• 한국염색가공학회지
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• 제13권1호
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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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• 제12권1호
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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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• 제51권12호
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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.

• 한국의류학회지
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• 제33권7호
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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.

• 한국식품과학회지
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• 제27권5호
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• pp.708-715
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• 1995

Pepsin, papain 및 trypsin 처리 참깨박 단백질의 기능성의 변화를 조사한 결과 용해도에 있어 pH 4에서 2%의 대조군에 비해 $53{\sim}94%$까지 뚜렷한 증가를 보였으며, trypsin에 의한 10%, 20% 가수분해도 처리군은 등전점에서 약 6배, papain에 의한 10% 가수분해도 처리군은 약 4.5배 가량의 유화능의 향상을 보였다. 기포 형성력은 각 효소 처리군의 30% 가수분해도 처리군의 알칼리 영역을 제외한 나머지 영역에서 전반적인 증가를 보였다. trypsin, papain 처리군의 겉보기 밀도와 수분 흡착력은 약 0.1 g/ml와 $0.3{\sim}0.7\;ml/g$ 정도 감소하였으나, 유지흡착력은 약 1 ml/g 정도의 증가를 보였다.

• 한국식품영양과학회지
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• 제21권6호
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• pp.706-711
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• 1992

Papain과 pepsin에 의한 부분 가수분해가 번데기 농축단백질의 기능적 특성에 미치는 영향을 검토하였다. TCA 가용성 질소량을 측정하여 얻은 가수분해 정도는 papain으로 10분과 60분간 처리한 결과 각각 10.23%와 19.17% 였으며 pepsin으로 10분과 60분간 처리한 경우는 각각 15.41%와 21.41%로 나타났다. 효소처리한 번데기 농축단백질의 질소 용해도는 실험한 pH 전범위에서 증가하였으며 특히 papain과 pepsin 모두 60분 처리한것이 10분간 처리한것 보다 높게 나타났다. 0.03M $CaCl_2$를 첨가한 결과 전반적으로 질소 용해도가 증가하는 경향을 나타내었다. 번데기 농축단백질의 겉보기 밀도는 papain으로 처리시 차이가 나타나지 않았으며 pepsin의 겨우는 다소 증가하는 경향이었다. 수분 흡수력의 경우 pepsin으로 10분간처리한것 이외에는 큰차이를 나타내지 않았으나 지방흡수력은 papain과 pepsin으로 부분 가수분해한 결과 전반적으로 증가하였다.

• BMB Reports
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• 제28권6호
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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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• 제18권5호
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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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• 제33권2호
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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.

• 생명과학회지
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• 제14권3호
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• pp.406-410
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• 2004

Glycation 반응은 glucose와 amino group 간에 일어나는 비효소적 축합 반응인 maillard 반응의 초기 반응으로 non enzymatic glycation 이라고도 한다. 생체내 glycation 반응을 통해 다수의 dicarbonyl화합물이 생성되고, 이들 dicarbonyl들 중에서 매우 반응성이 큰 것으로 확인된 glyoxal과 methylglyoxal과 catalase를 반응 시켜 glycation catalase의 활성 변화를 확인하였다. Non-glycated catalase에 비해 glycation catalase에서 구조적 인 modification과 degradation이 일어났으며, glycation반응 시간에 따라 활성이 크게 저하되는 것으로 확인 할 수 있었다. 특히 glycation 반응 시간 20일 경과 이후 glycation catalase 경우 활성이 거의 상실한 것으로 나타났다 Glyoxal과 methylglyoxal의 농도를 달리 해서 DNA와 반응 시켜 glycation propagator에 의한 직접적인 DNA damage를 확인 한 결과 Glyoxal과 methylglyoxal의 농도와 반응 시간에 따라 DNA mobility sit의 차이를 나타냈다. Fenton reaction 조건에 glyoxal과 methylglyoxal에 의해 활성이 저하된 catalase를 첨가 시켜 8-OH-dG의 생성을 확인한 결과 두 glycation propagator와의 반응 시간 의존적으로 8-OH-dG의 생성이 증가함을 보였다. 이상의 결과를 통해 glyoxal과 methylglyoxal의 antioxidant의 glycation은 oxidative stress의 증사를 유발해 생체내 활성 산소로부터 방어 기작에 심각한 문제를 야기하는 것으로 사료된다.