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Cytochrome P450

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https://www.readbyqxmd.com/read/28930448/direct-observation-of-oxygen-rebound-with-an-iron-hydroxide-complex
#1
Jan Paulo T Zaragoza, Timothy H Yosca, Maxime A Siegler, Pierre Moënne-Loccoz, Michael T Green, David P Goldberg
The rebound mechanism for alkane hydroxylation was invoked over 40 years ago to help explain reactivity patterns in cytochrome P450, and subsequently has been used to provide insight into a range of biological and synthetic systems. Efforts to model the rebound reaction in a synthetic system have been unsuccessful, in part because of the challenge in preparing a suitable metal-hydroxide complex at the correct oxidation level. Herein we report the synthesis of such a complex. The reaction of this species with a series of substituted radicals allows for the direct interrogation of the rebound process, providing insight into this uniformly invoked, but previously unobserved process...
September 20, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28929443/short-term-fasting-alters-pharmacokinetics-of-cytochrome-p450-probe-drugs-does-protein-binding-play-a-role
#2
Laureen A Lammers, Roos Achterbergh, Johannes A Romijn, Ron A A Mathôt
BACKGROUND AND OBJECTIVES: Short-term fasting differentially alters cytochrome P450 (CYP) mediated drug metabolism. This has been established by using CYP-enzyme selective probe drugs. However, the observed effects of fasting on the pharmacokinetics of these probe drugs may also include the effects of altered plasma protein binding of these drugs. Therefore, we studied the effect of short-term fasting on protein binding of five commonly used probe drugs [caffeine (CYP1A2), metoprolol (CYP2D6), midazolam (CYP3A4), omeprazole (CYP2C19) and S-warfarin (CYP2C9)]...
September 19, 2017: European Journal of Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/28928137/recovery-of-cyp3a-phenotype-following-kidney-transplantation
#3
Kristine Hole, Elisabet Storset, Ane Olastuen, Tore Haslemo, Grete Birkeland Kro, Karsten Midtvedt, Anders Asberg, Espen Molden
End-stage renal disease (ESRD) impairs drug metabolism via cytochrome P450 (CYP) 3A. However, it is unclear whether CYP3A activity recovers following kidney transplantation. Therefore, the aim of this study was to evaluate the change in CYP3A activity measured as 4β-hydroxycholesterol (4βOHC) concentration after kidney transplantation. In total, data from 58 renal transplant recipients with 550 prospective 4βOHC measurements were included in the study. One sample per patient was collected before transplantation, and 2-12 samples per patient were collected 1-82 days after transplantation...
September 19, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28927781/function-of-38-variants-cyp2c9-polymorphism-on-ketamine-metabolism-in%C3%A2-vitro
#4
Xiang Zheng, Ping Fang, Su-Su Bao, Dan Lin, Jian-Ping Cai, Guo-Xin Hu
BACKGROUND: Cytochrome P450 proteins (CYP 450) is the most important enzyme system of drug phase I metabolism in liver. In previous reports, reduced efficiency or increased risk of adverse events can be affected by primary sequence mutation in CYP450. AIM: To investigate the effect of gene polymorphism on the metabolism of ketamine in vitro, including the new alleles: 2C9*58, *59 and *60. METHOD: Incubation system which was contained insect microsome, b5, NADPH and 1M PBS incubated 10 μM-1000 μM ketamine in 37 °C for 40 min concentration of norketamine was analyzed by ultra-performance liquid chromatography-tandem mass spectrometry system (UPLC-MS/MS)...
September 1, 2017: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/28926141/working-at-the-membrane-interface-ligand-induced-changes-in-dynamic-conformation-and-oligomeric-structure-in-human-aromatase
#5
Giovanna Di Nardo, Giuseppe Cimicata, Roberta Baravalle, Valentina Dell'Angelo, Alberto Ciaramella, Gianluca Catucci, Piero Ugliengo, Gianfranco Gilardi
Aromatase catalyses the biosynthesis of estrogens from androgens. Due to the physiological importance of this conversion of lipophilic substrates, the interaction with the lipid bilayer for this cytochrome P450 is crucial for its dynamics that must allow an easy access to substrates and inhibitors. Here, aromatase-anastrozole interaction is studied combining computational methods to identify possible access/egress routes with the protein inserted in the membrane and experimental tools aimed at the investigation of the effect of the inhibitor on the protein conformation...
September 19, 2017: Biotechnology and Applied Biochemistry
https://www.readbyqxmd.com/read/28926112/chronic-kidney-disease-and-vitamin-d-metabolism-in-human-bone-marrow-derived-mscs
#6
REVIEW
Shuanhu Zhou, Julie Glowacki
Vitamin D that is synthesized in the skin or is ingested undergoes sequential steps of metabolic activation via a cascade of cytochrome P450 enzymatic hydroxylations in the liver and kidney to produce 1α,25-dihydroxyvitamin D (1α,25(OH)2 D). There are many tissues that are able to synthesize 1α,25(OH)2 D, but the biological significance of extrarenal hydroxylases is unresolved. Human marrow-derived mesenchymal stem cells (marrow stromal cells, hMSCs) give rise to osteoblasts, and their differentiation is stimulated by 1α,25(OH)2 D...
August 2017: Annals of the New York Academy of Sciences
https://www.readbyqxmd.com/read/28924743/a-physiologically-based-pharmacokinetic-model-for-pregnant-women-to-predict-the-pharmacokinetics-of-drugs-metabolized-via-several-enzymatic-pathways
#7
André Dallmann, Ibrahim Ince, Katrin Coboeken, Thomas Eissing, Georg Hempel
BACKGROUND: Physiologically based pharmacokinetic modeling is considered a valuable tool for predicting pharmacokinetic changes in pregnancy to subsequently guide in-vivo pharmacokinetic trials in pregnant women. The objective of this study was to extend and verify a previously developed physiologically based pharmacokinetic model for pregnant women for the prediction of pharmacokinetics of drugs metabolized via several cytochrome P450 enzymes. METHODS: Quantitative information on gestation-specific changes in enzyme activity available in the literature was incorporated in a pregnancy physiologically based pharmacokinetic model and the pharmacokinetics of eight drugs metabolized via one or multiple cytochrome P450 enzymes was predicted...
September 18, 2017: Clinical Pharmacokinetics
https://www.readbyqxmd.com/read/28924501/identification-and-analysis-of-cyp450-genes-from-transcriptome-of-lonicera-japonica-and-expression-analysis-of-chlorogenic-acid-biosynthesis-related-cyp450s
#8
Xiwu Qi, Xu Yu, Daohua Xu, Hailing Fang, Ke Dong, Weilin Li, Chengyuan Liang
BACKGROUND: Lonicera japonica is an important medicinal plant that has been widely used in traditional Chinese medicine for thousands of years. The pharmacological activities of L. japonica are mainly due to its rich natural active ingredients, most of which are secondary metabolites. CYP450s are a large, complex, and widespread superfamily of proteins that participate in many endogenous and exogenous metabolic reactions, especially secondary metabolism. Here, we identified CYP450s in L...
2017: PeerJ
https://www.readbyqxmd.com/read/28923870/associations-between-voriconazole-therapeutic-drug-monitoring-toxicity-and-outcome-in-liver-transplant-patients-an-observational-study
#9
Zahra Hashemizadeh, Parisa Badiee, Seyed Ali Malekhoseini, Hadi Raeisi Shahraki, Bita Geramizadeh, Hashem Montaseri
The aim of this study was to investigate the variability of voriconazole plasma level and its relationship with clinical outcomes and adverse events, among liver transplant recipients to optimize the efficacy and safety of their treatment. Liver transplant recipients treated with voriconazole were included and voriconazole trough levels were quantified by the validated high-performance liquid chromatography method. Cytochrome P450 genotypes of CYP2C19 were evaluated in allograft liver tissues. A total of 832 voriconazole trough levels from 104 patients were measured...
September 18, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28923019/evolutionary-history-and-functional-divergence-of-the-cytochrome-p450-gene-superfamily-between-arabidopsis-thaliana-and-brassica-species-uncover-effects-of-whole-genome-and-tandem-duplications
#10
Jingyin Yu, Sadia Tehrim, Linhai Wang, Komivi Dossa, Xiurong Zhang, Tao Ke, Boshou Liao
BACKGROUND: The cytochrome P450 monooxygenase (P450) superfamily is involved in the biosynthesis of various primary and secondary metabolites. However, little is known about the effects of whole genome duplication (WGD) and tandem duplication (TD) events on the evolutionary history and functional divergence of P450s in Brassica after splitting from a common ancestor with Arabidopsis thaliana. RESULTS: Using Hidden Markov Model search and manual curation, we detected that Brassica species have nearly 1...
September 18, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28922349/cytochrome-p450-and-flavin-containing-monooxygenase-families-age-dependent-differences-in-expression-and-functional-activity
#11
Nicole R Zane, Yao Chen, Michael Zhuo Wang, Dhiren R Thakker
BACKGROUND: Age-dependent differences in pharmacokinetics exist for metabolically cleared medications. Differential contributions in the cytochrome P450 3A (CYP3A), CYP2C, and flavin-containing monooxygenases (FMO) families play an important role in the metabolic clearance of a large number of drugs administered to children. METHODS: Unlike previous semi-quantitative characterization of age-dependent changes in the expression of genes and proteins (Western Analysis), this study quantifies both gene and absolute protein expression in the same fetal, pediatric and adult hepatic tissue...
September 18, 2017: Pediatric Research
https://www.readbyqxmd.com/read/28921992/a-mechanistic-understanding-of-the-synergistic-potential-of-azole-fungicides-in-the-aquatic-invertebrate-gammarus-pulex
#12
Andrea Rösch, Michele Gottardi, Caroline Vignet, Nina Cedergreen, Juliane Hollender
Azole fungicides are known inhibitors of the important enzyme class cytochrome P450 monooxygenases (CYPs), thereby influencing the detoxification of co-occurring substances via biotransformation. This synergism in mixtures containing an azole has mostly been studied by effect measurements, while the underlying mechanism has been less well investigated. In this study, six azole fungicides (cyproconazole, epoxiconazole, ketoconazole, prochloraz, propiconazole and tebuconazole) were selected to investigate their synergistic potential and their CYP inhibition strength in the aquatic invertebrate Gammarus pulex...
September 18, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28921805/cytochrome-p450-diversification-and-hostplant-utilization-patterns-in-specialist-and-generalist-moths-birth-death-and-adaptation
#13
Bernarda Calla, Katherine Noble, Reed M Johnson, Kimberly K O Walden, Mary A Schuler, Hugh M Robertson, May R Berenbaum
Across insect genomes, the size of the cytochrome P450 monooxygenase (CYP) gene superfamily varies widely. CYPome size variation has been attributed to reciprocal adaptive radiations in insect detoxification genes in response to plant biosynthetic gene radiations driven by coevolution between herbivores and their chemically defended hostplants. Alternatively, variation in CYPome size may be due to random "birth and death" processes, whereby exponential increase via gene duplications is limited by random decay via gene death or transition via divergence...
September 15, 2017: Molecular Ecology
https://www.readbyqxmd.com/read/28920579/point-of-care-companion-diagnostic-tests-for-personalizing-psychiatric-medications-fulfilling-an-unmet-clinical-need
#14
Anil S Modak
Over the last decade stable isotope labeled substrates have been used as probes for rapid, point of care, non invasive and user friendly phenotype breath tests to evaluate activity of drug metabolizing enzymes. These diagnostic breath tests can be potentially used as Companion diagnostics (CDx) by physicians to personalize medications especially psychiatric drugs with narrow therapeutic windows, to monitor the progress of disease severity, medication efficacy and to study in vivo the pharmacokinetics of xenobiotics, Several genotype tests have been approved by the FDA over the last 15 years, however, they have not been cleared for use in personalizing medications since they fall woefully short in identifying all non responders to drugs especially for the CYP450 enzymes...
September 18, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28919712/recent-developments-in-the-clinical-pharmacology-of-rolapitant-subanalyses-in-specific-populations
#15
REVIEW
Bernardo Leon Rapoport, Matti Aapro, Martin R Chasen, Karin Jordan, Rudolph M Navari, Ian Schnadig, Lee Schwartzberg
Knowledge of the involvement of the neurokinin substance P in emesis has led to the development of the neurokinin-1 receptor antagonists (NK-1 RAs) for control of chemotherapy-induced nausea and vomiting (CINV), in combination with serotonin type 3 receptor antagonists and corticosteroids. The NK-1 RA rolapitant, recently approved in oral formulation, has nanomolar affinity for the NK-1 receptor, as do the other commercially available NK-1 RAs, aprepitant and netupitant. Rolapitant is rapidly absorbed and has a long half-life in comparison to aprepitant and netupitant...
2017: Drug Design, Development and Therapy
https://www.readbyqxmd.com/read/28919450/seasonal-expression-of-p450c17-and-5%C3%AE-reductase-2-in-the-scented-gland-of-male-muskrats-ondatra-zibethicus
#16
Wentao Han, Wenqian Xie, Yan Zhang, Fengwei Zhang, Haolin Zhang, Yingying Han, Zhengrong Yuan, Qiang Weng
Cytochrome P450 17A1 (P450c17) is the key enzyme required for the production of androgenic sex steroids by converting progestogens to androgens. 5α-reductases are enzymes that convert testosterone (T) to dihydrotestosterone (DHT), which has a greater affinity for androgen receptors (AR) and stronger action than T. Our previous studies revealed that the scented glands of male muskrats expressed AR during the breeding and nonbreeding seasons. To further seek evidence of the activities of androgens in scented glands, the expression patterns of P450c17 and 5α-reductase 2 were investigated in the scented glands of male muskrats during the breeding and nonbreeding seasons...
September 14, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28919358/perfused-human-hepatocyte-microtissues-identify-reactive-metabolite-forming-and-mitochondria-perturbing-hepatotoxins
#17
Cliff Rowe, Mohsen Shaeri, Emma Large, Terri Cornforth, Angela Robinson, Tomasz Kostrzewski, Rowena Sison-Young, Christopher Goldring, Kevin Park, David Hughes
Hepatotoxins cause liver damage via many mechanisms but the formation of reactive metabolites and/or damage to liver mitochondria are commonly implicated. We assess 3D human primary hepatocyte microtissues as a platform for hepatotoxicity studies with reactive metabolite-forming and mitochondria-perturbing compounds. We show that microtissues formed from cryopreserved human hepatocytes had bile canaliculi, transcribed mRNA from genes associated with xenobiotic metabolism and expressed functional cytochrome P450 enzymes...
September 15, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28919040/heme-binding-biguanides-target-cytochrome-p450-dependent-cancer-cell-mitochondria
#18
Zhijun Guo, Irina F Sevrioukova, Ilia G Denisov, Xia Zhang, Ting-Lan Chiu, Dafydd G Thomas, Eric A Hanse, Rebecca A D Cuellar, Yelena V Grinkova, Vanessa Wankhede Langenfeld, Daniel S Swedien, Justin D Stamschror, Juan Alvarez, Fernando Luna, Adela Galván, Young Kyung Bae, Julia D Wulfkuhle, Rosa I Gallagher, Emanuel F Petricoin, Beverly Norris, Craig M Flory, Robert J Schumacher, M Gerard O'Sullivan, Qing Cao, Haitao Chu, John D Lipscomb, William M Atkins, Kalpna Gupta, Ameeta Kelekar, Ian A Blair, Jorge H Capdevila, John R Falck, Stephen G Sligar, Thomas L Poulos, Gunda I Georg, Elizabeth Ambrose, David A Potter
The mechanisms by which cancer cell-intrinsic CYP monooxygenases promote tumor progression are largely unknown. CYP3A4 was unexpectedly associated with breast cancer mitochondria and synthesized arachidonic acid (AA)-derived epoxyeicosatrienoic acids (EETs), which promoted the electron transport chain/respiration and inhibited AMPKα. CYP3A4 knockdown activated AMPKα, promoted autophagy, and prevented mammary tumor formation. The diabetes drug metformin inhibited CYP3A4-mediated EET biosynthesis and depleted cancer cell-intrinsic EETs...
August 29, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28918158/recombinant-expression-and-characterization-of-lucilia-cuprina-cyp6g3-activity-and-binding-properties-toward-multiple-pesticides
#19
Matthew J Traylor, Jong-Min Baek, Katelyn E Richards, Roberto Fusetto, W Huang, Peter Josh, Zhengzhong Chen, Padma Bollapragada, Richard A J O'Hair, Philip Batterham, Elizabeth M J Gillam
The Australian sheep blowfly, Lucilia cuprina, is a primary cause of sheep flystrike and a major agricultural pest. Cytochrome P450 enzymes have been implicated in the resistance of L. cuprina to several classes of insecticides. In particular, CYP6G3 is a L. cuprina homologue of Drosophila melanogaster CYP6G1, a P450 known to confer multi-pesticide resistance. To investigate the basis of resistance, a bicistronic Escherichia coli expression system was developed to co-express active L. cuprina CYP6G3 and house fly (Musca domestica) P450 reductase...
September 13, 2017: Insect Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28917943/chronic-fluoride-exposure-exacerbates-headkidney-pathology-and-causes-immune-commotion-in-clarias-gariepinus
#20
Rashmi Singh, Md Arafat Hussain, Jai Kumar, Manmohan Kumar, Usha Kumari, Shibnath Mazumder
The current study was aimed to understand the effects of chronic fluoride exposure on fish immune system. African sharp tooth catfish (Clarias gariepinus) were exposed to 73.45mg/L of fluoride corresponding to 1/10 96h LC50 for 30 d and the effects on general fish health and several immune parameters were studied. Chronic fluoride exposure led to significant alteration in serum biochemical parameters including alkaline phosphatase, alanine transaminase, aspartate transaminase, triglycerides, cholesterol and blood urea nitrogen levels revealing the detrimental effect of fluoride on general fish health...
September 6, 2017: Aquatic Toxicology
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