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Thomas J Lawton, Amy C Rosenzweig
Nature utilizes two groups of enzymes to catalyze methane conversions, methyl-coenzyme M reductases (MCRs) and methane monooxygenases (MMOs). These enzymes have been difficult to incorporate into industrial processes due to their complexity, poor stability, and lack of recombinant tractability. Despite these issues, new ways of preparing and stabilizing these enzymes have recently been discovered, and new mechanistic insight into how MCRs and MMOs break the C-H bond in nature's most inert hydrocarbon have been obtained...
October 18, 2016: Current Opinion in Chemical Biology
Paula Viviani, Adrian Lifschitz, Jorge García, María Laura Maté, Miguel Angel Quiroga, Carlos Lanusse, Guillermo Virkel
1. Precision-cut liver slices (PCLS) from food-producing animals have not been extensively used to study xenobiotic metabolism, and thus information on this field of research is sparse. 2. The aims of the present work were to further validate the technique of production and culture of bovine PCLS and to characterize the metabolic interaction between the anthelmintic albendazole (ABZ) and the flavin-monooxygenase (FMO) inhibitor methimazole (MTZ). 3. Nine (9) steers were used as donors. PCLS were produced and incubated under two methods, a dynamic organ culture (DOC) incubator and a well-plate (WP) system...
October 21, 2016: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
Juan Guillermo Cárcamo, Marcelo N Aguilar, Constanza F Carreño, Tamara Vera, Luis Arias-Darraz, Jaime E Figueroa, Alex P Romero, Marco Alvarez, Alejandro J Yañez
Rainbow trout (Oncorhynchus mykiss) subjected to three consecutive, alternating treatments with emamectin benzoate (EMB) and deltamethrin (DM) during outbreaks of Caligus rogercresseyi in a farm located in southern Chile (Hornopiren, Chiloé), were studied to determine the effects of these treatments on the protein and enzymatic activity levels of cytochrome P450 1A (CYP1A), flavin-containing monooxygenase (FMO) and glutathione S-transferase (GST) in different tissues. Consecutive and alternating EMB/DM treatments resulted in a 10-fold increase and 3-fold decrease of CYP1A protein levels in the intestine and gills, respectively...
October 17, 2016: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Ana C Henriques, Rui M S Azevedo, Paolo De Marco
Methanesulfonic acid (MSA) is a relevant intermediate of the biogeochemical cycle of sulfur and environmental microorganisms assume an important role in the mineralization of this compound. Several methylotrophic bacterial strains able to grow on MSA have been isolated from soil or marine water and two conserved operons, msmABCD coding for MSA monooxygenase and msmEFGH coding for a transport system, have been repeatedly encountered in most of these strains. Homologous sequences have also been amplified directly from the environment or observed in marine metagenomic data, but these showed a base composition (G + C content) very different from their counterparts from cultivated bacteria...
2016: PeerJ
J M Parrott, L Redus, D Santana-Coelho, J Morales, X Gao, J C O'Connor
The kynurenine pathway of tryptophan metabolism has an important role in mediating the behavioral effects of inflammation, which has implications in understanding neuropsychiatric comorbidity and for the development of novel therapies. Inhibition of the rate-limiting enzyme, indoleamine 2,3-dioxygenase (IDO), prevents the development of many of these inflammation-induced preclinical behaviors. However, dysregulation in the balance of downstream metabolism, where neuroactive kynurenines are generated, is hypothesized to be a functionally important pathogenic feature of inflammation-induced depression...
October 18, 2016: Translational Psychiatry
Andrew Willetts, David Kelly
The progressive titres of key monooxygenases and their requisite native donors of reducing power were used to assess the relative contribution of various camphor plasmid (CAM plasmid)- and chromosome-coded activities to biodegradation of (rac)-camphor at successive stages throughout growth of Pseudomonas putida NCIMB 10007 on the bicylic monoterpenoid. A number of different flavin reductases (FRs) have the potential to supply reduced flavin mononucleotide to both 2,5- and 3,6-diketocamphane monooxygenase, the key isoenzymic two-component monooxygenases that delineate respectively the (+)- and (-)-camphor branches of the convergent degradation pathway...
October 13, 2016: Microorganisms
Cornelia U Welte, Olivia Rasigraf, Annika Vaksmaa, Wouter Versantvoort, Arslan Arshad, Huub J M Op den Camp, Mike S M Jetten, Claudia Lüke, Joachim Reimann
Microbial methane oxidation is an important process to reduce the emission of the greenhouse gas methane. Anaerobic microorganisms couple the oxidation of methane to the reduction of sulfate, nitrate and nitrite, and possibly oxidized iron and manganese minerals. In this article, we review the recent finding of the intriguing nitrate- and nitrite-dependent anaerobic oxidation of methane (AOM). Nitrate-dependent AOM is catalyzed by anaerobic archaea belonging to the ANME-2d clade closely related to Methanosarcina methanogens...
October 18, 2016: Environmental Microbiology Reports
Elena Geiser, Sandra K Przybilla, Meike Engel, Wiebke Kleineberg, Linda Büttner, Eda Sarikaya, Tim den Hartog, Jürgen Klankermayer, Walter Leitner, Michael Bölker, Lars M Blank, Nick Wierckx
The Ustilaginaceae family of smut fungi, especially Ustilago maydis, gained biotechnological interest over the last years, amongst others due to its ability to naturally produce the versatile bio-based building block itaconate. Along with itaconate, U. maydis also produces 2-hydroxyparaconate. The latter was proposed to be derived from itaconate, but the underlying biochemistry and associated genes were thus far unknown. Here, we confirm that 2-hydroxyparaconate is a secondary metabolite of U. maydis and propose an extension of U...
October 14, 2016: Metabolic Engineering
Min Pang, Xin-Yan Bai, Yan Li, Ji-Zhong Bai, Li-Rong Yuan, Shou-An Ren, Xiao-Yun Hu, Xin-Ri Zhang, Bao-Feng Yu, Rui Guo, Hai-Long Wang
Clara cell protein (CC16) is an anti-inflammatory protein, which is expressed in the airway epithelium. It is involved in the development of airway inflammatory diseases, including chronic obstructive pulmonary disease and asthma. However, the exact molecular mechanism underlying its anti‑inflammatory action remains to be fully elucidated. The aim of the present study was to define the protein profiles of the anti‑inflammatory effect of CC16 in lipopolysaccharide (LPS)‑treated rat tracheal epithelial (RTE) cells using shotgun proteomics...
October 12, 2016: Molecular Medicine Reports
Letícia B Smith, Shinji Kasai, Jeffrey G Scott
Aedes aegypti and A. albopictus mosquitoes are vectors of important human disease viruses, including dengue, yellow fever, chikungunya and Zika. Pyrethroid insecticides are widely used to control adult Aedes mosquitoes, especially during disease outbreaks. Herein, we review the status of pyrethroid resistance in A. aegypti and A. albopictus, mechanisms of resistance, fitness costs associated with resistance alleles and provide suggestions for future research. The widespread use of pyrethroids has given rise to many populations with varying levels of resistance worldwide, albeit with substantial geographical variation...
October 2016: Pesticide Biochemistry and Physiology
Xi Sun, Lusheng Zhu, Jinhua Wang, Jun Wang, Benying Su, Tong Liu, Cheng Zhang, Chong Gao, Yuting Shao
Ionic liquids (ILs) were considered as "green" solvents and have been used widely because of their excellent properties. But ILs are not as "green" as has been suggested, and the toxic effects of ILs on organisms have been shown in recent years. In the present study, the toxic effects of the IL 1-octyl-3-methylimidazolium tetrafluoroborate ([Omim]BF4) on soil enzyme activity and soil microbial communities at three different concentrations (1.0, 5.0 and 10.0mg/kg) and a control treatment over 40 days of incubation time (sampled on days 10, 20, 30 and 40) were examined under laboratory conditions...
October 11, 2016: Ecotoxicology and Environmental Safety
Andy Beier, Sven Bordewick, Maika Genz, Sandy Schmidt, Tom Van Den Bergh, Christin Peters, Henk-Jan Joosten, Uwe Bornscheuer
Baeyer-Villiger monooxygenases (BVMOs) catalyze the oxidation of ketones to esters or lactones by utilizing molecular oxygen and a cofactor. Type I BVMOs display a strong preference for NADPH. However, for industrial purposes NADH is the preferred cofactor, as it is ten times cheaper and more stable. Thus, we created a variant of the cyclohexanone monooxygenase from Acinetobacter sp. NCIMB 9871 (CHMOAcineto), which utilizes NADH 4,200-fold better than NADPH. By combining structure analysis, sequence alignments and literature data, 21 residues in proximity of the cofactor were identified and targeted for mutagenesis...
October 13, 2016: Chembiochem: a European Journal of Chemical Biology
Zifei Xu, Yonghong Chen, Tianyang Song, Zhijun Zeng, Ni Yan, Keqin Zhang, Xuemei Niu
Arthrobotrys oligospora is the first recognized nematode-trapping fungus and by far the most abundant in the environment. Our recent study revealed the polyketide synthase (PKS) gene AOL_s00215g283 in A. oligospora involved in the production of many secondary metabolites and the trap formation of the fungus. Here we report that the disruption of two genes in the upstream flanking region of the gene AOL_s00215g283, AOL_s00215g281 and AOL_s00215g282, which putatively encoded one amidohydrolase and one cytochrome P450 monooxygenase, respectively, both resulted in significant nematicidal activity of the cultural broths of the mutants and loss of morphological regulatory arthrosporols...
October 11, 2016: Journal of Agricultural and Food Chemistry
Rebecca C Gregory, Glyn R Hemsworth, Johan P Turkenburg, Samuel J Hart, Paul H Walton, Gideon J Davies
The enzymatic deconstruction of recalcitrant polysaccharide biomass is central to the conversion of these substrates for societal benefit, such as in biofuels. Traditional models for enzyme-catalysed polysaccharide degradation involved the synergistic action of endo-, exo- and processive glycoside hydrolases working in concert to hydrolyse the substrate. More recently this model has been succeeded by one featuring a newly discovered class of mononuclear copper enzymes: lytic polysaccharide monooxygenases (LPMOs; classified as Auxiliary Activity (AA) enzymes in the CAZy classification)...
September 29, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Rui Pang, Meng Chen, Zhikun Liang, Xiangzhao Yue, Hu Ge, Wenqing Zhang
The cytochrome P450 CYP6ER1 has been reported to play an important role in imidacloprid resistance of the brown planthopper (BPH), Nilaparvata lugens, and is overexpressed in most resistant populations. In the present study, we confirmed that CYP6ER1 expression can be induced by certain levels of imidacloprid. Developmental expression analysis revealed that CYP6ER1 was expressed highly in the adult stage, and tissue distribution analysis showed that CYP6ER1 was expressed mainly in the fat body and midgut. RNA interference (RNAi) of CYP6ER1 and transgenic expression of CYP6ER1 in Drosophila melanogaster both suggested that the expression of CYP6ER1 is sufficient to confer imidacloprid resistance...
October 10, 2016: Scientific Reports
Hongyun Nie, Maiqian Nie, Ting Xiao, Yan Wang, Xiaoting Tian
For further understanding of the roles of small organic acids commonly produced during alkane degradation, glutaric acid was found to be effective for promoting hexadecane degradation by P. aeruginosa NY3. Our results demonstrated that the synchronous metabolism of glutaric acid could increase both the growth rates and hexadecane degradation ability of P. aeruginosa NY3. Glutaric acid was proved to be able to increase the ratios of the concentrations of NAD(+) and NADH inside strain NY3 cells, and subsequently accelerated cell growth rates through improving electron respiration rates...
October 4, 2016: Science of the Total Environment
Jae Ho Shin, Seok Hyun Park, Young Hoon Oh, Jae Woong Choi, Moon Hee Lee, Jae Sung Cho, Ki Jun Jeong, Jeong Chan Joo, James Yu, Si Jae Park, Sang Yup Lee
BACKGROUND: 5-Aminovaleric acid (5AVA) is an important five-carbon platform chemical that can be used for the synthesis of polymers and other chemicals of industrial interest. Enzymatic conversion of L-lysine to 5AVA has been achieved by employing lysine 2-monooxygenase encoded by the davB gene and 5-aminovaleramidase encoded by the davA gene. Additionally, a recombinant Escherichia coli strain expressing the davB and davA genes has been developed for bioconversion of L-lysine to 5AVA...
October 7, 2016: Microbial Cell Factories
Guangchao Liu, Shan Gao, Huiyu Tian, Wenwen Wu, Hélène S Robert, Zhaojun Ding
Auxin is necessary for the inhibition of root growth induced by aluminium (Al) stress, however the molecular mechanism controlling this is largely unknown. Here, we report that YUCCA (YUC), which encodes flavin monooxygenase-like proteins, regulates local auxin biosynthesis in the root apex transition zone (TZ) in response to Al stress. Al stress up-regulates YUC3/5/7/8/9 in the root-apex TZ, which we show results in the accumulation of auxin in the root-apex TZ and root-growth inhibition during the Al stress response...
October 2016: PLoS Genetics
Katrin Luck, Jan Jirschitzka, Sandra Irmisch, Meret Huber, Jonathan Gershenzon, Tobias G Köllner
BACKGROUND: Amino acid-derived aldoximes and nitriles play important roles in plant defence. They are well-known as precursors for constitutive defence compounds such as cyanogenic glucosides and glucosinolates, but are also released as volatiles after insect feeding. Cytochrome P450 monooxygenases (CYP) of the CYP79 family catalyze the formation of aldoximes from the corresponding amino acids. However, the majority of CYP79s characterized so far are involved in cyanogenic glucoside or glucosinolate biosynthesis and only a few have been reported to be responsible for nitrogenous volatile production...
October 4, 2016: BMC Plant Biology
Julie Laborde, Céline Deraeve, Carine Duhayon, Geneviève Pratviel, Vania Bernardes-Génisson
Ethionamide (ETH), a second-line anti-tubercular drug that is regaining a lot of interest due to the increasing cases of drug-resistant tuberculosis, is a pro-drug that requires an enzymatic activation step to become active and to exert its therapeutic effect. The enzyme responsible for ETH bioactivation in Mycobacterium tuberculosis is a monooxygenase (EthA) that uses flavin adenine dinucleotide (FAD) as a cofactor and is NADPH- and O2-dependant to exert its catalytic activity. In this work, we investigated the activation of ETH by various oxygen-donor oxidants and the first biomimetic ETH activation methods were developed (KHSO5, H2O2, and m-CPBA)...
September 21, 2016: Organic & Biomolecular Chemistry
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