• Journal of Life Science
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• v.8 no.6
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• pp.627-637
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• 1998

In order to utilize tuna pyloric caeca among fish intestines wasted when treated raw fish in fish processing manufactory, a crude enzyme with high proteolytic activity was extracted and its optimum condition were investigated. An immobilized enzymes also were prepared by adsorption method to enhance thermostability of the crude proteinase. The yield of the crude proteinase was approximately 2.7% on dry basis. The proteolytic activity for casein was 0.54 U/mg protein, for BTEE 1.10 U/mg protein, and for BAEE 2.69 U/mg protein. It was almost similar to that of the commercial trypsin purified. Optimum hydrolysis activity of the crude proteinase was about 80%, as the degree of hydrolysis for casein, at pH 10.0 and 45$^{\circ}C$ for 12 hrs. Also, when the crude proteinase was immobilized on DEAE-Cellulose and chitin, the residual activities remained after 7 days of pre-incubation time were maintained about 90% or more and their thermostabilities were enhanced by about 50%, compared with the native enzyme.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.531-536
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• 2004

Synthesis conditions were optimized using response surface methodology for producing structured lipids (SL) by interesterification of DHA-enriched algae oil derived from microalgae, Schizochytrium sp. and corn oil. Reaction was performed fer 24 hr at $55^{\circ}C$ catalyzed by immobilized lipase from Rhizomucor miehei (RM IM) in shaking water bath. Major fatty acids of SL were palmitic (21.70 mol%), oleic (20.20 mol%), and linoleic (27.34 mol%) acids, and DHA (15.06 mol%). To separate newly synthesized SL-triglycerides (TG) species, HPLC with evaporative light scatting detector (ELSD) was used. Production conditions were optimized using central composite design with reaction temperature $(35-75^{\circ}C,\;X_1)$, reaction time $(2-42\;hr,\;X_2)$, and enzyme concentration $(2-14%,\;X_3)$ as variables. When variables were $70.28^{\circ}C\;(X_1),\;28.74\;hr\;(X_2),\;and\;11.30%\;(X_3)$, maximum content of selected three peaks of synthesized SL-TG species was predicted as 6.97 area%.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.504-510
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• 1992

Several single or mixed water-miscible organic solvent systems were investigated to develop the most effective solvent system for enzymatic synthesis of N-benzoylaspartame(BzAPM). The BzAPM was prepared by immobilized thermolysin with using N-benzoyl-L-aspartic acid(Bz-Asp) and L-phenylalanine methyl ester(PheOMe). The solubilities of BzAPM and L-phenylalanine were highest in 4.5% methanol(1.89 and 1.79%, respectively) among the solvents system investigated while a mixed solvent system of 25% dimethyl sulfoxide(DMSO) and 20% polyethylene glycol(PEG) 200 showed relatively high values. The synthetic activity of BzAPM as well as initial reaction rate were found to be high in 45% methanol, 45% DMSO and a mixed solvent of 25% DMSO and 20% PEM 200. The imobilized thermolysin was most stable in 25% DMSO and 20% PEG 200 during storage at $40^{\circ}C$ for 42 days. PheOMe in the same solvent system was also found fairly stable against non-enzymatic decomposition at $40^{\circ}C$. Based on the synthetic efficiency and stability, the solvent system containing 25% DMSO and 20% PEG 200 was selected to be appropriate for the enzymatic synthesis of BzAPM.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.30-36
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• 2014

Redox complexes to transport electrons from enzyme to electrodes are very important part in glucose sensor. Pentacyanoferrate-bound aniline ($Fe(CN)_5$-aminopyridine), was prepared as a potential redox mediator in a glucose dehydrogenase (GDH)-glucose sensor. The synthesized pyridyl-$NH_2$ to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. A amperometric enzyme-linked electrode was developed based on GDH, which catalyses the oxidation of glucose. Glucose was detected using GDH that was co-immobilized with an $Fe(CN)_5$-aminopyridine and gold nano-particles (AuNPs) on ITO electrodes. The $Fe(CN)_5$-aminopyridine and AuNPs immobilized onto ITO electrodes provided about a two times higher electrochemical response compared to that of a bare ITO electrode. As glucose was catalyzed by wired GDH, the electrical signal was monitored at 0.4 V versus Ag/AgCl by cyclic voltammetry. The anode currents was linearly increased in proportion to the glucose concentration over the 0~10 mM range.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.39-50
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• 2004

T7 RNA polymerase is a single subunit RNA polymerase able to accomplish whole transcription process without auxiliary factors. In order to study transcription elongation mechanism of phage T7 RNA polymerse, stepwise walking of RNA polymerase was established by immobilizing biotinylated DNA template with streptavidin bead, series of active and stable elongation complexes were obtained, Transcripts were radio isotope labeled at the 16thm 17th and 18th nucleotide residues so stable elongation transcription complex of T7 RNA polymerase containing 22-40 nucleotide residues could be identified. We identified the positions of stablely formed transcription elongation complexes of termination site in intrinsic hairpin-independent PTH terminator sequence through the established stepwise walking of wild-type of mutant R173C T7 RNA polymerases. The results suggest that stable elongation transcription complexes were at the site of passing PTH terminator signal by mutant R173C RNA polymerase.

• Journal of Life Science
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• v.22 no.4
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• pp.552-558
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• 2012

Severe acute respiratory syndrome (SARS) is a severe respiratory infectious disease caused by a novel human coronavirus, SARS-CoV. The 3CL protease is a key enzyme in the proteolytic processing of replicase polyprotein precursors, pp1a and pp1ab, which mediate all the functions required for viral genomic replication and transcription. Therefore, this enzyme is a target for the development of chemotherapeutic agents against SARS. A large quantity of active SARS-3CL protease is required for development of anti-SARS agents. Here we have constructed overexpression vector for the production of the SARS-3CL protease. The gene encoding SARS-3CL protease was amplified using polymerase chain reaction and cloned into the pET29a expression vector, resulting in pET29a/SARS-3CLP. Recombinant SARS-3CL protease was successfully synthesized by the dialysis mode of the cell-free protein expression system, and purified by three-step fast protein liquid chromatography using HighQ and MonoP column chromatographies and Sephacryl S-300 gel filtration. In addition, the produced SARS-3CL protease was found to be an active mature form. This study provides efficient methods not only for the development of anti-SARS materials from natural sources, but also for the study of basic properties of the SARS-3CL protease.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1977.10a
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• pp.197.5-198
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• 1977

일반적으로 protease는 고정화되면 저분자 기질에 대하여는 높은 활성을 내 주나 고분자 기질에 대하여는 낮은 활성을 나타내 줄다. 이것은 고정화된 Pretense의 구조적인 영향으로 생각된다. 본 실험에서 polysaccharide의 표면에 ac교lamide 및 N-hydroxysuccinmidyl acrylate (NHSA)을 graft 공중합 시킴으로서 긴축쇄에 활성 ester을 가지는 새로운 carrier을 합성하여 Bacillus thermoproteolyticus가 생산하는 중성 pretense인 thermolysin을 고정화시켰으며 아울러 고정화된 thermolysin의 몇가지 효소적 성질을 조사검토 하였다.(중략)

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.584-589
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• 2005

Structured triacylglycerol (SL-TAG) was synthesized by enzymatic interesterification with algae oil and soybean oil in solvent-free system. Structured di- and monoacylglycerol (SL-DAG/MAG) were produced by glycerolysis with SL-TAG and glycerol catalyzed by lipase. Reactions were performed by sn-1.3 specific Lipozyme RM IM lipase from Rhizomucor miehei (interesterification, 11%; glycerolysis 5% by weight of total substrates) in solvent-free system using stirred-batch type reactor. SL-DAG/MAG contained TAG (42,3 area%), 1,3-DAG (19.2 area%), 1,2-DAG (22.2 area%), MAG (16.0 area%), and free fatty acid (0.2 area%). Iodine and saponification values of SL-DAG/MAG were 208.8 and 179.6, respectively. SL-DAG/MAG appeared yellowish in color.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.107-121
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• 2021

Skin hypopigmentation, which is observed in albinism or vitiligo, occurs when melanin synthesis is decreased by genetic, epigenetic, and other factors. To identify drug candidates that can promote melanin synthesis in cells, we screened an epigenetic modulator library consisting of 141 cell-permeable, small molecule drugs. B16/F10 murine melanoma cells were treated with each drug at 0.1 𝜇M and melanin synthesis and cell viability were subsequently monitored. As a result, (-)-neplanocin A, 3-deazaneplanocin A (DZNep), and DZNep hydrochloride were found to increase cellular melanin synthesis without causing cytotoxicity. Because these three structurally related drugs exhibited similar dose-dependent effects on melanin synthesis and cell viability, DZNep was selected as a representative drug for additional experiments. DZNep increased intracellular melanin content and tyrosinase (TYR) activity. DZNep also induced the expression of TYR, tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT) at the mRNA and protein levels. DZNep also induced the mRNA and protein expression of microphthalmia-associated transcription factor (MITF), a key regulator of melanin synthesis. DZNep is a specific inhibitor of S-adenosylhomocysteine hydrolase and it caused the accumulation of S-adenosylhomocysteine that inhibits histone methyltransferases in cells. This study suggests that melanogenesis can be modulated by targeting S-adenosylhomocysteine hydrolase in certain cellular contexts.

• Food Science and Preservation
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• v.16 no.2
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• pp.246-252
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• 2009

Diacylglycerol(DAG) was produced by enzymatic esterification of glyceryl mono-oleate(GMO) and conjugated linoleic acid(CLA) in a stirred-batch type reactor. The reaction was catalyzed by lipozyme RMIM(an immobilized lipase from Rizomucor miehei). DAG was isolated by a short-path distillation process and decolorized. DAG oil was composed of 87.3% DAG, 11.4% triacylglycerol(TAG), and 1.5% monoacylglycerol(MAG)(all w/w). Major fatty acids in DAG oil were oleic acid(54%), CLA(31.1%), and linoleic acid(7%). DAG oil iodine,and acid values were 108.8, 2.57, and 1, respectively. The DAG oil solid fat index(SFI) and thermograms were obtained using differential scanning calorimetry.