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biocatalysis and enzyme

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https://www.readbyqxmd.com/read/30529567/a-novel-thermophilic-laccase-like-multicopper-oxidase-from-thermothelomyces-thermophila-and-its-application-in-the-oxidative-cyclization-of-2-3-4-trihydroxychalcone
#1
Anastasia Zerva, Efthymia Koutroufini, Ioanna Kostopoulou, Anastasia Detsi, Evangelos Topakas
Laccase-like multicopper oxidases (LMCOs) are a heterogeneous group of oxidases, acting mainly on phenolic compounds and which are widespread among many microorganisms, including Basidiomycetes and Ascomycetes. Here, we report the cloning, heterologous expression, purification and characterization of a novel LMCO from the thermophilic fungus Thermothelomyces thermophila. The 1953 bp lmco gene sequence comprises 3 exons interrupted by 2 introns and according to the LccED database the translated sequence belongs to superfamily 6 of multicopper oxidases...
December 5, 2018: New Biotechnology
https://www.readbyqxmd.com/read/30521853/tools-and-strategies-for-constructing-cell-free-enzyme-pathways
#2
REVIEW
Kerstin Petroll, Dominik Kopp, Andrew Care, Peter L Bergquist, Anwar Sunna
Single enzyme systems or engineered microbial hosts have been used for decades but the notion of assembling multiple enzymes into cell-free synthetic pathways is a relatively new development. The extensive possibilities that stem from this synthetic concept makes it a fast growing and potentially high impact field for biomanufacturing fine and platform chemicals, pharmaceuticals and biofuels. However, the translation of individual single enzymatic reactions into cell-free multi-enzyme pathways is not trivial...
December 3, 2018: Biotechnology Advances
https://www.readbyqxmd.com/read/30521785/molecular-optimization-of-autotransporter-based-tyrosinase-surface-display
#3
David Hörnström, Gen Larsson, Antonius J A van Maris, Martin Gustavsson
Display of recombinant enzymes on the cell surface of Gram-negative bacteria is a desirable feature with applications in whole-cell biocatalysis, affinity screening and degradation of environmental pollutants. One common technique for recombinant protein display on the Escherichia coli surface is autotransport. Successful autotransport of an enzyme largely depends on the following: (1) the size, sequence and structure of the displayed protein, (2) the cultivation conditions, and (3) the choice of the autotransporter expression system...
December 3, 2018: Biochimica et biophysica acta. Biomembranes
https://www.readbyqxmd.com/read/30511668/neutron-and-x-ray-crystal-structures-of-lactobacillus-brevis-alcohol-dehydrogenase-reveal-new-insights-into-hydrogen-bonding-pathways
#4
Johannes Hermann, Phillip Nowotny, Tobias E Schrader, Philipp Biggel, Dariusch Hekmat, Dirk Weuster-Botz
Lactobacillus brevis alcohol dehydrogenase (LbADH) is a well studied homotetrameric enzyme which catalyzes the enantioselective reduction of prochiral ketones to the corresponding secondary alcohols. LbADH is stable and enzymatically active at elevated temperatures and accepts a broad range of substrates, making it a valuable tool in industrial biocatalysis. Here, the expression, purification and crystallization of LbADH to generate large, single crystals with a volume of up to 1 mm3 suitable for neutron diffraction studies are described...
December 1, 2018: Acta Crystallographica. Section F, Structural Biology Communications
https://www.readbyqxmd.com/read/30507170/biocatalytic-degradation-of-parabens-mediated-by-cell-surface-displayed-cutinase
#5
Baotong Zhu, Na Wei
Parabens are emerging environmental contaminants with known endocrine-disrupting effects. This study created a novel biocatalyst (named as SDFsC) by expressing the enzyme Fusarium solani pisi cutinase (FsC) on the cell surface of Baker's yeast Sacchromyces cerevisiae and demonstrated successful enzyme-mediated removal of parabens for the first time. Parabens with different side chain structures had different degradation rates by the SDFsC. The SDFsC preferentially degraded the parabens with relatively long alkyl or aromatic side chains...
December 3, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/30500101/synthesis-and-biochemical-evaluation-of-nicotinamide-derivatives-as-nadh-analogues-in-ene-reductase
#6
Natashya Falcone, Zhe She, Jebreil Syed, Alan Lough, Heinz-Bernhard Kraatz
Nicotinamide and pyridine-containing conjugates have attracted a lot of attention in research as they have found use in a wide range of applications including as redox flow batteries, calcium channel blockers, and in biocatalysis, and metabolism. The interesting redox character of the compounds' pyridine/dihydropyridine system allows them to possess very similar, if not able to mimic, the functions and characteristics of the natural chiral redox agents NAD+/NADH. Considerable interest has been given in designing and synthesizing NAD+/NADH mimics with similar redox properties...
November 30, 2018: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/30488166/whole-cell-biocatalysis-in-ionic-liquids
#7
Ngoc Lan Mai, Yoon-Mo Koo
The use of whole-cell biocatalysis in ionic liquid (IL)-containing systems has attracted increasing attention in recent years. Compared to bioreactions catalyzed by isolated enzymes, the major advantage of using whole cells in biocatalytic processes is that the cells provide a natural intracellular environment for the enzymes to function with in situ cofactor regeneration. To date, the applications of whole-cell biocatalysis in IL-containing systems have focused on the production of valuable compounds, mainly through reduction, oxidation, hydrolysis, and transesterification reactions...
November 29, 2018: Advances in Biochemical Engineering/biotechnology
https://www.readbyqxmd.com/read/30485666/whole-cell-biocatalysis-platform-for-gram-scale-oxidative-dearomatization-of-phenols
#8
Summer A Baker Dockrey, Tyler J Doyon, Jonathan C Perkins, Alison R H Narayan
Technologies enabling new enzyme discovery and efficient protein engineering have spurred intense interest in the development of biocatalytic reactions. In recent years, whole-cell biocatalysis has received attention as a simple, efficient, and scalable biocatalytic reaction platform. Inspired by these developments, we have established a whole-cell protocol for oxidative dearomatization of phenols using the flavin-dependent monooxygenase, TropB. This approach provides a scalable biocatalytic platform for accessing gram-scale quantities of chiral synthetic building blocks...
November 28, 2018: Chemical Biology & Drug Design
https://www.readbyqxmd.com/read/30481644/immobilized-baliospermum-montanum-hydroxynitrile-lyase-catalyzed-synthesis-of-chiral-cyanohydrins
#9
Nisha Jangir, Santosh Kumar Padhi
Hydroxynitrile lyase (HNL) catalyzed enantioselective CC bond formation is an efficient approach to synthesize chiral cyanohydrins which are important building blocks in the synthesis of a number of fine chemicals, agrochemicals and pharmaceuticals. Immobilization of HNL is known to provide robustness, reusability and in some cases also enhances activity and selectivity. We optimized the preparation of immobilization of Baliospermium montanum HNL (BmHNL) by cross linking enzyme aggregate (CLEA) method and characterized it by SEM...
November 19, 2018: Bioorganic Chemistry
https://www.readbyqxmd.com/read/30478460/dna-flower-encapsulated-horseradish-peroxidase-with-enhanced-biocatalytic-activity-synthesized-by-an-isothermal-one-pot-method-based-on-rolling-circle-amplification
#10
Yongcun Yan, Juan Li, Wenhui Li, Ye Wang, Weiling Song, Sai Bi
DNA nanotechnology has been developed to construct a variety of functional two- and three-dimensional structures for versatile applications. Rolling circle amplification (RCA) has become prominent in the assembly of DNA-inorganic composites with hierarchical structures and attractive properties. Here, we demonstrate a one-pot method to directly encapsulate horseradish peroxidase (HRP) in DNA flowers (DFs) during RCA. The growing DNA strands and Mg2PPi crystals lead to the construction of porous DFs, which provide sufficient interaction sites for spontaneously incorporating HRP molecules into DFs with high loading capacity and good stability...
November 27, 2018: Nanoscale
https://www.readbyqxmd.com/read/30475592/construction-of-enzyme-cofactor-mediator-conjugates-for-enhanced-in-vitro-bioelectricity-generation
#11
Haiyan Song, Chunling Ma, Wei Zhou, Chun You, Yi-Heng P Job Zhang, Zhiguang Zhu
Cofactor-dependent oxidoreduction and electron transfer play an important role in in vitro bioelectricity generation and many other enzyme biocatalysis reactions. To facilitate such electron generation and transfer, several approaches based on the coimmobilization of cofactors and oxidoreductases have been demonstrated. Herein, a convenient and immobilization-free approach of constructing enzyme-cofactor and enzyme-mediator conjugates was developed. The in vitro bioelectricity generation reactions via enzymatic fuel cells were evaluated...
November 29, 2018: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/30471671/integrating-biocatalysis-and-multicomponent-reactions
#12
REVIEW
Chiara Lambruschini, Andrea Basso, Luca Banfi
While often multicomponent reactions (MCR) are used for the diversity-oriented synthesis of racemic (or achiral) molecular entities, this short review describes two alternative approaches for accessing enantiopure products exploiting the power of biocatalysis. Enzymes or microorganisms may be used for preparing enantiopure MCR inputs or for resolving racemic (or achiral) MCR adducts.
November 2018: Drug Discovery Today. Technologies
https://www.readbyqxmd.com/read/30458384/whole-cell-based-synthetic-enzyme-cascades-light-and-shadow-of-a-promising-technology
#13
REVIEW
Florian Rudroff
Mimicking Nature by biocatalytic cascade reactions in a whole-cell environment is a revolutionary development in multistep synthesis for the production of bulk and fine chemicals. In the past decade, several proof of concept success stories demonstrated the power of those synthetic cascades and paved the road for future industrial applications. Although enzymes and their promiscuity are best suited to construct such artificial pathways, the complexity and the lack of understanding of the cellular machinery slowed down this progress significantly...
November 17, 2018: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/30445665/molecular-mechanism-of-enzyme-tolerance-against-organic-solvents-insights-from-molecular-dynamics-simulation
#14
Mahnaz Mohtashami, Jamshid Fooladi, Aliakbar Haddad-Mashadrizeh, Mohammad Reza Housaindokht, Hassan Monhemi
Biocatalysis in presence of organic solvents has numerous industrially attractive advantages in comparison to traditional aqueous solvents. In some cases, the presence of organic molecules such as methanol in the processes such as enzymatic production of biodiesel is inevitable. However, enzyme inactivation and/or instability in organic solvents limits such biotechnological processes. Although it was found that some enzymes are more and others are less tolerant against organic solvents, the structural basis of such differences is relatively unknown...
October 26, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/30445133/computation-aided-rational-design-of-a-halophilic-choline-kinase-for-cytidine-diphosphate-choline-production-in-high-salt-condition
#15
Cheng Zheng, Zhenjian Li, Haifeng Yang, Tianyi Zhang, Huanqing Niu, Dong Liu, Junzhi Wang, Hanjie Ying
Biocatalysis has become the main approach to produce cytidine diphosphate choline (CDP-choline), which has been applied for treatment of acute craniocerebral injury and consciousness after brain surgery. However, salt accumulates with the production and inhibits enzyme activity, and eventually reduces yield and product accumulation rate. Our work provided a possible solution to this problem by applying a computational designed halophilic choline kinase. The halotolerant CKI (choline kinase) was designed following a unique strategy considering the most variable residue positions on the protein surface among target enzymes from different sources...
November 13, 2018: Journal of Biotechnology
https://www.readbyqxmd.com/read/30417568/revisiting-the-origin-of-bacterial-bioluminescence-qm-mm-study-on-oxygenation-reaction-of-reduced-flavin-in-protein
#16
Yanling Luo, Ya-Jun Liu
Bacterial bioluminescence is initiated by the oxygenation reaction of reduced flavin mononucleotide in luciferase. This enzymatic oxygenation occurs in a wide range of biological processes including cellular redox metabolism, biocatalysis, biosynthesis and homeostasis. However, little is known about the mechanism of the enzymatic reaction between singlet reduced flavin and triplet oxygen. To explore the enigmatic oxygenation, for the first time, the reaction of reduced flavin anion with oxygen was studied in bacterial luciferase by a combined quantum mechanics and molecular mechanics method as well as molecular dynamics simulation...
November 11, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/30398344/wearable-bioelectronics-enzyme-based-body-worn-electronic-devices
#17
Jayoung Kim, Itthipon Jeerapan, Juliane R Sempionatto, Abbas Barfidokht, Rupesh K Mishra, Alan S Campbell, Lee J Hubble, Joseph Wang
In this Account, we detail recent progress in wearable bioelectronic devices and discuss the future challenges and prospects of on-body noninvasive bioelectronic systems. Bioelectronics is a fast-growing interdisciplinary research field that involves interfacing biomaterials with electronics, covering an array of biodevices, encompassing biofuel cells, biosensors, ingestibles, and implantables. In particular, enzyme-based bioelectronics, built on diverse biocatalytic reactions, offers distinct advantages and represents a centerpiece of wearable biodevices...
November 6, 2018: Accounts of Chemical Research
https://www.readbyqxmd.com/read/30371985/mesoporous-encapsulated-chiral-nanogold-used-for-enantioselective-reaction
#18
Xiaogang Qu, Ya Zhou, Hanjun Sun, Hongcheng Xu, Silvina Matysiak, Jinsong Ren
Although various nanomaterials have been designed for biocatalysis, few of them can accelerate chemical reactions with high selectivity and stereocontrol, which remains them from being perfect alternatives to nature enzymes. Herein, inspired by the natural enzymes, an enantioselective nanomaterial has been constructed, with gold nanoparticles (AuNPs) as active centers, chiral cysteine (Cys) as selectors for chiral recognition and expanded mesoporous silica (EMSN) as skeleton of the artificial enzyme. In the oxidation of chiral 3,4-dihydroxy-phenylalanine (DOPA), the nanozyme with D-Cys shows preference to L-DOPA while the artificial enzyme with L-Cys shows preference to D-DOPA...
October 29, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/30369915/catalytic-performance-of-a-class-iii-old-yellow-enzyme-and-its-cysteine-variants
#19
Anika Scholtissek, Eric Gädke, Caroline E Paul, Adrie H Westphal, Willem J H van Berkel, Dirk Tischler
Class III old yellow enzymes (OYEs) contain a conserved cysteine in their active sites. To address the role of this cysteine in OYE-mediated asymmetric synthesis, we have studied the biocatalytic properties of OYERo2a from Rhodococcus opacus 1CP (WT) as well as its engineered variants C25A, C25S and C25G. OYERo2a in its redox resting state (oxidized form) is irreversibly inactivated by N -methylmaleimide. As anticipated, inactivation does not occur with the Cys variants. Steady-state kinetics with this maleimide substrate revealed that C25S and C25G doubled the turnover frequency ( k cat ) while showing increased K M values compared to WT, and that C25A performed more similar to WT...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/30369053/ancestral-diterpene-cyclases-show-increased-thermostability-and-substrate-acceptance
#20
Natalie M Hendrikse, Gwenaëlle Charpentier, Erik Nordling, Per-Olof Syrén
Bacterial diterpene cyclases are receiving increasing attention in biocatalysis and synthetic biology for the sustainable generation of complex multicyclic building blocks. Herein, we explore the potential of ancestral sequence reconstruction (ASR) to generate remodeled cyclases with enhanced stability, activity, and promiscuity. Putative ancestors of spiroviolene synthase, a bacterial class I diterpene cyclase, display an increased yield of soluble protein of up to fourfold upon expression in the model organism Escherichia coli...
October 28, 2018: FEBS Journal
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