• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.68-75
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• 2011

A new lectin was purified from Bombyx mori (BML) by physiological saline extraction, ammonium sulfate precipitants, anion exchange column chromatography on DEAE Sephadex A-50 and gel filtration column chromatography on Sephadex G-200. BML agglutinated trypsinized and glutaraldehyde-fixed erythrocytes, and was observed the most high activity with rabbit, chicken erythrocytes and rat splenic lymphocytes. Agglutinability was markedly affected at highly acidic pH, but was relatively stable with high temperature. The effect of metal ions was observed and BML was affected by bivalaent cations, especially depending on $Ca^{2+}$, $Fe^{2+}$, $Mn^{2+}$, whereas, inhibited by $Mg^{2+}$. Agglutination was strongly inhibited by heparin and glucuronic acid. BML was proved to be a glycoprotein which contains 17.16% of sugars. By mass spectrometry analysis, we found 2 bands that were considered as lectin subunits.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.215-220
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• 1987

Under the extreme change of the environment, animals react physiologically to adapt to the stress and secrete catecholamines. Cold exposure is a kind of the environmental stress. Author tried to determine the amount of catecholamines in rat urine as a parameter of physiological response to cold stress. Urinary catecholamine was measured by using HPLC with fluorescence detector, cation exchange column prepacked with Bio·Rex 70 and ammonium pentaborate as catecholamine eluent. The amount of dopaminc in normal state rat urine was 42.0 ng, but under the low temperature of $5^{\circ}C$, the dopamine amount was increased to 221.25 ng/5 ml. Above findings are suggesting that catecholamine secretion, especially dopamine, increases in the stressful condition such as cold exposure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.728-735
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• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• BMB Reports
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• v.29 no.4
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• pp.294-299
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• 1996

Glyoxalase I (Ee 4.4.1.5, lactoylglutathione lyase) from Chlamydomonas reinhardtii was purified to homogeneity by ammonium sulfate fractionation, anion-exchange chromatography, hydrophobic interaction chromatography, and affinity chromatography on S-hexylglutathione agarose. The purified enzyme was judged to be homogeneous on SDS-PAGE, and consisted of a single polypeptide chain with a relative molecular weight of 24,000. The enzyme was most active at $40^{\circ}C$ and pH 7.5. It was catalytically most active with methylglyoxal as substrate. A number of properties of the Chlamydomonas glyoxalase I enzyme, such as substrate specificity, molecular mass, kinetic parameters, pi, metal ion effect, have been determined and compared with those reported for preparations from other sources. It had somewhat different characteristics from mammalian enzymes.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.85-89
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• 1991

The aim of this study is to elucidate characteristics of ${\beta}-lactamase$ inhibitor produced by Streptomyces sp. SMF-19 isolated from soil was found to produce proteinaceous extracellular ${\beta}-lactamase$ inhibitor. The ${\beta}-lactamase$ inhibitor was purified through ammonium sulfate fractionation, gel filtration, anion exchange chromatography and fast performace liquid chromatography. The molecular weight of the ${\beta}-lactamase$ inhibitor was estimated to be about 48,000 by SDS-PAGE. The mode of inhibition against penicillin G as a substrate was uncompetitive. The ${\beta}-lactamase$ inhibitor was stable in wide pH range but unstable at high temperature above $50^{\circ}C$.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.581-585
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• 2005

The antimicrobial activity of partially purified enterocin K25, produced by Enterococcus sp. K25, was abolished by proteases such as pepsin and proteinase K. The bacteriocin was resistant to heat treatment at $75^{\circ}C$ for 15 min and lost 75% of its activity at $100^{\circ}C$ for 30 min. Enterocin K25 showed bactericidal mode of action against an indicator strain, Lactobacillus plantarum NCDO 955. Enterocin K25 was purified to 112.6-fold purity via conventional steps of ammonium sulfate precipitation, ion exchange chromatography, and reversed phase high performance liquid chromatography (RP-HPLC). The molecular mass of the purified enterocin K25 was estimated as 4.3 kDa on an electrophoresis gel. Plasmid (${\sim}6.5\;kb$) linkage of production of enterocin K25 was confirmed by plasmid curing.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.176-180
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• 2000

Microbial protease has been interesting due to the biological roles in the producing microorganism. A thermophilic Actinomyces produing protease was isolated from soil. The optimal medium composition and culture conditions for maximum protease production was as follows 0.5% soluble starch, 0.5% yeast extract. 0.1% K2HPO4, 0.05% CaCl2, initial pH 8.0 at 50$^{\circ}C$ for 48hours. The protease was purified by the procedure of ammonium sulfate precipitation, anion exchange chromatography(LC), DEAE high performance liquid chromatography and GPC HPLC. The purification fold of the purified enzyme was increased about 22.6. The optimal pH and temperature for reaction of the purified enzyme were 7.5 and 60$^{\circ}C$. The purified enzyme was stable for the pH range from 6.0 to 8.5, but was unstable when treated at 80$^{\circ}C$ for 10 minutes. The activity of the enzyme was inhibited by Ag+ and Cu2+.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.58-58
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• 1993

면역 조절능이 우수하고 독성이 적은 신물질의 개발을 목표로 하여 초유에 들어있는 면역물질을 검색한 결과 초유로부터 자연 살해 세포의 기능을 활성화시키는 물질을 순수분리 하였다. 이 물질은 초유의 유청으로부터 ammonium sulfate에 의한 침전, DEAE-cellulose ion exchange, Sephadex G-200 gel filtration 등의 방법에 의하여 분리되었으며, 초유의 유청 100ml로부터 최종 수득량은 1.2 mg이었다. 이 물질은 SDS-polyacrylamide gel electrophoresis에서도 분자량의 변화가 없는 것으로부터 interchain disulfide bond가 없음을 확인할 수 있었다. 이 물질은 실온에 방치하거나 또는 37$^{\circ}C$로 가온하면 침전을 형성하고, 생성된 침전물을 4$^{\circ}C$로 냉각시키면 다시 용해되는 특이한 특성을 갖고 있으며, 침전이 형성되는 정도는 농도, 온도 및 이온 강도에 비례하여 증가하는 것으로 나타났다. 침전에 최적 pH는 중성인 것으로 나타났다. 이 물질을 사람의 말초혈액으로부터 분리한 림파구의 배양액에 가하고 18 시간동안 배양한 결과 림파구의 적 백혈병 암세포인 K-562 세포에 대한 자연 살해능이 증가됨을 확인할 수 있었다. 자연살해 세포의 활성화는 1.0 - 0.01$\mu\textrm{g}$/ml의 농도 범위에서 확인되었다.

• Korean Journal of Microbiology
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• v.29 no.3
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• pp.172-178
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• 1991

Intracellular purine nucleoside phosphorylase (PNP) from Saccharomyces cerevisiae was partially purified using ammonium sulfate fractionation, heat treatment, a DEAE-Sephadex A-50 anion exchange chromatography and a Sephadex G-100 gel filtration chromatography. The enzyme was purified 20 fold with 3% recovery. The stability of enzyme was kept by addition of inosine and dithiothreitol. The pH optimum was found to be from 6.3 to 7.3 PNP was sensitive to 10mM of $Hg^{2+}$ , $Cu^{2+}$ , and was inactivated completely by 2 mM of p-chloromercuribenzoate and 5,5'-dithiobis (2-nitrobenzoate). The enzyme was capable of catalyzing the phosphorolysis of inosine, deoxyinosine, guanosine, deoxyguanosine and adenosine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.4
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• pp.388-394
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• 1991

Alkaline protease producing bacteria were isolated from soil and identified as Bacillus sp. CW-1121. It was found that the production of alkaline protease reached to maximum in 5 day of fermentation at 4$0^{\circ}C$. The enzyme was purified by ammonium sulfate precipitation, gel filtration on Sephadex G-150 and DEAE-cellulose ion-exchange chromatography. The homogeneity of the purified enzyme was verified by polyacrylamide gel electrophoresis. The enzyme was purified 5.72 fold and yield of the enzyme purification was 16.71%. When the purified enzyme was applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 55, 000.