• Korean Journal of Microbiology
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• v.32 no.2
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• pp.132-138
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• 1994

L-Ascorbic acid-producing enzyme in Neurospora crassa was found to exist in mitochondria and the activity of this enzyme was increased by the addition of D-fluconno-${\gamma}$-lactone or L-gulono-${\gamma}$-lactone in the media. L-Ascorbic acid-producin enzyme in N. crassa has been purified with ammonium sulfate precipitation. DEAE Sepharose CL-6B ion exchange chromatography. Sephacryl S-200 gel filtration chromatography and Reactive yellow 3-agarose dye affinity column chromatography. The specific activity of this enzyme was increased to 239.6 fold and the yield was 2.1%. The molecular weight of the native enzyme was 150.000 dalton when it was estimated with Sephacryl S-200 gel filtration chromatography. Its molecular weight appeared as 75.000 dalton by SDS-polyacrylamide gel electrophoresis. which suggested that this enzyme was consisted with two identical subunits. The optimal pH for this enzyme was 9.0 and the $K_m$ value for D-galactono-${\gamma}$-lactone was 0.073 mM.

• Analytical Science and Technology
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• v.22 no.3
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• pp.228-234
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• 2009

To gain further insight into herbicide detoxification of plant, we purified a glutathione S-transferase from Brassica oleracea (BoGST) and studied its substrate specificity towards several xenobiotic compounds. The BoGST was purified to electrophoretic homogeneity with approximately 10% activity yield by DEAE-Sephacel and GSHSepharose column chromatography. The molecular weight of the BoGST was determined to be approximately 23,000 by SDS-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. The activity of the BoGST was significantly inhibited by S-hexyl-GSH and S-(2,4-dinitrophenyl)GSH. The substrate specificity of the BoGST displayed high activities towards CDNB, a general GST substrate and ethacrynic acid. It also exhibited GSH peroxidase activity toward cumene hydroperoxide.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.101-107
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• 1992

Cytochrome c oxida5e from chemotrophically grown R p , geliitinosu was purified by cytochrome c affinity chromatography and DEAE-Sephacel ion exchange chromatography. The molecular weight of the cytochrome c oxidase was approximately 110.000 Da by sephacryl s-300 gel chromatography and approximately 52, 000 Da by SDS-gel electrophoresis, respectively. Therefore. cytochrolne c oxidase of Rps. gehtinosu seems to be dimer. The cytochrome c oxidasc was very sensitive to temperature. It's Km and Vmax were 20 pM and 44 unitlmg protein for horsc heart cytochrome c as a substrate. respectively, and its optimum pH and temperature were 6.4 and 25$^{\circ}$C. respectively. The absorption peaks of the reduced cytochrome c oxidase showed at 554 nm, 523 nm. and 422 nm. The activiiy of cytochrome c oxidase was inhibited by KCN, and NaN3, but not by CO, antimycir~ A. and myxothiazol. The cytochrome c-551 was produced either in phototrophically or chemotrophically grown Rps. gelaiinosci. The rcduced cytochrome c-551 was oxidized by b-type cytochrome c oxidase from Rp.v. gc.lrtino.sc~. Km and Vmax of cytochrome c oxidase was 26 pM and 31 unitlnlg protein For cytochrome c-551 as a substrate. respectively. Thercfore. thc electron transfer chain of chemotrophically grown Rps. glatinosa seems lo be ubiquinol cytochrome bc, complex -'cytochrome c-55lMb-type cytochrome c oxidase+02.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.120-123
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• 1998

1. 서론 : 생물기술이 급속히 발전함에 따라 다양한 생물제품들(예, 단백질, 효소, 항생제 등)이 생산되고 있으나, 그 생산량은 극단적으로는 기질용액 1g당 10$^{-8}$g 정도로까지 낮아, 이를 고순도로 정제하기 위해서는 다단계의 공정이 필요하여 분리정제의 비용이 크다. 따라서 생물제품의 산업적 생산이 경제성을 갖기 위해서는 생물제품을 보다 경제적으로 분리정제할 수 있는 효율적인 공정개발이 필수적이다. (생략)

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.147-152
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• 2009

A xylanase was purified from the culture supernatant of Bacillus sp. A-6 by using ultrafiltration and ion exchange chromatography on the column of SP-Sepharose using 5 mM acetate buffer, pH 5.0. The xylanase was eluted from the column at the concentration less than 0.05 M NaCl. The eluted xylanase was shown to be a single protein band in SDS-PAGE. Zymogram analysis indicated that the protein band in SDS-PAGE had the enzyme activity to hydrolyze oat spelt xylan. The molecular weights of the xylanase were 15,000 based on SDS-PAGE and 14,100 based on gel filtration chromatography. Thin layer chromatography showed that the xylanase hydrolyzed oat spelt xylan into xylobiose and high-molecular-weight xylooligosaccharides. The relative activities of the heated xylanase decreased to 80% at $40^{\circ}C$ after 7 hr and less than 40% at $60^{\circ}C$ after 1 hr.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.165-174
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• 1979

A purification technique of glucose oxidase was developed. Using the gluconyl-${\omega}$-aminohexyl Sepharose affinity chromatography, it was partially purified 14.6 folds with 79.7% yield. With the combination of the affinity chromatography and Sepharose 6B gel filtration, the enzyme was purified 27.2 folds from the broth with 74.1% yield. The final purified preparation showed 90.83 U of glucose oxidase activity per mg of protein and a single band by 7% polyacrylamide gel electrophoresis. The absorption spectrum and substrate specificity of the enzyme were studied and the fianal preparation showed the optimal pH between 5.6 and 6.0, the optimal temperature at $40^{\circ}C$, $8.5{\times}10^{-3}M$ of $K_m$ for D-glucose, and 3.43 kcal/mole of the activation energy.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.381-383
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• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.448-457
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• 1993

Deterioration of fish muscle is known to occur more quickly in the dark fleshed fish than in the white fleshed fish, causing by their high intestinal proteolytic activity. Muscle degradation which suffer post-mortem autoproteolysis is affected by trypsin with its unique activation function towards other enzymes. To compare physicochemical and enzymatic properties for the trypsins of the dark fleshed fish, trypsins from the viscera of anchovy (Engraulis japonica), and the pyloric caeca of mackerel (Scomber japonicus), yellowfin tuna (Thunnus albacores) and albacore (Thunnus alalunga) were purified through ammonium sulfate fractionation, benzamidine-Sepharose 6B, DEAE-Sephadex A-50, and Sephadex G-75 chromatography Two trypsins from mackerel (designated mackerel trypsin A and mackerel trypsin B), and one each from anchovy, yellowfin tuna and albacore were isolated as electrophoretical homogeneity, The purities of anchovy trypsin, mackerel trypsin A and B, yellowfin tuna trypsin, and albacore trypsin increased to 78.1, 4.8, 9.3, 120, and 160-fold, respectively, compared to crude enzyme solutions. Molecular weights of the trypsins from the dark fleshed fish estimated by SDS-polyacrylamide electrophoresis were ranged from 22kDa to 26kDa. The trypsins contained higher amount of glycine, serine and aspartic acid, and less amount of tryptophan, methionine, lysine and tyrosine. Optimal conditions for amidotici reactions of the enzymes were pH 8.0 and 45$^{\circ}C$ for anchovy trypsin, pH 8.0 and 5$0^{\circ}C$ for mackerel trypsin A and B, pH 9.0 and 55$^{\circ}C$ for yellowfin tuna trypsin, and pH 9.0 and 5$0^{\circ}C$ for albacore trypsin. It was supposed that the habitat temperature of the dark fleshed fish is slightly connected with the optimal reaction temperature of the trypsins of the fish.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.258-258
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• 1994

본 연구에서는 토양균이 생성하는 2차 대사산물로부터 세포증식 촉진인자 (Maturation Promoting Factor. MPF)인 cdc2/cdk2-cyclin의 복합체를 특이적으로 억제하는 물질을 분리하고 그 물질의 생리활성을 조사하였다. 토양으로부터 순수분리된 300여개의 토양균에서 생성된 배양액을 취하여 MPF의 특이적인 기질인 합성 peptide (CSH103 :HATPPKKKRK)를 사용하여 인산화 활성을 측정하였다. 그중 MPF 활성 억제능이 90％ 이상인 19개의 균주를 1차적으로 선정한 후 각각에 대하여 열/pH에 대한 안정성, 각종 용매에 대한 추출성 등 이화학적 성질을 규명하였으며 이중 균주 LPL 931로부터 MPF 활성 억제제를 분리하고자 하였다. 예비실험의 결과로부터 토양균 LPL 931을 대량배양하여 열처리하고, 비이온성 수지인Amberlite XAD-2에 결합시키고 70% acetone으로 용출시켰다. 이 추출물로부터 ethylacetate와 n-butanol을 사용하여 MPF 억제 활성물질을 추출하였다. 이 추출액을 실리카겔 관 크로마토그래피, 분취 TLC, 분취 HPL를 하여 MPF 활성 억제 분획을 분리하였다.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.588-591
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• 1991

S-adenosyl-L-methionine (SAM) is essential substrate for biological methylation reactions. The present work describes a reoptimized procedure of SAM preparation in laboratory scale by the method of yeast fermentation. The fermentation medium enriched with methionine and the culture conditions were reoptimized. The isolation steps consisted of 5 steps including extractions, precipitations, and chromatography. This improved procedure over original method provides relatively high yield of biologically active product within a 4 day-period.