• 한국식품저장유통학회지
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• 제10권2호
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• pp.246-251
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• 2003

Bacillus subtilis PANH765 균주가 생산하는 pretense를 황산암모늄에 의한 염석, DEAE-cellulose ion exchange chromatography, Sephacryl S 200 HR 및 Sepharose CL-6B gel filtration을 이용하여 정제하였다. DEAE-cellulose ion exchange chromatography를 행한 결과, 흡착 단백질 부분에서 활성이 높은 분획을 얻었다. 이 분획을 Sephacryl S 200 HR 및 Sepharose CL-6B gel filtration을 행한 결과 protease 활성을 가지는 단일 분획을 얻을 수 있었다. 정제한 protease의 분자량을 SDS-PAGE와 Sepharose CL-6B gel filtration으로 측정한 결과, 분자량은 35.0 kDa으로 추정되었으며, 각 효소의 비활성도는 6.27 U/mg이었으며, 회수율은 각각. 28.0%, 정제도는 4.35배로 나타났다. 최적 반응 온도는 $65^{\circ}C$, 최적 반응 pH는 7.05로 나타났으며, 온도 안정성은50 ∼ 75$^{\circ}C$, pH 안정성은 6.0 ∼ 7.5로 나타났다. 금속 이온의 영향은 $Na^{+}$, $K^{+}$, $Mg^{2＋}$ 및 NH$_4$$^{+}$ 이온이 효소 활성을 촉진하였으며, 그 중에서 $Mg^{2＋}$가 119.5%로 가장 높게 나타났다. 저해제인 경우 PMSF및 DFP에 의해 저해되었고 특히 DFP 보다는 PMSF 첨가시 뚜렷한 저해를 나타내었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.262-262
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• 2005

• 한국세라믹학회지
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• 제22권1호
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• pp.35-39
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• 1985

Synthetic mica $NaMg_{2.5}(Si_4O_{10})F_2 (Na-TSM)$ was treated with HCl solution and H-type exchange resin to investigate the chemical stability and the ion exchange by measuring the dissolution of chemical components and the exchanged $H^+$ ion. The replacement of $Na^+$ ion occurred in contact with HCl solution and H-type ion exchange resin at the surface of Na-TSM particles reached $Na^+$ ions at maximum value of 70~80%. $Mg^{2+}$ ion of octahedral layer became to dissolve from the pH2 solution and th amount of it dissolved in-creased almost proportional to $H^+$ ion concentration from around 0.02N $H^+$ ion equilibrium concentration. The crystalline structure of Na-TSM was destructed by dissolution of Mg2+ ion in cncentrated hydrochloric acid solution and resulted silica gel precipitation.

• Journal of Life Science
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• 제9권1호
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• pp.45-49
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• 1999

Seaweed alginate was acetylated by activated carbon immobilized Pseudomonas syringae in a fluidized bed, up-flow reactor. The acetylation degree of seaweed alginate was about 30%. Calcium-acetylated seaweed alginate gel bead was made and compared to calcium-seaweed alginate gel bead by the scanning electron microscopy (SEM). Structural difference of two gel beads may results from increased viscosity and decreased affinity of acetylated seaweed alginate for calcium ion. On the basis of interior and exterior structure of calcium-acetylated seaweed alginate gels and property of acetylated seaweed alginate, it seems that acetylated seaweed alginate is used for the supporter for electrophoresis and packing materials for liquid chromatography and gel filtration.

• 한국전기전자재료학회논문지
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• 제17권6호
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• pp.608-614
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• 2004

The gel polymer electrolyte was prepared by radical polymerization using tetra(ethylene glycol) diacrylate and tri(ethylene glycol) dimethacrylate to investigate affect of the number of ethylene oxide. The gel polymer electrolyte showed good electrochemical stability up to 4.5 V vs. Li/Li and high ionic conductivity at various temperatures. The lithium-ion polymer batteries with the gel polymer electrolyte, tetra(ethylene glycol) diacrylate- and tri(ethylene glycol) dimethacrylate-based, also represented good electrochemical performances such as rate capability, low-temperature performances and cycleability. However, the cell with tri(ethylene glycol) dimethacrylate, which has three ethylene oxide, showed better electrochemical performance.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1997년도 제12회 학술발표회 논문개요집
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• pp.118-119
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• 1997

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2003년도 춘계총회 및 학술발표회
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• pp.21-21
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• 2003

• BMB Reports
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• 제32권3호
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• pp.239-246
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• 1999

A tripeptidase (PepT) was purified to homogeneity from Bacillus subtilis through four sequential chromatographies including DEAE-Sepharose ion exchange, hydroxylapatite, mono-Q FPLC ion exchange, and Superose-12 FPLC gel filtration. The apparent molecular mass of the enzyme was 49,200 Da and 51,400 Da as determined by sodium dodecylsulfatepolyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography, respectively, and the enzyme exists in a monomeric form. The physicochemical properties of the enzyme were as follows: optimum pH at 7.5, optimum temperature at $60^{\circ}C$, and pI at 4.9. The $K_m$ and $V_{max}$ values of the enzyme were 4.3 mM and 2.5 mmol/min/mg, respectively, with MetAla-Ser as substrate. The B. subtilis PepT requires $Co^{2+}$ ion(s) for activation, while it is inactivated by EOTA and 1,10-phenanthroline, suggesting that it is a metalloprotein. The enzyme was not inhibited by any of serine protease, aspartic protease, or leucine aminopeptidase inhibitors. The enzyme showed comparable activities towards four different substrates including Met-Ala-Ser, Leu-Gly-Gly, Leu-Ser-Phe, and Leu-Leu-Tyr. The amino terminal sequence of PepT determined by Edman degradation was found to be MKEEIIERFTTYVXV and turned out to be identical to that of PepT deduced from a cloned B. subtilis pepT.

• 한국응용과학기술학회지
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• 제29권2호
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• pp.278-285
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• 2012

낮은 농도와 높은 농도의 염 용액에서 Poly(styrene sulfonic acid)(PSSA) 겔의 팽윤도에 대한 이온 특성화 효과를 ${SO_3}^-$와 페닐 고리의 수소결합을 통하여 조사하였다. 낮은 농도에서 PSSA 수화 겔의 수축 정도는 ${SO_3}^-$와 물 사이의 수소 결합에 대한 음이온의 불안정화 영향 때문에 음이온에서는 $SCN^-$<$Br^-$<$Cl^-$<$F^-$의 순서를 따랐다. 재 팽윤은 계에서 특별한 상호 작용이 있을 때 높은 농도에서 관찰되었다. 반면 양이온에서 PSSA 겔의 수축은 $Li^+$<$Na^+$<$K^+$<$Ca^{+2}$ 순서를 따랐다. $Ca^{+2}$ 이온에서의 큰 수축 효과는 이가 양이온(+2)에 의한 PSSA 겔의 물리적 가교 때문에 나타난 것으로 보인다. 양이온에서의 수축은 ${SO_3}^-$와 양이온 사이의 상호작용 정도에 비례하였다. PSSA의 팽윤에 대한 이온 특성화 효과는 ${SO_3}^-$와 페닐 고리의 수화 수소결합에 대한 이온의 영향 정도, 양이온과 ${\pi}$ 전자의 상호작용, 소수성 상호작용, 그리고 분산력 등이 복합적으로 작용하여 나타난다고 볼 수 있다.

• 한국식품영양학회지
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• 제7권1호
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• pp.23-28
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• 1994

Soybean $\beta$-amylase was purified by DEAE-cellulose ion exchange chromatography, Sephadex G-100 gel chromatography, CM Sephadex C-50 ion exchange chromatography and CM Sephadex C-50 ion exchange rechromatography The purified enzyme showed 1, 020 unit/mg of specific activity. The purified enzyme was identified as homogenious by disc PAGE and analysis of reaction product.