (also known as GSAP). Because GSAP interacts with the γ-secretase without affecting the cleavage of Notch, it is an ideal target for a viable anti-Aβ therapy. However, despite much interest in this protein, the mechanisms involved in its neurobiology are not known. Methods Post-mortem brain tissues from AD patients, transgenic mouse models of AD and neuronal cells were used to investigate the molecular mechanism involved in GSAP formation and subsequent amyloidogenesis. Results We identify a caspase-3 processing domain in the GSAP sequence and provide experimental evidence that this caspase is essential for GSAP activation and biogenesis of Aβ peptides. Furthermore, we demonstrate that caspase-3-dependent GSAP formation occurs in brains of individuals with AD and two different mouse models of AD, and that the process is biologically relevant since its pharmacological blockade reduces Aβ pathology in vivo. Interpretation Our data by identifying caspase-3 as the endogenous modulator of GSAP and Aβ production establish it as a novel, attractive and viable Aβ lowering therapeutic target for AD. PMID:25052851

  14. Tracking Dynamics of Plant Biomass Composting by Changes in Substrate Structure, Microbial Community, and Enzyme Activity

    Energy Technology Data Exchange (ETDEWEB)

    Wei, H.; Tucker, M. P.; Baker, J. O.; Harris, M.; Luo, Y. H.; Xu, Q.; Himmel, M. E.; Ding, S. Y.

    2012-04-01

    Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera) wood-chips and mown lawn grass clippings (85:15 in dry-weight) and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP) and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  15. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Directory of Open Access Journals (Sweden)

    Wei Hui

    2012-04-01

    Full Text Available Abstract Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera wood-chips and mown lawn grass clippings (85:15 in dry-weight and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  16. CHEMICAL, PHYSICAL AND SENSORY ANALYSIS OF ACTIVITY DIFFERENT YEAST SPECIES ON IDENTICAL SUBSTRATE IN WINE PRODUCTION

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    Vladimír Vietoris

    2013-02-01

    Full Text Available Rizling vlašský is the second most important variety in Slovakia. The science of wine production includes a summary of knowledge and experience in the field of grape growing and wine making, or the production of different types of wines using specific methods of production. Wine quality is the result of the interaction between yeast, bacteria and microscopic funguses. In this research, we studied the effects of active dry wine yeasts on chemical, physical and sensory parameters in wine production. We have applied five kinds of yeasts (FERMIVIN, FERMIVIN PDV, FERMICRU AR2, FERMIFLOR and FERMICRU VB1. It can be concluded that the application of active dry wine yeasts is beneficial for the production of rizling vlašský. The best showing were yeasts FERMIFLOR and FERMIVIN PDM. In the last sample where they were left the original yeasts the varietal aroma was preserved. It can be noted that the wine was right technologically produced and all wines were harmonious with a pleasant fresh taste.

  17. Active lakes in Antarctica survive on a sedimentary substrate – Part 1: Theory

    Directory of Open Access Journals (Sweden)

    S. P. Carter

    2015-03-01

    Full Text Available Over the past decade satellite observations have revealed that active subglacial lake systems are widespread under the Antarctic ice sheet, including the ice streams, yet we have insufficient understanding of the lake-drainage process to incorporate it into ice sheet models. Process models for drainage of ice-dammed lakes based on conventional "R-channels" incised into the base of the ice through melting are unable to reproduce the timing and magnitude of drainage from Antarctic subglacial lakes estimated from satellite altimetry given the low hydraulic gradients along which such lakes drain. We developed a process model in which channels are mechanically eroded into deformable subglacial sediment (till instead ("T-channel". When applied to the known lakes of the Whillans/Mercer system, the model successfully reproduced the key characteristics of estimated lake volume changes for the period 2003–2009. If our model is realistic, it implies that most active lakes are shallow and only exist in the presence of saturated sediment, explaining why they are difficult to detect with classical radar methods. It also implies that the lake-drainage process is sensitive to the composition and strength of the underlying till, suggesting that models could be improved with a realistic treatment of sediment – interfacial water exchange.

  18. Non-invasive imaging of tumors by monitoring autotaxin activity using an enzyme-activated near-infrared fluorogenic substrate.

    Directory of Open Access Journals (Sweden)

    Damian Madan

    Full Text Available Autotaxin (ATX, an autocrine motility factor that is highly upregulated in metastatic cancer, is a lysophospholipase D enzyme that produces the lipid second messenger lysophosphatidic acid (LPA from lysophosphatidylcholine (LPC. Dysregulation of the lysolipid signaling pathway is central to the pathophysiology of numerous cancers, idiopathic pulmonary fibrosis, rheumatoid arthritis, and other inflammatory diseases. Consequently, the ATX/LPA pathway has emerged as an important source of biomarkers and therapeutic targets. Herein we describe development and validation of a fluorogenic analog of LPC (AR-2 that enables visualization of ATX activity in vivo. AR-2 exhibits minimal fluorescence until it is activated by ATX, which substantially increases fluorescence in the near-infrared (NIR region, the optimal spectral window for in vivo imaging. In mice with orthotopic ATX-expressing breast cancer tumors, ATX activated AR-2 fluorescence. Administration of AR-2 to tumor-bearing mice showed high fluorescence in the tumor and low fluorescence in most healthy tissues with tumor fluorescence correlated with ATX levels. Pretreatment of mice with an ATX inhibitor selectively decreased fluorescence in the tumor. Together these data suggest that fluorescence directly correlates with ATX activity and its tissue expression. The data show that AR-2 is a non-invasive and selective tool that enables visualization and quantitation of ATX-expressing tumors and monitoring ATX activity in vivo.

  19. Detection of Bacillus anthracis Spores Using Peptide Functionalized SERS-Active Substrates

    Directory of Open Access Journals (Sweden)

    Atanu Sengupta

    2012-01-01

    Full Text Available The need for portable technologies that can rapidly identify biological warfare agents (BWAs in the field remains an international priority as expressed at the 2011 Biological Weapons Convention. In recent years, the ability of surface-enhanced Raman spectroscopy (SERS to rapidly detect various BWAs at very low concentrations has been demonstrated. However, in the specific case of Bacillus anthracis, differentiation at the species level is required since other bacilli are common in the environment, representing potential false-positive responses. To overcome this limitation, we describe the use of a peptide attached to the SERS-active metal that selectively binds Bacillus anthracis-Sterne as the target analyte. Using this approach, 109  B. anthracis-Sterne spores/mL produced an intense dipicolinic acid spectrum upon the addition of acetic acid, while the same concentration and treatment of B. cereus and B. subtilis did not.

  20. Diazomethyl ketone substrate derivatives as active-site-directed inhibitors of thiol proteases. Papain

    Energy Technology Data Exchange (ETDEWEB)

    Leary, R.; Larsen, D.; Watanabe, H.; Shaw, E.

    1977-12-27

    The diazomethyl ketones of z-Phe and z-Phe-Phe inactivate papain by a stoichiometric reaction at the active-center thiol. Since the reagents are stable in mercaptoethanol, their reaction with papain is judged to be the result of complex formation characteristic of affinity-labeling reagents. The diazomethyl ketones react by a mechanism different from that of chloromethyl ketones, since the pH dependence of their inactivation of papain is different, the rate increasing with decreasing pH. This relationship has been observed in other cases, such as the reaction of azaserine with glutamine amidotransferases (Buchanan, J. M. (1973), Adv. Enzmol. Relat. Areas Mol. Biol. 39, 91), and is interpreted as an indication of reaction with a thiol group in its protonated form.

  1. The uridine diphosphate glucuronosyltransferases: quantitative structure-activity relationships for hydroxyl polychlorinated biphenyl substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Degao [Dalian University of Technology, Department of Environmental Science and Technology, Dalian (China)

    2005-10-01

    Quantitative structure-activity relationships (QSARs), which relate the glucuronidation of hydroxyl polychlorinated biphenyls (OH-PCBs) - catalyzed by the uridine diphosphate glucuronosyltransferases (UGTs) - to their physicochemical properties and molecular structural parameters, can be used to predict the rate constants and interpret the mechanism of glucuronidation. In this study, QSARs have been developed that use 23 semi-empirical calculated quantum chemical descriptors to predict the logarithms of the constants 1/K{sub m} and V{sub max}, related to enzyme kinetics. A partial least squares regression method was used to select the optimal set of descriptors to minimize the multicollinearity between the descriptors, as well as to maximize the cross-validated coefficient (Q{sup 2} {sub cum}) values. The key descriptors affecting log(1/K{sub m}) were E{sub lumo}- E{sub homo} (the energy gap between the lowest unoccupied molecular orbital and the highest occupied molecular orbital) and q{sub C}{sup -} (the largest negative net atomic charge on a carbon atom), while the key descriptors affecting log V{sub max} were the polarizability {alpha}, the Connolly solvent-excluded volume (CSEV), and logP (the logarithm of the partition coefficient for octanol/water). From the results obtained it can be concluded that hydrophobic and electronic aspects of OH-PCBs are important in the glucuronidation of OH-PCBs. (orig.)

  2. Reactive Oxygen Species (ROS)-Activated ATM-Dependent Phosphorylation of Cytoplasmic Substrates Identified by Large-Scale Phosphoproteomics Screen.

    Science.gov (United States)

    Kozlov, Sergei V; Waardenberg, Ashley J; Engholm-Keller, Kasper; Arthur, Jonathan W; Graham, Mark E; Lavin, Martin

    2016-03-01

    Ataxia-telangiectasia, mutated (ATM) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signaling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoints, initiating DNA repair, and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here, we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach to identify cytoplasmic proteins altered in their phosphorylation state in control and ataxia-telangiectasia (A-T) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites, including 6,686 high-confidence sites mapping to 2,536 unique proteins. A total of 62 differentially phosphorylated peptides were identified; of these, 43 were phosphorylated in control but not in A-T cells, and 19 varied in their level of phosphorylation. Motif enrichment analysis of phosphopeptides revealed that consensus ATM serine glutamine sites were overrepresented. When considering phosphorylation events, only observed in control cells (not observed in A-T cells), with predicted ATM sites phosphoSerine/phosphoThreonine glutamine, we narrowed this list to 11 candidate ATM-dependent cytoplasmic proteins. Two of these 11 were previously described as ATM substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens, and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (oxidative stress responsive 1 (OSR1), HDGF, and ccdc82) as ATM dependent after H2O2 exposure, and another protein (S100A11) demonstrated ATM

  3. Characterization of the Deoxynucleotide Triphosphate Triphosphohydrolase (dNTPase) Activity of the EF1143 Protein from Enterococcus faecalis and Crystal Structure of the Activator-Substrate Complex

    Energy Technology Data Exchange (ETDEWEB)

    Vorontsov, Ivan I.; Minasov, George; Kiryukhina, Olga; Brunzelle, Joseph S.; Shuvalova, Ludmilla; Anderson, Wayne F. (NWU)

    2012-06-19

    The EF1143 protein from Enterococcus faecalis is a distant homolog of deoxynucleotide triphosphate triphosphohydrolases (dNTPases) from Escherichia coli and Thermus thermophilus. These dNTPases are important components in the regulation of the dNTP pool in bacteria. Biochemical assays of the EF1143 dNTPase activity demonstrated nonspecific hydrolysis of all canonical dNTPs in the presence of Mn{sup 2+}. In contrast, with Mg{sup 2+} hydrolysis required the presence of dGTP as an effector, activating the degradation of dATP and dCTP with dGTP also being consumed in the reaction with dATP. The crystal structure of EF1143 and dynamic light scattering measurements in solution revealed a tetrameric oligomer as the most probable biologically active unit. The tetramer contains four dGTP specific allosteric regulatory sites and four active sites. Examination of the active site with the dATP substrate suggests an in-line nucleophilic attack on the {alpha}-phosphate center as a possible mechanism of the hydrolysis and two highly conserved residues, His-129 and Glu-122, as an acid-base catalytic dyad. Structural differences between EF1143 apo and holo forms revealed mobility of the {alpha}3 helix that can regulate the size of the active site binding pocket and could be stabilized in the open conformation upon formation of the tetramer and dGTP effector binding.

  4. Facile synthesis of large-scale Ag nanosheet-assembled films with sub-10 nm gaps as highly active and homogeneous SERS substrates

    Science.gov (United States)

    Li, Zhongbo; Meng, Guowen; Liang, Ting; Zhang, Zhuo; Zhu, Xiaoguang

    2013-01-01

    We report a facile low-cost synthetic approach to large-scale Ag nanosheet-assembled films with a high density of uniformly distributed sub-10 nm gaps between the adjacent nanosheets on Si substrates via galvanic cell reactions. The distribution density of Ag nanosheets on substrates could be tailored by tuning the duration of the HF-etching and the concentration of citric acid in the solution. Furthermore, in conjunction with a conventional photolithography, highly uniform patterned Ag nanosheet-assembled structures with different morphologies can be achieved on Si substrates via galvanic-cell-induced growth. By using rhodamine 6G as a standard test molecule, the large-scale Ag nanosheet-assembled films exhibit highly active and homogenous surface-enhanced Raman scattering (SERS) effect and also show promising potentials as reliable SERS substrates for rapid detection of trace polychlorinated biphenyls (PCBs).

  5. Heterogeneous Antibody-Based Activity Assay for Lysine Specific Demethylase 1 (LSD1) on a Histone Peptide Substrate.

    Science.gov (United States)

    Schmitt, Martin L; Ladwein, Kathrin I; Carlino, Luca; Schulz-Fincke, Johannes; Willmann, Dominica; Metzger, Eric; Schilcher, Pierre; Imhof, Axel; Schüle, Roland; Sippl, Wolfgang; Jung, Manfred

    2014-07-01

    Posttranslational modifications of histone tails are very important for epigenetic gene regulation. The lysine-specific demethylase LSD1 (KDM1A/AOF2) demethylates in vitro predominantly mono- and dimethylated lysine 4 on histone 3 (H3K4) and is a promising target for drug discovery. We report a heterogeneous antibody-based assay, using dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA) for the detection of LSD1 activity. We used a biotinylated histone 3 peptide (amino acids 1-21) with monomethylated lysine 4 (H3K4me) as the substrate for the detection of LSD1 activity with antibody-mediated quantitation of the demethylated product. We have successfully used the assay to measure the potency of reference inhibitors. The advantage of the heterogeneous format is shown with cumarin-based LSD1 inhibitor candidates that we have identified using virtual screening. They had shown good potency in an established LSD1 screening assay. The new heterogeneous assay identified them as false positives, which was verified using mass spectrometry. PMID:24687155

  6. Evaluation of Hydrolytic Activity of Different Pectinases on Sugar Beet (Beta vulgaris Substrate Using FT-MIR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Adina CHIŞ

    2011-11-01

    Full Text Available The aim of this study was to evaluate the pectinase activity of two commercial enzymes Rohament PL and Rohapect 10L, using as substrate the sugar beet pulp, in different conditions. The method applied to check the rate of hydrolysis was Fourier-transformed infrared spectroscopy (FT-MIR, by recording the absorption spectra of different carbohydrates in the specific, MIR (middle IR spectral range (650-4000 cm-1. In order to calibrate the method, it has been recorded the FT-MIR spectrum of standard solutions of glucose, fructose, sucrose and galacturonic acid, at different concentrations, establishing also the peaks and the fingerprint regions specific to these compounds. Considering the specific peak intensities identified for glucose (at 1033 cm-1, fructose (at 1063 cm-1, sucrose (at 995 cm-1, and based on peak area for galacturonic acid (1500-700 cm-1, it has been calculated their concentrations, as a result of the Rohament PL or Rohapect 10L activity. Based on calibration curves for each sugar type, it has been calculated their concentrations in the sugar beet samples, and after their release by enzymatic treatment, establishing an optimized protocol of action for the two enzymes. Differences among the two enzymes activity were identified, specifically their optimum concentration and hydrolysis timing. FT-MIR spectroscopy proves to be an adequate method to evaluate the enzymatic activity of the different enzyme types, having certain advantages in comparison with the chromatographic methods, being a rapid, non-destructive method, at relatively low costs.

  7. Unprecedented access of phenolic substrates to the heme active site of a catalase: substrate binding and peroxidase-like reactivity of Bacillus pumilus catalase monitored by X-ray crystallography and EPR spectroscopy.

    Science.gov (United States)

    Loewen, Peter C; Villanueva, Jacylyn; Switala, Jacek; Donald, Lynda J; Ivancich, Anabella

    2015-05-01

    Heme-containing catalases and catalase-peroxidases catalyze the dismutation of hydrogen peroxide as their predominant catalytic activity, but in addition, individual enzymes support low levels of peroxidase and oxidase activities, produce superoxide, and activate isoniazid as an antitubercular drug. The recent report of a heme enzyme with catalase, peroxidase and penicillin oxidase activities in Bacillus pumilus and its categorization as an unusual catalase-peroxidase led us to investigate the enzyme for comparison with other catalase-peroxidases, catalases, and peroxidases. Characterization revealed a typical homotetrameric catalase with one pentacoordinated heme b per subunit (Tyr340 being the axial ligand), albeit in two orientations, and a very fast catalatic turnover rate (kcat  = 339,000 s(-1) ). In addition, the enzyme supported a much slower (kcat  = 20 s(-1) ) peroxidatic activity utilizing substrates as diverse as ABTS and polyphenols, but no oxidase activity. Two binding sites, one in the main access channel and the other on the protein surface, accommodating pyrogallol, catechol, resorcinol, guaiacol, hydroquinone, and 2-chlorophenol were identified in crystal structures at 1.65-1.95 Å. A third site, in the heme distal side, accommodating only pyrogallol and catechol, interacting with the heme iron and the catalytic His and Arg residues, was also identified. This site was confirmed in solution by EPR spectroscopy characterization, which also showed that the phenolic oxygen was not directly coordinated to the heme iron (no low-spin conversion of the Fe(III) high-spin EPR signal upon substrate binding). This is the first demonstration of phenolic substrates directly accessing the heme distal side of a catalase.

  8. Activation of the ERK1/2 Signaling Pathway during the Osteogenic Differentiation of Mesenchymal Stem Cells Cultured on Substrates Modified with Various Chemical Groups

    Directory of Open Access Journals (Sweden)

    Bing Bai

    2013-01-01

    Full Text Available The current study examined the influence of culture substrates modified with the functional groups –OH, –COOH, –NH2, and –CH3 using SAMs technology, in conjunction with TAAB control, on the osteogenic differentiation of rabbit BMSCs. The CCK-8 assay revealed that BMSCs exhibited substrate-dependent cell viability. The cells plated on –NH2- and –OH-modified substrates were well spread and homogeneous, but those on the –COOH- and –CH3-modified substrates showed more rounded phenotype. The mRNA expression of BMSCs revealed that –NH2-modified substrate promoted the mRNA expression and osteogenic differentiation of the BMSCs. The contribution of ERK1/2 signaling pathway to the osteogenic differentiation of BMSCs cultured on the –NH2-modified substrate was investigated in vitro. The –NH2-modified substrate promoted the expression of integrins; the activation of FAK and ERK1/2. Inhibition of ERK1/2 activation by PD98059, a specific inhibitor of the ERK signaling pathway, blocked ERK1/2 activation in a dose-dependent manner, as revealed for expression of Cbfα-1 and ALP. Blockade of ERK1/2 phosphorylation in BMSCs by PD98059 suppressed osteogenic differentiation on chemical surfaces. These findings indicate a potential role for ERK in the osteogenic differentiation of BMSCs on surfaces modified by specific chemical functional groups, indicating that the microenvironment affects the differentiation of BMSCs. This observation has important implications for bone tissue engineering.

  9. The mechanisms of substrates interaction with the active site of Mycobacterium tuberculosis tyrosyl-tRNA synthetase studied by molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Mykuliak V. V.

    2014-03-01

    Full Text Available Aim. To study the mechanisms of substrates interaction with the active site of Mycobacterium tuberculosis tyrosyl-tRNA synthetase (MtTyrRS. Methods. Complexes of MtTyrRS with tyrosine, ATP and tyrosyl adenylate were constructed by superposition of the MtTyrRS structure and crystallographic structures of bacterial TyrRS. All complexes of MtTyrRS with substrates were investigated by molecular dynamics (MD simulations in solution. Results. It was shown the formation of network of hydrogen bonds between substrates and the MtTyrRS active center, which were stable in the course of MD simulations. ATP binds in the active site both by hydrogen bonds and via electrostatic interactions with Lys231 and Lys234 of catalytic KFGKS motif. Conclusions. The L-tyrosine binding site in the enzyme active site is negatively charged, whereas the ATP binding site contains positive Lys231 and Lys234 residues of catalytic KFGKS motif. The occupancy of H-bonds between substrates and the enzyme evidences a significant conformational mobility of the active site.

  10. Bactericidal Activity of Aqueous Acrylic Paint Dispersion for Wooden Substrates Based on TiO2 Nanoparticles Activated by Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Diana Di Gioia

    2013-08-01

    Full Text Available The photocatalytic effect of TiO2 has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO2, while visible light has been used only in a few applications. In these studies, high concentrations of TiO2, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing low TiO2 content (2 vol % for the inactivation of microorganisms involved in hospital-acquired infections. The nanoparticles and the coating have been characterized using spectroscopic techniques and transmission electron microscopy, showing their homogenous dispersion in the acrylic urethane coating. A common fluorescent light source was used to activate the photocatalytic activity of TiO2. The paint dispersion showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The coating containing the TiO2 nanoparticles maintained good UV stability, strong adhesion to the substrate and high hardness. Therefore, the approach used is feasible for paint formulation aimed at disinfection of healthcare surfaces.

  11. Activity prediction of substrates in NADH-dependent carbonyl reductase by docking requires catalytic constraints and charge parameterization of catalytic zinc environment.

    Science.gov (United States)

    Dhoke, Gaurao V; Loderer, Christoph; Davari, Mehdi D; Ansorge-Schumacher, Marion; Schwaneberg, Ulrich; Bocola, Marco

    2015-11-01

    Molecular docking of substrates is more challenging compared to inhibitors as the reaction mechanism has to be considered. This becomes more pronounced for zinc-dependent enzymes since the coordination state of the catalytic zinc ion is of greater importance. In order to develop a predictive substrate docking protocol, we have performed molecular docking studies of diketone substrates using the catalytic state of carbonyl reductase 2 from Candida parapsilosis (CPCR2). Different docking protocols using two docking methods (AutoDock Vina and AutoDock4.2) with two different sets of atomic charges (AM1-BCC and HF-RESP) for catalytic zinc environment and substrates as well as two sets of vdW parameters for zinc ion were examined. We have selected the catalytic binding pose of each substrate by applying mechanism based distance criteria. To compare the performance of the docking protocols, the correlation plots for the binding energies of these catalytic poses were obtained against experimental Vmax values of the 11 diketone substrates for CPCR2. The best correlation of 0.73 was achieved with AutoDock4.2 while treating catalytic zinc ion in optimized non-bonded (NBopt) state with +1.01 charge on the zinc ion, compared to 0.36 in non-bonded (+2.00 charge on the zinc ion) state. These results indicate the importance of catalytic constraints and charge parameterization of catalytic zinc environment for the prediction of substrate activity in zinc-dependent enzymes by molecular docking. The developed predictive docking protocol described here is in principle generally applicable for the efficient in silico substrate spectra characterization of zinc-dependent ADH.

  12. Serine Hydroxymethyltransferase from the Cold Adapted Microorganism Psychromonas ingrahamii: A Low Temperature Active Enzyme with Broad Substrate Specificity

    Directory of Open Access Journals (Sweden)

    Stefano Pascarella

    2012-01-01

    Full Text Available Serine hydroxymethyltransferase from the psychrophilic microorganism Psychromonas ingrahamii was expressed in Escherichia coli and purified as a His-tag fusion protein. The enzyme was characterized with respect to its spectroscopic, catalytic, and thermodynamic properties. The properties of the psychrophilic enzyme have been contrasted with the characteristics of the homologous counterpart from E. coli, which has been structurally and functionally characterized in depth and with which it shares 75% sequence identity. Spectroscopic measures confirmed that the psychrophilic enzyme displays structural properties almost identical to those of the mesophilic counterpart. At variance, the P. ingrahamii enzyme showed decreased thermostability and high specific activity at low temperature, both of which are typical features of cold adapted enzymes. Furthermore, it was a more efficient biocatalyst compared to E. coli serine hydroxymethyltransferase (SHMT particularly for side reactions. Many β-hydroxy-α-amino acids are SHMT substrates and represent important compounds in the synthesis of pharmaceuticals, agrochemicals and food additives. Thanks to these attractive properties, this enzyme could have a significant potential for biotechnological applications.

  13. The N-terminal hybrid binding domain of RNase HI from Thermotoga maritima is important for substrate binding and Mg2+-dependent activity.

    Science.gov (United States)

    Jongruja, Nujarin; You, Dong-Ju; Kanaya, Eiko; Koga, Yuichi; Takano, Kazufumi; Kanaya, Shigenori

    2010-11-01

    Thermotoga maritima ribonuclease H (RNase H) I (Tma-RNase HI) contains a hybrid binding domain (HBD) at the N-terminal region. To analyze the role of this HBD, Tma-RNase HI, Tma-W22A with the single mutation at the HBD, the C-terminal RNase H domain (Tma-CD) and the N-terminal domain containing the HBD (Tma-ND) were overproduced in Escherichia coli, purified and biochemically characterized. Tma-RNase HI prefers Mg(2+) to Mn(2+) for activity, and specifically loses most of the Mg(2+)-dependent activity on removal of the HBD and 87% of it by the mutation at the HBD. Tma-CD lost the ability to suppress the RNase H deficiency of an E. coli rnhA mutant, indicating that the HBD is responsible for in vivo RNase H activity. The cleavage-site specificities of Tma-RNase HI are not significantly changed on removal of the HBD, regardless of the metal cofactor. Binding analyses of the proteins to the substrate using surface plasmon resonance indicate that the binding affinity of Tma-RNase HI is greatly reduced on removal of the HBD or the mutation. These results indicate that there is a correlation between Mg(2+)-dependent activity and substrate binding affinity. Tma-CD was as stable as Tma-RNase HI, indicating that the HBD is not important for stability. The HBD of Tma-RNase HI is important not only for substrate binding, but also for Mg(2+)-dependent activity, probably because the HBD affects the interaction between the substrate and enzyme at the active site, such that the scissile phosphate group of the substrate and the Mg(2+) ion are arranged ideally.

  14. The formation mechanism and photocatalytic activity of hierarchical NiAl-LDH films on an Al substrate prepared under acidic conditions.

    Science.gov (United States)

    Xue, Li; Cheng, Yingzhi; Sun, Xiuyu; Zhou, Ziyan; Xiao, Xiaoling; Hu, Zhongbo; Liu, Xiangfeng

    2014-03-01

    NiAl-LDH films with hierarchical morphology have been fabricated by immersion of an Al substrate in Ni(2+)-containing solutions under strong acidic conditions, and the growth processes of the films are discussed in this communication. The as-prepared LDH films exhibit high activity in the photocatalytic degradation of organic contaminants. PMID:24445754

  15. High Resolution Nuclear Magnetic Resonance Studies of the Active Site of Chymotrypsin. II. Polarization of Histidine 57 by Substrate Analogues and Competitive Inhibitors

    NARCIS (Netherlands)

    Robillard, G.; Shulman, R.G.

    1974-01-01

    The proton nuclear magnetic resonance signal of the His57-Asp102 hydrogen bonded proton in the charge relay system of chymotrypsinogen A and chymotrypsin Aδ has been monitored to determine the influence of substrate analogues and competitive inhibitors on the electronic state of the active site regi

  16. 2-(Nitroaryl)benzothiazole and benzoxazole derivatives as fluorogenic substrates for the detection of nitroreductase activity in clinically important microorganisms.

    Science.gov (United States)

    Cellier, Marie; Gignoux, Amandine; James, Arthur L; Orenga, Sylvain; Perry, John D; Robinson, Shaun N; Stanforth, Stephen P; Turnbull, Graeme

    2015-12-15

    A series of carboxy-substituted 2-(nitroaryl)benzothiazole derivatives and carboxy-substituted 2-(nitroaryl)benzoxazole derivatives were prepared and evaluated as potential nitroreductase substrates for the purpose of detecting clinically important microorganisms. Several of the substrates produced highly fluorescent colonies with the majority of a panel of 10 Gram-negative bacteria and also with two of a panel of 8 Gram-positive bacteria.

  17. Silver nanocube on gold microplate as a well-defined and highly active substrate for SERS detection.

    Science.gov (United States)

    Xia, Xiaohu; Rycenga, Matthew; Qin, Dong; Xia, Younan

    2013-10-14

    Strong enhancement and good reproducibility in Raman signals are two major requirements for a surface-enhanced Raman scattering (SERS) substrate to be used for sensitive detection of an analyte. Here we report a new type of SERS substrate that was fabricated by depositing a Ag nanocube (AgNC) on the surface of a Au microplate (AuMP). Owing to the strong and reproducible hot spots formed at corner sites of the AgNC in proximity with the AuMP surface, the new substrate showed high sensitivity and reproducibility. Using 1,4-benzenedithiol as a probe, the SERS enhancement factor of a typical "AgNC on AuMP" substrate could reach a level as high as 4.7×10(7). In addition to the high sensitivity and reproducibility, the "AgNC on AuMP" substrate also displayed very good stability. Potential use of the "AgNC on AuMP" substrate was demonstrated by detecting crystal violet with high sensitivity. PMID:24187611

  18. Deep green emission at 570nm from InGaN/GaN MQW active region grown on bulk AlN substrate

    Science.gov (United States)

    Shahedipour-Sandvik, F.; Grandusky, J. R.; Jamil, M.; Jindal, V.; Schujman, S. B.; Schowalter, L. J.; Liu, R.; Ponce, F. A.; Cheung, M.; Cartwright, A.

    2005-09-01

    Relatively intense deep-green/yellow photoluminescence emission at ~600 nm is observed for InGaN/GaN multi quantum well (MQW) structures grown on bulk AlN substrates, demonstrating the potential to extend commercial III-Nitride LED technology to longer wavelengths. Optical spectroscopy has been performed on InGaN MQWs with an estimated In concentration of greater than 50% grown by metalorganic chemical vapor phase epitaxy at 750oC. Temperature- and power-dependence, time-resolved photoluminescence as well as spatially resolved cathodoluminescence measurements and transmission electron microscopy have been applied to understand and elucidate the nature of the mechanism responsible for radiative recombination at 600nm as well as higher energy emission band observed in the samples. A comparison between samples grown on bulk AlN and sapphire substrates indicate a lower degree of compositional and/or thickness fluctuation in the latter case. Our results indicate the presence of alloy compositional fluctuation in the active region despite the lower strain expected in the structure contrary to that of low In composition active regions deposited on bulk GaN substrates. Transient photoluminescence measurements signify a stretched exponential followed by a power decay to best fit the luminescence decay indicative of carrier hopping in the active region. Our results point to the fact that at such high In composition (>30%) InGaN compositional fluctuation is still a dominant effect despite lower strain at the substrate-epi interface.

  19. The investigation of a series of n-hydroxybenzoic acids ( n = p, m, o) on a new surface enhanced Raman scattering active substrate

    Science.gov (United States)

    Wang, Li-Ran; Fang, Yan

    2005-12-01

    Ag nanoparticles, organized on indium tin oxide (ITO) surface, can act as a new surface enhanced Raman scattering (SERS) active substrate as well as a dry electrode. Compared with the traditional SERS-active substrate, its notable advantage is that the microcosmic changes of the film can be reflected by the SERS spectrum during the investigation of the film's electrical and other macroscopic characteristics. To illuminate the above-mentioned property of this new substrate, a series of n-hydroxybenzoic acids ( n-HBA; n = p, m and o) was tested as probe molecules by SERS technique. These SERS spectra indicate that the significant changes of frequencies as well as intensities, respectively, arise from the changes of the adsorption behavior along with the proportional variation of molecules and silver nanoparticles. Excellent SERS signals prove that the silver nanoparticles-coated ITO is a highly SERS-active substrate and can efficiently reflect the microcosmic property of the film, which suggest it has promising potential of being a new technique for further application in the field of thin-film research.

  20. Offshore Substrate

    Data.gov (United States)

    California Department of Resources — This shapefile displays the distribution of substrate types from Pt. Arena to Pt. Sal in central/northern California. Originally this data consisted of seven paper...

  1. Determination of the photocatalytic activity of TiO2 coatings on clay roofing tile substrates methylene blue as model pollutant

    Directory of Open Access Journals (Sweden)

    Skapin Andrea S.

    2009-01-01

    Full Text Available The photocatalytically active mesoporous coatings, based on titanium dioxide sols (Degussa, of the fired clay roofing tiles substrate were prepared by using poly(ethylene glycol (PEG M-600 and M-4000, as the structure directing agents. The coatings were deposited using spray technique followed by thermal treatment. Photocatalytic activity of the TiO2 coatings was evaluated by aqueous solution of methylene blue as model dye, deposited on the top of the coatings, after irradiation with UV light. The results were compared with the photocatalytic efficiency of some commercial self-cleaning products (clay roofing tiles, glass. The newly design coatings showed an interesting decolourisation performance (over 30 % after 24 h. It appeared that the procedure of photocatalytic activity determination, in the case of porous substrates, should be renewed by a preadsorption process.

  2. Chemical probing of the human sirtuin 5 active site reveals its substrate acyl specificity and peptide-based inhibitors.

    Science.gov (United States)

    Roessler, Claudia; Nowak, Theresa; Pannek, Martin; Gertz, Melanie; Nguyen, Giang T T; Scharfe, Michael; Born, Ilona; Sippl, Wolfgang; Steegborn, Clemens; Schutkowski, Mike

    2014-09-26

    Sirtuins are NAD(+)-dependent deacetylases acting as sensors in metabolic pathways and stress response. In mammals there are seven isoforms. The mitochondrial sirtuin 5 is a weak deacetylase but a very efficient demalonylase and desuccinylase; however, its substrate acyl specificity has not been systematically analyzed. Herein, we investigated a carbamoyl phosphate synthetase 1 derived peptide substrate and modified the lysine side chain systematically to determine the acyl specificity of Sirt5. From that point we designed six potent peptide-based inhibitors that interact with the NAD(+) binding pocket. To characterize the interaction details causing the different substrate and inhibition properties we report several X-ray crystal structures of Sirt5 complexed with these peptides. Our results reveal the Sirt5 acyl selectivity and its molecular basis and enable the design of inhibitors for Sirt5. PMID:25111069

  3. 4-Oxalocrotonate tautomerase, its homologue YwhB, and active vinylpyruvate hydratase : Synthesis and evaluation of 2-fluoro substrate analogues

    NARCIS (Netherlands)

    Johnson, William H; Wang, Susan C; Stanley, Thanuja M; Czerwinski, Robert M; Almrud, Jeffrey J; Poelarends, Gerrit J; Murzin, Alexey G; Whitman, Christian P

    2004-01-01

    A series of 2-fluoro-4-alkene and 2-fluoro-4-alkyne substrate analogues were synthesized and examined as potential inhibitors of three enzymes: 4-oxalocrotonate tautomerase (4-OT) and vinylpyruvate hydratase (VPH) from the catechol meta-fission pathway and a closely related 4-OT homologue found in B

  4. Comparison of Peptide Array Substrate Phosphorylation of c-Raf and Mitogen Activated Protein Kinase Kinase Kinase 8

    NARCIS (Netherlands)

    Parikh, Kaushal; Diks, Sander H.; Tuynman, Jurriaan H. B.; Verhaar, Auke; Lowenberg, Mark; Hommes, Daan W.; Joore, Jos; Pandey, Akhilesh; Peppelenbosch, Maikel P.

    2009-01-01

    Kinases are pivotal regulators of cellular physiology. The human genome contains more than 500 putative kinases, which exert their action via the phosphorylation of specific substrates. The determinants of this specificity are still only partly understood and as a consequence it is difficult to pred

  5. Mechanism of the Quorum-Quenching Lactonase (AiiA) from Bacillus thuringiensis. 2. Substrate Modeling and Active Site Mutations

    Energy Technology Data Exchange (ETDEWEB)

    Momb, Jessica; Wang, Canhui; Liu, Dali; Thomas, Pei W.; Petsko, Gregory A.; Guo, Hua; Ringe, Dagmar; Fast, Walter (UNM); (Brandeis); (Texas)

    2008-12-02

    The N-acyl-l-homoserine lactone hydrolases (AHL lactonases) have attracted considerable attention because of their ability to quench AHL-mediated quorum-sensing pathways in Gram-negative bacteria and because of their relation to other enzymes in the metallo-{beta}-lactamase superfamily. To elucidate the detailed catalytic mechanism of AHL lactonase, mutations are made on residues that presumably contribute to substrate binding and catalysis. Steady-state kinetic studies are carried out on both the wild-type and mutant enzymes using a spectrum of substrates. Two mutations, Y194F and D108N, present significant effects on the overall catalysis. On the basis of a high-resolution structural model of the enzyme-product complex, a hybrid quantum mechanical/molecular mechanical method is used to model the substrate binding orientation and to probe the effect of the Y194F mutation. Combining all experimental and computational results, we propose a detailed mechanism for the ring-opening hydrolysis of AHL substrates as catalyzed by the AHL lactonase from Bacillus thuringiensis. Several features of the mechanism that are also found in related enzymes are discussed and may help to define an evolutionary thread that connects the hydrolytic enzymes of this mechanistically diverse superfamily.

  6. 2-Arylbenzothiazole, benzoxazole and benzimidazole derivatives as fluorogenic substrates for the detection of nitroreductase and aminopeptidase activity in clinically important bacteria.

    Science.gov (United States)

    Cellier, Marie; Fabrega, Olivier J; Fazackerley, Elizabeth; James, Arthur L; Orenga, Sylvain; Perry, John D; Salwatura, Vindhya L; Stanforth, Stephen P

    2011-05-01

    A series of 2-(2-nitrophenyl)benzothiazole 7, 2-(2-nitrophenyl)benzoxazole 10 and 2-(2-nitrophenyl)benzimidazole 13 derivatives have been synthesised and assessed as indicators of nitroreductase activity across a range of clinically important Gram negative and Gram positive bacteria. The majority of Gram negative bacteria produced strongly fluorescent colonies with substrates 7 and 10 whereas fluorescence production in Gram positive bacteria was less widespread. The l-alanine 16 and 19 and β-alanine 21 and 23 derivatives have been prepared from 2-(2-aminophenyl)benzothiazole 14 and 2-(2-aminophenyl)benzoxazole 17. These four compounds have been evaluated as indicators of aminopeptidase activity. The growth of Gram positive bacteria was generally inhibited by these substrates but fluorescent colonies were produced with the majority of Gram negative bacteria tested.

  7. Flower-like gold nanostructures electrodeposited on indium tin oxide (ITO) glass as a SERS-active substrate for sensing dopamine

    International Nuclear Information System (INIS)

    Flower-like gold nanostructures (so called gold nanoflowers) were electrodeposited on indium tine oxide (ITO) glass and served as a SERS-active substrate for sensing dopamine. A double-potential method was applied for the deposition of gold nanostructures on the glass. The density, size, and morphology of the gold nanostructures were controlled by adjusting parameters such as deposition potentials, duration, and concentrations of gold precursors. The particle density on the glass was controlled by changing the overvoltage potentials, while the size and morphology were controlled by changing the concentration of gold precursors and growth times of Gold crystal seeds. The intensity of the Raman spectrum of dopamine was distinctly enhanced on the gold nanostructures with unique flower-like topography, thereby demonstrating the utility of this SERS-active substrate that is facilely obtained by the double-potential deposition method without supporting electrolytes. (author)

  8. SLITHER: a web server for generating contiguous conformations of substrate molecules entering into deep active sites of proteins or migrating through channels in membrane transporters.

    Science.gov (United States)

    Lee, Po-Hsien; Kuo, Kuei-Ling; Chu, Pei-Ying; Liu, Eric M; Lin, Jung-Hsin

    2009-07-01

    Many proteins use a long channel to guide the substrate or ligand molecules into the well-defined active sites for catalytic reactions or for switching molecular states. In addition, substrates of membrane transporters can migrate to another side of cellular compartment by means of certain selective mechanisms. SLITHER (http://bioinfo.mc.ntu.edu.tw/slither/or http://slither.rcas.sinica.edu.tw/) is a web server that can generate contiguous conformations of a molecule along a curved tunnel inside a protein, and the binding free energy profile along the predicted channel pathway. SLITHER adopts an iterative docking scheme, which combines with a puddle-skimming procedure, i.e. repeatedly elevating the potential energies of the identified global minima, thereby determines the contiguous binding modes of substrates inside the protein. In contrast to some programs that are widely used to determine the geometric dimensions in the ion channels, SLITHER can be applied to predict whether a substrate molecule can crawl through an inner channel or a half-channel of proteins across surmountable energy barriers. Besides, SLITHER also provides the list of the pore-facing residues, which can be directly compared with many genetic diseases. Finally, the adjacent binding poses determined by SLITHER can also be used for fragment-based drug design.

  9. Development of Novel Rifampicin-Derived P-Glycoprotein Activators/Inducers. Synthesis, In Silico Analysis and Application in the RBE4 Cell Model, Using Paraquat as Substrate

    Science.gov (United States)

    Vilas-Boas, Vânia; Silva, Renata; Palmeira, Andreia; Sousa, Emília; Ferreira, Luísa Maria; Branco, Paula Sério; Carvalho, Félix; Bastos, Maria de Lourdes; Remião, Fernando

    2013-01-01

    P-glycoprotein (P-gp) is a 170 kDa transmembrane protein involved in the outward transport of many structurally unrelated substrates. P-gp activation/induction may function as an antidotal pathway to prevent the cytotoxicity of these substrates. In the present study we aimed at testing rifampicin (Rif) and three newly synthesized Rif derivatives (a mono-methoxylated derivative, MeORif, a peracetylated derivative, PerAcRif, and a reduced derivative, RedRif) to establish their ability to modulate P-gp expression and activity in a cellular model of the rat’s blood–brain barrier, the RBE4 cell line P-gp expression was assessed by western blot using C219 anti-P-gp antibody. P-gp function was evaluated by flow cytometry measuring the accumulation of rhodamine123. Whenever P-gp activation/induction ability was detected in a tested compound, its antidotal effect was further tested using paraquat as cytotoxicity model. Interactions between Rif or its derivatives and P-gp were also investigated by computational analysis. Rif led to a significant increase in P-gp expression at 72 h and RedRif significantly increased both P-gp expression and activity. No significant differences were observed for the other derivatives. Pre- or simultaneous treatment with RedRif protected cells against paraquat-induced cytotoxicity, an effect reverted by GF120918, a P-gp inhibitor, corroborating the observed P-gp activation ability. Interaction of RedRif with P-gp drug-binding pocket was consistent with an activation mechanism of action, which was confirmed with docking studies. Therefore, RedRif protection against paraquat-induced cytotoxicity in RBE4 cells, through P-gp activation/induction, suggests that it may be useful as an antidote for cytotoxic substrates of P-gp. PMID:23991219

  10. Adsorption mechanism of physiologically active L-phenylalanine phosphonodipeptide analogues: Comparison of colloidal silver and macroscopic silver substrates

    Science.gov (United States)

    Podstawka, E.; Kudelski, A.; Proniewicz, L. M.

    2007-11-01

    Here we present SERS spectra of several L-phenylalanine (Phe) phosphonodipeptides, i.e., L-Phe- L-Ala-PO 3H 2 ( MD1), L-Phe- L-Va L-PO 3H 2 ( MD2), L-Phe-β-Ala-CH(OH)-PO 3H 2 ( MD3), L-Phe- L-Ala-CH(OH)-PO 3H 2 ( MD4), L-Ala-(3,4-dimethoxy)- L-Phe-PO 3H 2 ( MD5), and L-Ala-(3,4-dimethoxy)-(des-CH 2)- L-Phe-PO 3H 2 ( MD6), immobilized on electrochemically roughened silver electrodes. These spectra are analyzed by theoretical calculations using density functional theory (DFT) at the B3LYP level with 6-31++G∗∗ basis set. In addition, these spectra are compared with SERS spectra of these species adsorbed on a colloidal silver surface. We showed that on the macroscopic silver substrate, the Phe aromatic ring of MD3 and MD4 is oriented vertically, while for MD1 it almost "stands up" on this surface. In the other three cases, the Phe ring adopts a tilted orientation in regard to the substrate. We also find that the phosphonate (-PO32-), methyl/methane, or dimethoxy groups of MD1, MD2, MD3, MD5, and MD6 are involved in the interaction of these phosphonodipeptides with the electrochemically roughened surface. This phenomenon is clearly seen for -CH 2-/-CH 3/-OCH 3 moieties as well as for the PO32- group that adsorbs on the macroscopic silver substrates mainly via the P dbnd O fragment. We also showed that MD4 binds to the macroscopic silver substrate through the hydroxyl, amine, and phosphonate groups, while the methylene/methane moieties are remote from this surface. We found that studied phosphonodipeptides often adsorb differently on the macroscopic silver substrate and on the colloidal silver nanoparticles. For example, MD1 adopts an almost vertical orientation on the electrochemically roughened silver substrate and is tilted or close to flat on the silver nanoparticles.

  11. Co-activator independent differences in how the metaphase and anaphase APC/C recognise the same substrate

    Directory of Open Access Journals (Sweden)

    Takahiro Matsusaka

    2014-09-01

    Full Text Available The Anaphase Promoting Complex or Cyclosome (APC/C is critical to the control of mitosis. The APC/C is an ubiquitin ligase that targets specific mitotic regulators for proteolysis at distinct times in mitosis, but how this is achieved is not well understood. We have addressed this question by determining whether the same substrate, cyclin B1, is recognised in the same way by the APC/C at different times in mitosis. Unexpectedly, we find that distinct but overlapping motifs in cyclin B1 are recognised by the APC/C in metaphase compared with anaphase, and this does not depend on the exchange of Cdc20 for Cdh1. Thus, changes in APC/C substrate specificity in mitosis can potentially be conferred by altering interaction sites in addition to exchanging Cdc20 for Cdh1.

  12. Post-heparin LPL activity measurement using VLDL as a substrate: a new robust method for routine assessment of plasma triglyceride lipolysis defects.

    Directory of Open Access Journals (Sweden)

    Mathilde Di Filippo

    Full Text Available BACKGROUND: Determination of lipoprotein lipase (LPL activity is important for hyperchylomicronemia diagnosis, but remains both unreliable and cumbersome with current methods. Consequently by using human VLDL as substrate we developed a new LPL assay which does not require sonication, radioactive or fluorescent particles. METHODS: Post-heparin plasma was added to the VLDL substrate prepared by ultracentrifugation of heat inactivated normolipidemic human serums, diluted in buffer, pH 8.15. Following incubation at 37°c, the NEFA (non esterified fatty acids produced were assayed hourly for 4 hours. LPL activity was expressed as µmol/l/min after subtraction of hepatic lipase (HL activity, obtained following LPL inhibition with NaCl 1.5 mmol/l. Molecular analysis of LPL, GPIHBP1, APOA5, APOC2, APOE genes was available for 62 patients. RESULTS: Our method was reproducible (coefficient of variation (CV: intra-assay 5.6%, inter-assay 7.1%, and tightly correlated with the conventional radiolabelled triolein emulsion method (n = 26, r = 0.88. Normal values were established at 34.8 ± 12.8 µmol/l/min (mean ± SD from 20 control subjects. LPL activities obtained from 71 patients with documented history of major hypertriglyceridemia showed a trimodal distribution. Among the 11 patients with a very low LPL activity (10 µmol/l/min. CONCLUSION: This new reproducible method is a valuable tool for routine diagnosis and reliably identifies LPL activity defects.

  13. Energy substrate availability as a determinant of neuronal resting potential, GABA signaling and spontaneous network activity in the neonatal cortex in vitro.

    Science.gov (United States)

    Holmgren, Carl D; Mukhtarov, Marat; Malkov, Anton E; Popova, Irina Y; Bregestovski, Piotr; Zilberter, Yuri

    2010-02-01

    While the ultimate dependence of brain function on its energy supply is evident, how basic neuronal parameters and network activity respond to energy metabolism deviations is unresolved. The resting membrane potential (E(m)) and reversal potential of GABA-induced anionic currents (E(GABA)) are among the most fundamental parameters controlling neuronal excitability. However, alterations of E(m) and E(GABA) under conditions of metabolic stress are not sufficiently documented, although it is well known that metabolic crisis may lead to neuronal hyper-excitability and aberrant neuronal network activities. In this work, we show that in slices, availability of energy substrates determines whether GABA signaling displays an inhibitory or excitatory mode, both in neonatal neocortex and hippocampus. We demonstrate that in the neonatal brain, E(m) and E(GABA) strongly depend on composition of the energy substrate pool. Complementing glucose with ketone bodies, pyruvate or lactate resulted in a significant hyperpolarization of both E(m) and E(GABA), and induced a radical shift in the mode of GABAergic synaptic transmission towards network inhibition. Generation of giant depolarizing potentials, currently regarded as the hallmark of spontaneous neonatal network activity in vitro, was strongly inhibited both in neocortex and hippocampus in the energy substrate enriched solution. Based on these results we suggest the composition of the artificial cerebrospinal fluid, which bears a closer resemblance to the in vivo energy substrate pool. Our results suggest that energy deficits induce unfavorable changes in E(m) and E(GABA), leading to neuronal hyperactivity that may initiate a cascade of pathological events.

  14. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates

    OpenAIRE

    Namratha Pai Kotebagilu; Vanitha Reddy Palvai; Asna Urooj

    2015-01-01

    Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol) of four medicinal plants, Andrographis paniculata, Cost...

  15. α--AMYLASES OF Aspergillus flavus var. oryzae AND Bacillus subtilis: THE SUBSTRATE SPECIFICITY AND RESISTANCE TO A NUMBER OF CHEMICALLY ACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    K. V. Avdiyuk

    2013-06-01

    Full Text Available The ability of Aspergillus flavus var. oryzae 80428 and Bacillus subtilis 147 α-amylases to split different carbohydrate-containing substrates, such as maltose, sucrose, trehalose, dextrin, α- and β-cyclodextrin, amylose, amylopectin, glycogen, pullulan, soluble starch, insoluble starch, corn starch, wheat starch, dextran 500 has been studied. It was shown that investigated enzymes differ by substrate specificity. α-Amylase of A. flavus var. oryzae 80428 rapidly hydrolysed soluble potato and wheat starch, while the α-amylase of B. subtilis 147 — only wheat starch. Both enzymes don’t cleave maltose, α-cyclodextrin and dextran 500. A. flavus var. oryzae 80428 α-amylase display very small ability to hydrolyze pullulan, while α-amylase of B. subtilis 147 it does not act in general. The lowest values of Michaelis constant for both enzymes at splitting of glycogen have been obtained, indicating that enzymes have the greatest affinity to this substrate. The studies of influence of chemically active substances on activity of A. flavus var. oryzae 80428 and B. subtilis 147 ?-amylases show there are resistant to urea, deoxycholic acid, Tween-80, Triton X-100 and hydrogen peroxide. It’s indicate the enzymes tested may be competitive in compare with earlier described in literature enzymes. The obtained results give a possibility to propose in future usage these enzymes in different fields of industry, foremost in detergent industry.

  16. Cleavage Specificity of Mycobacterium tuberculosis ClpP1P2 Protease and Identification of Novel Peptide Substrates and Boronate Inhibitors with Anti-bacterial Activity*

    Science.gov (United States)

    Akopian, Tatos; Kandror, Olga; Tsu, Christopher; Lai, Jack H.; Wu, Wengen; Liu, Yuxin; Zhao, Peng; Park, Annie; Wolf, Lisa; Dick, Lawrence R.; Rubin, Eric J.; Bachovchin, William; Goldberg, Alfred L.

    2015-01-01

    The ClpP1P2 protease complex is essential for viability in Mycobacteria tuberculosis and is an attractive drug target. Using a fluorogenic tripeptide library (Ac-X3X2X1-aminomethylcoumarin) and by determining specificity constants (kcat/Km), we show that ClpP1P2 prefers Met ≫ Leu > Phe > Ala in the X1 position, basic residues or Trp in the X2 position, and Pro ≫ Ala > Trp in the X3 position. We identified peptide substrates that are hydrolyzed up to 1000 times faster than the standard ClpP substrate. These positional preferences were consistent with cleavage sites in the protein GFPssrA by ClpXP1P2. Studies of ClpP1P2 with inactive ClpP1 or ClpP2 indicated that ClpP1 was responsible for nearly all the peptidase activity, whereas both ClpP1 and ClpP2 contributed to protein degradation. Substrate-based peptide boronates were synthesized that inhibit ClpP1P2 peptidase activity in the submicromolar range. Some of them inhibited the growth of Mtb cells in the low micromolar range indicating that cleavage specificity of Mtb ClpP1P2 can be used to design novel anti-bacterial agents. PMID:25759383

  17. Insights into the Activity and Substrate Binding of Xylella fastidiosa Polygalacturonase by Modification of a Unique QMK Amino Acid Motif Using Protein Chimeras.

    Directory of Open Access Journals (Sweden)

    Jeremy G Warren

    Full Text Available Polygalacturonases (EC 3.2.1.15 catalyze the random hydrolysis of 1, 4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. Xylella fastidiosa possesses a single polygalacturonase gene, pglA (PD1485, and X. fastidiosa mutants deficient in the production of polygalacturonase are non-pathogenic and show a compromised ability to systemically infect grapevines. These results suggested that grapevines expressing sufficient amounts of an inhibitor of X. fastidiosa polygalacturonase might be protected from disease. Previous work in our laboratory and others have tried without success to produce soluble active X. fastidiosa polygalacturonase for use in inhibition assays. In this study, we created two enzymatically active X. fastidiosa / A. vitis polygalacturonase chimeras, AX1A and AX2A to explore the functionality of X. fastidiosa polygalacturonase in vitro. The AX1A chimera was constructed to specifically test if recombinant chimeric protein, produced in Escherichia coli, is soluble and if the X. fastidiosa polygalacturonase catalytic amino acids are able to hydrolyze polygalacturonic acid. The AX2A chimera was constructed to evaluate the ability of a unique QMK motif of X. fastidiosa polygalacturonase, most polygalacturonases have a R(I/LK motif, to bind to and allow the hydrolysis of polygalacturonic acid. Furthermore, the AX2A chimera was also used to explore what effect modification of the QMK motif of X. fastidiosa polygalacturonase to a conserved RIK motif has on enzymatic activity. These experiments showed that both the AX1A and AX2A polygalacturonase chimeras were soluble and able to hydrolyze the polygalacturonic acid substrate. Additionally, the modification of the QMK motif to the conserved RIK motif eliminated hydrolytic activity, suggesting that the QMK motif is important for the activity of X. fastidiosa polygalacturonase. This result suggests X. fastidiosa polygalacturonase may preferentially hydrolyze a different

  18. Insights into the Activity and Substrate Binding of Xylella fastidiosa Polygalacturonase by Modification of a Unique QMK Amino Acid Motif Using Protein Chimeras.

    Science.gov (United States)

    Warren, Jeremy G; Lincoln, James E; Kirkpatrick, Bruce C

    2015-01-01

    Polygalacturonases (EC 3.2.1.15) catalyze the random hydrolysis of 1, 4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. Xylella fastidiosa possesses a single polygalacturonase gene, pglA (PD1485), and X. fastidiosa mutants deficient in the production of polygalacturonase are non-pathogenic and show a compromised ability to systemically infect grapevines. These results suggested that grapevines expressing sufficient amounts of an inhibitor of X. fastidiosa polygalacturonase might be protected from disease. Previous work in our laboratory and others have tried without success to produce soluble active X. fastidiosa polygalacturonase for use in inhibition assays. In this study, we created two enzymatically active X. fastidiosa / A. vitis polygalacturonase chimeras, AX1A and AX2A to explore the functionality of X. fastidiosa polygalacturonase in vitro. The AX1A chimera was constructed to specifically test if recombinant chimeric protein, produced in Escherichia coli, is soluble and if the X. fastidiosa polygalacturonase catalytic amino acids are able to hydrolyze polygalacturonic acid. The AX2A chimera was constructed to evaluate the ability of a unique QMK motif of X. fastidiosa polygalacturonase, most polygalacturonases have a R(I/L)K motif, to bind to and allow the hydrolysis of polygalacturonic acid. Furthermore, the AX2A chimera was also used to explore what effect modification of the QMK motif of X. fastidiosa polygalacturonase to a conserved RIK motif has on enzymatic activity. These experiments showed that both the AX1A and AX2A polygalacturonase chimeras were soluble and able to hydrolyze the polygalacturonic acid substrate. Additionally, the modification of the QMK motif to the conserved RIK motif eliminated hydrolytic activity, suggesting that the QMK motif is important for the activity of X. fastidiosa polygalacturonase. This result suggests X. fastidiosa polygalacturonase may preferentially hydrolyze a different pectic substrate or

  19. Nitrification in a zeoponic substrate

    Science.gov (United States)

    McGilloway, R. L.; Weaver, R. W.; Ming, D. W.; Gruener, J. E.

    2003-01-01

    Clinoptilolite is a zeolite mineral with high cation exchange capacity used in zeoponic substrates that have been proposed as a solid medium for growing plants or as a fertilizer material. The kinetics of nitrification has not been measured for NH4+ saturated zeoponic substrate. Experiments were conducted to evaluate the production of NO2- and NO3-, and nitrifier populations in zeoponic substrates. Small columns were filled with zeoponic substrate inoculated with a commercial inoculum or soil enrichment culture of nitrifying bacteria. In addition to column studies, a growth chamber study was conducted to evaluate the kinetics of nitrification in zeoponic substrates used to grow radishes (Raphanus sativus L.). The zeoponic substrate provided a readily available source of NH4+, and nitrifying bacteria were active in the substrate. Ammonium oxidation rates in column studies ranged from 5 to 10 micrograms N g-1 substrate h-1, and NO2- oxidation rates were 2 to 9.5 micrograms N g-1 substrate h-1. Rates determined from the growth chamber study were approximately 1.2 micrograms N g-1 substrate h-1. Quantities of NH4+ oxidized to NO2- and NO3- in inoculated zeoponic substrate were in excess of plant up-take. Acidification as a result of NH4+ oxidation resulted in a pH decline, and the zeoponic substrate showed limited buffering capacity.

  20. Micropatterning of biomolecules on a glass substrate in fused silica microchannels by using photolabile linker-based surface activation

    International Nuclear Information System (INIS)

    We report on a straightforward method for creating micropatterns of multiple biomolecules. The anti-fouling agent 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and a photolabile linker (PL) were covalently linked to an amino-terminated silane surface. Patterns were generated by selective removal of the MPC polymer via UV irradiation. Multiple micropatterns of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (BSA) and rhodamine-labeled goat fragment antigen-binding fragments (FAB) were deposited on a same glass substrate. We also employed micropatterning of multiple biomolecules in that Texas red-labeled BSA and FITC-labeled rabbit anti-mouse IgG were placed inside a microchannel. (author)

  1. Electrochemical biosensor based on enzyme substrate as a linker: Application for aldolase activity with pectin-thionine complex as recognization element and signal amplification probe.

    Science.gov (United States)

    Wang, Xiaonan; Wang, Meiwen; Zhang, Yuanyuan; Miao, Xiaocao; Huang, Yuanyuan; Zhang, Juan; Sun, Lizhou

    2016-09-15

    A new strategy to fabricate electrochemical biosensor is reported based on the linkage of enzyme substrate, thereby an electrochemical method to detect aldolase activity is established using pectin-thionine complex (PTC) as recognization element and signal probe. The linkage effect of fructose-1,6-bisphosphate (FBP), the substrate of aldolase, can be achieved via its strong binding to magnetic nanoparticles (MNPs)/aminophenylboronic acid (APBA) and the formation of phosphoramidate bond derived from its reaction with p-phenylenediamine (PDA) on the surface of electrode. Aldolase can reversibly catalyze the substrates into the products which have no binding capacity with MNPs/APBA, resulting in the exposure of the corresponding binding sites and its subsequent recognization on signal probe. Meanwhile, signal amplification can be accomplished by using the firstly prepared PTC which can bind with MNPs/APBA, and accuracy can be strengthened through magnetic separation. With good precision and accuracy, the established sensor may be extended to other proteins with reversible catalyzed ability. PMID:27107145

  2. Genetic variation in the 3'-UTR of CYP1A2, CYP2B6, CYP2D6, CYP3A4, NR1I2 and UGT2B7: potential effect on regulation by microRNA and pharmacogenomics relevance

    Directory of Open Access Journals (Sweden)

    Marelize eSwart

    2014-06-01

    Full Text Available Introduction: Pharmacogenomics research has concentrated on variation in genes coding for drug metabolising enzymes, transporters and nuclear receptors. However, variation affecting microRNA could also play a role in drug response. This project set out to investigate potential microRNA target sites in 11 genes and the extent of variation in the 3'-UTR of six selected genes; CYP1A2, CYP2B6, CYP2D6, CYP3A4, NR1I2 and UGT2B7. Methods: Fifteen microRNA target prediction algorithms were used to identify microRNAs predicted to regulate 11 genes. The 3'-UTR of the 6 genes which topped the list of potential microRNA targets was sequenced in 30 black South Africans. In addition, genetic variants within these genes were investigated for interference with mRNA-microRNA interactions. Potential effects of observed variants were determined using in silico prediction tools. Results: The 11 genes coding for DMEs, transporters and nuclear receptors were predicted to be targets of microRNAs with CYP2B6, NR1I2 (PXR, CYP3A4 and CYP1A2, interacting with the most microRNAs. The majority of identified genetic variants were predicted to interfere with microRNA regulation. For example, the variant, rs1054190C in NR1I2 was predicted to result in the presence of a binding site for the microRNA miR-1250-5p, while the variant rs1054191G was predicted to result in the absence of a recognition site for miR-371b-3p, miR-4258 and miR-4707-3p. Fifteen of the seventeen, novel variants occurred within microRNA target sequences.Conclusion: The 3'-UTR harbours variation that is likely to influence regulation of specific genes by microRNA. In silico prediction followed by functional validation could aid in decoding the contribution of variation in the 3'-UTR, to some unexplained heritability that affects drug response. Understanding the specific role of each microRNA may lead to identification of markers for targeted therapy and therefore improve personalized drug treatment.

  3. Complex Hydrocarbon Chemistry in Interstellar and Solar System Ices Revealed: A Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry Analysis of Ethane (C2H6) and D6-Ethane (C2D6) Ices Exposed to Ionizing Radiation

    Science.gov (United States)

    Abplanalp, Matthew J.; Kaiser, Ralf I.

    2016-08-01

    The irradiation of pure ethane (C2H6/C2D6) ices at 5.5 K, under ultrahigh vacuum conditions was conducted to investigate the formation of complex hydrocarbons via interaction with energetic electrons simulating the secondary electrons produced in the track of galactic cosmic rays. The chemical modifications of the ices were monitored in situ using Fourier transform infrared spectroscopy (FTIR) and during temperature-programmed desorption via mass spectrometry exploiting a quadrupole mass spectrometer with electron impact ionization (EI-QMS) as well as a reflectron time-of-flight mass spectrometer coupled to a photoionization source (PI-ReTOF-MS). FTIR confirmed previous ethane studies by detecting six molecules: methane (CH4), acetylene (C2H2), ethylene (C2H4), the ethyl radical (C2H5), 1-butene (C4H8), and n-butane (C4H10). However, the TPD phase, along with EI-QMS, and most importantly, PI-ReTOF-MS, revealed the formation of at least 23 hydrocarbons, many for the first time in ethane ice, which can be arranged in four groups with an increasing carbon-to-hydrogen ratio: C n H2n+2 (n = 3, 4, 6, 8, 10), C n H2n (n = 3-10), {{{C}}}n{{{H}}}2n-2 (n = 3-10), and {{{C}}}n{{{H}}}2n-4 (n = 4-6). The processing of simple ethane ices is relevant to the hydrocarbon chemistry in the interstellar medium, as ethane has been shown to be a major product of methane, as well as in the outer solar system. These data reveal that the processing of ethane ices can synthesize several key hydrocarbons such as C3H4 and C4H6 isomers, which ha­ve been found to synthesize polycyclic aromatic hydrocarbons like indene (C9H8) and naphtha­lene (C10H8) in the ISM and in hydrocarbon-rich atmospheres of planets and their moons such as Titan.

  4. Evaluation of polysaccharides content in fruit bodies and their antimicrobial activity of four Ganoderma lucidum (W Curt.: Fr. P. Karst. strains cultivated on different wood type substrates

    Directory of Open Access Journals (Sweden)

    Krystyna Skalicka-Woźniak

    2012-03-01

    Full Text Available Quantitative determination of polysaccharides in Ganoderma lucidum fruit bodies from different sawdust cultivation substrates and their antibacterial activity was done. Thirty six samples were analyzed. Four strains of Ganoderma lucidum (GL01, GL02, GL03 and GL04 were cultivated on the growth substrates of three different sawdust types: birch (Bo, maple (Kl or alder (Ol amended with wheat bran in three different concentrations: 10, 20 and 30% (w/w. Even though the richest in polysaccharides was GL01 strain, the highest yields of the polysaccharides were determined in GL04Kl3 sample and was 112.82 mg/g of dry weight. The antibacterial activity of polysaccharides was determined in vitro using micro-dilution broth method. The panel of eight reference bacterial strains was used. All the polysaccharide samples tested showed the broad spectrum and the moderate antibacterial activity. Micrococcus luteus ATCC 10240 strain was the most sensitive with MIC (minimal inhibitory concentration = 0.63 − 1.25 mg/mL.

  5. Active site directed irreversible inactivation of brewers' yeast pyruvate decarboxylase by the conjugated substrate analogue (E)-4-(4-chlorophenyl)-2-oxo-3-butenoic acid: development of a suicide substrate.

    Science.gov (United States)

    Kuo, D J; Jordan, F

    1983-08-01

    (E)-4-(4-Chlorophenyl)-2-oxo-3-butenoic acid (CPB) was found to irreversibly inactivate brewers' yeast pyruvate decarboxylase (PDC, EC 4.1.1.1) in a biphasic, sigmoidal manner, as is found for the kinetic behavior of substrate. An expression was derived for two-site irreversible inhibition of allosteric enzymes, and the kinetic behavior of CPB fit the expression for two-site binding. The calculated Ki's of 0.7 mM and 0.3 mM for CPB were assigned to the catalytic site and the regulatory site, respectively. The presence of pyruvic acid at high concentrations protected PDC from inactivation, whereas low concentrations of pyruvic acid accelerated inactivation by CPB. Pyruvamide, a known allosteric activator of PDC, was found to enhance inactivation by CPB. The results can be explained if pyruvamide binds only to a regulatory site, but CPB and pyruvic acid compete for both the regulatory and the catalytic centers. [1-14C]CPB was found to lose 14CO2 concurrently with the inactivation of the enzyme. Therefore, CPB was being turned over by PDC, in addition to inactivating it. CPB can be labeled a suicide-type inactivator for PDC.

  6. Intramolecular redox-active ligand-to-substrate single-electron transfer : Radical reactivity with a palladium(II) complex

    NARCIS (Netherlands)

    Broere, Daniël L J; De Bruin, Bas; Reek, Joost N H; Lutz, Martin; Dechert, Sebastian; Van Der Vlugt, Jarl Ivar

    2014-01-01

    Coordination of the redox-active tridentate NNO ligand LH2 to PdII yields the paramagnetic iminobenzosemiquinonato complex 3. Single-electron reduction of 3 yields diamagnetic amidophenolato complex 4, capable of activating aliphatic azide 5. Experimental and computational studies suggest a redox-no

  7. NIR and visible investigation of some potential SERS-active substrates for studying antitumour agent all- trans retinoic acid

    Science.gov (United States)

    Beljebbar, A.; Sockalingum, G. D.; Morjani, H.; Angiboust, J. F.; Manfait, M.

    1997-01-01

    Red and near-infrared excited Fourier transform surface-enhanced Raman spectra of an anticancer agent, all- trans retinoic acid (ATRA), adsorbed on gold island films are reported. Best results have been obtained with plates 80 Å and 40 Å thick respectively in the red and near-infrared and at concentrations of 10 -5 and 5 × 10 -6 M with a spinning system. The use of near-infrared laser excitation with low photon energy, allows us to overcome the problems of isomerisation when the sample is exposed for a long time to the laser radiation. Comparison between the Raman and SERS spectra in the visible shows that the adsorption on the surface does not perturb the structure of ATRA and confirms the long range enhancement of the island films with this type of molecule. Spectral data show that while gold island films and colloids are appropriate substrates for use with red excitation, silver and gold colloids as well as gold island films exhibit satisfactory enhancement levels in the near-infrared. This study will in the future allow us to choose the appropriate system that will serve to investigate the interaction of ATRA with its target in vitro and the effect of this differentiating agent in human leukaemia cell lines such as K562 and HL60.

  8. Activation and control of microlens liquid arrays on functionalized polar electric crystal substrates by electro-wetting effect and temperature

    International Nuclear Information System (INIS)

    In recent years a variety of liquid bases optical elements have been conceived, designed and fabricated even for commercial products like digital cameras o cellular phone cameras. The impressive development of microfluidic systems in conjunction with optics has led to the creation of a completely new Science field of investigation named optofludics. Optofludics, among others topics, deals with investigation and methods for realizing liquid micro-lenses. A variety of liquid micro-lenses have been designed and realized by using different configurations. We demonstrate that a lensing effect can be obtained in an open microfluidic system by using a thin layer of liquid on a polar electric crystal such as Lithium Niobate (LiNbO3). Electrowetting patterning on LiNbO3 surface is obtained by pyroelectric effect consisting in a simple but reliable electrodes-less and circuit-less configuration. The electrodes are intrinsically embedded into the substrate. The material is functionalised by means of a micro-engineering electric filed poling process. Lens array with variable focus has been demonstrated with a large number of lens elements (10x10) on micrometric scale (aperture of single lens 100 microns).

  9. 5´AMP activated protein kinase α2 controls substrate metabolism during post-exercise recovery via regulation of pyruvate dehydrogenase kinase 4

    DEFF Research Database (Denmark)

    Fritzen, Andreas Mæchel; Lundsgaard, Anne-Marie; Jeppesen, Jacob;

    2015-01-01

    after prolonged exercise and during the following six hours post exercise in 5´AMP activated protein kinase (AMPK)α2 and α1 knock-out (KO) and wild type (WT) mice with free access to food. Substrate oxidation was similar during exercise at the same relative intensity between genotypes. During post...... in muscle pyruvate dehydrogenase kinase 4 (PDK4) mRNA expression in WT and AMPKα2 KO was observed following exercise, which is consistent with AMPKα2 -deficiency not affecting the exercise-induced activation of the PDK4 transcriptional regulators, HDAC4 and SIRT1. Interestingly, PDK4 protein content...... increased (63 %, P protein content, lower (P

  10. Identification of in vivo enzyme activities in the cometabolism of glucose and acetate by Saccharomyces cerevisiae by using C-13-labeled substrates

    DEFF Research Database (Denmark)

    Santos, Maria Margarida M. dos; Gombert, A.K.; Christensen, B.;

    2003-01-01

    A detailed characterization of the central metabolic network of Saccharomyces cerevisiae CEN.PK 113-7D was carried out during cometabolism. of different mixtures of glucose and acetate, using aerobic C-limited chemostats in which one of these two substrates was labeled with C-13. To confirm...... the role of malic enzyme, an isogenic strain with the corresponding gene deleted was grown under the same conditions. The labeling patterns of proteinogenic amino acids were analyzed and used to estimate metabolic fluxes and/or make inferences about the in vivo activities of enzymes of the central carbon...... metabolism and amino acid biosynthesis. Malic enzyme flux increased linearly with increasing acetate fraction. During growth on a very-high-acetate fraction, the activity of malic enzyme satisfied the biosynthetic needs of pyruvate in the mitochondria, while in the cytosol pyruvate was supplied via pyruvate...

  11. Fuel-Stimulated Insulin Secretion Depends upon Mitochondria Activation and the Integration of Mitochondrial and Cytosolic Substrate Cycles

    OpenAIRE

    Gary W Cline

    2011-01-01

    The pancreatic islet β-cell is uniquely specialized to couple its metabolism and rates of insulin secretion with the levels of circulating nutrient fuels, with the mitochondrial playing a central regulatory role in this process. In the β-cell, mitochondrial activation generates an integrated signal reflecting rates of oxidativephosphorylation, Kreb's cycle flux, and anaplerosis that ultimately determines the rate of insulin exocytosis. Mitochondrial activation can be regulated by proton leak ...

  12. Nutrition Intensity in Ternary Diagrams Interpretation for Some Ornamental Species Cultivated on Organic Substrate with Increased Biological Activity

    Directory of Open Access Journals (Sweden)

    Roxana Maria MADJAR

    2014-12-01

    Full Text Available Nowadays, many biodegradable organic wastes no longer need to represent an environmental hazard and as a consequence, they could be recycled to obtain horticultural substrates. An experiment was conducted on two deciduous (Tamarix tetrandra, Ligustrum ovalifolium ‘Aureum’ and two coniferous species (Chamaecyparis pisifera ‘Boulevard’, Chamaecyparis lawsoniana ‘Stardust’ grown on a soil mixture of forestry compost, leaves compost, peat and grape marc compost. The aim of the research was to investigate the response to fertilization and to obtain valuable information regarding absorption rate of nutritive elements during vegetation. Nitrogen data show a lowering of its nutritive equilibrium point towards autumn in the leaves of deciduous shrubs species. Resorption of nutrients before leaves fall occurs due to conservation process in woody plants with deciduous leaves. In the case of coniferous species the lowering of nitrogen content is less intense. The monthly fertilization with Coïc solution indicates no influence on nitrogen metabolism of this species. The exception was on Ligustrum with differences between nitrogen content in fertilized and unfertilized plants. The phosphorus nutritive equilibrium point reveals a decrease during the summer months (July - August, the species presenting the lowest values in this period and the cause of this behaviour was the plants adaptation to high temperature and low humidity. Potassium nutritive equilibrium data indicates small differences in the unfertilized plants in comparison with those fertilized in all species. The novelty of the research is represented by the ternary diagrams N-P-K that were constructed, interpreted and reported for dendrologic species.

  13. Insulin Receptor Substrate-1 Activation Mediated p53 Downregulation Protects Against Hypoxic-Ischemia in the Neonatal Brain.

    Science.gov (United States)

    Tu, Yi-Fang; Jiang, Si-Tse; Chow, Yen-Hung; Huang, Chao-Ching; Ho, Chien-Jung; Chou, Ya-Ping

    2016-08-01

    This study determined if dietary restriction (DR) protects against hypoxic-ischemia (HI) in the neonatal brain via insulin receptor substrate-1 (IRS-1)/Akt pathway-mediated downregulation of p53 in the neurovascular unit. On postnatal (P) day 7, HI was induced in rat pups grouped from P1 into normal litter size (NL, 12 pups/dam) and increased litter size (DR, 18 pups/dam). In vivo IRS-1 anti-sense oligonucleotide and IRS-1 overexpressed recombinant adenovirus were given, and neurovascular damage was assessed. In vitro models of oxygen-glucose deprivation (OGD) examined the inhibition and overexpression of IRS-1 on p53 and cell death in neurons and endothelial cells. Compared to NL pups, DR pups had significantly higher IRS-1, p-IRS-1, and pAkt levels, decreased p53, more tight junction proteins, reduced blood-brain barrier (BBB) damage after HI, and less infarct volumes at P21. Immunofluorescence revealed that IRS-1 was upregulated in the endothelial cells and neurons of DR pups. IRS-1 downregulation in DR pups reduced p-Akt, increased p53, worsened BBB damage, and increased brain injury, whereas IRS-1 overexpression in NL pups upregulated p-Akt, decreased p53, attenuated BBB damage, and decreased brain injury. In vitro, IRS-1 downregulation aggravated cell death in neurons and endothelial cells and is associated with decreased p-Akt and increased p53. In contrast, IRS-1 overexpression reduced cell death in endothelial cells with increased p-Akt and decreased p53. In conclusion, DR reduces neurovascular damage after HI in the neonatal brain through an IRS-1/Akt-mediated p53 downregulation, suggesting that IRS-1 signaling is a therapeutic target for hypoxic brain injury in neonates. PMID:26111627

  14. Wrinkled substrate and Indium Tin Oxide-free transparent electrode making organic solar cells thinner in active layer

    Science.gov (United States)

    Liu, Kong; Lu, Shudi; Yue, Shizhong; Ren, Kuankuan; Azam, Muhammad; Tan, Furui; Wang, Zhijie; Qu, Shengchun; Wang, Zhanguo

    2016-11-01

    To enable organic solar cells with a competent charge transport efficiency, reducing the thickness of active layer without sacrificing light absorption efficiency turns out to be of high feasibility. Herein, organic solar cells on wrinkled metal surface are designed. The purposely wrinkled Al/Au film with a smooth surface provides a unique scaffold for constructing thin organic photovoltaic devices by avoiding pinholes and defects around sharp edges in conventional nanostructures. The corresponding surface light trapping effect enables the thin active layer (PTB7-Th:PC71BM) with a high absorption efficiency. With the innovative MoO3/Ag/ZnS film as the top transparent electrode, the resulting Indium Tin Oxide-free wrinkled devices show a power conversion efficiency as 7.57% (50 nm active layer), higher than the planner counterparts. Thus, this paper provides a new methodology to improve the performance of organic solar cells by balancing the mutual restraint factors to a high level.

  15. Multifunctional human transcriptional coactivator protein PC4 is a substrate of Aurora kinases and activates the Aurora enzymes.

    Science.gov (United States)

    Dhanasekaran, Karthigeyan; Kumari, Sujata; Boopathi, Ramachandran; Shima, Hiroki; Swaminathan, Amrutha; Bachu, Mahesh; Ranga, Udaykumar; Igarashi, Kazuhiko; Kundu, Tapas K

    2016-03-01

    Positive coactivator 4 (PC4), a human transcriptional coactivator, is involved in diverse processes like chromatin organization and transcription regulation. It is hyperphosphorylated during mitosis, with unknown significance. For the first time, we demonstrate the function of PC4 outside the nucleus upon nuclear envelope breakdown. A fraction of PC4 associates with Aurora A and Aurora B and undergoes phosphorylation, following which PC4 activates both Aurora A and B to sustain optimal kinase activity to maintain the phosphorylation gradient for the proper functioning of the mitotic machinery. This mitotic role is evident in PC4 knockdown cells where the defects are rescued only by the catalytically active Aurora kinases, but not the kinase-dead mutants. Similarly, the PC4 phosphodeficient mutant failed to rescue such defects. Hence, our observations establish a novel mitotic function of PC4 that might be dependent on Aurora kinase-mediated phosphorylation.

  16. Determination of bacteriocin activity with bioassays carried out on solid and liquid substrates: assessing the factor "indicator microorganism"

    Directory of Open Access Journals (Sweden)

    Ambrosiadis Ioannis

    2006-10-01

    Full Text Available Abstract Background Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried out on solid -agar diffusion assay- and liquid -turbidometric assay- substrates, applied in the quantification of the most studied bacteriocin nisin. Results The performance of characterized microorganisms of known sources, belonging to the genera of Lactobacillus, Pediococcus, Micrococcus and Leuconostoc, has been assessed in this work in the assays of plate agar diffusion and turbidometry. Dose responses and sensitivities were examined and compared over a range of assay variables in standard bacteriocin solutions, fermentation broth filtrates and processed food samples. Measurements on inhibition zones produced on agar plates were made by means of digital image analysis. The data produced were analyzed statistically using the ANOVA technique and pairwise comparisons tests. Sensitivity limits and linearity of responses to bacteriocin varied significantly among different test-microorganisms in both applied methods, the lower sensitivity limits depending on both the test-microorganism and the applied method. In both methods, however, only two of the nine tested microorganisms (Lactobacillus curvatus ATCC 51436 and Pediococcus acidilactici ATCC 25740 were sensitive to very low concentrations of the bacteriocin and produced a linear-type of response in all kinds of samples used in this work. In all cases, very low bacteriocin concentrations, e.g. 1 IU/ml nisin, were more accurately determined in the turbidometric assay. Conclusion The present work shows that in

  17. Sanfilippo D syndrome: Estimation of N-acetylglucosamine-6-sulfatase activity with a radiolabeled monosulfated disaccharide substrate

    International Nuclear Information System (INIS)

    N-Acetylglucosamine-6-sulfatase activity was assayed by incubation of the radiolabeled disaccharide O-(a-N-acetylglucosamine-6-sulfate)-(1----3)-L-[6-3H]-idonic acid (GlcNAc6S-IdOA), with homogenates of leucocytes, cultured fibroblasts, and urine from normal individuals, patients affected with N-acetylglucosamine-6-sulfatase-deficiency (Sanfilippo D syndrome, mucopolysaccharidosis type IIID), and patients affected with other mucopolysaccharidoses and lysosomal storage disorders. The assay clearly distinguished affected homozygotes from their obligate heterozygotes and normal controls and other lysosomal storage disorders. Sulfatase activity in fibroblasts, leucocytes, and urine toward GlcNAc6S-IdOA exhibited a pH optimum at 4.2, 4.5, and 5.1, respectively. Sulfatase activity in fibroblasts had an apparent Km of 7.2 microM and was significantly inhibited by both sulfate and phosphate ions. The action of fibroblast or leucocyte N-acetylglucosamine-6-sulfatase activity toward GlcNAc6S-IdOA is recommended for the routine enzymatic detection and classification of mucopolysaccharidosis type IIID patients

  18. Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine [beta]-synthase

    Energy Technology Data Exchange (ETDEWEB)

    Koutmos, Markos; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma (Michigan-Med)

    2011-08-17

    The catalytic potential for H{sub 2}S biogenesis and homocysteine clearance converge at the active site of cystathionine {beta}-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes {beta}-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H{sub 2}S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 {angstrom}) and an aminoacrylate intermediate (1.55 {angstrom}) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory 'energy-sensing' CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.

  19. Electrocatalytic and photocatalytic activity of Pt-TiO2 films on boron-doped diamond substrate

    Science.gov (United States)

    Spătaru, Tanţa; Marcu, Maria; Spătaru, Nicolae

    2013-03-01

    In the present work boron-doped diamond (BDD) polycrystalline films were used as support for direct anodic deposition of hydrous titanium oxide, and continuous TiO2 coatings were obtained by appropriately adjusting the deposition charge. The photoelectrochemical activity of the TiO2/BDD electrodes was investigated and it was found that, in terms of charge carriers separation efficiency, conductive diamond is a much better support for TiO2, compared to traditional carbonaceous materials such as glassy carbon. Further electrochemical deposition of platinum particles on the oxide-coated conductive diamond enabled the formation of a composite with enhanced electrochemically active surface area. The electrocatalytic and photocatalytic properties of the Pt/TiO2/BDD electrodes thus obtained were also scrutinized and it appeared that these hybrid systems also exhibit promising features for methanol anodic oxidation.

  20. Assay for quantitative determination of CYP1A1 enzyme activity using 7-Ethoxyresorufin as standard substrate (EROD assay)

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Afshin Mohammadi-Bardbori ### Abstract The activity of the enzyme 7-ethoxy-resorufin-O-deethylase (EROD) has been extensively employed in biomonitoring studies of persistent organic pollutants (POPs) for more than a decade. Although the procedure is simple, convenient, sensitive and accurate. The cytochrome P450 monooxygenase 1A (CYP1A) is induced by several planar toxic compounds and endogenous chemicals, and the induction of this protein is often measured in terms of EROD a...

  1. Ser649 and Ser650 are the major determinants of protein kinase A-mediated activation of human hormone-sensitive lipase against lipid substrates.

    Directory of Open Access Journals (Sweden)

    Christian Krintel

    Full Text Available BACKGROUND: Hormone-sensitive lipase (HSL is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA in vitro as well as in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In this study we employed site-directed mutagenesis, in vitro phosphorylation and mass spectrometry to show that in vitro phosphorylation of human HSL by PKA occurs primarily on Ser649 and Ser650 (Ser659 and Ser660 in rat HSL. The wild type enzyme and four mutants were expressed in C-terminally His-tagged form in Sf9 insect cells and purified to homogeneity. HSL variants in which Ser552 and/or Ser554 were mutated to Ala or Glu retained both lipolytic and non-lipolytic activity and were phosphorylated by PKA and activated to a similar extent as the wild type enzyme. (32P-labeling studies revealed that the bulk of the phosphorylation was on the Ser649/Ser650 site, with only a minor phosphorylation of Ser552 and Ser554. MS/MS analysis demonstrated that the peptide containing Ser649 and Ser650 was primarily phosphorylated on Ser650. The mutant lacking all four serines had severely reduced lipolytic activity, but a lesser reduction in non-lipolytic activity, had S(0.5 values for p-nitrophenol butyrate and triolein comparable to those of wild type HSL and was not phosphorylated by PKA. PKA phosphorylation of the wild type enzyme resulted in an increase in both the maximum turnover and S(0,5 using the TO substrate. CONCLUSIONS: Our results demonstrate that PKA activates human HSL against lipid substrates in vitro primarily through phosphorylation of Ser649 and Ser650. In addition the results suggest that Ser649 and Ser650 are located in the vicinity of a lipid binding region and that PKA phosphorylation controls the accessibility of this region.

  2. Expression of constitutively active CDK1 stabilizes APC-Cdh1 substrates and potentiates premature spindle assembly and checkpoint function in G1 cells.

    Directory of Open Access Journals (Sweden)

    Yan Ma

    Full Text Available Mitotic progression in eukaryotic cells depends upon the activation of cyclin-dependent kinase 1 (CDK1, followed by its inactivation through the anaphase-promoting complex (APC/cyclosome-mediated degradation of M-phase cyclins. Previous work revealed that expression of a constitutively active CDK1 (CDK1AF in HeLa cells permitted their division, but yielded G1 daughter cells that underwent premature S-phase and early mitotic events. While CDK1AF was found to impede the sustained activity of APC-Cdh1, it was unknown if this defect improperly stabilized mitotic substrates and contributed to the occurrence of these premature M phases. Here, we show that CDK1AF expression in HeLa cells improperly stabilized APC-Cdh1 substrates in G1-phase daughter cells, including mitotic kinases and the APC adaptor, Cdc20. Division of CDK1AF-expressing cells produced G1 daughters with an accelerated S-phase onset, interrupted by the formation of premature bipolar spindles capable of spindle assembly checkpoint function. Further characterization of these phenotypes induced by CDK1AF expression revealed that this early spindle formation depended upon premature CDK1 and Aurora B activities, and their inhibition induced rapid spindle disassembly. Following its normal M-phase degradation, we found that the absence of Wee1 in these prematurely cycling daughter cells permitted the endogenous CDK1 to contribute to these premature mitotic events, since expression of a non-degradable Wee1 reduced the number of cells that exhibited premature cyclin B1oscillations. Lastly, we discovered that Cdh1-ablated cells could not be forced into a premature M phase, despite cyclin B1 overexpression and proteasome inhibition. Together, these results demonstrate that expression of constitutively active CDK1AF hampers the destruction of critical APC-Cdh1 targets, and that this type of condition could prevent newly divided cells from properly maintaining a prolonged interphase state. We

  3. In situ X-ray scattering of perovskite solar cell active layers roll-to-roll coated on flexible substrates

    DEFF Research Database (Denmark)

    Rossander, Lea Hildebrandt; Larsen-Olsen, Thue T.; Dam, Henrik Friis;

    2016-01-01

    In an effort to understand recent results showing differences between the power conversion efficiencies of lead halide (CH3NH3PbI3-xClx) solar cells on glass versus flexible substrates, this study investigates the influence that substrate and processing methods have on morphological and crystallo......In an effort to understand recent results showing differences between the power conversion efficiencies of lead halide (CH3NH3PbI3-xClx) solar cells on glass versus flexible substrates, this study investigates the influence that substrate and processing methods have on morphological...... crystallographic developments between the substrates, especially seen through the behaviour of a crystalline precursor which survived longer on the flexible substrates than on glass. Additionally, the common degradation product PbI