• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.145-149
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• 2016

Thermal acid hydrolysis pretreatment of Kappaphycus alvarezii was carried out with 12% (w/v) seaweed slurry and 180 mM H₂SO₄ at 140°C for 5 min. Utility of the thermotolerant yeast Kluyveromyces marxianus KCTC7150 was evaluated with respect to cell growth and ethanol fermentation at 40°C was close to optimal for enzymatic hydrolysis. This could lead to the integration of both the saccharification and fermentation processes. The levels of ethanol production by simultaneous saccharification and fermentation (SSF) with non-adapted and adapted K. marxianus KCTC7150 were 9.1 g/l with an ethanol yield (Y_EtOH) of 0.24 and 10.2 g/l with an ethanol yield (Y_EtOH) of 0.27 at 156 h, respectively. The two-phase SSF process was employed in this study to improve the efficiency of ethanol fermentation. Adapted K. marxianus KCTC7150 using the two-phase SSF process produced 13.5 g/l with an ethanol yield (Y_EtOH) of 0.35 at 96 h. Development of the two-phase SSF process could enhance the overall ethanol fermentation yields of the seaweed K. alvarezii.

• Applied Microscopy
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• v.35 no.1
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• pp.15-22
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• 2005

Metallothionein (MT) is a low molecular weight, cysteine-rich, metal-binding, and non-enzymatic protein. The present study was carried out to investigate the expression of MT gene as well as the localization of MT in regenerating rat liver. In partial hepatectomized rats, MT mRNA was detected as early as 1 hr and reached a maximal level by 8 hr after the operation. Thereafter, this level decreased gradually until 24 hr, and it became similar to that of sham control. Meanwhile, time course of MT immunoreactivity using immunogold-labelling revealed that the number of gold particles in hepatocytes increased significantly by 12 hr, but decreased at 48 hr after partial hepatectomy. Ultrastructurally, immunogold particles indicating the presence of MT were distributed in both the cytoplasm and the nucleus of the rat hepatocytes, particularly the particles were distributed at rough endoplasmic reticulum and nucleolus and did not seem to adhere to mitochondria or lysosomes in proliferating hepatocytes. Briefly, high level of MT mRNA expression and the intense immunoreactivity and/or the specific localization of MT was observed during liver regeneration. These results suggest that MT possibly involves hepatocyte proliferation via the storage or the supply of various metal ions in the regenerating rat liver.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.277-283
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• 1984

In the forward reaction (ADP formation) of the adenylate kinase from baker's yeast, dissociation constants from binary complexes are higher by a factor of about 4 times then those from at ternary complexes. In the reverse reaction, dissociation constants from the binary complexes are 2 times higher then those from the ternary complexes. The enzyme showed activities against various nucleotide triphospate in following orders; ATP 100, UTP 18, ITP 9 and GTP 5, of the necleotide monophosphate. only dAMP showed 33% activity of that AMP as phosphate acceptor. Divalent cations were required in enzyme reaction in following orders; $Mg^{2＋}$ 100, Co$^{2＋}$ 57, Mn$^{2＋}$ 54, $Ca^{2＋}$ 51, Ni$^{2＋}$ 10 and Sn$^{2＋}$ 6. AMP, as a substrate inhibitor, competitively inhibited the adenylate kinase at pH 7.2 or 8.0. Inhibition constants of the enzyme showed greater dependence on the pH of the reaction mixture, which was the lower Ki values under higher pH. Adenosine pentaphospho adenosine was competive inhibitor to the enzyme against all substrate, and it showed the same Ki values, 2.9mM. Further, PEP was competive inhibitor with respect to AMP and non-competive inhibitor with respect to MgATP. Adenylate kinase from bakers yeast was similar to mitochondrial type of animal in the contents of aianine, leucine and asparagine or asparatic acid differing from muscle type enzyme. Based on the results and observation, characteristic of yeast adenylate kinase resembled the adenylate kinase of mitochondrial type from animals. Further, difference of characteristics in adenylate kinasa depending upon the workers might be due to the difference of strain used.

• Journal of Life Science
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• v.13 no.4
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• pp.457-462
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• 2003

Houttuynia Cordata thunb has been used as folk medicine for analgesics, beriberi, edema, hepatitis and icterus etc. We investigated, the effects of Houttuynia Cordata thunb administration on protective in liver of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) treated rats. Seven days after the injection of TCDD(1${\mu}g$/kg), Houttuynia Cordata thunb (200mg/kg) was administered into rats intraperitoneally for four weeks. We examined the antioxidative enzymatic activity by measuring the level of GOT, GPT in serum and MDA, GSH, GSSG, GPx, SOD and Catalase in liver tissue of rats. GOT activity of Houttuynia Cordata thunb and TCDD administered group(HTT) showed 49.00% of inhibitive effect compared to TCDD-treated abnormal group(TTA). GPT level of HTT group was decreased to the level of Non TCDD-treated group(NTT). MDA content in the TTA group was 1.27 times increased compared to NTT group. HTT group was inhibited by 69.53% compared to TTA group. GSH contents in HTT group was 1.91 times increased compared to TTA group. GSSG contents in HTT group was 46.72% decreased compared to TTA group. SOD and Catalase in TTA group were lower than in NTT group, but SOD and Catalase in HTT group were increased by 82% and 55.45% respectively compared to TTA group.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.1-6
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• 2022

As the demand for wearable devices increases, many studies have been studied on the development of flexible electrode materials recently. In particular, the development of high-performance flexible electrode materials is very important for wearable sensors for healthcare because it is necessary to continuously monitor and accurately detect body information such as body temperature, heart rate, blood glucose, and oxygen concentration in real time. In this study, we fabricated the nonenzymatic glucose sensor based on polyaniline/carbon nanotube fiber (PANI/CNT fiber) electrode. PANI layer was synthesized on the flexible CNT fiber electrode through electrochemical polymerization process in order to improve the performance of a flexible CNT fiber based electrode material. Surface morphology of the PANI/CNT fiber electrode was observed by scanning electron microscopy. And its electrochemical characteristics were investigated by chronoamperometry, cyclic voltammetry, electrochemical impedance spectroscopy. Compared to bare CNT fiber electrode, this PANI/CNT fiber electrode exhibited small electron transfer resistance, low peak separation potential and large surface area, resulting in enhanced sensing properties for glucose such as wide linear range (0.024~0.39 and 1.56~50 mM), high sensitivity (52.91 and 2.24 ㎂/mM·cm²), low detection limit (2 μM) and good selectivity. Therefore, it is expected that it will be possible to develop high performance CNT fiber based flexible electrode materials using various nanomaterials.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.458-467
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• 2021

The effect of 16 cultivars on the quality of the rice porridge was investigated. The 'Geunnun' had the highest water absorption rate, but the 'Segyejinmi' yield (w/w) was the highest. The total sugar content of the rice porridge was 0.29~8.10%, showing significant variation among the cultivars. High amylose 'Dodamssal' and 'Hwaseonchalbyeo' glutinous rice displayed rotational viscosities of <20,000 cP. Rotational viscosities for boiled rice cultivars were 30,000~40,000 cP, representing an intermediate level, and the rotational viscosities of 'Geonyang2' and 'Hanareum4' were over 50,000 cP. These results suggest that the viscosity of rice porridge varies significantly among raw material cultivars. Among other variables affecting the texture profile of rice porridge, there were significant differences in hardness and gumminess among the cultivars. As a raw material, 'Baekokchal', a kind of glutinous rice, is known to be whiter than the non-glutinous rice, but after processing to porridge, it showed the lowest L value (71.1). Starch degrading enzyme activity was not significant in most types of rice porridges within 30 or 60 minutes. Therefore, enzymatic starch degradation is thought to be completed within 30 minutes. Among the tested raw materials, 'Miho' was 73.5 ㎍/mg, indicating the best digestibility in vitro.

• Research in Plant Disease
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• v.18 no.3
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• pp.186-193
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• 2012

Biotransformation is an eco-friendly and efficient method for enhancing the bioavailability of biopesticide. To increase the antifungal activity of the crude extract of Cynanchum wilfordii roots against barely powdery mildew, we performed biotransformation of wilfoside C1G using ${\beta}$-glucosidase (cellobiase from Aspergillus niger). The mixture (G sample) of partially purified wilfoside C1G and cynauricuoside A (K1G) was treated with ${\beta}$-glucosidase to remove a glucopyranosyl moiety. The enzyme completely converted C1G to C1N and K1G to K1N. Optimal conditions for enzymatic biotransformation of G sample were determined to be 10% ethanol, 1,555 ${\mu}U$ ${\beta}$-glucosidase/ml, pH 5, and $45^{\circ}C$. In in vivo experiment, the G sample transformed by ${\beta}$-glucosidase showed stronger antifungal activity against barley powdery mildew than the non-treated G sample. These results suggest that ${\beta}$-glucosidase biotransformation can be applied to increase the antifungal activity of the crude extract of C. wilfordii roots against powdery mildews.

• Analytical Science and Technology
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• v.26 no.1
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• pp.42-50
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• 2013

This paper describes the electrocatalytic activity for the oxidation of small biomolecules on the surface of Pt-Ru nanoparticles supported by $TiO_2$-hollow sphere prepared for use in sensor applications or fuel cells. The $TiO_2$-hollow sphere supports were first prepared by sol-gel reaction of titanium tetraisopropoxide with poly(styrene-co-vinylphenylboronic acid), PSB used as a template. Pt-Ru nanoparticles were then deposited by chemical reduction of the $Pt^{4+}$ and $Ru^{3+}$ ions onto $TiO_2$-hollow sphere ($Pt-Ru@TiO_2-H$). The prepared $Pt-Ru@TiO_2-H$ nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and elemental analysis. The electrocatalytic efficiency of Pt-Ru nanoparticles was evaluated via ethanol, methanol, dopamine, ascorbic acid, formalin, and glucose oxidation. The cyclic voltammograms (CV) obtained during the oxidation studies revealed that the $Pt-Ru@TiO_2-H$ nanocomposites showed high electrocatalytic activity for the oxidation of biomolecules. As a result, the prepared Pt-Ru catalysts doped onto $TiO_2$-H sphere nanocomposites supports can be used for non-enzymatic biosensor or fuel cell anode electrode.

• Journal of Life Science
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• v.31 no.1
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• pp.83-89
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• 2021

Uu-ilys, an i-type lysozyme from spoon worm (Urechis unicinctus), is an innate immune factor that plays an important role in the defense against pathogens. It also possesses non-enzymatic antibacterial activity. Thus, there is a possibility to develop an antimicrobial model peptide from Uu-ilys. In this study, we report the design, production, and antibacterial activity of an Uu-ilys analog that exhibits antibacterial activity. The Uu-ilys structure was fragmented according to its secondary structures to predict the regions with antimicrobial activity using antimicrobial peptide (AMP) prediction tools from different AMP databases. A peptide containing the C-terminal fragment was predicted to exert antimicrobial activity. The chosen fragment was designated as an Uu-ilys analog containing the C-terminal fragment, Uu-ilys-CF. To examine the possibility of developing an AMP using the sequence of Uu-ilys-CF, recombinant fusion protein (TrxA-Uu-ilys-CF) was produced in an expression system that was heterologous. The produced fusion protein was cleaved after methionine leaving Uu-ilys-CF free from the fusion protein. This was then isolated through high performance liquid chromatography and reverse phase column, CapCell-Pak C18. The antibacterial activity of Uu-ilys-CF against different microbial strains (four gram-positive, six gram-negative, and one fungal strain) were assessed through the ultrasensitive radial diffusion assay (URDA). Among the bacterial strains tested, Salmonella enterica was the most susceptible. While the fungal strain tested was not susceptible to Uu-ilys-CF, broad spectrum antibacterial activity was observed.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.37-42
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• 2013

Gaucher disease is a lysosomal storage disease caused by deficiency of glucocerebrosidase (GBA). This condition is characterized by accumulation of glucocerebrosidase in liver, spleen, lung, skeletal system, and central nervous system. Gaucher disease is the prototype of disease in which efficacy of enzyme replacement therapy has been established. However, because recombinant enzyme is not able to enter the central nervous system, its efficacy is limited to the non-neurological manifestations of Gaucher disease. Importantly, approximately a half of Korean patients with Gaucher disease suffer from neurological manifestations. In addition, Korean Gaucher disease patients exhibit distinct mutation spectrum from those in other populations. Common mutations in Korean patients with Gaucher disease are also associated with neurological phenotype. Therefore, therapeutic strategies tailored to Korean patients were necessary. Interestingly, a chemical chaperone, ambroxol, has been known to increase residual enzymatic activities of the select mutant GBAs encoded by mutations prevalent in Korean patients. One promising aspect of this drug is that it can cross blood-brain barrier, and enhance the enzyme activity in the brain. In vitro study suggested this chemical chaperone as one of new therapeutic agents in Gaucher disease, and a well-designed human trial is required to confirm its efficacy.