• The Korean Journal of Pharmacology
• /
• v.19 no.2
• /
• pp.35-44
• /
• 1983

reactive oxygen species에 의해 나타나는 reactivity에 있어서 metal ions이 관여함이 시사되고 있다. 이미 알려진 reactive oxygen species와 metal ions의 상호작용 이외에 특히 $Cu^{++}$과 $H_2O_2$가 강력한 peroxidative action을 나타낸다는 사실이 알려져 있으며 $Cu^{++}-H_2O_2$가 biological system 에서의 조직파괴에 관여할 가능성이 저자들에 의해서 효소 및 조직치 구조 단백질의 gradation 효과를 관찰함으로써 시사되었다. 본 연구는 $H_2O_2$ 혹은 $H_2O_2$를 생성하는 효소계(xanthine과 xanthine oxidase 및 glucose과 glucose oxidase)에 $Cu^{++}$을 첨가하여 $Cu^{++}-H_2O_2$에 의한 peroxidation의 효과를 collagen gelation을 통하여 확인코저 수행하였으며 다음과 같은 결과를 얻었다. 1) $Cu^{++}(20\;{\mu}M)$과 $H_2O_2$에 의하며 collagen gelation은 현저히 억제되었으며 이같은 억제효과는 양자의 농도에 비례하였다. 2) $Cu^{++}-H_2O_2$ reactivity를 확인하는 다른 방법으로 glucose oxidase system를 이용하였다. glucose oxidase$(2.5{\mu}g/ml)$ 와 glucose(0.5 mM)는 collagen gelation에 영향을 미치지 않았으나 이에 $Cu^{++}$이 존재하면 gelation이 억제되었다. 이때 억제정도는 $glucose(0.125{\sim}l.25\;mM)$와 $Cu^{++}$의 농도에 비례하였다. 3) 여러 reactive oxygen species 가운데 $Cu^{++}-H_2O_2$ reactivity를 xanthine oxidase system을 이용하여 확인하였다. (a) collagen gelation은 xanthine oxidase(30 munits/ml)와 xanthine$(0.25{\sim}2\;mM)$에 의하여 억제되었다. (b) 이때 나타나는 collagen gelation의 억제는 superoxide dismutase에 의하여 완전히 회복되었으나 catalase에 의해서는 더욱 촉진되었다. 그러나 catalase에 의한 억제효과의 촉진은 1,4-diazabicyclo(2,2,2)octane에 의하여 완전히 소실되었다. 따라서 이 xanthine oxidase system에서는 $O_2-,\;H_2O_2,\;^1O_2$이 관여함을 알 수 있었다. (c) 그러나 $Cu^{++}(10\;{\mu}M)$이 존재하였을 때 collagen gelation은 superoxie dismutase에 의해 더욱 억제되었고 catalase에 의해서는 완전히 회복되었다. xanthine oxidase계에서 얻어진 결과는 여러 reactive oxygen species가운데 $H_2O_2$가 $Cu^{++}$에 의하여 peroxidation효과를 나타냄을 알 수 있었다. 이상의 결과로 미루어 볼 때 reactive oxygen species와 metal ions과의 상호작용 가운데 $Cu^{++}-H_2O_2$는 강한 반응을 나타내는 특이한 구성요소이고 헌재 시사되고 있는 reactive oxygen species의 biological effects에 비추어 $Cu^{++}-catalyzed peroxidation$도 병적상태에서 생체에 유해한 작용을 나타내는 요소임을 시사하며 특히 염증시 조직파괴역할에 관하여 고찰하였다.

• Korean Journal of Chemical Engineering
• /
• v.35 no.12
• /
• pp.2421-2429
• /
• 2018

Thiol-based self-assembled anchor linked to glucose oxidase (GOx) and gold nanoparticle (GNP) cluster is suggested to enhance the performance of glucose biosensor. By the adoption of thiol-based anchors, the activity of biocatalyst consisting of GOx, GNP, polyethyleneimine (PEI) and carbon nanotube (CNT) is improved because they play a crucial role in preventing the leaching out of GOx. They also promote electron collection and transfer, and this is due to a strong hydrophobic interaction between the active site of GOx and the aromatic ring of anchor, while the effect is optimized with the use of thiophenol anchor due to its simple configuration. Based on that, it is quantified that by the adoption of thiophenol as anchor, the current density of flavin adenine dinucleotide (FAD) redox reaction increases about 42%, electron transfer rate constant ($k_s$) is $9.1{\pm}0.1s^{-1}$ and the value is 26% higher than that of catalyst that does not use the anchor structure.

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

• Korean Journal of Food Science and Technology
• /
• v.30 no.1
• /
• pp.22-34
• /
• 1998

The purpose of this study is to develop biosensor for determination of glucose, lactate, and ethanol in foods and food-stuffs simultaneously. The multiple cathode system was prepared with an oxygen electrode having one anode and hexagonal cathode. Glucose oxidase, mutarotase, lactate oxidase, alcohol oxidase and catalase were used for immobilization to determine glucose, lactate, and ethanol. These components including ethanol were simultaneously determined by the immobilized enzymes in the multiple cathode system. The determination of the components by enzyme sensor was based on the maximum slope of oxygen consumption from enzyme reaction of each sensor part. The response time for analysis was 1 min. The optimum condition for glucose, lactate and ethanol sensor was found to be 0.1 M potassium phosphate buffer, pH 7.0 at $40^{\circ}C$. Interferences of various sugars and organic acids were investigated. Less than 10% of error was found in determination of the components except organic acids. This difference was compensated by the modified equation. This system was confirmed by conventional methods. It was concluded that the multiple cathode system of this study is for an effective method to determine sugar, organic acid, ethanol simultaneously in foods.

• Journal of Sensor Science and Technology
• /
• v.15 no.1
• /
• pp.28-33
• /
• 2006

Optical-fiber sensors have been developed to determine the concentrations of glucose and lactic acid in blood samples. Fluorescence dye [tris(2,2'-biphenyridine)-ruthenium(II)-chloride (RuBPY)] was entrapped by using a silicon to the unclad tip of a glass optic fiber. Enzymes like glucose oxidase (GOD) and lactate oxidase (LOD) have been immobilized by acrylamide resin adhesive, adsorption with zeolite or covalent bonding with aminopropyl-triethoxysilan. The fiber-optic glucose/lactate sensor was then used to analyze the concentrations of glucose and lactate in blood samples. The results were compared with the results of HPLC analysis and their difference was in error by less then 5 %.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.52-57
• /
• 1998

The present work proposes a simple electrochemical method applicable to any immobilization processes of oxidase using a Clark type oxygen electrode as a base transducer. The present work suggests an optimal immobilization technique among three different methods of glucose oxidase(GOD) onto one side of $37[\mu}$mthick blend membranes, composed o 80% of cellulose triacetate and 20% of polycaprolactone, on the basis of the maximum Michaelis-Menten parameter(Vm) determined by either steady state or transient analyses. The electrode system was made of disk type gold cathode(4mm diameter) and Ag/AgCl anode. One side of the blend membrane was in contact with the cathode surface while the other side was immobilized with GOD either in covalent-bond or cross-linked forms, the latter being covered by $25{\mu}$m thick dialysis membrane of cellulose acetate. The resultant current density was on-line monitored by a potentiostat while glucose level was varied from 1 to 20 mM. The present study shows that direct cross-linking of GOD with glutaraldehyde was mostly preferred for fabrication of glucose sensor, on the basis of resultant kinetic parameters from either steady state or transient analyses.

• KSBB Journal
• /
• v.9 no.1
• /
• pp.40-47
• /
• 1994

A simplified mathematical model for the production of high-purity fructo-oligosaccharides by the mixed-enzyme system of fructosyl transferees and glucose oxidase was proposed and compared with the experimental results. The kinetic parameters including $K_m,\;V_{max}\;and\;K_{iG}$ were estimated at $40^{\circ}C$, in which $K_m$, values decreased and $K_{iG}$ and $V_{max}$ values increased compared with those of fructosyl transferees alone. The kinetics of the mixed-enzyme system was successfully described in the form of Michaelis-Menten equations. At the reasonable sucrose concentrations tested, the simulated sugar profiles were of good agreement with the experimental ones.

• Korean Journal of Food Science and Technology
• /
• v.28 no.5
• /
• pp.974-980
• /
• 1996

A biosensor was prepared with dual cathode electrode and immobilized enzyme membrane. A nylon net was used for the immobilization of glucose oxidase and alcohol oxidase. The immobilized enzymes were placed on the surface of the electrode which was prepared with one anode and two cathodes as an oxygen electrode. The determination of components by the biosensor was based on the consumption of dissolved oxygen. The optimum condition of this system was 0.1 M potassium phosphate buffer solution, pH 7.5 at $35^{\circ}C$. Glucose and ethanol in takju were simultaneously determined by the biosensor. Comparing with UV-spectrophotometer and gas chromatograph for cross checking, there was a good correlation between the biosensor and the conventional methods. Biosensor with dual cathode electrode required no clarification or pretreatments. It was used for simultaneous determination of glucose and ethanol during the fermentation of takju.

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

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.1
• /
• pp.269-278
• /
• 2019

We fabricated glucose oxidase (GOx)-modified biosensor for detection of glucose by physical immobilization of GOx after electrochemical polymerization of the conductive mixture monomers of the 3-thiophenecarboxylic acid (TCA) and thiophene (Th) onto ITO electrode in this study. We confirmed the successfully fabrication of GOx-modified biosensor via FT-IR spectroscopy, SEM, contact angle, and cyclic voltammetry. The fabricated biosensor has the detection limit of $0.1{\mu}M$, the linearity of 0.001-27 mM, and sensitivity of $38.75mAM^{-1}cm^{-2}$, respectively. The fabricated biosensor exhibits high interference effects to dopamine, ascorbic acid, and L-cysteine, respectively. From these results, the fabricated GOx-modified biosensor with long linearity and high sensitivity could be used as glucose sensor in human blood sample.