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Enzyme immobilization

Johannes A Eble
The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record...
February 15, 2018: Journal of Visualized Experiments: JoVE
Adriana Ferreira Lopes Vilela, Cláudia Seidl, Juliana Maria de Lima, Carmen Lúcia Cardoso
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are key cholinesterase enzymes responsible for the hydrolysis of acetylcholine into choline and acetic acid, an essential process for the restoration of the cholinergic neuron. The loss of cholinergic function in the central nervous system contributes to the cognitive decline associated with advanced age and Alzheimer's disease (AD). Inhibitions assays represent a significant role in the drug discovery process. Herein, we describe an improved label free method to screen and characterize new BChE ligands...
March 14, 2018: Analytical Biochemistry
Jana Löwe, Aaron A Ingram, Harald Gröger
In recent years, the reductive amination of ketones in the presence of amine dehydrogenases emerged as an attractive synthetic strategy for the enantioselective preparation of amines starting from ketones, an ammonia source, a reducing reagent and a cofactor, which is recycled in situ by means of a second enzyme. Current challenges in this field consists of providing a broad synthetic platform as well as process development including enzyme immobilization. In this contribution these issues are addressed. Utilizing the amine dehydrogenase EsLeuDH-DM as a mutant of the leucine dehydrogenase from Exigobacterium sibiricum, a range of aryl-substituted ketones were tested as substrates revealing a broad substrate tolerance...
December 5, 2017: Bioorganic & Medicinal Chemistry
Rafiq Ahmad, Nirmalya Tripathy, Min-Sang Ahn, Jin-Young Yoo, Yoon-Bong Hahn
Seed layer plays a crucial role to achieve high electrical conductivity and ensure higher performance of the devices. In this study, we report fabrication of a solution-gated field-effect transistor (FET) sensor based on zinc oxide nanorods (ZnO NRs) modified iron oxide nanoparticles (α-Fe2O3 NPs) grown on a highly conductive sandwich-like seed layer (ZnO seed layer/Ag nanowires/ZnO seed layer). The sandwich-like seed layer and ZnO NRs modification with α-Fe2O3 NPs provide excellent conductivity and prevent possible ZnO NRs surface damage from low pH enzyme immobilization, respectively...
March 16, 2018: ACS Sensors
Homa Torabizadeh, Asieh Mahmoudi
Inulinase can produce a high amount of fructose syrup from inulin in a one-step enzymatic process. Inulinase from Aspergillus niger was immobilized covalently on Fe3 O4 magnetic nanoparticles functionalized with wheat gluten hydrolysates (WGHs). Wheat gluten was enzymatically hydrolyzed by two endopeptidases Alcalase and Neutrase and related nanoparticles were prepared by desolvation method. Magnetite nanoparticles were coated with WGHs nanoparticles and then inulinase was immobilized onto it using glutaraldehyde as crosslinking agent...
March 2018: Biotechnology Reports
Karthikumar Sankar, Anant Achary
The lipophilic antioxidants, glyceryl ferulate and feruloyl glyceryl linoleate, were synthesized using lipase from Bacillus subtilis AKL 13. The extracellular lipase was produced by cultivation of the strain in modified minimal medium and the enzyme was recovered by fractionation at 80% ammonium salt saturation. The concentrated enzyme with the specific activity of (4647±66) U/mg was immobilized on Celite® 545 and crosslinked using glutaraldehyde. The prepared enzyme catalyst was used for esterification of ferulic and linoleic acids with glycerol separately in hexane butane solvent system at 50 °C and 3...
December 2017: Food Technology and Biotechnology
Natalya Cherno, Sophya Osolina, Oleksandra Nikitina
One of the methods for curing obesity is the inclusion of some substances with the antilipase activity in the diet and thus reducing the uptake of fat components from food. The aim of this research is to provide a stabilized form of lipase inhibitor by immobilization of enzyme on the biopolymers from Agaricus bisporus cell walls. The phenolic compounds extracted from the rapeseed were considered as the lipase inhibitor. The activity of the inhibitor was considerably reduced in the gastric juice, as well as at temperatures above 37 °C and during its storage, which determined the suitability of the inhibitor for stabilization on the matrix...
December 2017: Food Technology and Biotechnology
Maísa Pessoa Pinheiro, Nathalia Saraiva Rios, Thiago de S Fonseca, Francisco de Aquino Bezerra, Enrique Rodríguez-Castellón, Roberto Fernandez-Lafuente, Marcos Carlos de Mattos, José C S Dos Santos, Luciana R B Gonçalves
Novozyme 435, which is a commercial immobilized lipase B from Candida antarctica (CALB), has been proven to be inadequate for the kinetic resolution of rac-indanyl acetate. As it has been previously described that different immobilization protocols may greatly alter lipase features, in this work CALB was covalently immobilized on epoxy Immobead-350 (IB-350) and on glyoxyl-agarose to ascertain if better kinetic resolution would result. Afterwards, all CALB biocatalysts were utilized in the hydrolytic resolution of rac-indanyl acetate and rac-(chloromethyl)-2-(o-methoxyphenoxy)ethyl acetate...
March 14, 2018: Biotechnology Progress
Teresa Ramon-Marquez, Antonio L Medina-Castillo, Naveen Nagiah, Alberto Fernandez-Gutierrez, Jorge F Fernandez-Sanchez
A multifunctional material based on co-electrospinning has been developed as a basic material for the development of biosensors with optical oxygen transduction. It is based on coaxial nanofibres: inner fibres containing an oxygen sensitive dye and outer fibres containing aldehyde groups to allow the formation of Schiff bases with the amino groups of the enzyme. The resulting material preserves the oxygen sensing properties of the inner optical transducer as well as exhibits a high capacity for immobilizing molecules on its surface...
July 26, 2018: Analytica Chimica Acta
Boris Zacchetti, Agathoklis Andrianos, Dino van Dissel, Evelien de Ruiter, Gilles P van Wezel, Dennis Claessen
BACKGROUND: Filamentous bacteria of the genus Streptomyces produce a large arsenal of industrially relevant antibiotics and enzymes. The industrial production of these molecules occurs in large fermenters, where many streptomycetes form dense mycelial networks called pellets. Pellets are characterized by slow growth and inefficient nutrient transfer and therefore regarded as undesirable from the perspective of productivity. Although non-pelleting strains have increased growth rates, their morphology also leads to a dramatic increase in the viscosity of the culture broth, which negatively impacts the process dynamics...
March 12, 2018: BMC Biotechnology
Feriel Boussema, Andrew J Gross, Fatma Hmida, Brahim Ayed, Hatem Majdoub, Serge Cosnier, Abderrazak Maaref, Michael Holzinger
Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (C4 H10 N)6 [P2 Mo18 O62 ]·4H2 O (P2 Mo18 ) and (C6 H8 NO)4 [H2 P2 W18 O62 ]·6H2 O (P2 W18 ) are reported as mediators for electron transfer between FAD-dependent glucose dehydrogenase (FAD-GDH) and a multiwalled carbon nanotube (MWCNT) matrix for glucose biofuel cell and biosensor applications. These polyoxometalates were chosen due to their promising redox behavior in a potential range for mediated electron transfer with the glucose oxidizing enzyme, FAD-GDH...
February 28, 2018: Biosensors & Bioelectronics
Pankajkumar R Waghmare, Anuprita D Watharkar, Byong-Hun Jeon, Sanjay P Govindwar
In this study, we have described three steps to produce ethanol from Pogonatherum crinitum , which was derived after the treatment of textile wastewater. (a) Production of biomass: biomass samples collected from a hydroponic P. crinitum phytoreactor treating dye textile effluents and augmented with Ca-alginate immobilized growth-promoting bacterium, Bacillus pumilus strain PgJ (consortium phytoreactor), and waste sorghum husks were collected and dried. Compositional analysis of biomass (consortium phytoreactor) showed that the concentration of cellulose, hemicelluloses and lignin was 42, 30 and 17%, respectively, whereas the biomass samples without the growth-promoting bacterium (normal phytoreactor) was slightly lower, 40, 29 and 16%, respectively...
March 2018: 3 Biotech
Wesley Böhmer, Tanja Knaus, Francesco G Mutti
The amination of alcohols is an important transformation in chemistry. The redox-neutral (i.e., hydrogen-borrowing) asymmetric amination of alcohols is enabled by the combination of an alcohol dehydrogenase (ADH) with an amine dehydrogenase (AmDH). In this work, we enhanced the efficiency of hydrogen-borrowing biocatalytic amination by co-immobilizing both dehydrogenases on controlled porosity glass FeIII ion-affinity beads. The recyclability of the dual-enzyme system was demonstrated (5 cycles) with total turnover numbers of >4000 and >1000 for ADH and AmDH, respectively...
February 2018: ChemCatChem
Fareeha Bashir, Muhammad Asgher, Fatima Hussain, Muhammad Atif Randhawa
An alkaline protease was produced by B. licheniformis with 132.43 ± 3.4 U/mL activity in LSF which was further enhanced by optimizing culture conditions. The optimum enzyme activity (148.9 ± 4.1 U/mL) was harvested at pH 7.5; temperature, 40 °C and inoculum, 1.5 mL after 48 h incubation. Alkaline protease was immobilization by forming cross linked enzyme aggregates (CLEAs) and the processes of CLEAs formation was also optimized. The protease CLEAs developed using 80% ammonium sulfate, 65 mM glutaraldehyde and 0...
March 3, 2018: International Journal of Biological Macromolecules
Shruthi Sunderrajan, Lima Rose Miranda, Gautam Pennathur
Graphene oxide/ chitosan and reduced graphene oxide/ chitosan (GO/CS and RGO/CS) beads were prepared by precipitation with NaOH. Porcine liver esterase was immobilized on these beads to give GO/CS/E and RGO/CS/E beads. The optimum conditions for the maximum activity of RGO/CS/E beads was pH 8 and 50°C. The stability of the enzyme immobilized on GO/CS/E and RGO/CS/E was high in the pH range of 5-8. The GO/CS/E beads showed superior stability compared to that of the free enzyme and CS/E beads between 20°C and 50°C...
March 6, 2018: Preparative Biochemistry & Biotechnology
Lei-Peng Cao, Jing-Jing Wang, Ting Zhou, Roger Ruan, Yu-Huan Liu
Lignin polymers in bamboo (Phyllostachys pubescens) were decomposed into polyphenols at high temperatures and oxidized for the introduction of quinone groups from peroxidase extracted from bamboo shoots and catalysis of UV. According to the results of FT-IR spectra analysis, neutral proteases (NPs) can be immobilized on the oxidized lignin by covalent bonding formed by amine group and quinone group. The optimum condition for the immobilization of NPs on the bamboo bar was obtained at pH 7.0, 40 °C, and duration of 4 h; the amount of immobilized enzyme was up to 5 mg g-1 bamboo bar...
March 6, 2018: Applied Biochemistry and Biotechnology
Xiao-Yan Dai, Li-Min Kong, Xiao-Ling Wang, Qing Zhu, Kai Chen, Tao Zhou
Pectinase was immobilized onto sodium alginate/graphene oxide beads via amide bonds by using N,N'-dicyclohexylcarbodiimide/N-hydroxysuccinimide as the activating agent. The immobilized pectinase was characterized by Fourier transform infrared spectra and scanning electron microscopy analyses. Immobilization conditions were optimized by Box-Behnken design and the response surface method. The activity of the immobilized pectinase prepared under optimal conditions reached 1236.86 ± 40.21 U/g, with an enzyme activity recovery of 83...
July 1, 2018: Food Chemistry
Wenya Feng, Juan Qiao, Junfang Jiang, Bingbing Sun, Zhiwei Li, Li Qi
Alanine aminotransferase (ALT) plays significant role in biological and clinical research. In this study, a unique ALT enzyme reactor based on multifunctional polymer@magnetic nanoparticles has been constructed for the first time and the enzymolysis efficiency has been evaluated by chiral ligand exchange capillary electrophoresis technique. Poly(N-acryloxysuccinimide) has been synthesized by reversible addition-fragmentation chain transfer polymerization method and immobilized on the magnetic nanoparticles via the succinimide group in the polymer...
May 15, 2018: Talanta
Ting Huang, Zaichun Liu, Yunlong Li, Yanqiu Li, Long Chao, Chao Chen, Yueming Tan, Qingji Xie, Shouzhuo Yao, Yuping Wu
Poly(5-hydroxytryptamine) (poly(5-HT)) is exploited as a new and efficient enzyme-immobilization matrix for amperometric and biofuel cell (BFC)-based biosensing. A GOx-poly(5-HT)-Pd nanoparticles (PdNPs) bionanocomposite is prepared by Na2 PdCl4 -initiated oxidized polymerization of 5-hydroxytryptamine (5-HT) in a neutral aqueous solution containing glucose oxidase (GOx), and this bionanocomposite and then chitosan (CS) are cast-coated on a Pd-plated Au electrode to yield a CS/GOx-poly(5-HT)-PdNPs/Pdplate /Au enzyme electrode...
July 12, 2018: Analytica Chimica Acta
Francisco Vásquez-Garay, Regis Teixeira Mendonça, Steven W Peretti
An innovative chemoenzymatic catalytic system for functionalizing lignin from Organosolv and Kraft pulping processes to obtain oxirane rings was investigated. Novozym435 (immobilized C. antarctica lipase B: CalB) was used to catalyze the peroxidation of caprylic acid to peroxycaprylic acid, which in turn reacted with unsaturated CC bonds to form the oxirane ring. The conversion of OH groups to oxirane rings (epoxides) reached 90% and 55% after 12 h for the two processes, respectively. The residual enzyme activity over the time course of the reactions indicated transient denaturing due to association with the lignin substrate (10-50%) as well as irreversible denaturation due to exposure to hydrogen peroxide...
May 2018: Enzyme and Microbial Technology
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