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Flavoenzyme

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https://www.readbyqxmd.com/read/28288625/functional-differentiation-of-3-ketosteroid-%C3%AE-1-dehydrogenase-isozymes-in-rhodococcus-ruber-strain-chol-4
#1
Govinda Guevara, Laura Fernández de Las Heras, Julián Perera, Juana María Navarro Llorens
BACKGROUND: The Rhodococcus ruber strain Chol-4 genome contains at least three putative 3-ketosteroid Δ(1)-dehydrogenase ORFs (kstD1, kstD2 and kstD3) that code for flavoenzymes involved in the steroid ring degradation. The aim of this work is the functional characterization of these enzymes prior to the developing of different biotechnological applications. RESULTS: The three R. ruber KstD enzymes have different substrate profiles. KstD1 shows preference for 9OHAD and testosterone, followed by progesterone, deoxy corticosterone AD and, finally, 4-BNC, corticosterone and 19OHAD...
March 14, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28274732/flavins-as-covalent-catalysts-new-mechanisms-emerge
#2
REVIEW
Valentina Piano, Bruce A Palfey, Andrea Mattevi
With approximately 1% of proteins being flavoproteins, flavins are at the heart of a plethora of redox reactions in all areas of biology. Thanks to a series of fascinating recent discoveries, in addition to redox chemistry, covalent catalysis is now being recognized more frequently as a common strategy in flavoenzymes, with unprecedented mechanisms becoming apparent. Thus, noncanonical covalent reactions by flavins are emerging as a new pervasive concept in basic enzymology and biochemistry. These diverse enzymes are engaged in most biological processes, positioning the knowledge being gained from these new mechanisms to be translated into drugs that function through covalent mechanisms...
March 5, 2017: Trends in Biochemical Sciences
https://www.readbyqxmd.com/read/28256579/proline-dehydrogenase-from-thermus-thermophilus-does-not-discriminate-between-fad-and-fmn-as-cofactor
#3
Mieke M E Huijbers, Marta Martínez-Júlvez, Adrie H Westphal, Estela Delgado-Arciniega, Milagros Medina, Willem J H van Berkel
Flavoenzymes are versatile biocatalysts containing either FAD or FMN as cofactor. FAD often binds to a Rossmann fold, while FMN prefers a TIM-barrel or flavodoxin-like fold. Proline dehydrogenase is denoted as an exception: it possesses a TIM barrel-like fold while binding FAD. Using a riboflavin auxotrophic Escherichia coli strain and maltose-binding protein as solubility tag, we produced the apoprotein of Thermus thermophilus ProDH (MBP-TtProDH). Remarkably, reconstitution with FAD or FMN revealed that MBP-TtProDH has no preference for either of the two prosthetic groups...
March 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28225078/distribution-of-valence-electrons-of-the-flavin-cofactor-in-nadh-cytochrome-b5-reductase
#4
Kiyofumi Takaba, Kazuki Takeda, Masayuki Kosugi, Taro Tamada, Kunio Miki
Flavin compounds such as flavin adenine dinucleotide (FAD), flavin mononucleotide and riboflavin make up the active centers in flavoproteins that facilitate various oxidoreductive processes. The fine structural features of the hydrogens and valence electrons of the flavin molecules in the protein environment are critical to the functions of the flavoproteins. However, information on these features cannot be obtained from conventional protein X-ray analyses at ordinary resolution. Here we report the charge density analysis of a flavoenzyme, NADH-cytochrome b5 reductase (b5R), at an ultra-high resolution of 0...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28192293/the-intrinsic-fluorescence-of-fad-and-its-application-in-analytical-chemistry-a-review
#5
Javier Galbán, Isabel Sanz-Vicente, Jesús Navarro, Susana de Marcos
This review (with 106 references) mainly deals with the analytical applications of flavin-adenine dinucleotide (FAD) fluorescence. In the first section, the spectroscopic properties of this compound are reviewed at the light of his different acid-base, oxidation and structural forms; the chemical and spectroscopic properties of flavin mononucleotide (FMN) and other flavins will be also briefly discussed. The second section discusses how the properties of FAD fluorescence changes in flavoenzymes (FvEs), again considering the different chemical and structural forms; the glucose oxidase (GOx) and the choline oxidase (ChOx) cases will be commented...
December 19, 2016: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28126656/structural-basis-for-the-role-of-mammalian-aldehyde-oxidases-in-the-metabolism-of-drugs-and-xenobiotics
#6
REVIEW
Maria João Romão, Catarina Coelho, Teresa Santos-Silva, Alessandro Foti, Mineko Terao, Enrico Garattini, Silke Leimkühler
Aldehyde oxidases (AOXs) are molybdo-flavoenzymes characterized by broad substrate specificity, oxidizing aromatic/aliphatic aldehydes into the corresponding carboxylic acids and hydroxylating various heteroaromatic rings. Mammals are characterized by a complement of species-specific AOX isoenzymes, that varies from one in humans (AOX1) to four in rodents (AOX1, AOX2, AOX3 and AOX4). The physiological function of mammalian AOX isoenzymes is unknown, although human AOX1 is an emerging enzyme in phase-I drug metabolism...
January 23, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28120165/investigating-the-link-of-acad10-deficiency-to-type-2-diabetes-mellitus
#7
Kaitlyn Bloom, Al-Walid Mohsen, Anuradha Karunanidhi, Dina El Demellawy, Miguel Reyes-Múgica, Yudong Wang, Lina Ghaloul-Gonzalez, Chikara Otsubo, Kimi Tobita, Radhika Muzumdar, Zhenwei Gong, Emir Tas, Shrabani Basu, Jie Chen, Michael Bennett, Charles Hoppel, Jerry Vockley
The Native American Pima population has the highest incidence of insulin resistance (IR) and type 2 diabetes mellitus (T2DM) of any reported population, but the pathophysiologic mechanism is unknown. Genetic studies in Pima Indians have linked acyl-CoA dehydrogenase 10 (ACAD10) gene polymorphisms, among others, to this predisposition. The gene codes for a protein with a C-terminus region that is structurally similar to members of a family of flavoenzymes-the acyl-CoA dehydrogenases (ACADs)-that catalyze α,β-dehydrogenation reactions, including the first step in mitochondrial FAO (FAO), and intermediary reactions in amino acids catabolism...
January 24, 2017: Journal of Inherited Metabolic Disease
https://www.readbyqxmd.com/read/28098177/an-extended-n-h-bond-driven-by-a-conserved-second-order-interaction-orients-the-flavin-n5-orbital-in-cholesterol-oxidase
#8
Emily Golden, Li-Juan Yu, Flora Meilleur, Matthew P Blakeley, Anthony P Duff, Amir Karton, Alice Vrielink
The protein microenvironment surrounding the flavin cofactor in flavoenzymes is key to the efficiency and diversity of reactions catalysed by this class of enzymes. X-ray diffraction structures of oxidoreductase flavoenzymes have revealed recurrent features which facilitate catalysis, such as a hydrogen bond between a main chain nitrogen atom and the flavin redox center (N5). A neutron diffraction study of cholesterol oxidase has revealed an unusual elongated main chain nitrogen to hydrogen bond distance positioning the hydrogen atom towards the flavin N5 reactive center...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28080034/mechanism-of-flavoprotein-l-6-hydroxynicotine-oxidase-ph-and-solvent-isotope-effects-and-identification-of-key-active-site-residues
#9
Paul F Fitzpatrick, Fatemeh Chadegani, Shengnan Zhang, Vi Dougherty
The flavoenzyme l-6-hydroxynicotine oxidase is a member of the monoamine oxidase family that catalyzes the oxidation of (S)-6-hydroxynicotine to 6-hydroxypseudooxynicotine during microbial catabolism of nicotine. While the enzyme has long been understood to catalyze oxidation of the carbon-carbon bond, it has recently been shown to catalyze oxidation of a carbon-nitrogen bond [Fitzpatrick, P. F., et al. (2016) Biochemistry 55, 697-703]. The effects of pH and mutagenesis of active site residues have now been utilized to study the mechanism and roles of active site residues...
February 14, 2017: Biochemistry
https://www.readbyqxmd.com/read/28070495/an-atypical-presentation-of-acad9-deficiency-diagnosis-by-whole-exome-sequencing-broadens-the-phenotypic-spectrum-and-alters-treatment-approach
#10
H K Aintablian, V Narayanan, N Belnap, K Ramsey, T A Grebe
Acyl-CoA dehydrogenase 9 (ACAD9), linked to chromosome 3q21.3, is one of a family of multimeric mitochondrial flavoenzymes that catalyze the degradation of fatty acyl-CoA from the carnitine shuttle via β-oxidation (He et al. 2007). ACAD9, specifically, is implicated in the processing of palmitoyl-CoA and long-chain unsaturated substrates, but unlike other acyl-CoA dehydrogenases (ACADs), it has a significant role in mitochondrial complex I assembly (Nouws et al. 2010 & 2014). Mutations in this enzyme typically cause mitochondrial complex I deficiency, as well as a mild defect in long chain fatty acid metabolism (Haack et al...
March 2017: Molecular Genetics and Metabolism Reports
https://www.readbyqxmd.com/read/28055208/thiol-based-probe-for-electrophilic-natural-products-reveals-that-most-of-the-ammosamides-are-artifacts
#11
Daniela Reimer, Chambers C Hughes
To date, 16 members of the ammosamide family of natural products have been discovered, and except for ammosamide D each of these metabolites is characterized by an unusual chlorinated pyrrolo[4,3,2-de]quinoline skeleton. Several ammosamides have been shown to inhibit quinone reductase 2, a flavoenzyme responsible for quelling toxic oxidative species in cells or for killing cancer cells outright. Treatment of the extract from an ammosamide-producing culture (Streptomyces strain CNR-698) with a thiol-based reagent designed to label electrophilic natural products produced an ammosamide C-thiol adduct...
January 27, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28032983/two-flavoenzymes-catalyze-the-post-translational-generation-of-5-chlorotryptophan-and-2-aminovinyl-cysteine-during-nai-107-biosynthesis
#12
Manuel A Ortega, Dillon P Cogan, Subha Mukherjee, Neha Garg, Bo Li, Gabrielle N Thibodeaux, Sonia I Maffioli, Stefano Donadio, Margherita Sosio, Jerome Escano, Leif Smith, Satish K Nair, Wilfred A van der Donk
Lantibiotics are ribosomally synthesized and post-translationally modified antimicrobial peptides containing thioether rings. In addition to these cross-links, the clinical candidate lantibiotic NAI-107 also possesses a C-terminal S-[(Z)-2-aminovinyl]-d-cysteine (AviCys) and a unique 5-chloro-l-tryptophan (ClTrp) moiety linked to its potent bioactivity. Bioinformatic and genetic analyses on the NAI-107 biosynthetic gene cluster identified mibH and mibD as genes encoding flavoenzymes responsible for the formation of ClTrp and AviCys, respectively...
February 17, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28032259/role-of-the-nad-p-h-quinone-oxidoreductase-nqr-and-the-cytochrome-b-air12-in-controlling-superoxide-generation-at-the-plasma-membrane
#13
Catherine Biniek, Eiri Heyno, Jerzy Kruk, Francesca Sparla, Paolo Trost, Anja Krieger-Liszkay
The quinone reductase NQR and the b-type cytochrome AIR12 of the plasma membrane are important for the control of reactive oxygen species in the apoplast. AIR12 and NQR are two proteins attached to the plant plasma membrane which may be important for generating and controlling levels of reactive oxygen species in the apoplast. AIR12 (Auxin Induced in Root culture) is a single gene of Arabidopsis that codes for a mono-heme cytochrome b. The NADPH quinone oxidoreductase NQR is a two-electron-transferring flavoenzyme that contributes to the generation of O 2(•-) in isolated plasma membranes...
April 2017: Planta
https://www.readbyqxmd.com/read/27995996/the-quantum-biology-of-reactive-oxygen-species-partitioning-impacts-cellular-bioenergetics
#14
Robert J Usselman, Cristina Chavarriaga, Pablo R Castello, Maria Procopio, Thorsten Ritz, Edward A Dratz, David J Singel, Carlos F Martino
Quantum biology is the study of quantum effects on biochemical mechanisms and biological function. We show that the biological production of reactive oxygen species (ROS) in live cells can be influenced by coherent electron spin dynamics, providing a new example of quantum biology in cellular regulation. ROS partitioning appears to be mediated during the activation of molecular oxygen (O2) by reduced flavoenzymes, forming spin-correlated radical pairs (RPs). We find that oscillating magnetic fields at Zeeman resonance alter relative yields of cellular superoxide (O2(•-)) and hydrogen peroxide (H2O2) ROS products, indicating coherent singlet-triplet mixing at the point of ROS formation...
December 20, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27992654/repair-of-6-4-lesions-in-dna-by-6-4-photolyase-20-years-of-quest-for-the-photoreaction-mechanism
#15
REVIEW
Junpei Yamamoto, Pascal Plaza, Klaus Brettel
Exposure of DNA to ultraviolet (UV) light from the Sun or from other sources causes the formation of harmful and carcinogenic crosslinks between adjacent pyrimidine nucleobases, namely cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts. Nature has developed unique flavoenzymes, called DNA photolyases, that utilize blue light, that is photons of lower energy than those of the damaging light, to repair these lesions. In this review, we focus on the chemically challenging repair of the (6-4) photoproducts by (6-4) photolyase and describe the major events along the quest for the reaction mechanisms, over the 20 years since the discovery of (6-4) photolyase...
December 19, 2016: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/27922192/evidence-for-pipecolate-oxidase-in-mediating-protection-against-hydrogen-peroxide-stress
#16
Sathish Kumar Natarajan, Ezhumalai Muthukrishnan, Oleh Khalimonchuk, Justin L Mott, Donald F Becker
Pipecolate, an intermediate of the lysine catabolic pathway, is oxidized to Δ(1) -piperideine-6-carboxylate (P6C) by the flavoenzyme l-pipecolate oxidase (PIPOX). P6C spontaneously hydrolyzes to generate α-aminoadipate semialdehyde, which is then converted into α-aminoadipate acid by α-aminoadipatesemialdehyde dehydrogenase. l-pipecolate was previously reported to protect mammalian cells against oxidative stress. Here, we examined whether PIPOX is involved in the mechanism of pipecolate stress protection...
December 6, 2016: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/27825927/flavin-dependent-methylation-of-rnas-complex-chemistry-for-a-simple-modification
#17
REVIEW
Djemel Hamdane, Henri Grosjean, Marc Fontecave
RNA methylation is the most abundant and evolutionarily conserved chemical modification of bases or ribose in noncoding and coding RNAs. This rather simple modification has nevertheless major consequences on the function of maturated RNA molecules and ultimately on their cellular fates. The methyl group employed in the methylation is almost universally derived from S-adenosyl-L-methionine via a simple SN2 displacement reaction. However, in some rare cases, the carbon originates from N5,N10-methylenetetrahydrofolate (CH2=THF)...
December 4, 2016: Journal of Molecular Biology
https://www.readbyqxmd.com/read/27816454/identification-of-an-extracellular-bacterial-flavoenzyme-that-can-prevent-re-polymerisation-of-lignin-fragments
#18
Rahman Rahmanpour, Lloyd D W King, Timothy D H Bugg
A significant problem in the oxidative breakdown of lignin is the tendency of phenolic radical fragments to re-polymerise to form higher molecular weight species. In this paper we identify an extracellular flavin-dependent dehydrolipoamide dehydrogenase from Thermobifida fusca that prevents oxidative dimerization of a dimeric lignin model compound, which could be used as an accessory enzyme for lignin depolymerisation.
January 1, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/27777067/securinine-disturbs-redox-homeostasis-and-elicits-oxidative-stress-mediated-apoptosis-via-targeting-thioredoxin-reductase
#19
Junmin Zhang, Juan Yao, Shoujiao Peng, Xinming Li, Jianguo Fang
Thioredoxin reductase (TrxR) and thioredoxin (Trx) are two major components of the thioredoxin system, which plays essential roles in regulating cellular redox signaling. Mammalian TrxRs are essential seleno-flavoenzymes with a conserved penultimate selenocysteine (Sec) residue at the C-terminus, and have attracted considerable interests as promising targets for anticancer drugs. Securinine (SCR), a major active alkaloid lactone from the Chinese herbal medicine Securinega suffruticosa, has been established clinical success in treatment of neurological disorders...
January 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27742866/engineering-a-trifunctional-proline-utilization-a-chimaera-by-fusing-a-dna-binding-domain-to-a-bifunctional-puta
#20
Benjamin W Arentson, Erin L Hayes, Weidong Zhu, Harkewal Singh, John J Tanner, Donald F Becker
Proline utilization A (PutA) is a bifunctional flavoenzyme with proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate (P5C) dehydrogenase (P5CDH) domains that catalyses the two-step oxidation of proline to glutamate. Trifunctional PutAs also have an N-terminal ribbon-helix-helix (RHH) DNA-binding domain and moonlight as autogenous transcriptional repressors of the put regulon. A unique property of trifunctional PutA is the ability to switch functions from DNA-bound repressor to membrane-associated enzyme in response to cellular nutritional needs and proline availability...
December 2016: Bioscience Reports
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