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Biocatalysis

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https://www.readbyqxmd.com/read/28320294/solid-gas-biocatalysis
#1
REVIEW
L M Kulishova, D O Zharkov
Solid/gas biocatalysis is a nontraditional reaction system that employs the ability of some enzymes, being in the solid state, to catalyze reactions of substrates in the gas phase. Manipulation of the reaction parameters (temperature and pressure) in the solid/gas system allows precise control over the thermodynamic activity of water and substrate and creation of a controlled microenvironment for the enzyme, making it an appropriate model for enzymology studies. Owing to such advantages as high stability of dry enzymes and cofactors and easy fractionation of gas mixtures, solid/gas biotechnology has already found several industrial applications...
February 2017: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/28299937/noncovalent-protein-and-peptide-functionalization-of-single-walled-carbon-nanotubes-for-biodelivery-and-optical-sensing-applications
#2
Alessandra Antonucci, Justyna Kupis-Rozmysłowicz, Ardemis A Boghossian
The exquisite structural and optical characteristics of single-walled carbon nanotubes (SWCNTs), combined with the tunable specificities of proteins and peptides, can be exploited to strongly benefit technologies with applications in fields ranging from biomedicine to industrial biocatalysis. The key to exploiting the synergism of these materials is designing protein/peptide-SWCNT conjugation schemes that preserve biomolecule activity while keeping the near-infrared optical and electronic properties of SWCNTs intact...
March 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28297194/corrigendum-merging-iron-catalysis-and-biocatalysis-iron-carbonyl-complexes-as-efficient-hydrogen-autotransfer-catalysts-in-dynamic-kinetic-resolutions
#3
Osama El-Sepelgy, Nurtalya Alandini, Magnus Rueping
No abstract text is available yet for this article.
March 13, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28287660/biocatalysis-engineering-the-big-picture
#4
Roger A Sheldon, Pedro C Pereira
In this tutorial review we describe a holistic approach to the invention, development and optimisation of biotransformations utilising isolated enzymes. Increasing attention to applied biocatalysis is motivated by its numerous economic and environmental benefits. Biocatalysis engineering concerns the development of enzymatic systems as a whole, which entails engineering its different components: substrate engineering, medium engineering, protein (enzyme) engineering, biocatalyst (formulation) engineering, biocatalytic cascade engineering and reactor engineering...
March 13, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28286694/highly-stereoselective-biocatalytic-synthesis-of-key-cyclopropane-intermediate-to-ticagrelor
#5
Kari E Hernandez, Hans Renata, Russell D Lewis, S B Jennifer Kan, Chen Zhang, Jared Forte, David Rozzell, John A McIntosh, Frances H Arnold
Extending the scope of biocatalysis to important non-natural reactions such as olefin cyclopropanation will open new opportunities for replacing multi-step chemical syntheses of pharmaceutical intermediates with efficient, clean, and highly selective enzyme-catalyzed processes. In this work, we engineered the truncated globin of Bacillus subtilis for the synthesis of a cyclopropane precursor to the antithrombotic agent ticagrelor. The engineered enzyme catalyzes the cyclopropanation of 3,4-difluorostyrene with ethyl diazoacetate on a preparative scale to give ethyl-(1R, 2R)-2-(3,4-difluorophenyl)-cyclopropanecarboxylate in 79% yield, with very high diastereoselectivity (>99% dr) and enantioselectivity (98% ee), enabling a single-step biocatalytic route to this pharmaceutical intermediate...
November 4, 2016: ACS Catalysis
https://www.readbyqxmd.com/read/28286413/optimising-terpene-synthesis-with-flow-biocatalysis
#6
Xiaoping Tang, Rudolf K Allemann, Thomas Wirth
Sesquiterpenes are an important family of natural products, many of which exhibit important pharmaceutical and agricultural properties. They are biosynthesised from farnesyl diphosphate in sesquiterpene synthase catalysed reactions. Here, we report the development of a highly efficient segmented flow system for the enzyme-catalysed continuous flow production of sesquiterpenes. Design of experiment (DoE) methods were used to optimise the performance of the flow biocatalysis, and quantitative yields were achieved by using an operationally simple but highly effective segmented flow system...
January 10, 2017: European Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28284313/one-step-combined-focused-eppcr-and-saturation-mutagenesis-for-thermostability-evolution-of-a-new-cold-active-xylanase
#7
Juan Pablo Acevedo, Manfred T Reetz, Juan A Asenjo, Loreto P Parra
Enzymes active at low temperature are of great interest for industrial bioprocesses due to their high efficiency at a low energy cost. One of the particularities of naturally evolved cold-active enzymes is their increased enzymatic activity at low temperature, however the low thermostability presented in this type of enzymes is still a major drawback for their application in biocatalysis. Directed evolution of cold-adapted enzymes to a more thermostable version, appears as an attractive strategy to fulfill the stability and activity requirements for the industry...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28282058/sequence-controlled-methacrylic-multiblock-copolymers-via-sulfur-free-raft-emulsion-polymerization
#8
Nikolaos G Engelis, Athina Anastasaki, Gabit Nurumbetov, Nghia P Truong, Vasiliki Nikolaou, Ataulla Shegiwal, Michael R Whittaker, Thomas P Davis, David M Haddleton
Translating the precise monomer sequence control achieved in nature over macromolecular structure (for example, DNA) to whole synthetic systems has been limited due to the lack of efficient synthetic methodologies. So far, chemists have only been able to synthesize monomer sequence-controlled macromolecules by means of complex, time-consuming and iterative chemical strategies such as solid-state Merrifield-type approaches or molecularly dissolved solution-phase systems. Here, we report a rapid and quantitative synthesis of sequence-controlled multiblock polymers in discrete stable nanoscale compartments via an emulsion polymerization approach in which a vinyl-terminated macromolecule is used as an efficient chain-transfer agent...
February 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28273118/simultaneous-photocatalytic-and-microbial-degradation-of-dye-containing-wastewater-by-a-novel-g-c3n4-p25-photosynthetic-bacteria-composite
#9
Xinying Zhang, Yan Wu, Gao Xiao, Zhenping Tang, Meiyin Wang, Fuchang Liu, Xuefeng Zhu
Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation...
2017: PloS One
https://www.readbyqxmd.com/read/28259085/recent-advances-in-methyltransferase-biocatalysis
#10
REVIEW
Matthew R Bennett, Sarah A Shepherd, Victoria A Cronin, Jason Micklefield
S-adenosyl-L-methionine-dependent methyltransferses are ubiquitous in nature, methylating a vast range of small molecule metabolites, as well as biopolymers. This review covers the recent advances in the development of methyltransferase enzymes for synthetic applications, focusing on the methyltransferase catalyzed transformations with S-adenosyl methionine analogs, as well as non-native substrates. We discuss how metabolic engineering approaches have been used to enhance S-adenosyl methionine production in vivo...
March 2, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28259084/redesign-of-water-networks-for-efficient-biocatalysis
#11
REVIEW
Michael J Fink, Per-Olof Syrén
Herein we highlight recent findings on the importance of water networks in proteins, and their redesign and reconfiguration as a new engineering strategy to generate enzymes with modulated binding affinity and improved catalytic versatility. Traditionally, enzyme engineering and drug design have focused on tailoring direct and favorable interactions between protein surfaces and ligands/transition states to achieve stronger binding, or an accelerated manufacturing of medicines, biofuels, fine chemicals and materials...
March 18, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28256275/biocatalytic-phosphorylations-of-metabolites-past-present-and-future
#12
REVIEW
Roland Wohlgemuth, Andreas Liese, Wolfgang Streit
Phosphorus is a key element for life that occurs in living cells as a structural part of many key biochemicals. Phosphorus plays important functional roles in biocatalysis, such as making metabolic reaction steps irreversible by transferring energy-rich groups, using phosphate groups as leaving groups, or selectively hydrolyzing phosphorus-oxygen or phosphorus-nitrogen bonds. The large number of biocatalysts known to catalyze the transfer of phosphorus-containing groups from donor molecules to acceptor molecules covers a wide variety of reaction classes...
February 27, 2017: Trends in Biotechnology
https://www.readbyqxmd.com/read/28251390/co-expression-of-l-glutamate-oxidase-and-catalase-in-escherichia-coli-to-produce-%C3%AE-ketoglutaric-acid-by-whole-cell-biocatalyst
#13
Qingdai Liu, Xiaoqian Ma, Haijiao Cheng, Ning Xu, Jun Liu, Yanhe Ma
OBJECTIVES: To improve the production of α-ketoglutaric acid (α-KG) from L-glutamate by whole-cell biocatalysis. RESULTS: A novel and highly active L-glutamate oxidase, SmlGOX, from Streptomyces mobaraensis was overexpressed and purified. The recombinant SmlGOX was approx. 64 kDa by SDS-PAGE. SmlGOX had a maximal activity of 125 ± 2.7 U mg(-1) at pH 6.0, 35 (o)C. The apparent Km and Vmax values of SmlGOX were 9.3 ± 0.5 mM and 159 ± 3 U mg(-1), respectively...
March 1, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28251267/systematic-comparison-of-co-expression-of-multiple-recombinant-thermophilic-enzymes-in-escherichia-coli-bl21-de3
#14
Hui Chen, Rui Huang, Y-H Percival Zhang
The precise control of multiple heterologous enzyme expression levels in one Escherichia coli strain is important for cascade biocatalysis, metabolic engineering, synthetic biology, natural product synthesis, and studies of complexed proteins. We systematically investigated the co-expression of up to four thermophilic enzymes (i.e., α-glucan phosphorylase (αGP), phosphoglucomutase (PGM), glucose 6-phosphate dehydrogenase (G6PDH), and 6-phosphogluconate dehydrogenase (6PGDH)) in E. coli BL21(DE3) by adding T7 promoter or T7 terminator of each gene for multiple genes in tandem, changing gene alignment, and comparing one or two plasmid systems...
March 1, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28243985/efficient-synthesis-of-s-n-boc-3-hydroxypiperidine-using-an-r-specific-carbonyl-reductase-from-candida-parapsilosis
#15
Jingjing Chen, Ming Yan, Lin Xu
(S)-N-Boc-3-hydroxypiperidine (S-NBHP) is a critical chiral intermediate in the synthesis of pharmaceuticals, including ibrutinib, the active pharmaceutical ingredient of the new drug Imbruvica approved for the treatment of lymphoma. An (R)-specific carbonyl reductase from Candida parapsilosis (CprCR, also known as R-specific alcohol dehydrogenase) that catalyzes asymmetric reduction to produce (S)-N-Boc-3-hydroxypiperidine (S-NBHP) was identified for the first time. When co-expressed with a glucose dehydrogenase from Bacillus megaterium in Escherichia coli Rosetta (DE3), recombinant crude enzyme exhibited an activity of 9 U/mg with N-Boc-3-piperidone as the substrate and 12 U/mg with glucose as the substrate...
March 2017: World Journal of Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28238759/in-vitro-metabolic-engineering-for-the-production-of-%C3%AE-ketoglutarate
#16
Barbara Beer, André Pick, Volker Sieber
α-Ketoglutarate (aKG) represents a central intermediate of cell metabolism. It is used for medical treatments and as a chemical building block. Enzymatic cascade reactions have the potential to sustainably synthesize this natural product. Here we report a systems biocatalysis approach for an in vitro reaction set-up to produce aKG from glucuronate using the oxidative pathway of uronic acids. Because of two dehydrations, a decarboxylation, and reaction conditions favoring oxidation, the pathway is driven thermodynamically towards complete product formation...
February 22, 2017: Metabolic Engineering
https://www.readbyqxmd.com/read/28221702/localized-and-controlled-delivery-of-nitric-oxide-to-the-conventional-outflow-pathway-via-enzyme-biocatalysis-toward-therapy-for-glaucoma
#17
Rona Chandrawati, Jason Y H Chang, Ester Reina-Torres, Coline Jumeaux, Joseph M Sherwood, W Daniel Stamer, Alexander N Zelikin, Darryl R Overby, Molly M Stevens
Nitric oxide (NO) is able to lower intraocular pressure (IOP); however, its therapeutic effects on outflow physiology are location- and dose-dependent. An NO delivery platform that directly targets the resistance-generating region of the conventional outflow pathway and locally liberates a controlled dose of NO is reported. An increase in outflow facility (decrease in IOP) is demonstrated in a mouse model.
February 21, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28220537/immobilization-of-horseradish-peroxidase-on-zno-nanowires-macroporous-sio2-composites-for-the-complete-decolorization-of-anthraquinone-dyes
#18
Huaiyan Sun, Xinyu Jin, Feng Jiang, Ruifeng Zhang
A Zinc Oxide (ZnO) nanowires/ macroporous Silicon dioxide (SiO2 ) composite was used as support to immobilize horseradish peroxidase (HRP) simply by in-situ cross-linking method. As cross-linker was adsorbed on the surface of ZnO nanowires, the cross-linked HRP was quite different from the traditional cross-linking enzyme aggregates (CLEAs) on both structure and catalytic performance. Among three epoxy compounds diethylene glycol diglycidyl ether (DDE) was the best cross-linker, with which the loading amount of HRP with pI of 5...
February 21, 2017: Biotechnology and Applied Biochemistry
https://www.readbyqxmd.com/read/28217846/enhanced-peroxidase-like-performance-of-gold-nanoparticles-by-hot-electrons
#19
Xinghua Xia, Chen Wang, Yi Shi, Xing-Guo Nie, Yuan-Yuan Dan, Jian Li
Enzyme mimics have been widely used as alternatives to natural enzymes. However, the catalytic performances of enzyme mimics are often decreased due to different spatial structures or absence of functional groups compared to natural enzymes. Herein, we report a highly efficient enzyme-like catalytic performance of gold nanoparticles (AuNPs) by visible light stimulation. The enzyme-like reaction is evaluated by the catalytic reaction of AuNPs oxidizing a typical chromogenic substrate 3, 3', 5, 5'-tetramethylbenzydine (TMB) with hydrogen peroxide as an oxidant...
February 20, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28215518/rational-engineering-of-diol-dehydratase-enables-1-4-butanediol-biosynthesis-from-xylose
#20
Jia Wang, Rachit Jain, Xiaolin Shen, Xinxiao Sun, Mengyin Cheng, James C Liao, Qipeng Yuan, Yajun Yan
Establishing novel synthetic routes for microbial production of chemicals often requires overcoming pathway bottlenecks by tailoring enzymes to enhance bio-catalysis or even achieve non-native catalysis. Diol dehydratases have been extensively studied for their interactions with C2 and C3 diols. However, attempts on utilizing these insights to enable catalysis on non-native substrates with more than two hydroxyl groups have been plagued with low efficiencies. Here, we rationally engineered the Klebsiella oxytoca diol dehydratase to enable and enhance catalytic activity toward a non-native C4 triol, 1,2,4-butanetriol...
February 13, 2017: Metabolic Engineering
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