• BMB Reports
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• v.28 no.2
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• pp.143-148
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• 1995

In E. coli, chromosomal DNA associated with proteins is condensed into an organized structure known as nucleoid. Using a nitrocellulose filter binding assay to identify proteins forming nucleoid, a 21 kDa protein was purified from E. coli. The molecular weight of the purified protein was 21 kDa on SDS-polyactylamide gel electrophoresis and 24 kDa on gel permeation chromatography. A molecular weight of 21 kDa on SDS-polyacrylamide gel electrophoresis is unique among known proteins which are believed to be involved in the formation of nucleoid in E. coli. The 21 kDa protein nonspecifically binds to both double-stranded and single-stranded DNA. Sedimentation in a sucrose gradient revealed that the protein induced significant condensation of both supercoiled plasmid DNA and linear bacteriophage $\lambda$ DNA On the basis of quantitative Western-blot analysis, approximately 40,000 molecules of the protein were estimated to exist in an E. coli. The biochemical properties and cellular abundance of the 21 kDa protein suggest that this protein participates in the formation of nucleoid in E. coli.

• Bulletin of the Korean Chemical Society
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• v.21 no.8
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• pp.817-822
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• 2000

Crack-free hard coating siIica films were prepared by sol-gel processfrom twokinds of silicon alkoxide (tetra-ethoxysilane and methyltrimethoxysilane) and two kinds of alcohol (methanol and isopropyl alcohol) with an acid catalyst,acetic acid. A silicate framework of the precursor solution was investigated by infrared spectros-copy (IR) in the process of hydrolysis and condensation. Theextent of the condensation in the intermediates was elucidated by gel permeation chromatography (GPC) and 29Si-NMR spectroscopy. The hard coating films werecharacterized by IR,scanning electron microscope (SEM), thermo gravimetric analyzer (TGA) and dif-ferential scanning calroimeter (DSC). The synthetic condition for the crack-free and transparent silica film for-mation was optimized interms of starting materials for the precursor solution as well as preparation method of the silica film.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.488-494
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• 1994

Apolipophorin-III (ApoLp-III) was purified from adult haemolynph of Hyphantriu cuneo and their molecular weight and synthetic place were investigated. ApoLp-III purification was performed by KBr-density gradient ultracentrifugation followed by gel permeation chromatographv (Sephadex G-1001 and ion-exchange chromatography (CM-52) and their purity was confirmed on 10% SDS-PAGE. ApoLp-III has the molecular weight of 18 ItDa and is synthesized by fat body.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1288-1291
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• 1997

4-Allylanisole was polymerized with AlCl3 as a catalyst. The polymerization was carried out in nitroethane at various temperatures with changing the ratio of the initiator to the monomer concentration. The weight averge molecular weights measured by gel permeation chromatography in chloroform with polystyrene standards were between 1,500 and 4,700. 1H NMR spectroscopy showed that the polymerization proceeded through a stepwise aromatic electrophilic substitution reaction along with a minor chain-reaction, resulting in a branched polymer. 4-Chloromethylanisole was also polymerized with AlCl3 in nitroethane through an aromatic electrophilic substitution reaction to give a high molecular weight polymer (Mw=88,000).

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.23-23
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• 1997

Tolaasin, a 1.9 kDa peptide forming membrane pores, is produced by Pseudomonas tolaasii and causes a brown blotch disease on cultivated oyster mushroom. During the purification of peptide by a gel permeation chromatography, we have found that fractions of molecular weight ranges between ∼2 to 40 kDa have hemolytic activities and the fractions of higher M.W. showed faster hemolysis.(omitted)

• Membrane Journal
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• v.13 no.2
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• pp.81-87
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• 2003

The permeation experiments f3r the aqueous dextran solutions of which the molecular weights were distributed between several thousands and million daltons were carried out using the dead-end cell system equipped with sheet membrane to determine the molecular weight cut-off (MWCO) of ultrafiltration membranes. The dextran rejections with respect to molecular weight were obtained by GPC analysis of feed and permeate solutions, then the MWCO was decided as the dextran molecular weight corresponding to the 90% rejection. The MWCO of PBTK membrane manufactured by Millipore was varied between 63,000 and 68,000 daltons as the pressure increased from 0.5 to 2.0 bar. However, the MWCO of PBQK(Millipore) and UE 1812(Saehan) under the above operating pressure increased to 3.5 and 4.3 times, respectively. Also, the MWCO of PBTK increased to 25% as the membrane permeation increased from 10 to 40% of the feed solution.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.136-144
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• 1989

The purification of myrosinase from radish roots was performed using Concannavalin A-Sepharose affinity chromatography and gel permeation HPLC, which gave a 22-fold-purification(S.P.A.=39,000 units/mg) with 50% recovery, SDS-polyacrylamide gel electrophoresis showed a single major band, suggestive of a relatively pure myrosinase, and the M.W. of the enzyme determined on gel permeation HPLC was ca. 124K. The enzyme showed on optimum pH of 6.5 and was stable at pH 6 to 7 at room temperature, but unstable below pH 4. The enzyme possessed an optimum temperature of $37^{\circ}C$, and gave a Vmax value of $40\;{\mu}moles/mg{\cdot}min$ and a Km value of 0.12mM for sinigrin. The purified myrosinase was activated maximally by 0.6mM of ascorbic acid, but somewhat inhibited by more than 2 mM ascorbic acid. The activities of myrosinase present in the peelings and the peeled radish amounted to approximately 1,333 units/g and 140 units/g weight, respectively and the peelings contained much more myrosinase activity than the peeled radish.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.564-569
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• 1992

A green sulfur bacterium, Chlorobium limicola f. thiosulfatophilum NCIB 8327, was grown in modified Pfennig's medium including glu1amate as a nitrogen source. Glutamine synthetase was isolated through a series of ultracentrifugation. DEAE-Sepharose CL-6B ion exchange chromatography. Sephacryl S-300 gel permeation chromatography, and preparative HPLC. The recovery and purification fold of the enzyme were 2% and 46.3. respectively. The isolated enzyme was homogeneous on UV-Visible spectrum and polyacrylamide gel electrophoretogram. The relative molecular mass of the native enzyme was estimated to be 280,000 by gel permeation chromatography. The enzyme consisted of ten subunits with relative similar molecular mass. 30.000. which was estimated by SDS-polyacrylamide gel electrophoresis. The optimal temperature and pH of the enzyme were $30^{\circ}C$ and 7.0. Km values were 27.9 mM for L-glutamine and 0.92 mM for hydroxylamine-HCr. The enzyme activity was inhibited by alanine. glycine. and tryptophan considerably, but was not affected by asparagine, lysine. leucine. and valine.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.160-166
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• 2007

This study was performed to analyze the molecular structural and physical properties changes of modified rice starch, which particle structure was broken using high impact planetary mill and ultra fine pulverizing techniques. The average diameter and specific surface area of rice starch after pulverization decreased 20% and increased 25%, respectively. Low molecular substances content in rice starch using GPC (gel permeation chromatography) increased from 36.5% to 59.5% after pulverizing of rice starch. Damaged starch contents in rice starch also increased from 16.4% to 99.2% after pulverizing of rice starch. Water holding capacity, solubility and transmittance of rice starch after pulverization increased compared to those of control. Apparent viscosity value of rice starch after pulverization decreased to 7% in control based on $30^{\circ}C$ and 20 RPM conditions.

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.1-9
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• 2005

This is a basic research for producing hot-mix recycled asphalt mixtures and suggesting methods for solving quality problems, if any. Various mixing methods are introduced to mate aging evenly between old and virgin aggregates and to improve aging conditions. Gel-permeation chromatography(GPC) analysis was performed to evaluate aging of binders coated on coarse aggregates and a matrix separately. Round-shaped aggregates(13m gravel) were used in manufacturing mixtures for analysis of aging levels in recycled mixtures. It was found out that there was significant difference in aging levels between the binder coated on RAP's coarse aggregates and on virgin aggregates in a recycled mixture. The difference in the aging level was reduced by modifying mixing method(RAP and virgin binders were mixed first and then virgin aggregates were introduced). Among A to E mixing methods studied, the D was turned out to be the best.