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Omar Eduardo Tovar-Herrera, Adriana Mayrel Martha-Paz, Yordanis Pérez-LLano, Elisabet Aranda, Juan Enrique Tacoronte-Morales, María Teresa Pedroso-Cabrera, Katiushka Arévalo-Niño, Jorge Luis Folch-Mallol, Ramón Alberto Batista-García
Lignocellulose represents the most abundant source of carbon in the Earth. Thus, fraction technology of the biomass turns up as an emerging technology for the development of biorefineries. Saccharification and fermentation processes require the formulation of enzymatic cocktails or the development of microorganisms (naturally or genetically modified) with the appropriate toolbox to produce a cost-effective fermentation technology. Therefore, the search for microorganisms capable of developing effective cellulose hydrolysis represents one of the main challenges in this era...
May 21, 2018: MicrobiologyOpen
Li Cai, Lu Zhang, Qiantang Fu, Zeng-Fu Xu
The seed oil of Jatropha curcas is considered a potential bioenergy source that could replace fossil fuels. However, the seed yield of Jatropha is low and has yet to be improved. We previously reported that exogenous cytokinin treatment increased the seed yield of Jatropha . Cytokinin levels are directly regulated by isopentenyl transferase (IPT), cytochrome P450 monooxygenase, family 735, subfamily A (CYP735A), and cytokinin oxidase/dehydrogenase (CKX). In this study, we cloned six IPT genes, one JcCYP735A gene, and seven JcCKX genes...
2018: PeerJ
Erik Donovan Hedegård, Ulf Ryde
The lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes that can enhance polysaccharide depolymerization through an oxidative mechanism and hence boost generation of biofuel from e.g. cellulose. By employing density functional theory in a combination of quantum mechanics and molecular mechanics (QM/MM), we report a complete description of the molecular mechanism of LPMOs. The QM/MM scheme allows us to describe all reaction steps with a detailed protein environment and we show that this is necessary...
April 21, 2018: Chemical Science
Cheng Zhang, Jun Wang, Lusheng Zhu, Zhongkun Du, Jinhua Wang, Xi Sun, Tongtong Zhou
The toxicity of ionic liquids (ILs) on soil organisms has aroused wide attention due to their high-solubility. The present investigation focused on the toxicity of 1-octyl-3-methylimidazolium nitrate ([C8 mim]NO3 ) on the microbial populations (bacteria, fungi, and actinomycetes), soil enzyme (urease, dehydrogenase, acid phosphatase, and β-glucosidase) activities, microbial community diversity using terminal restriction fragment length polymorphism (T-RFLP), and abundance of the ammonia monooxygenase (amoA) genes of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) using quantitative real-time polymerase chain reaction (q-PCR) in brown soil at each trial with doses of 0, 1...
May 2018: Journal of Environmental Sciences (China)
Stanislav Yanev, Tsveta Stoyanova, Violeta Valcheva, Paul R Ortiz De Montellano
Ethionamide (ETH) plays a central role in the treatment of tuberculosis in patients resistant to the first-line drugs. The ETH, thioamide, and thiourea class of antituberculosis agents are pro-drugs that are oxidatively converted to their active S-oxides by the flavin monooxygenase EtaA of M. tuberculosis, thus initiating the chain of reactions that result in inhibition of mycolic acid biosynthesis and cell lysis. As part of a search for new lead candidates, we report here that several xanthates are oxidized by purified EtaA to S-oxide metabolites (perxanthates) that are implicated in the antimycobacterial activity of these compounds...
May 18, 2018: Drug Metabolism and Disposition: the Biological Fate of Chemicals
Toshiki Furuya, Masahiko Sai, Kuniki Kino
Piceatannol is a rare, costly plant-based stilbene derivative and exhibits various health-enhancing properties. Recently, we demonstrated that piceatannol could be produced from resveratrol through site-selective hydroxylation using Escherichia coli cells expressing the monooxygenase HpaBC. However, piceatannol production ceased at approximately 25 mM, even when sufficient levels of the substrate resveratrol remained in the reaction mixture. In this study, we found that high concentrations (>20-25 mM) of piceatannol significantly inhibited the HpaBC-catalyzed reaction...
May 12, 2018: Journal of Bioscience and Bioengineering
Dake Zhao, Yong Shen, Yana Shi, Xingqiao Shi, Qin Qiao, Shuhui Zi, Erqiang Zhao, Diqiu Yu, Edward J Kennelly
Aconitum carmichaelii has long been used as a traditional Chinese medicine, and its processed lateral roots are known commonly as fuzi. Aconitine-type C19 -diterpenoid alkaloids accumulating in the lateral roots are some of the main toxicants of this species, yet their biosynthesis remains largely unresolved. As a first step towards understanding the biosynthesis of aconitine-type C19 -diterpenoid alkaloids, we performed de novo transcriptome assembly and analysis of rootstocks and leaf tissues of Aconitum carmichaelii by next-generation sequencing...
May 11, 2018: Phytochemistry
Yan Zhang, Feng Liu, Na Xu, Yin-Qi Wu, Yu-Cong Zheng, Qian Zhao, Guoqiang Lin, Hui-Lei Yu, Jian-He Xu
Two Baeyer-Villiger monooxygenases (BVMOs) designated Bo BVMO and Am BVMO were discovered from Bradyrhizobium oligotrophicum and Aeromicrobium marinum , respectively. Both monooxygenases displayed novel features for catalyzing the asymmetric sulfoxidation of bulky and pharmaceutically relevant thioethers. Evolutionary relationship and sequence analysis revealed that the two BVMOs belong to the family of typical type I BVMO and the subtype ethionamide monooxygenase. Both BVMOs are active toward medium- and long-chain aliphatic ketones as well as various thioether substrates, but ineffective toward cyclohexanone, aromatic ketones and other typical BVMO substrates...
May 11, 2018: Applied and Environmental Microbiology
X Tian, S Zhao, Z Guo, B Hu, Q Wei, Y Tang, J Su
Enhanced detoxification is one of the important mechanisms for insecticide resistance. Most research in this field to date has focused on the role of cytochrome P450s. Our previous work revealed that flavin-dependent monooxygenases (FMOs) were involved in metabolic resistance of Spodoptera exigua. In the present study we investigated the molecular characteristics, expression patterns and oxidative activities of SeFMO on insecticides. Three FMO genes, which encode proteins with the typical FMO motifs, were cloned from S...
May 10, 2018: Insect Molecular Biology
Lishuai Feng, Chaoran Dou, Jianbo Wang, Chunyu Jiang, Xu Ma, Jingjing Liu
Mono‑unsaturated free fatty acids (FFAs) can serve as a predictive indicator of vascular restenosis following interventional therapy, particularly in individuals with high‑fat diet‑induced type 2 diabetes. However, the pathogenic mechanism remains to be fully elucidated. In the present study, the levels of tyrosine 3‑monooxygenase/tryptophan 5‑monooxygenase activation protein β (YWHAB; also known as 14‑3‑3β), in vascular smooth muscle cells (VSMCs) treated with different concentrations of oleic acid (OA) were examined by reverse transcription‑quantitative polymerase chain reaction and western blot analyses...
May 11, 2018: International Journal of Molecular Medicine
Stefanie Hessel-Pras, Anke Ehlers, Albert Braeuning, Alfonso Lampen
The epithelium of the small intestine plays an important role in detoxification processes due to the presence of various xenobiotic-metabolizing enzymes from phase I and II, as well as transport proteins of the ATP-binding cassette superfamily. Exposure to xenobiotics induces the expression of these proteins in the small intestine, with multiple signaling pathways stimulated by exogenous compounds converging at individual gene promoters by mechanisms which have not been fully understood yet. In this context the promoter region of the CYP1A1 gene, encoding the phase I monooxygenase cytochrome P450 1A1, was analyzed by chromatin immunoprecipitation with regard to binding of xeno-sensing receptors following stimulation of Caco-2 cells with agonists of the aryl hydrocarbon receptor (AHR) and retinoid receptors...
2018: EXCLI Journal
Gao-Qian Wang, Guo-Dong Chen, Sheng-Ying Qin, Dan Hu, Takayoshi Awakawa, Shao-Yang Li, Jian-Ming Lv, Chuan-Xi Wang, Xin-Sheng Yao, Ikuro Abe, Hao Gao
Furanosteroids, represented by wortmannin, viridin, and demethoxyviridin, are a special group of fungal-derived, highly oxygenated steroids featured by an extra furan ring. They are well-known nanomolar-potency inhibitors of phosphatidylinositol 3-kinase and widely used in biological studies. Despite their importance, the biosyntheses of these molecules are poorly understood. Here, we report the identification of the biosynthetic gene cluster for demethoxyviridin, consisting of 19 genes, and among them 15 biosynthetic genes, including six cytochrome P450 monooxygenase genes, are deleted...
May 9, 2018: Nature Communications
Shu-Shan Gao, Tao Zhang, Marc Garcia-Borràs, Yiu-Sun Hung, John M Billingsley, Kendall N Houk, Youcai Hu, Yi Tang
Duclauxins are dimeric and heptacyclic fungal polyketides with significant bioactivities. We characterized the cascade of redox transformations in the biosynthesis of duclauxin pathway from Talaromyces stipitatus. The redox reaction sequence is initiated by a cupin family dioxygenase DuxM that performs an oxidative cleavage of the peri-fused tricyclic phenalenone and affords a tran-sient hemiketal-oxaphenalenone intermediate. Additional redox enzymes then morph the oxaphenoalenone into either an anhydride or a dihydrocoumarin-containing monomeric building block that are found in dimeric duxlauxins...
May 9, 2018: Journal of the American Chemical Society
Soo Y Ro, Matthew O Ross, Yue Wen Deng, Sharon Batelu, Thomas J Lawton, Joseph D Hurley, Timothy L Stemmler, Brian M Hoffman, Amy C Rosenzweig
Particulate methane monooxygenase (pMMO) is a copper-dependent, integral membrane metalloenzyme that converts methane to methanol in methanotrophic bacteria. Studies of isolated pMMO have been hindered by loss of enzymatic activity upon its removal from the native membrane. To characterize pMMO in a membrane-like environment, we reconstituted pMMOs from Methylococcus ( Mcc. ) capsulatus (Bath) and Methylomicrobium ( Mm. ) alcaliphilum 20Z into bicelles. Reconstitution into bicelles recovers methane oxidation activity lost upon detergent solubilization and purification without substantial alterations to copper content or copper electronic structure as observed by electron paramagnetic resonance (EPR) spectroscopy...
May 8, 2018: Journal of Biological Chemistry
Andrew Willetts, Pamela Masters, Carol Steadman
For the first time, the differential rates of synthesis of all the key monooxygenases involved in the catabolism by Pseudomonas putida NCIMB 10007 of bicyclic ( rac )-camphor to ∆2,5 -3,4,4-trimethylpimelyl-CoA, the first aliphatic pathway intermediate, have been determined to help establish the relevant induction profile of each of the oxygen-dependent enzymes. The efficacy of both relevant substrates and pathway metabolites as inducers has been established. Further, inhibitors with characterised functionality have been used to indicate that the pertinent regulatory controls operate at the level of transcription of the corresponding genes...
May 7, 2018: Microorganisms
Yun-Chu Chen, Eric C Holmes, Jakub Rajniak, Jung-Gun Kim, Sandy Tang, Curt R Fischer, Mary Beth Mudgett, Elizabeth S Sattely
Systemic acquired resistance (SAR) is a global response in plants induced at the site of infection that leads to long-lasting and broad-spectrum disease resistance at distal, uninfected tissues. Despite the importance of this priming mechanism, the identity and complexity of defense signals that are required to initiate SAR signaling is not well understood. In this paper, we describe a metabolite, N -hydroxy-pipecolic acid ( N -OH-Pip) and provide evidence that this mobile molecule plays a role in initiating SAR signal transduction in Arabidopsis thaliana We demonstrate that FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1), a key regulator of SAR-associated defense priming, can synthesize N -OH-Pip from pipecolic acid in planta , and exogenously applied N -OH-Pip moves systemically in Arabidopsis and can rescue the SAR-deficiency of fmo1 mutants...
May 7, 2018: Proceedings of the National Academy of Sciences of the United States of America
Allison M Garrison, Jennifer M Parrott, Arnulfo Tuñon, Jennifer Delgado, Laney Redus, Jason C O'Connor
Chronic stress or inflammation increases tryptophan metabolism along the kynurenine pathway (KP), and the generation of neuroactive kynurenine metabolites contributes to subsequent depressive-like behaviors. Microglia regulate KP balance by preferentially producing oxidative metabolites, including quinolinic acid. Research has focused on the interplay between cytokines and HPA axis-derived corticosteroids in regulating microglial activity and effects of KP metabolites directly on neurons; however, the potential role that KP metabolites have directly on microglial activity is unknown...
April 22, 2018: Psychoneuroendocrinology
Ashutosh Fular, Anil Kumar Sharma, Sachin Kumar, Gaurav Nagar, Gajanan Chigure, D D Ray, Srikant Ghosh
Tick-borne diseases is a global threat and tick resistance to commonly used acaricides is a growing problem, thus calling for improved resistance monitoring tools. To aid in monitoring of resistance in field tick populations, a resistant colony of Rhipicephalus microplus was characterized with the aim to establish a reference multi-acaricide resistant tick strain. Using a standardized adult immersion test, the Lethal Concentration(LC)50 values for deltamethrin, cypermethrin, fenvalerate and diazinon against the laboratory selected resistant tick (LSRT) strain were determined as 306...
April 22, 2018: Ticks and Tick-borne Diseases
Chunqing Zhao, Genmiao Song, Kristopher Silver, Tao Tang, Chen Wang, Lihong Qiu
As important metabolic enzymes, the function of cytochrome P450 monooxygenases (CYPs) has been demonstrated repeatedly through various means, including heterologous expression systems. Unfortunately, most model systems typically lack expression of a conspecific NADPH-dependent cytochrome P450 reductase (CPR), which is the electron transfer partner of CYPs. As a result, the activities of heterologously expressed insect CYPs may not accurately reflect detoxification activities in vivo. Previously, CYP6B7 from Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) (HaCYP6B7) has been expressed in the Pichia pastoris GS115 strain and shown to detoxify bifenthrin, fenvalerate and chlorpyrifos...
May 3, 2018: Journal of Economic Entomology
Mingyue Gou, Xiuzhi Ran, Dwight W Martin, Chang-Jun Liu
Lignin is a complex and irregular biopolymer of crosslinked phenylpropanoid units in plant secondary cell walls. Its biosynthesis requires three endoplasmic reticulum (ER)-resident cytochrome P450 monooxygenases, C4H, C3'H and F5H, to establish the structural characteristics of its monomeric precursors. These P450 enzymes were reported to associate with each other or potentially with other soluble monolignol biosynthetic enzymes to form an enzyme complex or a metabolon. However, the molecular basis governing such enzyme or pathway organization remains elusive...
May 2018: Nature Plants
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