• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.8
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• pp.1323-1332
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• 2006

Lyocell is a regenerated cellulose fiber manufactured by an environmentally-friendly process. Since the fiber has more crystalline region compared to rayon, lyocell shows higher wet-strength than rayon. Although fibril generation of lyocell is lower than that of rayon because of the reason, the fibril generated during the wet process deteriorates the smooth look and soft touch of the fabric. The efficient way to remove the fibril yet retain the strength property was investigated in this work. In order to scour and remove the fibril from the fabric, cellulase enzymes were introduced and the traditional scouring was carried to be compared. Weight loss, dye-ability, and strength of treated fabric were measured after the treatments. Scanning electron microscopy was used to observe the surface of the fiber. Among the cellulases used in this work, Denimax 992L showed the best results for removal of fibril with low weight loss and tensile strength loss. The optimal conditions for the enzymatic treatment could be chosen depending on a characteristic for final purpose of the lyocell product.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.1 s.119
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• pp.30-37
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• 2007

The seed paper was used in farm field recently for a sound young plant. The most of seed paper are made of synthetic non-woven sheet. Therefore, it is very difficult to bio-degrade in soil and is very hard to have some special function, for example keeping herbicide and/or insecticide activity because of its lack of chemical acceptability. The purpose of this research is manufacture of seedling paper which have a function of herbicide activity from waste paper. The fiber properties from waste paper were remarkably improved by fine removal with washing and/or flotation process. The paper-making ability for seed paper was enhanced with enzyme treatment of secondary fibers. The paper for seedling must have a good bio-degradation ability in soils. The absorption amount of chemical like as dithiopyr was increased remarkably in enzyme treated base paper. The embossing treatment of base paper was very effective for seed attachment and chemicals retention. And also, the developed seed paper showed a good penetration property of young root through embossed paper.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1217-1221
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• 2000

L-alanine dehydrogenase from Bacillus subtilis exhibits allosteric kinetic properties in the presence of $ZN^{2+}$. $ZN^{2+}$ induces the binding of substrate (L-alanine) to be cooperative at pH 8.0. The effect of pH variation between pH 7.0 and pH 10.0 on the inhibition by $ZN^{2+}$ correlates with the pH effect on the $K_m$ values for L-alanine within these pH range indicating that $ZN^{2+}$ and substrate compete for the same site. No such cooperativity is induced by $ZN^{2+}$ when the reaction is carried out at pH 10. At this higher pH, $ZN^{2+}$ binds with the enzyme with lower affinity and noncompetitive with respect to L-alanine. Inhibition of L-alanine dehydrogenase by $ZN^{2+}$ depends on the ionic strength. Increase in KCI concentration reduced the inhibition, but allosteric property in $ZN^{2+}$ binding is conserved. A model for the regulatory mechanism of L-alanine dehydrogenase as a noncooperative substrate-cooperative cofactor allosteric enzyme, which is compatible in both concerted and the sequential allosteric mechanism, is proposed.

• Food Science and Preservation
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• v.16 no.2
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• pp.217-222
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• 2009

The objective of this study was to obtain basic data on Korean traditional meju collected in 17 regions of Korea, to define and control meju quality. The moisture, crude fat, crude protein, and amino nitrogen contents of meju were 9.83-36.24%(w/w), 17.46-28.74%(w/w), 42.00-45.54%(w/w), and 223.65-1137.68 mg%, respectively. Meju was the enzyme source which made the soy sauce and doenjang. The $\alpha$-amylase, $\beta$-amylase, and protease levels were 130.32-1254.45, 30.07-167.88 and 72.53-340.04 units, respectively. Regional enzyme activities differed widely. Bacterial levels were $4.8{\times}10^7-2.6{\times}10^{10}cfu/g$, and molds and yeasts were at $4.3{\times}10^4-7.9{\times}10^6cfu/g$.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.293-298
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• 2009

Korean mistletoe lectin (KML) is the major component found in Viscum album var. (coloratum), displaying anti-cancer and immunostimulating activities. Even though it has been shown to boost host immune defense mechanisms, the regulatory roles of KML on the functional activation of macrophages have not been fully elucidated. In this study, regulatory mechanism of KML on macrophage-mediated immune responses was examined in terms of KML-mediated signaling event. KML clearly induced mRNA expression of tumor necrosis factor (TNF)-$\alpha$, the generation of reactive oxygen species (ROS) and phagocytic uptake in RAW264.7 cells. All of these events were strongly suppressed by U0126, whereas TNF-$\alpha$ mRNA was not diminished by SB203580 and SP600125, indicating ERK as a central enzyme managing KML-induced up-regulation of macrophage functions. Indeed, KML strongly induced the phosphorylation of ERK in a time-dependent manner without altering its total level. Therefore, these data suggest that ERK may be a major signaling enzyme with regulatory property toward various KML-mediated macrophage responses.

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.71-76
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• 2010

A gene encoding the mannanase of Bacillus licheniformis WL-12, which had been isolated from Korean soybean paste, was cloned into Escherichia coli and nucleotide sequence of the mannanase gene was subsequently determined. The mannanase gene consisted of 1,080 nucleotides encoding a polypeptide of 360 amino acid residues. The deduced amino acid sequence was identical to that of putative mannanase from B. liceniformis DSM13 belonging to GH family 26. The mannanase was partially purified from cell-free extract of the recombinant Escherichia coli carrying a WL-12 mannanase gene by ammonium sulfate fractionation and DEAE-Sepharose column chromatography. Optimal conditions for the partially purified enzyme occurred at pH 6.0 and $65^{\circ}C$. The enzyme showed higher activity on locust bean gum (LBG) galactomannan and konjac glucomannan than on guar gum galactomannan. The predominant products resulting from the mannanase hydrolysis were mannose, mannobiose and mannotriose for LBG or mannooligosaccharides. The enzyme could hydrolyze mannooligosaccharides larger than mannobiose.

• BMB Reports
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• v.31 no.1
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• pp.25-30
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• 1998

Kinetic studies of L-Alanine dehydrogenase from Bacillus subtilis-catalyzed reactions in the presence of $Zn^{2+}$ were carried out. The substrate (L-alanine) saturation curve is hyperbolic in the absence of the metal ion but it becomes sigmoidal when $Zn^{2+}$ is added to the reaction mixture indicating the positive cooperative binding of the substrate in the presence of zinc ion. The cooperativity of substrate binding depends on the xinc ion concentration: the Hill coefficients ($n_H$) varied from 1.0 to 1.95 when the zinc ion concentration varied from 0 to $60\;{\mu}m$. The inhibition of AlaDH by $Zn^{2+}$ is reversible and noncompetitive with respect to $NAD^+$ ($K_i\;=\;5.28{\times}10^{-5}\;M$). $Zn^{2+}$ itself binds to AlaDH with positive cooperativity and the cooperativity is independent of substrate concentration. The Hill coefficients of substrate biding in the presence of $Zn^{2+}$ are not affected by the enzyme concentration indicating that $Zn^{2+}$ binding does not change the polymerization-depolymerization equilibria of the enzyme. Among other metal ions, $Zn^{2+}$ appears to be a specific reversible inhibitor inducing conformational change through the intersubunit interaction. These results indicate that $Zn^{2+}$ is an allosteric competitive inhibitor and substrate being a non-cooperative per se, excludes the $Zn^{2+}$ from its binding site and thus exhibits positive cooperativity. The allosteric mechanism of AlaDh from Bacillus subtilis is consistent with both MWC and Koshland's allosteric model.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.235-243
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• 2019

A special eosinophilic agarase exo-type ${\beta}$-agarase gene, AgaDL6, was cloned from a marine agar-degrading bacterium, Flammeovirga sp. HQM9. The gene comprised 1,383-bp nucleotides encoding a putative agarase AgaDL6 of 461 amino acids with a calculated molecular mass of 52.8 kDa. Sequence analysis revealed a ${\beta}$-agarase domain that belongs to the glycoside hydrolase family (GH) 16 and a carbohydrate-binding module (CBM_4_9) unique to agarases. AgaDL6 was heterologously expressed in Escherichia coli BL21 (DE3). Enzyme activity analysis of the purified protein showed that the optimal temperature and pH of AgaDL6 were $50^{\circ}C$ and 3.0, respectively. AgaDL6 showed thermal stability by retaining more than 98% of activity after incubation for 2 h at $50^{\circ}C$, a feature quite different from other agarases. AgaDL6 also exhibited outstanding acid stability, retaining 100% of activity after incubation for 24 h at pH 2.0 to 5.0, a property distinct from other agarases. This is the first agarase characterized to have such high acid stability. In addition, we observed no obvious stimulation or inhibition of AgaDL6 in the presence of various metal ions and denaturants. AgaDL6 is an exo-type ${\beta}$-1,4 agarase that cleaved agarose into neoagarotetraose and neoagarohexaose as the final products. These characteristics make AgaDL6 a potentially valuable enzyme in the cosmetic, food, and pharmaceutical industries.

• Journal of the Korean Society of Food Culture
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• v.21 no.2
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• pp.171-178
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• 2006

Tarakjuk with different amylose content was made up using roasted rice flours that consisted of the highest enzyme-resistant starch (RS), while differential scanning calorimetry (DSC) was also utilized to measure the gelatinization temperature of these roasted rice flours in order to establish cooking temperature of tarakjuk. The following qualities of tarakjuk with different amylose content were studied: color, viscosity, spreadability, starch fractions involving total starch (TS), rapidly digestible starch (RDS), slowly digestible starch (SDS) and RS, in vitro starch digestibility (IVSD) and sensory properties. During experimentation, it was found that as the amylose content of the rice flour decreased, the L value of tarakjuk decreased, whereas a value increased significantly (p<0.05). Also, while viscosity showed to increase significantly (p<0.05), on the opposite end, the property of spreadability decreased. TS ranged from $15.95{\sim}17.31%$, RDS $9.36{\sim}10.16%$, SDS $5.46{\sim}6.91%$ and RS $0.33{\sim}1.07%$, on a dry basis. Although the amylose content of rice flours decreased, IVSD increased, however showing no significant difference. When testing the sensory properties of tarakjuk, color and viscosity increased, whereas clumpiness decreased. Ilpum tarakjuk showed the highest score for nutty taste and overall acceptance levels. In fact a high correlation was shown between nutty taste and overall acceptance level (p<0.01), which leads one to believe that nutty taste is a prime factor that greatly influences overall acceptance. Furthermore, viscosity was positively correlated with both a and b values, however negatively correlated with L value (p<0.05). Moreover, roasted nutty taste and overall acceptance were positively correlated with a value (p<0.05), respectively. In conclusion, the above results suggest that tarakjuk could be made by choosing the appropriate rice flour based on the nutritional or sensory purpose.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.984-986
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• 1999

In the case of immobilizing of glucose oxidase in organic polymer using electrosynthesis, the glucose oxidase obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and make charge-coupling weak between the glucose oxidase and the backbone of the polymer. That is mainly due to insulating property and net chain of the glucose oxidase. Such being the case, it is useless to increase in amount of glucose oxidase more than reasonable in the synthetic solution. We establish by means of qualitative analysis that amount of immobilized glucose oxidase can be improved by adding a hole ethyl alcohol in the synthetic solution. As ethyl alcohol was added by 0.1mol $dm^{-3}$ in the synthetic solution, the faradic impedance of resultant electrode was increased about five times as much as the case of ethyl alcohol free in the solution, and mass transport was limited more than over. That is due to insulating property and net chain of the glucose oxidase. Moreover, in ultraviolet spectra of the synthetic solution, the adsorption peak at 285nm corresponding to glucose oxidase was decreased. It suggests increase in amount of immobilized glucose oxidase.