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Enzyme immobilization

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https://www.readbyqxmd.com/read/29148558/ultrasound-propelled-nanowire-motors-enhance-asparaginase-enzymatic-activity-against-cancer-cells
#1
Murat Uygun, Beatriz Jurado-Sánchez, Deniz Aktas Uygun, Virendra Vikram Singh, Liangfang Zhang, Joseph Wang
Ultrasound-(US) propelled nanowires consisting of Au/Ni/Au/PEDOT-PPy-COOH segments are modified with asparaginase enzyme and applied as an effective anti-cancer agent. After immobilization of asparaginase onto the surface of the nanowire motors, the enzyme displays enhanced thermal and pH stabilities, improved resistance towards protease, and higher affinity for the substrate. The fast motion of the motor-carrying asparaginase leads to greatly accelerated biocatalytic depletion of asparagine and hence to a significantly enhanced inhibition efficacy against El4 lymphoma cancer cells (92%) as compared to free enzyme counterpart (17%) and other control groups...
November 17, 2017: Nanoscale
https://www.readbyqxmd.com/read/29147710/step-by-step-build-up-of-covalent-poly-ethylene-oxide-nanogel-films
#2
S Zahouani, L Hurman, M De Giorgi, C Vigier-Carrière, F Boulmedais, B Senger, B Frisch, P Schaaf, P Lavalle, L Jierry
Hydrogels based on poly(ethylene glycol) (PEG) are commonly used for studies related to cell fate and tissue engineering. Here we present a new covalent layer-by-layer build-up process leading to PEG coatings of nanometer size called "nanogel films". Compared to macroscopic hydrogels, such nanogels should provide a fine control over the structure and the thickness of the coating. Alternated deposition of bifunctional and tetra functional PEG molecules reacting through thiol/maleimide click chemistry is evaluated by quartz crystal microbalance...
November 17, 2017: Nanoscale
https://www.readbyqxmd.com/read/29144385/preparation-and-characterization-of-cellulose-triacetate-as-support-for-lecitase-ultra-immobilization
#3
Francielle Batista da Silva, Wilson Galvão de Morais Júnior, Cleuzilene Vieira da Silva, Andressa Tironi Vieira, Antônio Carlos Ferreira Batista, Anízio Márcio de Faria, Rosana Maria Nascimento Assunção
The use of polymers as supports for enzyme immobilization is a strategy that enables to remove the enzymes from a chemical reaction and improve their efficiency in catalytic processes. In this work, cellulose triacetate (CTA) was used for physical adsorption of phospholipase Lecitase ultra (LU). CTA is more hydrophobic than cellulose, shows good performance in the lipases immobilization being a good candidate for immobilization of phospholipases. We investigated the immobilization of LU in CTA, the stability of the immobilized enzyme (CTA-LU) and the performance of CTA-LU using soybean oil as a substrate...
November 16, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29144009/immobilization-of-superoxide-dismutase-on-polyelectrolyte-functionalized-titania-nanosheets
#4
Paul Rouster, Marko Pavlovic, Istvan Szilagyi
Superoxide dismutase (SOD) enzyme was successfully immobilized on titania nanosheets (TNS) functionalized with poly(diallyldimethylammonium chloride) (PDADMAC) polyelectrolyte. The TNS-PDADMAC solid support was prepared by hydrothermal synthesis followed by self-assembled polyelectrolyte layer formation. It was found that the SOD strongly adsorbed on the oppositely charged TNS-PDADMAC through electrostatic and hydrophobic interactions. The TNS-PDADMAC-SOD material was characterized by light scattering and microscopy techniques...
November 16, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/29143760/nano-aptasensing-in-mycotoxin-analysis-recent-updates-and-progress
#5
REVIEW
Amina Rhouati, Gonca Bulbul, Usman Latif, Akhtar Hayat, Zhan-Hong Li, Jean Louis Marty
Recent years have witnessed an overwhelming integration of nanomaterials in the fabrication of biosensors. Nanomaterials have been incorporated with the objective to achieve better analytical figures of merit in terms of limit of detection, linear range, assays stability, low production cost, etc. Nanomaterials can act as immobilization support, signal amplifier, mediator and artificial enzyme label in the construction of aptasensors. We aim in this work to review the recent progress in mycotoxin analysis. This review emphasizes on the function of the different nanomaterials in aptasensors architecture...
October 28, 2017: Toxins
https://www.readbyqxmd.com/read/29138567/resveratrol-ameliorates-chronic-unpredictable-mild-stress-induced-depression-like-behavior-involvement-of-the-hpa-axis-inflammatory-markers-bdnf-and-wnt-%C3%AE-catenin-pathway-in-rats
#6
Xin-Hua Yang, Su-Qi Song, Yun Xu
Classic antidepressant drugs are modestly effective across the population and most are associated with intolerable side effects. Recently, numerous lines of evidence suggest that resveratrol (RES), a natural polyphenol, possesses beneficial therapeutic activity for depression. The aim of the present study was to explore whether RES exhibits an antidepressant-like effect in a depression model and to explore the possible mechanism. A depression model was established via chronic unpredictable mild stress (CUMS), after which the model rats in the RES and fluoxetine groups received a daily injection of RES or fluoxetine, respectively...
2017: Neuropsychiatric Disease and Treatment
https://www.readbyqxmd.com/read/29137708/smartphone-based-non-invasive-salivary-glucose-biosensor
#7
Anuradha Soni, Sandeep Kumar Jha
The present work deals with the development of a non-invasive optical glucose biosensor using saliva samples and a smartphone. The sensor was fabricated with a simple methodology by immobilization of Glucose oxidase enzyme along with a pH responsive dye on a filter paper based strip. The strip changes color upon reaction with glucose present in saliva and the color changes were detected using a smartphone camera through RGB profiling. This standalone biosensor showed good sensitivity and low interference while operating within 20 s response time...
December 15, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/29137135/an-electrochemical-enzyme-biosensor-for-3-hydroxybutyrate-detection-using-screen-printed-electrodes-modified-by-reduced-graphene-oxide-and-thionine
#8
Gonzalo Martínez-García, Elena Pérez-Julián, Lourdes Agüí, Naomí Cabré, Jorge Joven, Paloma Yáñez-Sedeño, José Manuel Pingarrón
A biosensor for 3-hydroxybutyrate (3-HB) involving immobilization of the enzyme 3-hydroxybutyrate dehydrogenase onto a screen-printed carbon electrode modified with reduced graphene oxide (GO) and thionine (THI) is reported here. After addition of 3-hydroxybutyrate or the sample in the presence of NAD⁺ cofactor, the generated NADH could be detected amperometrically at 0.0 V vs. Ag pseudo reference electrode. Under the optimized experimental conditions, a calibration plot for 3-HB was constructed showing a wide linear range between 0...
November 11, 2017: Biosensors
https://www.readbyqxmd.com/read/29136925/piezoelectric-biosensor-for-the-determination-of-tumor-necrosis-factor-alpha
#9
Miroslav Pohanka
Tumor Necrosis Factor Alpha (TNFα) is an important marker of inflammatory processes in human body. In the current healthcare, determination of TNFα blood or plasma level is done by Enzyme Linked Immuno-Sorbent Assay (ELISA) as a primary choice method. Piezoelectric immunosensors are analytical platform recording affinity interactions on their surface. It is inferred that the immunosensors would be a functional alternative to the ELISA. In this study, antibody against TNFα was immobilized on Quartz Crystal Microbalance (QCM) sensor and the same was made on magnetic particles...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136917/one-step-direct-immunoassay-with-horseradish-peroxidase-as-antigen-for-studying-the-functionality-of-antibody-surfaces
#10
G Coussot, C Faye, A Le Postollec, M Dobrijevic
Antibody-coated surfaces (Ab surfaces) play a key role in bioanalytical tools developed for biosensors and diagnostics. Therefore, a high and well-defined functional activity of the Ab surface is required. The functional activity of the Ab surface depends on its available binding sites i.e. "the active sites" that are able to capture antigen (Ag). The number of active binding sites strongly depends on the immobilization strategy used to fix the Ab on the solid surface. Determination of layer thickness or surface topology are often used to characterize the Ab surfaces but there is no gold standard method for the study of the functionality of the Ab surfaces...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136853/electrochemical-strategy-for-pyrophosphatase-detection-based-on-the-peroxidase-like-activity-of-g-quadruplex-cu-2-dnazyme
#11
Yonghong Wang, Yaohui Wu, Wen Liu, Lei Chu, Zhibin Liao, Wentao Guo, Gao-Qiang Liu, Xiaoxiao He, Kemin Wang
A new simple and highly sensitive electrochemical method for pyrophosphatase (PPase) activity detection was developed based on the peroxidase-like activity of G-quadruplex-Cu(2+) DNAzyme. In the absence of PPase, Cu(2+) could coordinate with pyrophosphate (PPi) to form Cu(2+)-PPi compound. While in the presence of PPase, it could destroy the coordinate compound because PPase catalyzed the hydrolysis of PPi into inorganic phosphate and produced free Cu(2+), which then could be coupled with G-rich DNA to form G-quadruplex-Cu(2+) DNAzyme...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136588/a-facile-way-to-fabricate-manganese-phosphate-self-assembled-carbon-networks-as-efficient-electrochemical-catalysts-for-real-time-monitoring-of-superoxide-anions-released-from-hepg2-cells
#12
Xuan Cai, Libo Shi, Wenqian Sun, Hongli Zhao, Hong Li, Haiyan He, Minbo Lan
Quantification of superoxide anions (O2(•-)) is significant in the monitoring of many serious diseases and the design of enzyme-mimic catalysts plays the main role in the development of non-enzymatic O2(•-) sensors. Herein, we proposed a facile self-assembly process to synthesize manganese phosphate modified carbon networks using three kinds of widely-used carbon materials (MWCNTs, NGS and GO) as pillar connectors. Characterizations demonstrate that manganese phosphate is widely dispersed inside and on the surface of carbon networks without visible morphology...
November 6, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29135232/confocal-raman-microscopy-for-the-determination-of-protein-and-quaternary-ammonium-ion-loadings-in-biocatalytic-membranes-for-electrochemical-energy-conversion-and-storage
#13
Rong Cai, Sofiene Abdellaoui, Jay P Kitt, Cullen Irvine, Joel Harris, Shelley D Minteer, Carol Korzeniewski
The need to immobilize active enzyme, while ensuring high rates of substrate turnover and electronic charge transfer with an electrode, is a centrally important challenge in the field of bioelectrocatalysis. In this work, we demonstrate the use of confocal Raman microscopy as a tool for quantitation and molecular-scale structural characterization of ionomers and proteins within biocatalytic membranes to aid in the development of energy efficient biofuel cells. A set of recently available short side chain Aquivion ionomers spanning a range of equivalent weight (EW) suitable for enzyme immobilization was investigated...
November 14, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29133199/isolation-and-characterization-of-a-novel-tyrosinase-produced-by-sahara-soil-actinobacteria-and-immobilization-on-nylon-nanofiber-membranes
#14
Mohammed Harir, Bellahcene Miloud, Maria Camilla Baratto, Simona Pollini, Gian Maria Rossolini, Lorenza Trabalzini, Enrico Fatarella, Rebecca Pogni
In the present study different actinomycete strains were collected and isolated from algerian Sahara soil with the aim to select novel enzymes with promising features for biotechnological applications. The Ms1 strain was selected, amongst the others, for its capability to produce melanin in different solid media. Ms1 chromosomal DNA was sequenced and the strain assigned to Streptomyces cyaneofuscatus sp. A tyrosinase (MW∼30kD) encoding sequence was identified and the corresponding enzyme was isolated and biochemically characterized...
November 10, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/29131610/real-time-imaging-of-single-molecule-enzyme-cascade-using-a-dna-origami-raft
#15
Lele Sun, Yanjing Gao, Yan Xu, Jie Chao, Huajie Liu, Lianhui Wang, Di Li, Chunhai Fan
The dynamics of enzymes are directly associated with their functions in various biological processes. Nevertheless, the ability to image motions of single enzymes in a highly parallel fashion remains a challenge. Here, we develop a DNA origami raft-based platform for in-situ real-time imaging of enzyme cascade at the single-molecule level. The motions of enzymes are rationally controlled via different tethering modes on a two-dimensional (2D) supported lipid bilayer (SLB). We construct an enzyme cascade by anchoring catalase on cholesterol-labeled double stranded (ds) DNA, and glucose oxidase on cholesterol-labeled origami rafts...
November 13, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29131473/production-of-hydroxynitrile-lyase-from-d-tyermanii-dthnl-in-komagataella-phaffii-and-its-immobilization-as-clea-to-generate-a-robust-biocatalyst
#16
Elisa Lanfranchi, Birgit Grill, Zainab Raghoebar, Sander van Pelt, Roger Sheldon, Kerstin Steiner, Anton Glieder, Margit Winkler
Hydroxynitrile lyase from the white rabbit's foot fern Davallia tyermanii (DtHNL) catalyzes the enantioselective synthesis of α-cyanohydrins, key building blocks for pharmaceutical and agrochemical industries. An efficient and competitive process necessitates the availability and robustness of the biocatalyst. Herein, the recombinant production of DtHNL1 in Komagataella phaffii is described, yielding approximately 900,000 U/L. DtHNL1 constitutes approximately 80% of the total protein content. The crude enzyme was immobilized...
November 13, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/29128298/cellobiose-dehydrogenase-hosted-in-lipidic-cubic-phase-to-improve-catalytic-activity-and-stability
#17
Valentina Grippo, Su Ma, Roland Ludwig, Lo Gorton, Renata Bilewicz
Lipidic cubic phase systems (LCPs) are excellent carriers for immobilized enzymes due to their biocompatibility and well-defined nanoporous structure. Lipidic cubic phases act as a convenient matrix to incorporate enzymes and hold them in the vicinity of electrode surfaces in their fully active forms. Corynascus thermophilus cellobiose dehydrogenase (CtCDH) was trapped in a monoolein cubic phase, which increased not only its stability, but also its catalytic performance with both enhanced mediated and direct electron transfer with electrodes...
October 13, 2017: Bioelectrochemistry
https://www.readbyqxmd.com/read/29127899/robust-immunosensing-system-based-on-biotin-streptavidin-coupling-for-spatially-localized-femtogram-ml-1-level-detection-of-interleukin-6
#18
Kaixin Zhang, Guozhen Liu, Ewa M Goldys
Detection of a very low amount of cytokines such as interleukin-6 (IL-6) in clinical fluids is important in biomedical research and clinical applications. Here, we demonstrate spatially-localized ultrasensitive (femtogram mL(-1)) level detection of IL-6 in serum and in cell culture media. Our approach is based on a sandwich immunosensor fabricated on the surface of an optical fibre. Firstly, the biotinylated IL-6 capture antibody was immobilized on the fibre surface by biotin-streptavidin coupling. Then the fabricated fibre was used for capturing IL-6 followed by exposure to detection antibody which was labeled with the fluorescent magnetic nanoparticles to report the signal...
November 6, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29127386/sno2-hollow-nanotubes-a-novel-and-efficient-support-matrix-for-enzyme-immobilization
#19
Muhammad Zahid Anwar, Dong Jun Kim, Ashok Kumar, Sanjay K S Patel, Sachin Otari, Primata Mardina, Jae-Hoon Jeong, Jung-Hoon Sohn, Jong Hak Kim, Jung Tae Park, Jung-Kul Lee
A major challenge in the industrial use of enzymes is maintaining their stability at elevated temperatures and in harsh organic solvents. In order to address this issue, we investigated the use of nanotubes as a support material for the immobilization and stabilization of enzymes in this work. SnO2 hollow nanotubes with a high surface area were synthesized by electrospinning the SnCl2 precursor and polyvinylpyrrolidone (dissolved in dimethyl formamide and ethanol). The electrospun product was used for the covalent immobilization of enzymes such as lipase, horseradish peroxidase, and glucose oxidase...
November 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29126465/facile-synthesis-of-magnetic-metal-organic-frameworks-for-highly-efficient-proteolytic-digestion-used-in-mass-spectrometry-based-proteomics
#20
Rui Zhai, Yifeng Yuan, Fenglong Jiao, Feiran Hao, Xiang Fang, Yangjun Zhang, Xiaohong Qian
Mass spectrometry (MS) based bottom-up strategy is now the first choice for proteomics analysis. In this process, highly efficient and complete enzymatic degradation of protein samples is extremely important to achieve in-depth protein coverage and high-throughput protein profiling. However, conventional in-solution digestion suffer from long digestion time and enzyme autolysis that limit the protein sample processing throughput and identification accuracy. Here, we developed a novel type of magnetic metal organic frameworks (MOFs)-based immobilized enzyme reactor, Fe3O4@DOTA-ZIF-90-trypsin...
November 22, 2017: Analytica Chimica Acta
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