• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.555-559
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• 2003

EK를 고정화하기 위해 니켈 친화결합 방법과 공유 결합형 고정화 방법을 수행하였으며 니켈 친화결합이 공유 결합형 고정화보다 높은 고정화 수율과 activity를 나타냈다. 풀림과 재접힘을 이용한 효소의 활성 회복은 공유결합형 고정화가 니켈 친화결합보다 높은 결과를 나타내었다. 또한 기질의 분자량 크기에 따른 절단율의 차이가 없었으므로 레진 공극 내부로의 확산도 차이에 의한 절단반응의 차이는 없는 것으로 나타났고, 기질 종류에 따른 EK의 활성은 작은 기질이 큰 기질보다 높은 활성을 보였다.

• Membrane Journal
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• v.19 no.2
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• pp.113-121
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• 2009

Porous affinity chitosan and chitin membranes with good mechanical strength and high protein binding capacity were prepared by using silica particles as porogen. The maximum binding capacity of affinity chitosan membrane for BSA protein is 21.8mg/mL, and that of affinity chitin membrane for lysozyme enzyme is 26.1mg/mL. Chromatographic separations of BSA and lysozyme proteins using the porous affinity chitosan and chitin membranes were performed with change of the flow rate, loading amount and concentration of protein loading solutions. Protein eluted amount and binding yield were calculated from the filtration chromatograms consisted of loading/washing/elution sequences. Protein binding amount and yield were increased with decreasing of flow rate, increasing of loading amount and concentration of protein loading solutions. Those results suggest that the porous chitosan and chitin membranes prepared by using silica particles as porogen are suitable in affinity filtration chromatography for large scale separation of proteins.

• Membrane Journal
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• v.8 no.1
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• pp.50-58
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• 1998

Protein affinity membranes were prepared via coating of chitosan gel on the porous flat and hollow-fiber polysulfone membranes, followed by the immobilization of the reactive dye (Cibacron Blue 3GA) to the chitosan gel. Maximum protein binding capacity of these affinity membranes was about 70 $\mu{g/cm}^2$. Using the affinity flat membrane module, the elution chromatography of human serum albumin (HSA) was performed to determine the optimum condition of eluent buffer. The optimum condition of eluent was the universal buffer solution of 0.06 M concentration containing 1 M KCl at pH 10. For the frontal chromatography of HSA using the flat module, the dynamic protein binding capacity was rapidly decreased from the equilibrium values with increasing flow rate and HSA concentration of the loading solution. However, in the case of hollow-fiber module, the dynamic binding capacity was maintained an equilibrium value without depending on the operating conditions. These results showed that the hollow-fiber module was more effective than the flat module as an affinity chromatography column.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.137-140
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• 1998

최근 면직물에 항균성을 부여하기 위해 생체친화성이 높은 키토산에 대한 연구가 활발히 진행되고 있다. 키토산이 갖고 있는 아미노기는 생체친화성과 항균성을 부여하며 미성숙면의 염색성향상, 의료용고분자 등에 응용되고 있다[1, 2]. 한편, 일반적으로 면직물에 키토산을 처리하면 섬유와 키토산은 화학결합이 아닌 반데르발스 결합 등의 약한 결합을 형성하기 때문에 내세탁성이 떨어지는 문제점이 있다[3, 4]. (중략)

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.927-932
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• 2009

Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

• Journal of Life Science
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• v.28 no.4
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• pp.408-414
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• 2018

Actein is the well-known active ingredient of Cimicifugae rhizoma (Black cohosh). In this study, we investigated and compared the binding affinity of tubocurarine, actein, and actein derivatives on the B&C domain of the acetylcholine binding protein through in silico computational docking studies. The three-dimensional crystallographic structure of the acetylcholine binding protein B&C domain was obtained from the PDB database (PDB ID: 2XYT). An in silico computational autodocking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and NX-QuickPharm based on scoring functions. The actein showed an optimum binding affinity (docking energy), with the acetylcholine binding protein at -10.50 kcal/mol as compared to the tubocurarine (-9.80 kcal/mol). The interacting amino acids tryptophan 84 and tryptophan 147, in the B domain of the acetylcholine binding protein active site, significantly interacted with the actein and 27-deoxyactein, and (26R)-actein. The centroid XYZ grid position of the tubocurarine was X=38.300689, Y=112.053467, and Z=51.991022, but the actein and its derivatives showed values around X=26.4, Y=127.3, Z=43.7. These results clearly indicated that actein and its derivatives could be a more potent antagonist to the acetylcholine binding protein than tubocurarine. Therefore, the extract of Cimicifugae rhizoma or actein containing biomaterials can substitute for the botulinum toxin-mediated acetylcholine receptor regulation, and be applied to the anti-wrinkle cosmetics industry.

• KSBB Journal
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• v.15 no.1
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• pp.96-99
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• 2000

Liposome-amino acid conjugates were prepared using phopholipid (dipalmitoylphosphatidylcholine (DPPC) or distearoylph-osphatidylcholine(DSPC)) and hydrophobically modified amino acids (glutamic acid(glu), glutamine(gln) or asparagine(asn)). The size of liposomes was about 100 nm. According to the glucose-induced turbidity changes, liposomes composed of DPPC and glutamic acid have higher glucose binding affinity than liposomes of DPPC-glutamine or DPPC-asparagine. Also, the liposomes were more stable in terms of aggregation or fusion than the others (DPPC-glutamine, DPPC-asparagine and DSPC-amino acids). As a rdsult, stable liposomes with an affinity for glucose could be prepared with DPPC and glutamic acid.

• Membrane Journal
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• v.16 no.1
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• pp.39-50
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• 2006

Porous chitosan and chitin membranes were prepared by using silica particles as porogen. Membrane preparation was achieved via the following three steps: (1) chitosan film formation by casting an chitosan solution containing silica particles, (2) preparation of porous chitosan membrane by dissolving the silica particles by immersing the film into an alkaline solution and (3) preparation of porous chitin membrane by acetylation of chitosan membrane with acetic anhydride. The optimum preparation conditions which could provide a chitosan and chitin membranes with good mechanical strength and adequate pure water flux were determined. To allow protein affinity, a reactive dye (Cibacron Blue 3GA) was immobilized on porous chitosan membrane. Binding capacities of affinity chitosan and chitin membranes for protein and enzyme were determined by the batch adsorption experiments of BSA protein and lysozyme enzyme. The maximum binding capacity of affinity chitosan membrane for BSA protein is about 22 mg/mL, and that of affinity chitin membrane for lysozyme enzyme is about 26 mg/mL. Those binding capacities are about $several{\sim}several$ tens times larger than those of chitosan and chitin-based hydrogel beads. Those results suggest that the porous chitosan and chitin membranes are suitable in affinity filtration chromatography for large scale separation of proteins.

• Journal of Life Science
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• v.28 no.2
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• pp.195-200
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• 2018

Beta-asarone is the well-known active ingredient of Rhizoma acori graminei. In this study, we investigated and compared the binding affinity of mosquito oviposition pheromone (MOP; (5R,6S)-6-acetoxy-5-hexadecanolide) and beta-asarone on the A domain of the mosquito odorant binding protein 1 (CquiOBP1) by in silico computational docking studies. The three-dimensional crystallographic structure of CquiOBP1 was obtained from the PDB database (PDB ID: 3OGN). In silico computational auto-docking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and the NX-QuickPharm option based on scoring functions. The beta-asarone showed optimum binding affinity (docking energy) with CquiOBP1 as -6.40 kcal/mol as compared to the MOP (-6.00 kcal/mol). Among the interacting amino acids (LEU76, LEU80, ALA88, MET89, HIS111, TRP114, and TYR122), tryptophan 114 in the CquiOBP1 active site significantly interacted with both MOP and beta-asarone. Amino acids substitution (mutation) from non-polar groups to the polar (or charged) groups of the CquiOBP1 dramatically changed the X, Y, Z grid position and binding affinity of both ligands. These results significantly indicated that beta-asarone could be a more potent ligand to the CquiOBP1 than MOP. Therefore, the extract of Rhizoma acori graminei or beta-asarone can be applied to the fields of insecticidal and repellant biomaterial development.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.305-312
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• 1994

The fed-batch process which combinded high selectivity of affinity chromatography and membrane process was developed. The mixture of trypsin and chymotrypsin, having almost the same molecular weight and the chemical structure, were used as model enzymes. The water soluble polymer having more affinity for trypsin and celluose acetate membrane gelated in 50vol.% ethanol for removing free enzymes and retentating trypsin-affinity polymer complex simutaneously were used in this system. The membrane pore size was controlled by ethanol concentration in the gellation bath, and the affinity polymer was prepared by polymerization of acrylamide with N-acryloyl-m-aminobenzamidine at $4^{\circ}C$. The trypsin could be effectively concentrated by utilizing an affinity polymer and a prepared UF-50 ultrafiltration membrane. As a result, 86% purity trypsin was recovered by the current purification process.