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Food Research International (Ottawa,... May 2021Peroxidase is an enzyme in the group of oxidoreductases that is widely distributed in nature. It can catalyze the oxidation of various organic and inorganic substrates... (Review)
Review
Peroxidase is an enzyme in the group of oxidoreductases that is widely distributed in nature. It can catalyze the oxidation of various organic and inorganic substrates by reacting with hydrogen peroxide and similar molecules. Due to its wide catalytic activity, peroxidases can act in the removal of both phenolic compounds and peroxides, in chemical synthesis and, according to recent studies, in mycotoxin degradation. Therefore, this study aimed at introducing an overview of the mechanism of peroxidase action, extraction sources, mycotoxin degradation capacity and other potential applications in the food industry.
Topics: Oxidation-Reduction; Oxidoreductases; Peroxidase; Peroxidases; Phenols
PubMed: 33992367
DOI: 10.1016/j.foodres.2021.110266 -
FEBS Letters Jun 2018Nitric oxide (NO) is an important gasotransmitter involved in numerous intra- and intercellular signaling events. In addition to the oxidative pathway of NO generation,... (Review)
Review
Nitric oxide (NO) is an important gasotransmitter involved in numerous intra- and intercellular signaling events. In addition to the oxidative pathway of NO generation, which includes three NO synthase (NOS) isoforms in mammals, a reductive pathway contributes to NO generation. In this pathway, nitrite is reduced to NO by various metal-containing proteins. Among these, all members of the eukaryotic molybdenum (Mo)-dependent enzyme family were found to be able to reduce nitrite to NO. This Review focuses on the current state of research in the field of Mo-dependent nitrite reduction in eukaryotes. An overview on the five eukaryotic Mo-enzymes is given, and similarities as well as differences in their nitrite reduction mechanisms are presented and discussed in the context of physiological relevance.
Topics: Aldehyde Oxidase; Animals; Biosynthetic Pathways; Humans; Molybdenum; Nitrate Reductase; Nitric Oxide; Nitrites; Oxidoreductases; Protein Conformation; Sulfite Oxidase; Xanthine Dehydrogenase
PubMed: 29749013
DOI: 10.1002/1873-3468.13089 -
Microbiology Spectrum Aug 2022Acetogenic bacteria are a group of strictly anaerobic bacteria that make a living from acetate formation from two molecules of CO via the Wood-Ljungdahl pathway (WLP)....
Acetogenic bacteria are a group of strictly anaerobic bacteria that make a living from acetate formation from two molecules of CO via the Wood-Ljungdahl pathway (WLP). The free energy change of this reaction is very small and allows the synthesis of only a fraction of an ATP. How this pathway is coupled to energy conservation has been an enigma since its discovery ~90 years ago. Here, we describe an electron transport chain in the cytochrome- and quinone-containing acetogen Sporomusa ovata that leads from molecular hydrogen as an electron donor to an intermediate of the WLP, methylenetetrahydrofolate (methylene-tetrahydrofolate [THF]), as an electron acceptor. The catalytic site of the hydrogenase is periplasmic and likely linked cytochrome to the membrane. We provide evidence that the MetVF-type methylenetetrahydrofolate reductase is linked proteins MvhD and HdrCBA to the cytoplasmic membrane. Membrane preparations catalyzed the H-dependent reduction of methylene-THF to methyl-THF. In our model, a transmembrane electrochemical H gradient is established by both scalar and vectorial protons that leads to the synthesis of 0.5 mol ATP/mol methylene-THF by a H-FF ATP synthase. This H- and methylene-THF-dependent electron transport chain may be present in other cytochrome-containing acetogens as well and represents a third way of chemiosmotic energy conservation in acetogens, but only in addition to the well-established respiratory enzymes Rnf and Ech. Acetogenic bacteria grow by making acetate from CO and are considered the first life forms on Earth since they couple CO reduction to the conservation of energy. How this is achieved has been an enigma ever since. Recently, two respiratory enzymes, a ferredoxin:NAD oxidoreductase (Rnf) and a ferredoxin:H oxidoreductase (Ech), have been found in cytochrome-free acetogenic model bacteria. However, some acetogens contain cytochromes in addition, and there has been a long-standing assumption of a cytochrome-containing electron transport chain in those acetogens. Here, we provide evidence for a respiratory chain in Sporomusa ovata that has a cytochrome-containing hydrogenase as the electron donor and a methylenetetrahydrofolate reductase as the terminal electron acceptor. This is the third way of chemiosmotic energy conservation found in acetogens.
Topics: Acetates; Adenosine Triphosphate; Bacteria; Carbon Dioxide; Energy Metabolism; Ferredoxins; Firmicutes; Hydrogenase; Methylenetetrahydrofolate Reductase (NADPH2); Oxidoreductases
PubMed: 35699467
DOI: 10.1128/spectrum.01385-22 -
International Journal of Molecular... Aug 2021Nitroaromatic compounds (ArNO) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation... (Review)
Review
Nitroaromatic compounds (ArNO) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.
Topics: Animals; Bacteria; Bacterial Proteins; Cytotoxins; Electrons; Flavoproteins; Humans; Nitro Compounds; Oxidation-Reduction; Oxidoreductases
PubMed: 34445240
DOI: 10.3390/ijms22168534 -
Scientific Reports Sep 2022In angiosperms, self-incompatibility (SI) is a common and widespread mechanism for plant prevention of inbreeding, and late-acting self-incompatibility (LSI) may be...
In angiosperms, self-incompatibility (SI) is a common and widespread mechanism for plant prevention of inbreeding, and late-acting self-incompatibility (LSI) may be ancestral in the group. In this work, we studied Schima superba, a species in Theaceae that is a commercially important timer and fire-resistant tree, and revealed its LSI mechanism. Hormones, enzymes, transcriptomes, and proteins were compared between self-pollination (SP) and outcross pollination (OP) in the styles and ovaries from 0 to 120 h after pollination. The self-pollen tubes grew to the bottom of the style and entered the ovary within 48 h but failed to penetrate the ovule. Meanwhile, the hormone and peroxidase levels dramatically changed. Transcriptome and proteome analyses explored the molecular mechanisms of LSI and candidate genes related to LSI in S. superba. Overall, 586.71 million reads were obtained, and 79,642 (39.08%) unigenes were annotated. KEGG and GO analysis showed that there were 4531 differentially expressed genes (DEGs) and 82 differentially expressed proteins (DEPs) at 48 h in self- (SP) versus outcross pollination (OP). Among these, 160 DEGs and 33 DEPs were involved in pollen-pistil interactions. "Pollen-pistil interaction," "signal recognition," and "component of membrane" were downregulated in SP, whereas "cell wall and membrane biosynthetic process," and "oxidoreductase activity" were upregulated. The DEGs involved with S-RNases and SCF during SP suggested that the LSI occurred at 48 h in the ovary and that the LSI in S. superba was under gametophyte control. Calcium ion increase and release, mitochondrial function loss, and ROS disruption further aggravated PCD progress and cell death. The LSI of S. superba, which happened 48 h after pollination, was a key time point. The incompatibility PT ceased growth in the ovary because of S-RNase recognition and PCD in this organ. This study highlights the LSI molecular mechanism in S. superba and provides a reference to other species in Theaceae.
Topics: Calcium; Hormones; Oxidoreductases; Peroxidases; Pollen; Proteome; Reactive Oxygen Species; Ribonucleases; Theaceae
PubMed: 36114363
DOI: 10.1038/s41598-022-19946-3 -
Journal of the Royal Society, Interface Jun 2017Enzymatic bioelectrocatalysis is being increasingly exploited to better understand oxidoreductase enzymes, to develop minimalistic yet specific biosensor platforms, and... (Review)
Review
Enzymatic bioelectrocatalysis is being increasingly exploited to better understand oxidoreductase enzymes, to develop minimalistic yet specific biosensor platforms, and to develop alternative energy conversion devices and bioelectrosynthetic devices for the production of energy and/or important chemical commodities. In some cases, these enzymes are able to electronically communicate with an appropriately designed electrode surface without the requirement of an electron mediator to shuttle electrons between the enzyme and electrode. This phenomenon has been termed direct electron transfer or direct bioelectrocatalysis. While many thorough studies have extensively investigated this fascinating feat, it is sometimes difficult to differentiate desirable enzymatic bioelectrocatalysis from electrocatalysis deriving from inactivated enzyme that may have also released its catalytic cofactor. This article will review direct bioelectrocatalysis of several oxidoreductases, with an emphasis on experiments that provide support for direct bioelectrocatalysis versus denatured enzyme or dissociated cofactor. Finally, this review will conclude with a series of proposed control experiments that could be adopted to discern successful direct electronic communication of an enzyme from its denatured counterpart.
Topics: Biosensing Techniques; Catalysis; Electrochemical Techniques; Electrophysiological Phenomena; Oxidoreductases; Protein Conformation
PubMed: 28637918
DOI: 10.1098/rsif.2017.0253 -
ChemSusChem Nov 2022Enzymatic processes, particularly those capable of performing redox reactions, have recently been of growing research interest. Substrate specificity, optimal activity... (Review)
Review
Enzymatic processes, particularly those capable of performing redox reactions, have recently been of growing research interest. Substrate specificity, optimal activity at mild temperatures, high selectivity, and yield are among the desirable characteristics of these oxidoreductase catalyzed reactions. Nicotinamide adenine dinucleotide (phosphate) or NAD(P)H-dependent oxidoreductases have been extensively studied for their potential applications like biosynthesis of chiral organic compounds, construction of biosensors, and pollutant degradation. One of the main challenges associated with making these processes commercially viable is the regeneration of the expensive cofactors required by the enzymes. Numerous efforts have pursued enzymatic regeneration of NAD(P)H by coupling a substrate reduction with a complementary enzyme catalyzed oxidation of a co-substrate. While offering excellent selectivity and high total turnover numbers, such processes involve complicated downstream product separation of a primary product from the coproducts and impurities. Alternative methods comprising chemical, electrochemical, and photochemical regeneration have been developed with the goal of enhanced efficiency and operational simplicity compared to enzymatic regeneration. Despite the goal, however, the literature rarely offers a meaningful comparison of the total turnover numbers for various regeneration methodologies. This comprehensive Review systematically discusses various methods of NAD(P)H cofactor regeneration and quantitatively compares performance across the numerous methods. Further, fundamental barriers to enhanced cofactor regeneration in the various methods are identified, and future opportunities are highlighted for improving the efficiency and sustainability of commercially viable oxidoreductase processes for practical implementation.
Topics: Biocatalysis; NAD; Niacinamide; Oxidation-Reduction; NADP; Oxidoreductases; Regeneration
PubMed: 36129761
DOI: 10.1002/cssc.202200888 -
Experimental Biology and Medicine... Mar 2015A number of key regulatory proteins contain one or two copies of the WW domain known to mediate protein-protein interaction via proline-rich motifs, such as PPxY. The... (Review)
Review
A number of key regulatory proteins contain one or two copies of the WW domain known to mediate protein-protein interaction via proline-rich motifs, such as PPxY. The Hippo pathway components take advantage of this module to transduce tumor suppressor signaling. It is becoming evident that tyrosine phosphorylation is a critical regulator of the WW proteins. Here, we review the current knowledge on the involved tyrosine kinases and their roles in regulating the WW proteins.
Topics: Humans; Oxidoreductases; Phosphorylation; Protein Binding; Protein Interaction Domains and Motifs; Protein-Tyrosine Kinases; Signal Transduction; Tumor Suppressor Proteins; Tyrosine; WW Domain-Containing Oxidoreductase
PubMed: 25627656
DOI: 10.1177/1535370214565991 -
Archives of Toxicology Aug 2022This is an overview of the metabolic reactions of drugs, natural products, physiological compounds, and other (general) chemicals catalyzed by flavin monooxygenase... (Review)
Review
This is an overview of the metabolic reactions of drugs, natural products, physiological compounds, and other (general) chemicals catalyzed by flavin monooxygenase (FMO), monoamine oxidase (MAO), NAD(P)H quinone oxidoreductase (NQO), and molybdenum hydroxylase enzymes (aldehyde oxidase (AOX) and xanthine oxidoreductase (XOR)), including roles as substrates, inducers, and inhibitors of the enzymes. The metabolism and bioactivation of selected examples of each group (i.e., drugs, "general chemicals," natural products, and physiological compounds) are discussed. We identified a higher fraction of bioactivation reactions for FMO enzymes compared to other enzymes, predominately involving drugs and general chemicals. With MAO enzymes, physiological compounds predominate as substrates, and some products lead to unwanted side effects or illness. AOX and XOR enzymes are molybdenum hydroxylases that catalyze the oxidation of various heteroaromatic rings and aldehydes and the reduction of a number of different functional groups. While neither of these two enzymes contributes substantially to the metabolism of currently marketed drugs, AOX has become a frequently encountered route of metabolism among drug discovery programs in the past 10-15 years. XOR has even less of a role in the metabolism of clinical drugs and preclinical drug candidates than AOX, likely due to narrower substrate specificity.
Topics: Aldehyde Oxidase; Biological Products; Humans; Molybdenum; Monoamine Oxidase; Oxidoreductases
PubMed: 35648190
DOI: 10.1007/s00204-022-03304-3 -
Chembiochem : a European Journal of... Jan 2022Ene-reductases from the Old Yellow Enzyme (OYE) superfamily are a well-known and efficient biocatalytic alternative for the asymmetric reduction of C=C bonds.... (Review)
Review
Ene-reductases from the Old Yellow Enzyme (OYE) superfamily are a well-known and efficient biocatalytic alternative for the asymmetric reduction of C=C bonds. Considering the broad variety of substituents that can be tolerated, and the excellent stereoselectivities achieved, it is apparent why these enzymes are so appealing for preparative and industrial applications. Different classes of C=C bonds activated by at least one electron-withdrawing group have been shown to be accepted by these versatile biocatalysts in the last decades, affording a vast range of chiral intermediates employed in the synthesis of pharmaceuticals, agrochemicals, flavours, fragrances and fine chemicals. In order to access both enantiomers of reduced products, stereodivergent pairs of OYEs are desirable, but their natural occurrence is limited. The detailed knowledge of the stereochemical course of the reaction can uncover alternative strategies to orient the selectivity via mutagenesis, evolution, and substrate engineering. An overview of the ongoing studies on OYE-mediated bioreductions will be provided, with particular focus on stereochemical investigations by deuterium labelling.
Topics: Molecular Structure; Oxidoreductases; Stereoisomerism
PubMed: 34586700
DOI: 10.1002/cbic.202100445