• Analytical Science and Technology
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• v.15 no.5
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• pp.445-450
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• 2002

A sensitive gas chromatographic method has been established for the determination of total iodide in seawater as their volatile organic derivative. The method is based on the formation of 4-iodo-2,6-dimethylphenol with 2,6-dimethylphenol in matrix and a single-step extraction of the derivative with ethyl ether, which are then measured by gas chromatography-mass spectrometry (selected ion monitoring). Iodate in sea water was completely reduced to iodide with ascorbic acid and acetic acid. The detection limit was 0.1 ng/mL in seawater and the calibration curve showed good linearity with r=0.9997. The method was sensitive, reproducible and simple enough to permit the reliable routine analysis of total iodide in seawater. Total iodide in sea water was found about 30 ng/ml.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.185-189
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• 1985

Extracellular $\beta$-galactosidase from the culture broth of L. sporogenes was purified to apparent homogeniety by procedures including ammonium sulfate fractionation, Sephadex G-200 gel filtration, DEAE-Sephadex A-50 ion exchange chromatography, and Hydroxyapatite adsorption chromatography. The purifying procedures resulted in 347-fold purification with the overall yield of 39.5％ The purified enzyme had a specific activity(using ONPG as a substrate) of about 1, 585 units per mg protein. The molecular weight of the enzyme protein was estimated to be 140, 000 by gel filtration on Sephadex G-200, and SDS-polyacrylamide gel electorphoresis showed that the enzyme consisted of two identical subunits with a molecular weight of 72, 000.

• The Korean Journal of Mycology
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• v.22 no.4
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• pp.298-308
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• 1994

The properties of polygalacturonase by Ganoderma lucidum in liquid culture were investigated. The enzyme was composed of an endo- and an exo-polygalacturonase. The endo- and exo-polygalacturonase were purified approximately 56 and 9.2-fold, respectively, through ammonium sulfate fractionation, gel filtration on Biogel P-100, anion exchange chromatography on DEAE-cellulose, gel chromatography on Sephadex G-150 and re-gel chromatography on Sephadex G-150. The endo- and exo-polygalacturonase had higher affinity for apple pectin than for citrus pectin or pectic acid. The Km values of the endo- and exo-polygalacturonase for apple pectin, determined on the Lineweaver-Burk plot, were 1.44 and 10.6 mg $ml^{-1}$ for apple pectin, respectively. Purified endo-polygalacturonase was found to be homogeneous electrophoretically and had a molecular weight of 54,000 estimated on SDS polyacrylamide gel. The optimal pH for the activity of the enzymes was 4.0. The endo- and exo-polygalacturonase were stable in the pH range of 4.0 to 6.0 and 3.5 to 5.5, respectively. The optimal temperatures of the endo- and exo-polygalacturonase were 40 and $60^{\circ}C$, respectively. The exo-polygalacturonase was more resistant to heat than the endo-polygalacturonase, requiring heating for 40 min at $80^{\circ}C$ for complete inactivation. The activity of the endo-polygalacturonase was increased by $Ca^{++}$ and $Mn^{++}\;ions$, while that of the exo-polygalacturonase was increased by $Ca^{++}\;ion$ only, and was not affected by $Mn^{++}\;ion$.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.45-45
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• 1993

괄루근으로부터 분리된 다당류에 대하여 continuous gel electrophoresis, SDS-Polyacrylamide gel eletrophoresis, ion exchange column chromatography, Hydroxyapatite column chromatography 및 Gel filtration등의 방법을 이용하여 다음과 같은 결과를 얻었다. 1) 황산암모늄 분별침전법에 의한 렉틴의 정제도는 초추출물의 4.85배이며 DEAE Sephadex A-50 column chromatography법에 의한 정제도는 24.17배로 나타났고, 마지막 정제단계인 Sephacryl S-200 gel filtration에 의한 정제도는 47.34배로 나타났다. 2) 정제된 렉틴의 분자량은 60,000da1ton으로 나타났다. 3) 사람의 혈액형에 따른 응집효과는 90-100％로 특이성은 없었다.

• Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.84-87
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• 2010

A peptide that inhibits HIV-1 protease was isolated from a hydrolysate of oyster (Crassostrea gigas) proteins digested with thermolysin. The peptide was using membrane filtration, gel permeation chromatography, ion exchange chromatography, and reverse-phase high performance liquid chromatography. Amino acid sequence of the peptide was determined to be Val-Phe-Glu-Leu. Chemically synthesized Val-Phe-Glu-Leu showed an $IC_{50}$ value of 106 ${\mu}M$.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.648-653
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• 1997

Acetolactate synthase was purified from Escherichia coli MF2000/pTATX containing Arabidopsis thaliana acetolactate synthase gene. Purification steps included DEAE cellulose ion exchange column chromatography, phenyl sepharose hydrophobic column chromatography, hydroxylapatite affinity column chromatography, and Mono-Q HPLC. Molecular weight was estimated to be ∼65 KDa and purification fold was 109 times. The enzyme showed a pH optimum of 7 and the $K_M$ value was 5.9 mM. The purified enzyme was not inhibited by any of the end products, valine, leucine, and isoleucine.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.529-532
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• 1994

• Journal of Life Science
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• v.11 no.6
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• pp.561-567
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• 2001

To isolate and purify fibrinolytic active substance from Sarcodon aspratus(N $H_4$)$_2$S $O_4$ precipitation, DE52 anion exchange column chromatography, Sephacryl-S 200gel filtration chromatography and Mono S cation FPLC were carried out and the characterizations of the purified enzyme were investigated. The bound active fraction on DE52 anion exchange column chromatography were eluted with 0.2 M NaCI and the fibrionlytic enzyme was purified after following Sephacryl-S200 gel fitration chromatography and Mono S cation EPLC. The specific activity of purified enzyme was 55.2 U/mg protein and increased 11.3 fold comparing crude extract and the yield was 49.5%. 12% SDS-PAGE electrophoresis and gel filtration chromatography revealed that Sarcodon aspratus fibrionloytic enzyme was highly purified and had 29.300 Da molecular weight. Enzyme activity of the purified fibrinolytic enzyme from Sarcodon aspratus was increased on higher pH and was stable until pH 10.5. On temperature dependent stability, the enzyme activity was decrease sharply but remained 25% relative activity on 8$0^{\circ}C$. This enzyme activity was inhibited by heavy metal ion, C $U^{2+}$ and $Co^{3+}$ with 68% and 38%, respectively. And also, the enzyme activity was inhibited with $Ca^{2+}$ chelator EDTA and serine protease inhibitor PMSF. These results from this study suggested that the fibrinolycit enzyme from Sarcodon aspratus is a serine protease and the enzyme activity was increased by $Ca^{2+}$ or $Mg^{2+}$ ion.n.ion.n.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.410-413
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• 1998

The major protein (GMP) from the roots of Panax ginseng C. A. Meyer was purified, using gel filtration and ion exchange chromatography followed by reversed-phase and ion exchange FPLC. Staining analysis indicated that the protein has a carbohydrate moiety, which was also shown by band shift experiments using various glycosidases. Electrophoretic and gel permeation studies showed that GMP has an apparent molecular weight of 63 kDa composed of possibly two subunits of 25 kDa containing carbohydrate moiety. GMP showed an anticomplementary activity on the hemolysis of red blood cells, which is a screening tool for inflammation mediator search.

• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.312-319
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• 1986

Dodecyltrimethylammonium bromide (DTAB) was examined as a counter-ion in the investigation of capacity factor and separation of aromatic carboxylic acids on alkyl-modified silica (ODS) column as a stationary phase by ion-pair chromatography on reversed-phase system. The capacity factor of samples was influenced by the several factors such as a concentration of counter-ion as well as kinds and concentration of electrolyte, concentration of methanol in mobile phase and kinds and position of functional group in sample molecule. Some mixtures of samples were able to be separated under optimum condition.