• Food Science and Biotechnology
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• v.15 no.2
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• pp.177-182
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• 2006

Polyphenol oxidase (PPO) was isolated from the flesh of Fuji apples by DEAE-Cellulose, ammonium sulfate precipitation, phenyl-Sepharose CL-4B, and Sephdex G-100 chromatography. The molecular mass of the purified PPO was estimated to be 40 kDa by SDS polyacrylamide gel electrophoresis. With regard to substrate specificity, maximum activity was achieved with chlorogenic acid as substrate, followed by catechin and catechol whereas, there was no detectable activity with hydroquinic acid, resorcinol, or tyrosine as substrate. The optimum pH and temperature with catechol as substrate were 6.5 and $35^{\circ}C$, respectively. The enzyme was most stable at pH 6.0 and unstable at acidic pH. The enzyme was stable when it was heated to $45^{\circ}C$ but heating at $50^{\circ}C$ for more than 30 min caused 50% loss of activity. Reduced $ZnSO_4$, L-cystein, epigallocatechin-3-o-gallate (EGCG), and gallocatechin gallate (GCG) also inhibited activity.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.255-260
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• 1991

Chitinase was partially purified from Allium fistulosum L (green onion_. Protein fraction precipitated from ammonium sulfate was passed through CM-Sepharose and Sephacryl HR-200. The specific activity of the chitinase was 6.4 units/mg and total recovery was 6.3%. The analysis of the products from the digestion of N-acetychitohexaose indicated that chitinase was endo in action, with oligerms from N-acetylchitobiose to chitotetraose. N-Acetylglucosaminidase from the same species hydrolyzed oligomers obtained from chitinase reaction to lower oligosaccharides. These data demonstrated that chitinolytic system exists in green onion.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.490-498
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• 1993

To find antitumor components in the hot water extract from the basidiocarps of Hypsizigus mamomus. protein-bound polysaccharides were purified and fractionated by DEAE-cellulose ion exchange column chromatography and Sepharose CL-4B gel filtration chromatography. When a dose of 20 mg/kg/day was injected intraperitoneally into ICR mice. fraction IV of the component showed the highest inhibition ratio of 73.8% against the count of hemolytic plaque forming cells in mice to 3.2 times. when IV was about 30 KD and the fraction was composed of 76.1% polysaccharide and 4.9% protein. The hexosamine was detected in all the fractions, showing that the polysaccharide and protein moieties were bound each other.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.203-208
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• 1998

We isolated and characterized an antifungal peptide from the seeds of Phytolacca americana. Growth inhibition assay with Botrytis cinerea was used to screen inhibitory proteins from 60 different plant species. A 4 kDa antifungal peptide (Pa-AFP) inhibitory to hyphal growth of B. cinerea was found in the seeds of P. americana. The peptide Pa-AFP was purified to homogeneity by chromatographies of Sephadex G-50, DEAE-Sepharose, Sephacryl S-300, and C18 reverse-phase HPLC. Western blot analysis showed that a polyclonal antibody raised against the purified peptide cross-reacted with a 4 kDa protein in seeds but not in root and leaf tissues of P. americana. Pa-AFP inhibited the hyphal growth of Botrytis cinerea, Rihzoctonia solani, Fusarium oxysporum, and Magnaporthe grisea. Pa-AFP exhibited growth inhibition of Saccharomyces cerevisiae strain BWG7a, which was sensitive to osmotin.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.438-442
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• 1988

The enzyme produced by Rhizopus japonicus was able to convert selectively ginsenoside-Rb$_1$which is the most abundant ginseng saponin, into ginsenoside-Rd which was known to be superior to ginsenoside-Rb$_1$pharmaceutically. The convertible enzyme was purified homogeneous from wheat bran culture of Rhizopus japonicus by ammonium sulfate fractionation and column chromatography of TEAE-cellulose, DEAE-Sephadex A-50, Sephadex G-150, Sepharose 2B. Specific activity of the purified enzyme was increased to a bent 96 folds and yield was appeared to be 11% of culture extract. Evidence for homogenity was obtained from polyacrylamide and SDS-polyacrylamide gel electrophoresis. Molecular weight of the enzyme was estimated about 88, 000 daltons by Sephadex G-l50 gel filtration and SDS-polyacrylamide gel electrophoresis, and it did not consist of any subunit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.844-850
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• 1997

$\alpha$-Galactosidase was partially purified from the culture filtrate of pichia guilliermondii by Mannobiose-Sepharose affinity column chromatography. The galactosidase exhibited maximum activity at pH 4.5 and 4$0^{\circ}C$, and was stable in the pH and temperature ranges of 4 to 5.5 and 30 to 6$0^{\circ}C$, respectively. The enzyme was inhibited by $Hg^{2+}$ and $Ag^{2+}$. The enzyme activity was ot affected considerably by treatment with other metal compounds. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and $Gal^{3}Man_{3}(6^{3}-$\alpha$-galactosyl-1,4-mannotriose)$ to galactose and mannotriose. On the contrary, it could not hydrolyze $Gal^{3}Man_{4}(6^{3}-galactosyl-1,4-$\alpha$-mannotetraose)$.

• Biomedical Science Letters
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• v.8 no.4
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• pp.245-250
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• 2002

Fibrinolytic enzyme has been purified from the edible mushroom, Tricholoma sejunctum using DEAE-cellulose chromatography, Phenyl-Sepharose chromatography and Mono-S column chromatography. The apparent molecular mass of purified enzyme was estimated to be 17100 Da by SDS-polyacrylamide gel electrophoresis and 19000 Da by gel filtration, Indicating that it was a monomer. The N-terminal amino acid sequence of the enzyme was Ala-Thr-Tyr-Lys-Ile-X-Ser-Ala-Thr-His-Gln-X-X-Leu-Val. It has a pH optimum at pH 9.5, suggested that purified enzyme was a alkaline protease. The activity of purified enzyme was inhibited by EDTA and 1,10-phenanthroline, indicating that purified enzyme is a metalloprotease. The activity of purified enzyme was increased by Zn$^{2+}$ and Co$^{2+}$, however, the enzyme activity was totally inhibited by Hg$^{2+}$.

• Journal of Microbiology
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• v.34 no.3
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• pp.255-262
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• 1996

The lipopolysaccharide (LPS) yields were measured in Rhodobacter capsulatus under several conditions by the ELISA method. The purification of LPS was done by affinity chromatography of IgG coupled CNBr-activated sepharose-4B instead of ultra-centrifugation. The purity of the LPS didn't show much difference between affinity chromatography and ultra-centrifugation method, but affinity chromatography method required much fewer organisms and was more convenient. LPS yield was measured in ng units by the ELISA method. Mannitol was a better single carbon source than other sugars, but mixing two carbon sources resulted in greater LPS yields than any sugar alone. LPS yield was directly proportional to $NH_ 4CI$ concentration, with optimum yields at 0.05% nitrogen. In contrest to LPS yields, which decreased at 0.005% nitrogen concentration total protein was increased 16 times. Calcium influenced LPS yields. At 0.7 mM $CaCI_ 2$, the LPS yield was 16.5 $\mu$g/mg DW, five times the yield without calcium.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.145-145
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• 1993

일반적으로 단백질의 정제를 위한 가장 효과적인 방법은 affinity chromatography법으로 알려져 있다. 본 연구에서는 베타 수용체의 순수정제를 위한 효과적인 affinity matrix를 제조하고 이의 특징을 확인함으로써 수용체 정제를 위한 기초를 수립하고자 하였다. Bisoxirane reagent인 1,4-butanediol diglycydyl ether를 Sepharose CL-4B gel과 반응시켜 탄노원자 10개 길이의 spacer arm을 부착시켰다. 여기에 sodium persulfate, dithiothreitol을 연속적으로 사용하여 -SH기를 도입시긴 추 free radical 반응을 이용하여 베타수용체 길항제인 alprenolol을 부착시킴으로써 affinity gel을 제조하였다. alprenolol치 부착반응을 위한 최적온도는 4$0^{\circ}C$로 나타났으며, semimicro Kjeldahl 질소 분석법을 적용하여 gel을 분석한 결과 ml당 0.4-0.6 $\mu$ mol의 alprenolol이 결합하였음을 확인하였다.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.569-577
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• 1992

Group A 로타바이러스 VP6에 특이적으로 반응하는 단크론 항체를 이용하여 로타바이러스 감염이 의심되는 돼지 분변으로부터 로타 바이러스를 검색할 수 있는 효소면역측정법을 개발하였다. 이 효소면역측정법에서는 capture antibody로서 protein A-sepharose를 이용하여 단크론 항체로부터 순수 분리한 immunoglobulin을 사용하였으며 detecting antibody는 토끼 면역혈청으로부터 순수 분리한 immunoglobulin에 biotin을 label하여 사용하였다. 개발된 효소면역측정법의 민감도와 특이성을 전자현미경법 및 형광항체법의 것과 비교하여 보았을 때 서로 유사하였으며 분변재료로부터 로타바이러스를 검색하는데 유용한 것으로 나타났다. 개발된 효소면역측정법은 야외로부터 로타바이러스 검색을 위하여 수집된 많은 양의 분변재료를 실험실내에서 screen하는데 유용하게 사용될 것으로 생각된다.