• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.853-859
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• 2017

This study was conducted in an effort to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of burdock and their anti-oxidant activity. The MRPs were prepared by heating glucose and amino acids at $90^{\circ}C$, which served to produce a strong inhibitory effect on burdock polyphenol oxidase. As the reaction time of the solution containing glucose and amino acid increased at $90^{\circ}C$, the production of MRPs increased and intensity of the brown color deepened. When MRPs were prepared by heating at $90^{\circ}C$ for five hours, the absorbance of MRPs from glucose and lysine was 6.44, while those of glucose and glycine was 1.95. The MRPs synthesized from the glucose and lysine also reduced the pH of MRPs from 5.60 to 4.51, but those from glucose and glycine decreased slightly from 5.57 to 5.33. The Michealis-Menten constant value ($K_m$) of burdock PPO with pyrocatechol as a substrate was 16.0 mM, and MRPs were a non-competitive inhibitor against burdock PPO. The anti-oxidant activity of MRPs was measured by evaluating its radical scavenging activities of DPPH radicals, ABTS radicals and reducing power. The color intensity of MRPs produced by lysine and glucose were deeper than that produced by glucose and glycine. It was also found that MRPs produced from glucose and lysine exhibited stronger anti-oxidant properties than those produced by glucose and glycine.

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.37-37
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• 1997

The catalytic efficiency of pyranose oxidase (EC 1.1.3.10.) determined for various sugars showed that D-glucose is the preferred substrate and the enzyme oxidized the various aldonolactones. The specificity constants of pyranose oxidase determined for deoxy- and deoxyfluoro-D-glucoses showed that a hydroxy group at C-4 of D-glucose acts as a hydrogen-bone acceptor, at C-6 as a hydrogen-bond donor, and at C-1 as a hydrogen-bond donor.(omitted)

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.56-61
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• 2011

In the present study, glucose-sensitive hydrogels using phenylboronic acid (PBA) without glucose oxidase and catalase were prepared. The swelling-shrinking behavior of the hydrogel according to the variation of pH and glucose and ionic concentrations was investigated. The swelling ratio of the hydrogel containing PBA increased with increasing the glucose concentration and the volume was very sensitively varied with the pH. However, the ionic concentration did not change significantly the relative swelling ratio on the hydrogel, indicating that the hydrogel was dimensionally stable.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.86-87
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• 2007

An amperometric glucose biosensor has been developed using viologen derivatives as electron mediator of glucose oxidase (GOD) at Au electrode. Highly stable self assembled monolayer (SAM) of thiol-based viologen is immobilized onto the Au electrode followed byGOD is immobilized onto the viologen modified electrode. This biosensor response to glucose was evaluated amperometrically in the potential of -300 mV. Upon immobilization of glucose oxidase onto the viologen modified-electrode, the biosensor showed rapid response towards glucose. Experimental conditions influencing the biosensor performance such as, pH, potential were optimized and assessed. This biosensor offered an excellent electrochemical response for glucose concentration below ${\mu}mol$ level with high sensitivity and selectivity and short response time. The levels of the RSD's (< 5 %) for the entire analyses reflected the highly reproducible sensor performance. Using the optimized a linear relationship between current and glucose concentration was obtained up to $4.5{\times}10^{-4}$ M. In addition, this biosensor showed well reproducibility and stability.

• BMB Reports
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• v.40 no.6
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• pp.875-880
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• 2007

Glucose oxidase (GOD) is an oxidoreductase catalyzing the reaction of glucose and oxygen to peroxide and gluconolacton (EC 1.1.3.4.). GOD is a widely used enzyme in biotechnology. Therefore the production of monoclonal antibodies and antibody fragments to GOD are of interest in bioanalytics and even tumor therapy. We describe here the generation of a panel of monoclonal antibodies to native and heat inactivated GOD. One of the hybridomas, E13BC8, was used for cloning of a single chain antibody(scFv). This scFv was expressed in Escherichia coli XL1-blue with the help of the vector system pOPE101. The scFv was isolated from the periplasmic fraction and detected by western blotting. It reacts specifically with soluble active GOD but does not recognize denatured GOD adsorbed to the solid phase. The same binding properties were also found for the monoclonal antibody E13BC8.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.526-532
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• 2016

In this study, we synthesized a mediator immobilized biocatalyst([FCA/GOx]/PEI/CNT) by surface modification using ferrocene carboxylic acid(FCA), and evaluated its performance as anode catalyst for biofuel cell. Through the application of FCA on glucose oxidase (GOx), the free amine groups on the lysine residue of GOx surface reacted with carboxylic acid of FCA and make amide bond between GOx and FCA. As the result of that, the electron transfer of catalyst was increased up to 1.91 times($0.468mA{\cdot}cm^{-2}$) than the catalyst without surface modification (GOx/PEI/CNT), and high maxium power density of $1.79mA{\cdot}cm^{-2}$ was gained.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.403-409
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• 2001

A novel strain of SFO41 producing a large amount of cholesterol oxidase as an extracellular enzyme isolate from Korean salt fermented foods. The strain was identified as Bacillus megaterium based on morphological, cultural and physiological characteristics. Experiments were carried out to optimized the condition of cholesterol oxidase production using B. megaterium SFO41. B. megaterium SFO41 was shown to give the maximum yield of cholesterol oxidase in the medium containing 2.0% glucose, 0.5% yeast extract. 0.03% $MgSO_4{\cdot}7H_2O,\;0.02%\;K_2HPO_4,\;0.2%\;NH_4NO_3$ and 0.2% cholesterol. The optimum culture conditions, temperature, initial pH and agitation speed were $30^{\circ}C$, 7.0 and 150 rpm, respectively. The enzyme production reached a maximum level at 24 hr of cultivation (2.37 U).

• Journal of Biomedical Engineering Research
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• v.3 no.2
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• pp.95-100
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• 1982

Glucose oxidase from A. niger was entrapped in polyacrylamide gel which was used in the enzyme electrode for glucose analysis. The electrode was assembled by placing the gel between the membranes on the surface of a Clark type electrode. In order to make it possible to analyze the experimental results later, the stagnation flow was adopted wheree the governing fluid mechanics were well known. The current increased with the increase concentration in the bulk below a certain level of glucose concentration beyond which no more current increase was observed. This is probably due to the diffusion limitation of oxygen from the bulk solution. Also the current increased witll the enzyme loading in the gel, but the linearity between the current and the glucose concentration was rather limited to a narrow range. Flow rate was found to be very important, which means that film diffusion is very important under the flow rate of 5cm/sec. As a conclusion, enzyme loading, gel layer thickness, stirring speed and bulk concentration of glucose were found to be most improtant parameters in yielding a linar current reponse with respect to the bulk glucose concentration.

• KSBB Journal
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• v.32 no.1
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• pp.35-45
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• 2017

In this work the optical fiber glucose and lactate biosensors were developed by using fluorescent dye and enzyme immobilized on the end tip of an optical fiber. 3-Glycidyloxypropyl)methyldiethoxysilane (GPTMS), (3-Aminopropyl) trimethoxysilane (APTMS) and Methyltrimethoxysilane (MTMS) were used to immobilize glucose oxidase (GOD), lactate oxidase (LOD) and ruthenium(II) complex (tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II), $Ru(dpp)_3^{2+}$) as oxygen sensitive fluorescent dye. MTMS sol-gel was an excellent supporting material for the immobilization of $Ru(dpp)_3^{2+}$, GOD, and LOD on the optical fiber. Storage stability of the optical fiber glucose sensor was kept constant over 20 days, while the optical fiber lactate sensor had constant storage stability over 17 days. The optical fiber glucose and lactate biosensors also maintained good operational stability for 20 hours and 14 hours, respectively. The activities of the immobilized enzymes were most excellent at pH 7 and at $25^{\circ}C$. On-line monitoring of glucose and lactate in a simulated process was performed with the optical fiber glucose and lactate biosensors. On-line monitoring results were agreed with those of off-line data measured with high performance liquid chromatography (HPLC).

• Korean Journal of Materials Research
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• v.19 no.1
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• pp.44-49
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• 2009

Conjugated nanocrystals using CdSe/ZnS core/shell nanocrystal quantum dots modified by organic linkers and glucose oxidase (GOx) were prepared for use as biosensors. The trioctylphophine oxide (TOPO)-capped QDs were first modified to give them water-solubility by terminal carboxyl groups that were bonded to the amino groups of GOx through an EDC/NHS coupling reaction. As the glucose concentration increased, the photoluminescence intensity was enhanced linearly due to the electron transfer during the enzymatic reaction. The UV-visible spectra of the as-prepared QDs are identical to that of QDs-MAA. This shows that these QDs do not become agglomerated during ligand exchanges. A photoluminescence (PL) spectroscopic study showed that the PL intensity of the QDs-GOx bioconjugates was increased in the presence of glucose. These glucose sensors showed linearity up to approximately 15 mM and became gradually saturated above 15 mM because the excess glucose did not affect the enzymatic oxidation reaction past that amount. These biosensors show highly sensitive variation in terms of their photoluminescence depending on the glucose concentration.