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Joseph Hosford, Morgane Valles, Florian W Krainer, Anton Glieder, Lu Shin Wong
Scanning probe lithography (SPL) offers a more accessible alternative to conventional photolithography as a route to surface nanofabrication. In principle, the synthetic scope of SPL could be greatly enhanced by combining the precision of scanning probe systems with the chemoselectivity offered by biocatalysis. This report describes the development of multiplexed SPL employing probes functionalized with horseradish peroxidase, and its subsequent use for the constructive fabrication of polyaniline features on both silicon oxide and gold substrates...
April 5, 2018: Nanoscale
Raziqa Hadjidj, Abdelmalek Badis, Sondes Mechri, Kamel Eddouaouda, Lamia Khelouia, Rachid Annane, Mohamed El Hattab, Bassem Jaouadi
A novel extracellular alkaline protease, called SAPHM, from Bacillus licheniformis K7A was purified by four steps procedure involving heat treatment (30 min at 70 °C) followed by ammonium sulfate precipitation (40-70%)-dialysis, UNO Q-12 FPLC, and ZORBAX PSM 300 HPLC, and submitted to biochemical characterization assays. The purified enzyme is a monomer of molecular mass of 30,325.12 Da. Its sequence of the 26 NH2 -terminal residues showed high homology with those of Bacillus proteases. The purified enzyme was optimally active at pH 10 and temperature 70 °C...
March 29, 2018: International Journal of Biological Macromolecules
Bing Liu, Lihui He, Liping Wang, Tao Li, Changcheng Li, Huayi Liu, Yunzi Luo, Rui Bao
Compared with traditional recycle strategies, biodegradation provides a sustainable solution for poly (ethylene terephthalate) (PET) wastes disposal. PETase, a newly identified enzyme from Ideonella sakaiensis, has high efficiency and specificity towards PET, which provides a prominent prospect on PET degradation. Based on the biochemical analysis, we propose that the wide substrate-binding pocket is critical for its excellent property on crystallized PET hydrolysis. Structure-guided site-directed mutagenesis exhibited improvement in PETase catalytic efficiency, providing valuable insight on how the molecular engineering of PETase can optimize its application in biocatalysis...
March 30, 2018: Chembiochem: a European Journal of Chemical Biology
Stanislava Voběrková, Veronika Solčány, Martina Vršanská, Vojtěch Adam
Ligninolytic enzymes from white-rot fungi are widely used in biotechnological processes. However, the application of these enzymes as free enzymes is limited due to their instability and lack of reusability. Enzyme stabilization is therefore a major challenge in biocatalytic process research, and immobilization methods are desirable. Using cross-linked enzyme aggregates (CLEAs) such as magnetic CLEAs, porous-CLEAs and combi-CLEAs is a promising technique for overcoming these issues. Cross-linking methods can stabilize and immobilize enzymes by interconnecting enzyme molecules via multiple bonds using cross-linking agents such as glutaraldehyde...
March 14, 2018: Chemosphere
Tongming Chen, Hang Zou, Xiaoju Wu, Chunchen Liu, Bo Situ, Lei Zheng, Guowei Yang
The enzymatic antioxidant system (EAS) guarantees the protection of aerobic cells from oxidative stress. However, it is delicate and susceptible of inactivation of extreme levels of reactive oxygen species (ROS). Here, we demonstrated that MoS2 nanosheets (few-layer MoS2), as a multifunctional nanozyme, possess intrinsic activity of mimicking enzymes of superoxide dismutases (SOD), catalases (CAT), and peroxidases (POD) under physiological conditions (pH 7.4, 25 oC). Further, MoS2 nanosheets showed POD-like activity by an electron transfer process instead of generating ROS...
March 29, 2018: ACS Applied Materials & Interfaces
Lunjie Huang, Wenxin Zhu, Wentao Zhang, Kai Chen, Jing Wang, Rong Wang, Qingfeng Yang, Na Hu, Yourui Suo, Jianlong Wang
The authors have discovered that vanadium disulfide (VS2 ) nanosheets, synthesized by a hydrothermal method, exert stable peroxidase-like activity. The catalytic activity, with H2 O2 as a cosubstrate, follows Michaelis-Menten kinetics and varies with temperature, pH value and H2 O2 concentration. Two-dimensional VS2 sheets acting as peroxidase (POx) mimics can replace horseradish peroxidase due to their availability, robustness, and reusability. The POx-like activity of VS2 sheets was exploited to design a colorimetric glucose assay by using 3,3',5,5'-tetramethylbenzidine as a substrate and by working at an analytical wavelength of 652 nm...
December 2, 2017: Mikrochimica Acta
Lionete Nunes de Lima, Adriano Aguiar Mendes, Roberto Fernandez-Lafuente, Paulo Waldir Tardioli, Raquel de Lima Camargo Giordano
Short-chain alkyl esters and sugar esters are widely used in the food, pharmaceutical and cosmetic industries due to their flavor and emulsifying characteristics, respectively. Both compounds can be synthesized via biocatalysis using lipases. This work aims to compare the performance of commercial lipases covalently attached to dry acrylic beads functionalized with oxirane groups (lipases from Candida antarctica type B-IMMCALB-T2-350, Pseudomonas fluorescens -IMMAPF-T2-150, and Thermomyces lanuginosus -IMMTLL-T2-150) and a home-made biocatalyst (lipase from Pseudomonas fluorescens adsorbed onto silica coated with octyl groups, named PFL-octyl-silica) in the syntheses of short- and long-chain carboxylic acid esters...
March 27, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Jiaheng Liu, Huiling Li, Guangrong Zhao, Qinggele Caiyin, Jianjun Qiao
NAD and NADP, a pivotal class of cofactors, which function as essential electron donors or acceptors in all biological organisms, drive considerable catabolic and anabolic reactions. Furthermore, they play critical roles in maintaining intracellular redox homeostasis. However, many metabolic engineering efforts in industrial microorganisms towards modification or introduction of metabolic pathways, especially those involving consumption, generation or transformation of NAD/NADP, often induce fluctuations in redox state, which dramatically impede cellular metabolism, resulting in decreased growth performance and biosynthetic capacity...
March 27, 2018: Journal of Industrial Microbiology & Biotechnology
T Krieg, L M P Phan, J A Wood, A Sydow, I Vassilev, J O Krömer, K-M Mangold, D Holtmann
Bioelectrochemical systems (BESs) have the potential to contribute to the energy revolution driven by the new bio-economy. Until recently, simple reactor designs with minimal process analytics have been used. In recent years, assemblies to host electrodes in bioreactors have been developed resulting in so-called "electrobioreactors". Bioreactors are scalable, well-mixed, controlled and therefore widely used in biotechnology and adding an electrode extends the possibilities to investigate bioelectrochemical production processes in a standard system...
March 26, 2018: Biotechnology and Bioengineering
Yuanzhi He, Feixue Chen, Meijing Sun, Huifang Gao, Zewang Guo, Hui Lin, Jiebo Chen, Wensong Jin, Yunlong Yang, Liaoyuan Zhang, Jun Yuan
(3 S )-Acetoin and (2 S ,3 S )-2,3-butanediol are important platform chemicals widely applied in the asymmetric synthesis of valuable chiral chemicals. However, their production by fermentative methods is difficult to perform. This study aimed to develop a whole-cell biocatalysis strategy for the production of (3 S )-acetoin and (2 S ,3 S )-2,3-butanediol from meso -2,3-butanediol. First, E. coli co-expressing (2 R ,3 R )-2,3-butanediol dehydrogenase, NADH oxidase and Vitreoscilla hemoglobin was developed for (3 S )-acetoin production from meso -2,3-butanediol...
March 19, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Nizaá Jiménez-Arroyo, Paloma C Gil-Rodríguez, Adelaida Díaz-Vilchis, Sonia P Rojas-Trejo, Enrique Rudiño-Piñera
Understanding Peroxidase (PRXs) enzymatic diversity and functional significance from a three-dimensional point of view is a key point for structural and mechanistic studies. In this context, Zo-peroxidase (ZoPrx) a member of the class III peroxidases and secreted by plants, differs from all previously described PRXs because of its remarkable catalytic stability in the presence of hydrogen peroxide. In this work, we present the crystallographic structure of ZoPrx isolated from Japanese radish, at 2.05 Å resolution...
March 2018: Biochemistry and Biophysics Reports
James W Hindley, Yuval Elani, Catriona M McGilvery, Simak Ali, Charlotte L Bevan, Robert V Law, Oscar Ces
Cell-sized vesicles have tremendous potential both as miniaturised pL reaction vessels and in bottom-up synthetic biology as chassis for artificial cells. In both these areas the introduction of light-responsive modules affords increased functionality, for example, to initiate enzymatic reactions in the vesicle interior with spatiotemporal control. Here we report a system composed of nested vesicles where the inner compartments act as phototransducers, responding to ultraviolet irradiation through diacetylene polymerisation-induced pore formation to initiate enzymatic reactions...
March 15, 2018: Nature Communications
Chandran Sathesh-Prabu, Sung Kuk Lee
The production of α,ω-dicarboxylic acids (DCAs) by whole-cell biocatalysis is often limited by cofactor regeneration. Here, ω-oxidation pathway genes (monooxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase) were co-expressed with a xylose reductase (XR) gene to regenerate cofactors in an engineered Escherichia coli strain that co-metabolizes glucose and xylose. The resulting strain exhibited a 180% increase in DCA production compared with the control strain without XR, and produced xylitol in the presence of xylose...
March 14, 2018: Journal of Agricultural and Food Chemistry
David Avnir
A unique materials' methodology enables the doping of metals with functional molecules, polymers, enzymes, and nanoparticles. The resulting materials have either the combined properties of the metal and the dopants, or new, sometimes synergetic properties that are not found in the separate components, emerge. Metals that have been doped so far include gold, silver, copper, iron, gallium, palladium, platinum, and several alloys. Numerous applications have been demonstrated including catalysis, biocatalysis, bioactivity, electrochemistry (including new type of batteries), corrosion resistance, induction of chirality, tailoring unconventional properties to metals, and more...
March 12, 2018: Advanced Materials
Nicholas J Turner, Rajesh Kumar
No abstract text is available yet for this article.
April 2018: Current Opinion in Chemical Biology
Garrett R Chado, Elijah N Holland, Andrew K Tice, Mark P Stoykovich, Joel L Kaar
Tuning the molecular interaction between enzymes and their solvent environment through polymer modification can greatly improve activity and thus utility in biocatalytic reactions. In this work, this approach was exploited to enhance the activity of lipase A (LipA) from Bacillus subtilis in anhydrous ionic liquids (IL), which are highly attractive solvents for biocatalysis. Specifically, we showed that the transesterification activity of LipA in anhydrous 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]) was improved up to 19-fold via covalently conjugating the enzyme with the IL-soluble polymer poly(4-acryloylmorpholine) (PAcMO)...
March 9, 2018: Biomacromolecules
Mathieu Odijk, Albert van den Berg
In this review, we summarize recent advances in nanoscale electrochemistry, including the use of nanoparticles, carbon nanomaterials, and nanowires. Exciting developments are reported for nanoscale redox cycling devices, which can chemically amplify signal readout. We also discuss promising high-frequency techniques such as nanocapacitive CMOS sensor arrays or heterodyning. In addition, we review electrochemical microreactors for use in (drug) synthesis, biocatalysis, water treatment, or to electrochemically degrade urea for use in a portable artificial kidney...
March 8, 2018: Annual Review of Analytical Chemistry
Vishruth Gowda, Brendan Foley, Jasmine Du, Megan Esteb, Coran M H Watanabe
Enzymes with a hydrophobic binding site and an active site lysine have been suggested to be promiscuous in their catalytic activity. β-Lactoglobulin (BLG), the principle whey protein found in milk, possesses a central calyx that binds non-polar molecules. Here, we report that BLG can catalyze the retro-aldol cleavage of α,β-unsaturated aldehydes making it a naturally occurring protein capable of catalyzing retro-aldol reactions on hydrophobic substrates. Retroaldolase activity was seen to be most effective on substrates with phenyl or naphthyl side-chains...
March 7, 2018: Organic & Biomolecular Chemistry
Suhui Ye, Alfredo F Braña, Javier González-Sabín, Francisco Morís, Carlos Olano, José A Salas, Carmen Méndez
Argimycins P are a recently identified family of polyketide alkaloids encoded by the cryptic gene cluster arp of Streptomyces argillaceus . These compounds contain either a piperideine ring, or a piperidine ring which may be fused to a five membered ring, and a polyene side chain, which is bound in some cases to an N -acetylcysteine moiety. The arp cluster consists of 11 genes coding for structural proteins, two for regulatory proteins and one for a hypothetical protein. Herein, we have characterized the post-piperideine ring biosynthesis steps of argimycins P through the generation of mutants in arp genes, the identification and characterization of compounds accumulated by those mutants, and cross-feeding experiments between mutants...
2018: Frontiers in Microbiology
Jelena Spasic, Mina Mandic, Lidija Djokic, Jasmina Nikodinovic-Runic
About 20,100 research publications dated 2000-2017 were recovered searching the PubMed and Web of Science databases for Streptomyces, which are the richest known source of bioactive molecules. However, these bacteria with versatile metabolism are powerful suppliers of biocatalytic tools (enzymes) for advanced biotechnological applications such as green chemical transformations and biopharmaceutical and biofuel production. The recent technological advances, especially in DNA sequencing coupled with computational tools for protein functional and structural prediction, and the improved access to microbial diversity enabled the easier access to enzymes and the ability to engineer them to suit a wider range of biotechnological processes...
March 3, 2018: Applied Microbiology and Biotechnology
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