• Textile Coloration and Finishing
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• v.13 no.1
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• pp.9-17
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• 2001

The purpose of this study is to present basic data for the enzymatic modification of acetate fabrics. The weight loss and rate of weight loss of acetate fabrics increased with increasing NaOH concentration and treating time. Acetyl value decreased as the weight loss became higher. The weight loss of alkaline-treated acetate fabrics were directly proportional to the concentration and treating time of cellulase. The optimum temperature and pH in cellulase treatment were $55^\circ{C}$ and pH 3.5. The surface shape revealed that density of fiber decreased by alkaline-treatment. With the treating time of cellulase, fibrillation occurred. In case of higher weight loss in alkaline treatment, fibril is removed after 180 min. The tensile strength decreased by alkaline and cellulase treatment. Especially, in case of higher weight loss of alkaline treatment, tensile strength decreased suddenly. Alkaline treatment increased the drapability of acetates, while cellulase treatment increased it initially but decreased gradually with treatment time. The dyeability after alkaline treatment was improved for reactive dye, but deteriorated for disperse dye. The cellulase treatment of acetate lowered the dyeability for both types of dyes.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.16-23
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• 2009

Lipids were extracted from marine rotifer, Brachionus rotundiformis in order to examine the functionality of lipid enzymatic modification. The fatty acids, palmitic, linoleic, oleic and stearic acids were the dominant forms accounting for approximately 35.8%, 21.5%, 15.9% and 7.7% of the total lipid content, respectively. Lipid fractions were categorized as neutral lipids (38.5%), glycolipids (45.9%) and phospholipids (17.6%), and after extraction from the rotifer were isolated by thin-layer chromatography (TLC) as free fatty acids (FFA), monoacylglycerol (MAG), diacylglycerol (DAG) and triacylglycerol (TAG). The production of polyunsaturated fatty acid (PUFA) concentrate from rotifer lipids was studied using lipase-catalyzed hydrolysis. In addition, rotifer lipids were modified by hydrolysis using lipases such as porcine pancreas, Candida rugosa and Rhizomucor miehei. The lipase from Rhizomucor miehei was effective in extracting linoleic acid (C 18:2), while the lipase from Candida rugosa was effective in palmitic acid (C16:0) extraction.

• BMB Reports
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• v.51 no.12
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• pp.609-610
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• 2018

Glycosylation is one form of protein modification and plays a key role in protein stability, function, signaling regulation and even cancer. NleB and SseK are bacterial effector proteins and possess glycosyltransferase activity, even though they have different substrate preferences. NleB/SseKs transfer the GlcNAc sugar to an arginine residue of host proteins, leading to reduced $NF-{\kappa}B-dependent$ responses. By combining X-ray crystallography, NMR, molecular dynamics, enzyme kinetic assays and in vivo experiments, we demonstrated that a conserved HEN (His-Glu-Asn) motif in the active site plays a key role in enzyme catalysis and virulence. The lid-domain regulates the opening and closing of the active site and the HLH domain determines the substrate specificity. Our findings provide evidence for the enzymatic mechanism by which arginine can be glycosylated by SseK/NleB enzymes.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.7
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• pp.1121-1127
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• 2009

This study presents an eco-friendly and one-step finishing method for modifying fiber property that reduces fiber damage in wool/polyester blend fabrics. Lipase from aspergillus oryzae is used in this experiment. The enzymatic treatment condition is optimized by measuring the relative activity of lipase depending on pH level, temperature, concentration of lipase, and treatment time. The concentration of $CaCl_2$as an activator is determined by the characteristics including whiteness, water contact angle (WCA), and dyeing property. The modified properties of lipase treated fabrics are tested for pill resistance and surface morphology. The results are described as follows: the optimum condions for lipase treatment constitute a pH level of 8.0, treatment temperature of 40$^{\circ}$$_C$, concentration of lipase at 100% (o.w.f), and a treatment time of 90 minutes. $CaCl_2$helps in raising lipase activation, and the optimum concentration is 50mM. The whiteness, wet ability, and pill resistance of lipase treated fabrics improves as compared to the control. The dyeing property of lipase treated fabrics improved by 53.5% after using the one-bath dyeing method. This means that lipase treatment can save time and cost during the dyeing process since lipase treatment modifies wool and polyester fibers. The surface of lipase treated wool fibers do not exhibit any change, however voids and cracks manifest on the surface of lipase treated polyester fibers.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.708-715
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• 1995

Effect of enzymatic modification with pepsin, papain and trypsin was studied on functional properties of isolated sesame meal protein hydrolysates. Solubility of protein hydrolysates distinctively increased from 2% to $53{\sim}94%$ at pH 4. Emulsifying properties showed marked increase 6 fold and 4.5 fold at degree of 10%, 20% hydrolysis by trypsin and degree of 10% hydrolysis by papain. The emulsion stability of the protein was unstable by heat treatment for 30 min. at $80^{\circ}C$. Foaming properties were also enhanced by enzymatic hydrolysis except at degree of 30% hydrolysis. Bulk density and water absorption of protein with trypsin and papain decreased about 0.1 g/ml and $0.3{\sim}0.7\;ml/g$, but oil absorption was increased about 1 ml/g.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.706-711
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• 1992

Silkworm larvae protein concentrate was partially hydrolyzed at $50^{\circ}C$ by papain at pH 2.0 and pepsin at pH 7.0 for 10min and 60min and the effect of enzymatic modification on the functional properties of silkworm larvae protein concentrate was examined. The degrees of hydrolysis measured by TCA-soluble nitrogen content were 10.2% and 19.2% when hydrolyzed by pepsin for 10min and 60min. The nitrogen solubility in water and 0.03M $CaCl_2$ was increased with increasing the degree of hydrolysis, and bulk density, water and oil absorption were also enhanced by enzymatic hydrolysis when compared with the control.

• BMB Reports
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• v.28 no.6
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• pp.509-514
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• 1995

A putative secondary structure of the mRNA for the human hepatitis B virus (HBV) X gene is proposed based on not only chemical and enzymatic determination of its single- and double-stranded regions but also selection by the computer program MFOLD for energy minimum conformation under the constraints that the experimentally determined nucleotides were forced or prohibited to base pair. An RNA of 536 nucleotides including the 461-nucleotide HBV X mRNA sequence was synthesized in vitro by the phage T7 RNA polymerase transcription. The thermally renatured transcripts were subjected to chemical modifications with dimethylsulfate and kethoxal and enzymatic hydrolysis with single strand-specific RNase T1 and double strand-specific RNase V1, separately. The sites of modification and cleavage were detected by reverse transcriptase extension of 4 different primers. Many nucleotides could be assigned with high confidence, twenty in double-stranded and thirty-seven in Single-stranded regions. These nucleotides were forced and prohibited, respectively, to base pair in running the recursive RNA folding program MFOLD. The results suggest that 6 different regions (5 within X mRNA) of 14~23 nucleotides are Single-stranded. This putative structure provides a good working model and suggests potential target sites for antisense and ribozyme inhibitors and hybridization probes for the HBV X mRNA.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.983-989
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• 2008

Human insulin is a hormone well-known to regulate the blood glucose level. Recombinant preproinsulin, a precursor of authentic insulin, is typically produced in E. coli as an inactive inclusion body, the solubilization of which needs the addition of reducing agents such as $\beta$-mercaptoethanol. To make authentic insulin, recombinant preproinsulin is modified enzymatically by trypsin and carboxypeptidase B. The effects of $\beta$-mercaptoethanol on the formation of human insulin derivatives were investigated in the enzymatic modification by using commercially available human proinsulin as a substrate. Addition of 1 mM $\beta$-mercaptoethanol induced the formation of various insulin derivatives. Among them, the second major one, impurity 3, was found to be identical to the insulin B chain fragment from $Phe_1$ to $Glu_{21}$. Minimization of the formation of insulin derivatives and concomitant improvement of the production yield of human insulin were achieved by the addition of hydrogen peroxide. Hydrogen peroxide bound with $\beta$-mercaptoethanol and thereby reduced the negative effects of $\beta$-mercaptoethanol considerably. Elimination of the impurity 3 and other derivatives by the addition of over 10 mM hydrogen peroxide in the presence of $\beta$-mercaptoethanolled to a 1.3-fold increase in the recovery efficiency of insulin, compared with those for the case without hydrogen peroxide. The positive effects of hydrogen peroxide were also confirmed with recombinant human preproinsulin expressed in recombinant E. coli as an inclusion body.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.78-84
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• 2016

The antioxidant activity of silkworm powder treated by proteolytic enzyme was investigated. Total protein content of silkworm power was assayed using BCA, Bradford assays and SDS-polyacrylamide gel electrophoresis (PAGE) with alkaline protease treatment conditions including temperature and pH. The optimum condition of alkaline protease treatment for silkworm powder was found to be $60^{\circ}C$ and pH 7. The alkaline protease treatment resulted in increased contents of free amino acids, total polyphenol and total flavonoid compared to control group. The silkworm hydrolysates showed excellent antioxidant activities in various in vitro models such as 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2 - azino-bis(3-ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity. These results provide useful information for using silkworm powder as an ingredient in functional foods and for exploiting alkaline protease treatment to improve the extractability and bioactivity of a raw material.

• Journal of Life Science
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• v.14 no.3
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• pp.406-410
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• 2004

Glyoxal or methylglyoxal was incubated with catalase in 0.24 M sodium phosphate buffer (pH 7.4) at 37$^{\circ}C$. Dicarbonyls modify and inactivate catalase. Plasmid DNA that is directly incubated with glycation propagators, glyoxal and methylglyoxal, showed different DNA mobility shift compared to nomal plasmid DNA. When plasmid DNA is added in Fenton reaction with glycated catalase, plasmid DNA was significantly strand broken and 8-hydroxydeoxyguanosine production was time dependently increased. These results suggest that glycation of antioxidant is synergistic effect to oxidative stress.