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Cytochrome P450

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https://www.readbyqxmd.com/read/28644476/enantioselective-intermolecular-benzylic-c-h-amination-catalysed-by-an-engineered-iron-haem-enzyme
#1
Christopher K Prier, Ruijie K Zhang, Andrew R Buller, Sabine Brinkmann-Chen, Frances H Arnold
C-H bonds are ubiquitous structural units of organic molecules. Although these bonds are generally considered to be chemically inert, the recent emergence of methods for C-H functionalization promises to transform the way synthetic chemistry is performed. The intermolecular amination of C-H bonds represents a particularly desirable and challenging transformation for which no efficient, highly selective, and renewable catalysts exist. Here we report the directed evolution of an iron-containing enzymatic catalyst-based on a cytochrome P450 monooxygenase-for the highly enantioselective intermolecular amination of benzylic C-H bonds...
July 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28644466/characterization-of-a-selenocysteine-ligated-p450-compound-i-reveals-direct-link-between-electron-donation-and-reactivity
#2
Elizabeth L Onderko, Alexey Silakov, Timothy H Yosca, Michael T Green
Strong electron-donation from the axial thiolate ligand of cytochrome P450 has been proposed to increase the reactivity of compound I with respect to C-H bond activation. However, it has proven difficult to test this hypothesis, and a direct link between reactivity and electron donation has yet to be established. To make this connection, we have prepared a selenolate-ligated cytochrome P450 compound I intermediate. This isoelectronic perturbation allows for direct comparisons with the wild-type enzyme. Selenium incorporation was achieved using a cysteine auxotrophic Escherichia coli strain...
July 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28642763/rootstock-sub-optimal-temperature-tolerance-determines-transcriptomic-responses-after-long-term-root-cooling-in-rootstocks-and-scions-of-grafted-tomato-plants
#3
Georgia Ntatsi, Dimitrios Savvas, Vassilis Papasotiropoulos, Anastasios Katsileros, Rita M Zrenner, Dirk K Hincha, Ellen Zuther, Dietmar Schwarz
Grafting of elite cultivars onto tolerant rootstocks is an advanced strategy to increase tomato tolerance to sub-optimal temperature. However, a detailed understanding of adaptive mechanisms to sub-optimal temperature in rootstocks and scions of grafting combinations on a physiological and molecular level is lacking. Here, the commercial cultivar Kommeet was grafted either onto 'Moneymaker' (sensitive) or onto the line accession LA 1777 of Solanum habrochaites (tolerant). Grafted plants were grown in NFT-system at either optimal (25°C) or sub-optimal (15°C) temperatures in the root environment with optimal air temperature (25°C) for 22 days...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28642370/in-vitro-cytochrome-p450-46a1-cyp46a1-activation-by-neuroactive-compounds
#4
Natalia Mast, Kyle W Anderson, Kevin M Johnson, Thanh T N Phan, F Peter Guengerich, Irina A Pikuleva
Cytochrome P450 46A1 (CYP46A1, cholesterol 24-hydroxylase) is the enzyme responsible for the majority of cholesterol elimination from the brain. Previously, we found that the anti-HIV drug efavirenz (EFV) can pharmacologically activate CYP46A1 in mice. Herein, we investigated whether CYP46A1 could also be activated by endogenous compounds, including major neurotransmitters. In vitro experiments with purified recombinant CYP46A1 indicated that CYP46A1 is activated by L-glutamate (L-Glu), L-aspartate, γ-aminobutyric acid, and acetylcholine, with L-Glu eliciting the highest increase (3-fold) in CYP46A1-mediated cholesterol 24-hydroxylation...
June 22, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28642117/soluble-epoxide-hydrolase-as-a-therapeutic-target-for-pain-inflammatory-and-neurodegenerative-diseases
#5
REVIEW
Karen M Wagner, Cindy B McReynolds, William K Schmidt, Bruce D Hammock
Eicosanoids are biologically active lipid signaling molecules derived from polyunsaturated fatty acids. Many of the actions of eicosanoid metabolites formed by cyclooxygenase and lipoxygenase enzymes have been characterized, however, the epoxy-fatty acids (EpFAs) formed by cytochrome P450 enzymes are newly described by comparison. The EpFA metabolites modulate a diverse set of physiologic functions that include inflammation and nociception among others. Regulation of EpFAs occurs primarily via release, biosynthesis and enzymatic transformation by the soluble epoxide hydrolase (sEH)...
June 19, 2017: Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28641720/fenofibrate-attenuates-hypertension-in-goldblatt-hypertensive-rats-role-of-20-hydroxyeicosatetraenoic-acid-in-the-nonclipped-kidney
#6
Alexandra Sporková, Věra Čertíková Chábová, Šárka Doleželová, Šárka Jíchová, Libor Kopkan, Zdeňka Vaňourková, Elzbieta Kompanowska-Jezierska, Janusz Sadowski, Hana Maxová, Luděk Červenka
BACKGROUND: There is vast evidence that the renin-angiotensin system is not the sole determinant of blood pressure (BP) elevation in human renovascular hypertension or the relevant experimental models. This study tested the hypothesis that kidney deficiency of 20-hydroxyeicosatetraenoic acid (20-HETE), a product of cytochrome P450 (CYP)-dependent ω-hydroxylase pathway of arachidonic acid metabolism, is important in the pathophysiology of the maintenance phase of 2-kidney, 1-clip (2K1C) Goldblatt hypertension...
June 2017: American Journal of the Medical Sciences
https://www.readbyqxmd.com/read/28641195/biotransformation-in-the-zebrafish-embryo-temporal-gene-transcription-changes-of-cytochrome-p450-enzymes-and-internal-exposure-dynamics-of-the-ahr-binding-xenobiotic-benz-a-anthracene
#7
Agnes Kühnert, Carolina Vogs, Bettina Seiwert, Silke Aulhorn, Rolf Altenburger, Henner Hollert, Eberhard Küster, Wibke Busch
Not much is known about the biotransformation capability of zebrafish (Danio rerio) embryos. For understanding possible toxicity differences to adult fish, it might be crucial to understand the biotransformation of chemicals in zebrafish embryos i.e. as part of toxicokinetics. The biotransformation capabilities were analysed for two different stages of zebrafish embryos in conjunction with the internal concentrations of a xenobiotic. Zebrafish embryos of the late cleavage/early blastula period (2-26 hpf) and the early pharyngula period (26-50 hpf) were exposed for 24 h to the AhR binding compound benz[a]anthracene (BaA)...
June 19, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28640934/substrate-specificity-and-safener-inducibility-of-the-plant-udp-glucose-dependent-family-1-glycosyltransferases-super-family
#8
Melissa Brazier-Hicks, Markus Gershater, David Dixon, Robert Edwards
Plants contain large numbers of family 1 UDP-glucose dependent glycosyltransferases (UGTs), including members that conjugate xenobiotics. Arabidopsis contains 107 UGT genes with 99 family members successfully expressed as glutathione transferase (GST)-fusion proteins in E.coli. A high-throughput catalytic screen was developed based on quantification of the fusion by measuring GST activity. UGT activity using UDP-glucose as donor was then determined using 11 synthetic acceptors bearing hydroxyl, amino and thiol groups that had been shown to undergo conjugation in plant extracts...
June 22, 2017: Plant Biotechnology Journal
https://www.readbyqxmd.com/read/28640225/herb-drug-interaction-between-the-traditional-hepatoprotective-formulation-and-sorafenib-on-hepatotoxicity-histopathology-and-pharmacokinetics-in-rats
#9
Chin-Tsung Ting, Yung-Yi Cheng, Tung-Hu Tsai
Sorafenib has been used as a standard therapy for advanced hepatocellular carcinoma (HCC). In Asia, patients with HCC are potentially treated with the combination of sorafenib and Chinese herbal medicines to improve the efficiency and reduce the side effects of sorafenib. However, limited information about the herb-drug interactions is available. We hypothesize that the Chinese herbal medicine may exert hepatoprotective effects on the sorafenib-treated group. The aim of this study is to investigate the pharmacokinetic mechanism of drug-drug interactions of sorafenib including interacting with hepatoprotective formulation, Long-Dan-Xie-Gan-Tang formulation (LDXGT) and with two cytochrome P450 3A4 (CYP3A4) inhibitors, grapefruit juice and ketoconazole...
June 22, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28639697/determination-of-metabolic-resistance-mechanisms-in-pyrethroid-resistant-and-fipronil-tolerant-brown-dog-ticks
#10
A L Eiden, P E Kaufman, F M Oi, M J Dark, J R Bloomquist, R J Miller
Rhipicephalus sanguineus (Latreille) (Ixodida: Ixodidae) is a three-host dog tick found worldwide that is able to complete its' entire lifecycle indoors. Options for the management of R. sanguineus are limited and its' control relies largely on only a few acaricidal active ingredients. Previous studies have confirmed permethrin resistance and fipronil tolerance in R. sanguineus populations, commonly conferred by metabolic detoxification or target site mutations. Herein, five strains of permethrin-resistant and three strains of fipronil-tolerant ticks were evaluated for metabolic resistance using synergists to block metabolic enzymes...
June 22, 2017: Medical and Veterinary Entomology
https://www.readbyqxmd.com/read/28639228/role-of-20-hydroxyeicosatetraenoic-acid-20-hete-in-androgen-mediated-cell-viability-in-prostate-cancer-cells
#11
Cecilia Colombero, Daniela Papademetrio, Paula Sacca, Eduardo Mormandi, Elida Alvarez, Susana Nowicki
20-Hydroxyeicosatetraenoic acid (20-HETE) is generated intracellularly through the ω-hydroxylation of arachidonic acid by the cytochrome P450 (in humans, CYP4A11 and CYP4F2). 20-HETE induces mitogenic responses in different cancer cells. The aim of this study was to analyze how 20-HETE impacts cell survival, proliferation, and apoptosis in prostate cancer cells. Incubation of the human androgen-sensitive cells (LNCaP) with 1-10 μM HET0016 (a selective inhibitor of 20-HETE synthesis) reduced cell viability by 49*-64%* (*p < 0...
June 21, 2017: Hormones & Cancer
https://www.readbyqxmd.com/read/28639016/accumulation-properties-of-polychlorinated-biphenyl-congeners-in-yusho-patients-and-prediction-of-their-cytochrome-p450-dependent-metabolism-by-in-silico-analysis
#12
Shusaku Hirakawa, Takashi Miyawaki, Tsuguhide Hori, Jumboku Kajiwara, Susumu Katsuki, Masashi Hirano, Yuka Yoshinouchi, Hisato Iwata, Chikage Mitoma, Masutaka Furue
In what has become known as the Yusho incident, thousands of people in western Japan were poisoned by the accidental ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds. In this study, we investigated the accumulation patterns of 69 PCB congeners in the blood of Yusho patients in comparison with those of non-exposed controls. The blood samples were collected at medical check-ups in 2004 and 2005. To compare the patterns of PCB congeners, we calculated the concentration ratio of each congener relative to the 2,2',4,4',5,5'-hexaCB (CB153) concentration...
June 21, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28638891/effect-of-astragaloside-on-vitamin-d-receptor-expression-after-endothelin-1-induced-cardiomyocyte-injury
#13
Chen Yunzhi, Chen Jiaxu, Gao Jie, Chai Yihui, Li Wen, Qin Zhong
BACKGROUND: Astragaloside, which is one of the main components of Astragalus membranaceus, has been widely used in the treatment of congestive heart failure in China, and it can protect cardiomyocytes. Its mechanism of action remains unclear. Therefore, the present study was carried out to investigate the influence of astragaloside on rat cardiomyocytes stimulated with endothelin-1 (ET-1), and explored the underlying mechanism. MATERIALS AND METHODS: ET-1 was used to stimulate primary rat cardiomyocytes and establish a cardiomyocyte hypertrophy model...
2017: African Journal of Traditional, Complementary, and Alternative Medicines: AJTCAM
https://www.readbyqxmd.com/read/28638398/discovery-of-putative-herbicide-resistance-genes-and-its-regulatory-network-in-chickpea-using-transcriptome-sequencing
#14
Mir A Iquebal, Khela R Soren, Priyanka Gangwar, P S Shanmugavadivel, K Aravind, Deepak Singla, Sarika Jaiswal, Rahul S Jasrotia, Sushil K Chaturvedi, Narendra P Singh, Rajeev K Varshney, Anil Rai, Dinesh Kumar
Background: Chickpea (Cicer arietinum L.) contributes 75% of total pulse production. Being cheaper than animal protein, makes it important in dietary requirement of developing countries. Weed not only competes with chickpea resulting into drastic yield reduction but also creates problem of harboring fungi, bacterial diseases and insect pests. Chemical approach having new herbicide discovery has constraint of limited lead molecule options, statutory regulations and environmental clearance. Through genetic approach, transgenic herbicide tolerant crop has given successful result but led to serious concern over ecological safety thus non-transgenic approach like marker assisted selection is desirable...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28637770/analgesia-and-opioids-a-pharmacogenetics-shortlist-for-implementation-in-clinical-practice
#15
REVIEW
Maja Matic, Saskia N de Wildt, Dick Tibboel, Ron H N van Schaik
BACKGROUND: The use of opioids to alleviate pain is complicated by the risk of severe adverse events and the large variability in dose requirements. Pharmacogenetics (PGx) could possibly be used to tailor pain medication based on an individual's genetic background. Many potential genetic markers have been described, and the importance of genetic predisposition in opioid efficacy and toxicity has been demonstrated in knockout mouse models and human twin studies. Such predictors are especially of value for neonates and young children, in whom the assessment of efficacy or side effects is complicated by the inability of the patient to communicate this properly...
June 21, 2017: Clinical Chemistry
https://www.readbyqxmd.com/read/28637420/bioinformatics-insights-on-targets-receptors-of-amiodarone-in-human-and-acanthamoeba-castellanii
#16
Abdul Baig, Zohaib Rana, H R Ahmad
BACKGROUND: Amiodarone is prescribed for certain cardiac arrhythmias in medical practice. The drug targets and inhibits voltage dependent sodium (Na+v), calcium (Ca+2v), potassium (K+v) channels, and enzymes like cytochrome P450 and oxidosqualene cyclase. Past studies have shown that amiodarone exerts anti-amoebic effects against Trypanosoma cruzi and Acanthamoeba castellanii. OBJECTIVES: The presence of aforementioned targets and the type of cell death induced by amiodarone in these pathogenic eukaryotes like Acanthamoeba castellanii remain to be verified...
June 21, 2017: Infectious Disorders Drug Targets
https://www.readbyqxmd.com/read/28635673/toxicity-of-naphthalene-and-benzene-on-tribollium-castaneum-herbst
#17
Nerlis Pajaro-Castro, Karina Caballero-Gallardo, Jesus Olivero-Verbel
Naphthalene and benzene are widely-used volatile organic compounds. The aim of this research was to examine the toxicological effects of naphthalene and benzene against Tribolium castaneum as an animal model. Adult insects were exposed to these aromatic compounds to assess mortality after 4-48 h of exposure. The lethal concentration 50 (LC50) for naphthalene, naphthalin, and benzene were 63.6 µL/L, 20.0 µL/L, and 115.9 µL/L in air, respectively. Real-time polymerase chain reaction (PCR) analysis revealed expression changes in genes related to oxidative stress and metabolism [Glutathione S-Transferase (Gst), and Cytochrome P450 6BQ8 (Cyp6bq8)]; reproduction and metamorphosis [Hormone receptor in 39-like protein (Hr39), Ecdysone receptor: (Ecr), and Chitin synthase 2 (Chs2)]; and neurotransmission [Histamine-gated chloride channel 2 (Hiscl2)] in insects exposed for 4 h to 70...
June 21, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28634536/telavancin-a-novel-semisynthetic-lipoglycopeptide-agent-to-counter-the-challenge-of-resistant-gram-positive-pathogens
#18
REVIEW
Biswadeep Das, Chayna Sarkar, Debasmita Das, Amit Gupta, Arnav Kalra, Shubham Sahni
Telavancin (TD-6424), a semisynthetic lipoglycopeptide vancomycin-derivative, is a novel antimicrobial agent developed by Theravance for overcoming resistant Gram-positive bacterial infections, specifically methicillin-resistant Staphylococcus aureus (MRSA). The US Food and Drug Administration (USFDA) had approved telavancin in 2009 for the treatment of complicated skin and skin structure infections (cSSSIs) caused by Gram-positive bacteria, including MRSA (S. aureus, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus anginosus group, or Enterococcus faecalis)...
March 2017: Therapeutic Advances in Infectious Disease
https://www.readbyqxmd.com/read/28633598/metabolism-of-inhaled-methylethylketone-in-rats
#19
Frédéric Cosnier, Stéphane Grossmann, Hervé Nunge, Céline Brochard, Samuel Muller, Anne-Marie Lambert-Xolin, Sylvie Sebillaud, Benoît Rieger, Aurélie Thomas, Marie-Josèphe Décret, Manuella Burgart, Laurent Gaté, Benoît Cossec, Pierre Campo
Methylethylketone (MEK) is widely used in industry, often in combination with other compounds. Although nontoxic, it can make other chemicals harmful. This study investigates the fate of MEK in rat blood, brain and urine as well as its hepatic metabolism following inhalation over 1 month (at 20, 200 or 1400 ppm). MEK did not significantly accumulate in the organism: blood concentrations were similar after six-hour or 1-month inhalation periods, and brain concentrations only increased slightly after 1 month's exposure...
February 28, 2017: Drug and Chemical Toxicology
https://www.readbyqxmd.com/read/28633515/crystal-structure-and-functional-characterization-of-a-cytochrome-p450-bacyp106a2-from-bacillus-sp-pamc-23377
#20
Ki-Hwa Kim, Chang Woo Lee, Bikash Dangi, Sun-Ha Park, Hyun Park, Tae-Jin Oh, Jun Hyuck Lee
Bacterial cytochrome P450 (CYP) steroid hydroxylases are effectively useful in the pharmaceutical industry for introducing hydroxyl groups to a wide range of steroids. We found a putative CYP steroid hydroxylase (BaCYP106A2) from the bacterium Bacillus sp. PAMC 23377 isolated from Kara Sea of the Arctic Ocean, showing 94% sequence similarity with BmCYP106A2 (Bacillus megaterium ATCC 13368). In this study, soluble BaCYP106A2 was overexpressed to evaluate its substrate-binding activity. The substrate affinity (Kd value) to 4-androstenedione was 387 ± 37 µM...
June 21, 2017: Journal of Microbiology and Biotechnology
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