• 제목/요약/키워드: natural purification

검색결과 511건 처리시간 0.041초

Purification and Properties of Phenylalanine Ammonia-lyase from Chinese Cabbage

  • Lim, Hye-Won;Sa, Jae-Hoon;Kim, Tae-Soo;Park, Eun-Hee;Park, Soo-Sun;Lim, Chang-Jin
    • BMB Reports
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    • 제31권1호
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    • pp.31-36
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    • 1998
  • Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), the first enzyme in the phenylpropanoid biosynthesis, catalyzes the elimination reaction of ammonium ion from L-phenylalanine. PAL was purified from the cytosolic fraction of Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography. It consists of four identical subunits, the molecular mass of which was estimated to be about 38,000 daltons on SDS-PAGE. The optimal pH and temperature of the purified enzyme are 8~9 and $45^{\circ}C$, respectively. Its activity is greatly inhibited by $Zn^{2+}$ ion, and strongly activated by caffeic acid. The purified PAL has some different characteristics compared to those obtained with other PALs.

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Agrobacterium tumefaciens 유래 인디칸 분해활성을 갖는 β-glucosidase의 분리와 특성분석 (Purification and Characterization of an Indican-hydrolyzing β-glucosidase from Agrobacterium tumefaciens)

  • 황창선;이진영;김근중
    • KSBB Journal
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    • 제27권6호
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    • pp.341-346
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    • 2012
  • Indican (indoxyl-${\beta}$-D-glucoside) is a colorless natural compound and can be used as a precursor for the production of indigo. This production step only require an enzyme, ${\beta}$-glucosidase, that readily screened from microbial resource by using selective media supplemented with indican as a sole carbon source. Agrobacterium tumefaciens was well grown in this media and thus presumed to produce a related enzyme. The corresponding gene, encoding a protein with a calculated molecular mass of 51 kDa, was cloned and overexpressed as MBP fusion proteins. The purified enzyme was determined to be a dimer and showed the maximum activity for indican at pH 7.0 and $40^{\circ}C$. The kinetic parameters for indican, Km and Vmax, were determined to be 1.4 mM and 373.8 ${\mu}M/min/mg$, respectively. The conversion yield of indican into indigo using this enzyme was about 1.7-1.8 folds higher than that of previously isolated enzyme from Sinorhizobium meliloti. Additionally, this enzyme was able to hydrolyze various ${\beta}$-1,4 glycoside substrates.

Purification and Characterization of Manganese Superoxide Dismutase from Staphylococcus sciuri

  • Song, Chi-Hyun;Park, Eun-Kyung;Suh, Hyung-Joo;Lee, Yong-Se;Choi, Jang-Won;Ra, Kyung-Soo
    • Journal of Microbiology and Biotechnology
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    • 제9권3호
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    • pp.271-275
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    • 1999
  • The intracellular superoxide dismutase (SOD) from Staphylococcus sciuri was isolated to homogeneity by continuous steps, including ammonium sulfate fractionation, DEAE-ion-exchange chromatography, gel filtration, and phenyl hydrophobic gel chromatography. Pure SOD had a specific activity of 4,625 U/mg and was purified 158-fold with a yield of 31 % from a cell free extract. The molecular weight of the purified SOD was determined to be approximately 35.5 kDa by gel filtration and the enzyme was also shown to be composed of dimeric subunits on denaturing SDS-PAGE. The enzyme activity remained stable at pH 5 to 11 and also to heat treatment of up to $50^{\circ}C$ at pH 7.8, with 80% relative activity. The enzyme was insensitive to cyanide, hydrogen peroxide, and azide, indicating that it is a manganese-containing SOD. The EPR spectrum showed the enzyme containing manganese as a cofactor.

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교반기의 진동 해석 기술 개발 (A Development of Vibration Analysis Technique of A Mixer)

  • 박진호;이정한;김봉수;안창기;강문후;주윤식
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.421-426
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    • 2003
  • Recently, mixers are being widely used in the water purification plant in order to increase the filtration efficiency. The mixer normally consists of impeller, shaft, hub, reduction gear, and the driving motor. It is one of the key design issues to confirm that the vibration caused by the rotation of the shaft should not coincide with the natural vibration frequency of the shaft itself. The vibration characteristics of the hydrofoil type mixer, which is the most widely used in real plants are evaluated through the finite element modeling and verified by experiment using the mock-up facility. The fundamental natural frequency of the mixer's shaft is found to be around 1.8 Hz which showed in good agreement with the experiment. The higher natural frequencies to the 2nd, 3rd, and 4th modes are also verified by the experiment. Thus the developed model is to be utilized for the structural design of the real mixer system.

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Purification and Characterization of Arginase from Schizosaccharomyces pombe

  • Kang, Jung-Hoon
    • BMB Reports
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    • 제28권3호
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    • pp.232-237
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    • 1995
  • Arginase was purified to homogeneity from Schizosaccharomyces pombe. The purified enzyme is a tetramer with a subunit molecular weight of 42,000. Activity is optimal at pH 10.0 and at $60^{\circ}C$ The enzyme migrated during isoelectric focusing showing a pl=5.4. The enzyme exhibited hyperbolic kinetics at pH 10.0 with an apparent $K_m$ for L-arginine of 18 mM. Arginase activity was strongly inhibited by L-glutamate.

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