• 한국미생물·생명공학회지
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• 제27권6호
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• pp.446-451
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• 1999

The protease produced by Mucor racemosus f. racemosus PDA 103 from meju was purified by precipitating with 80% saturated ammonium sulfate, CM Sephadex C-50 ion-exchange chromatography, and secondary Sephadex G-100 gel filtration chromatography. The specific activity of the purified enzyme was 60.1unit/mg protein and the purification fold of the enzyme was 83.5. The molecular weight of the enzyme was estimated 33,746Da and the enzyme was elucidated as monomer by LC-MS and SDS-PAGE. The number of amino acids was evaluated about 330 residues.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 춘계학술대회
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• pp.114.2-115
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• 1979

Horikoshi등이 호 alkali 성 미생물에 관한 연구에서 분리한 수종의 cellulolytic bacteria중에서 가장 강력한 균체의 효소를 생산하는 Aeromonas 속 세균의 cellulolytic 효소에 관한 연구 결과를 보고한다. 공업적으로 생산된 효소를 사용하여 효소작용의 최적조건을 측정하고 gel filtration, ion-exchange chromatography 및 affinity chromatography 로 cel-luplytic 효소를 분리정제하였다. 본 효소의 활성 최적 pH는 7.0~8.5로 alkaline 효소였으며 반응온도 5$0^{\circ}C$에서 가장 강한 활성을 보였다. 분리 정제과정에서 carboxymethyl cellulose (CMC)에 대하여 활성이 있는 단백질이 최소 8종이상 분리되었으며 이중 1개 효소는 CMC에 대해서는 극히 낮은 활성을 보였으나 결정성 기질인 Avicel 에는 강한 활성을 보였다. 본 연구의 결과를 Cellulomonas속 세균 및 Trichoderma속 곰팡이의 효소와 그 성질을 비교 검토하였다.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.152-156
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• 1998

A Fructan-degrading enzyme was partially purified from onion (Allium cepa)bulbs by a combination of ammonium sufate precipitation, concanavalin-A-Affinity chromatography, and ion-exchange and gel-filtration chromatography. The enzyme hydrolyzed sucrose more effectively than inulin and was identified as a $\beta$- fructofuranosidase (invertase). The optimum pH and temperature were pH 5.5 and 35$^{\circ}C$, respectively. The enzymehydrolyzed sucrose with a Km of 1.2mM . The soluble $\beta$-fructofuranosidase is likely glycoprotein based on its ability to bind the lectin concanavalin-A. The enzyme was heatlabie, with mose activity being lost at 5$0^{\circ}C$ in 1 hr of incubation. The onion $\beta$-fructofuranosidase was partially inhibited by ZnCl2 HgCl2 and CuSo4.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.160-164
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• 1998

The NADH-cytochrome b5 reductase (NCBR), a mitochondrial external electron carrier, was purified from bovine heart and turnip and their properties were examined. The mitochondrial outer membranes separated were subjected to NCBR isolation through DEAE-Cellulose ion exchange, DEAE-Sephadex gel chromatography, and hydroxyapatite adsorption chromatography. These processes yielded the purification folds of 88 and 42 and the recovery percentages of 0.2%, 5.67% for turnip and bovine heart, respectively. The molecular weight of the NCBR from the two sources was estimated to be 35,000 using SDS polyacrylamide gel electrophoresis. The Michaelis constant Km and maximum velocity Vmax were determined by measuring the NADH-ferricyanide redox system as well as the NADPH-ferricyanide redox system. The kinetics showed that both NCBRs had higher affinities for NADH than artificial electron-acceptor substrate ferricyanide. Although NADPH had a lower affinity for the enzymes than NADH, this study showed the 2'-phosphate dinucleotide could be used as a substrate.

• 한국균학회지
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• 제23권2호통권73호
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• pp.121-128
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• 1995

Agrocybe cylindracea의 톱밥배양 균사체로부터 항암효과가 있는 것으로 알려진 단백다당류를 분리, 정제하였으며 그 특성을 조사하였다. Agrocybe cylindracea 균사체로부터 열수추출한 조단백다당류(Fr.CB)의 수율은 ethanol 농도가 95%일 때 2.974 g으로서 원재료인 톱밥균사체를 기준으로 0.74%였다. 이 조단백다당류(Fr.CB)를 박막여과, ion exchange chromatography, 그리고 gel filtration에 의해 정제하였다. 조단백다당류 Fr.CB를 박막여과하여 분획한 결과 분자량 30만 이상의 분획(Fr.B)이 38.6%를 차지하여 고분자 단백다당류가 주성분임을 알 수 있었다. Fr.B를 ion exchange chromatography로 분리한 결과 2개의 분획이 17.4%(Fr.B-1), 10.3%(Fr.B-2)의 수율로 얻어졌다. 이들 분획을 농축한 다음 gel filtration한 결과 거의 순수한 단일 단백다당류의 peak를 얻을 수 있었다. Fr.B-1을 분리하여 얻은 $Fr.B-1-{\beta}$ 분획의 수율은 Fr.B-1을 기준으로 42.5%였다. 항암효과의 가능성이 가장 높은 것으로 판단되는 최종 정제된 분획인 $Fr.B-1-{\beta}$의 분자량은 710 KDa 부근이었으며 단당류의 조성을 HPLC로 분석한 결과, glucose가 주성분이었고 그외 fucose, galactose도 검출되었다. 또한 아미노산 조성을 분석한 결과 glutamic acid, alanine이 비교적 많이 검출되었고 cysteine은 검출되지 않았다.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2039-2044
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• 2011

A semi-continuous and automated method for quantifying atmospheric ammonia at the parts per billion level has been developed. The instrument consists of a high efficiency diffusion scrubber, an electrolytic on-line anion exchange device, and a conductivity detector. Water soluble gases in sampled air diffuse through the porous membrane and are absorbed in an absorbing solution. Interferences are eliminated by using an anion exchange devises. The electrical conductivity of the solution is measured without chromatographic separation. The collection efficiency was over 99%. Over the 0-200 ppbv concentration range, the calibration was linear with $r^2$ = 0.99. The lower limit of detection was 0.09 ppbv. A parallel analysis of Seoul air over several days using this method and a diffusion scrubber coupled to an ion chromatography system showed acceptable agreement, $r^2$ = 0.940 (n = 686). This method can be applied for ambient air monitoring of ammonia.

• BMB Reports
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• 제31권4호
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• pp.377-383
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• 1998

Thioltransferase, also known as glutaredoxin, was purified from Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) by a combination of ion-exchange chromatography and gel filtration. Its purity was confirmed by SDS-polyacrylamide gel electrophoresis and its molecular weight was estimated to be about 12,000 which is comparable with those of most known thioltransferases. The enzyme utilizes 2-hydroxyethyl disulfide, S-sulfocysteine, ${\alpha}-chymotrypsin$, insulin, and trypsin as substrates in the presence of reduced glutathione. The enzyme has Km values of 0.03-0.97 mM for these substrates. It appeared to contain dehydroascorbate reductase activity. The pH optimum of the enzyme was 8.5, when 2-hydroxyethyl disulfide was used as a substrate. It was greatly activated by reduced glutathione. Its activity was not significantly lost when stored at high temperature, indicating its thermostable character. It may play an important role in thiol-disulfide exchange in plant cells.

• 대한핵의학회지
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• 제3권1호
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• pp.69-72
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• 1969

In 1968 total 94,660 mc of radioactive iodocompound were prepared and distributed to the urers. In order to obtain an effective liver scanning In-113 m colloidal of even particle size from a $^{113}Sn-^{113m}In$ cow, the eluate(pH; 1.5) was examined by a radio paper partition chromatography. It was found that the eluate was composed of two components, ionic form and colloidal form. The ionid form could be eliminated by cation exchange resine and the eluate from the ion exchange resine was of even particle size to give an excellent liver scanning result. Labelling of $^{113m}In$ to human serum albumine was attempted.

• 미생물학회지
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• 제21권2호
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• pp.86-94
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• 1983

Polygalacturonase of Byssochlamys fulva was purified and characterized. Specific activity increased from 2.21 units/mg protein to 10.47 units/mg protein through $(NH_4)_2SO_4$ treatment, SephadexG-100 gel filtration, and DEAE-Sephadex ion exchange chromatography. Divalent cations, such as $Ca^{++}\;and\;Cu^{++}$, increased polygalacturonase activity greatly. Added as $10^{-3}M$ concentration, $Ca^{++}$ ion enhanced enzyme activity 9.8folds. Optimum temperature was $50^{\circ}C$ and optimum pH was 5.0. Activation energy of reaction was 8.69 Kcal/mole. Michaelis-Menten $constant(K_M)\;and\;V_{max}$ of reaction were $6.27{\times}10^{-3}mole/l\;and\;2.85{$\mu}moles/min$. Polygalacturonase of Byssochlamys fulva preferred polygalacturonic acid to pectin as substrate and was presumed as endo-type on the basis of the relationship between viscosity reduction and substrate degradation. Molecular weight of polygalacturonase was estimated as 55,000.

• BMB Reports
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• 제41권3호
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• pp.254-258
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• 2008

Lipase was purified from squid (Todarodes pacificus) liver in an attempt to investigate the possibility of applying the enzyme for biotechnological applications. Crude extract of squid liver was initially fractionated by the batch type ion exchange chromatography. The fraction containing lipase activity was further purified with an octyl-Sepharose column. Finally, lipase was purified by eluting active protein from a non-dissociating polyacrylamide gel after zymographic analysis. Molecular weight of the purified enzyme was determined to be 27 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme showed the highest activity at a temperature range of $35-40^{\circ}C$ and at pH 8.0. The activity was almost completely inhibited at 1 mM concentration of $Hg^{2+}$ or $Cu^{2+}$ ion. Partial amino acid sequence of the enzyme was also determined.