• Analytical Science and Technology
• /
• v.6 no.3
• /
• pp.307-311
• /
• 1993

Ionophore, which contains 5-membered heterocyclic compound, was prepared. $Mg^{2+}$ was determined by salting-out technique using ionophore as a chelating reagent. After $Mg^{2+}$ was extracted into the acetonitrile layer as a Mg-$(Ionophore)_2$ complex from acetate buffered aqueous solution by salting-out extraction technique, absorbance of complex was recorded by atomic absorption spectrophotometry. Optimum pH was between 2.5 and 5.0 for extraction and 1:2([$Mg^{2+}$]/[ionophore]) complex were formed. The range of detection was 0.24ppm~2.4ppm and $Ca^{2+}$ and EDTA were interfered in the determination of $Mg^{2+}$.

• Korean Journal of Microbiology
• /
• v.37 no.3
• /
• pp.182-188
• /
• 2001

The glucoamylase was purified from the induced culture filtrate of hybrid between Saccharomycopsis sp. and Saccharomycopsis sp. made by nuclear transfer and characterized for some enzyme properties. The enzymewas purified 76-fold in an overall yield of 16% from the culture medium by ammonium sulfate fractionation,Sephadex G-150 gel permeation chromatography and DEAE-Sephadex A-50 ion exchage chromatography.The molecular weight of the purified glucoamylase was estimated to be 57.5 KDa on SDS-polyacrylamidegel electrophoresis and Sephadex G-150 gel permeation chromatography. The purified enzyme was active atpH-5.0 and $40^{\circ}C$. The Km value for soluble starch was 2.6 mg/ml. The enzymatic activity was stimulated inthe presence of TEX>$Ca^{2+}$, EDTA, $Co^{2+}$, $Mg^{2+}$, and $Mn^{2+}$

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.427-434
• /
• 1998

An alkaline protease was 4-fold purified, yielding 2.3% of recovery by ammonium sulfate precipitation, CM-cellulose column chromatography and Sephadex G-100 column chromatography. The purified enzyme was estimated to be monomeric with molecular weight of about 62,000 from polyacrylamide gel eletrophoresis (PAGE) and sodiumdodecylsulfate polyacrylamide gel electrophoresis (SDS-FAGE). The optimal pH and temperature of the alkaline pretense activity were 11.0 and 50$^{\circ}C$, respectively, exhibiting high stability at pH value from 6.0 to 11.0 at 50$^{\circ}C$ for 30 minute. The alkaline pretense was activated by MnSO$_4$, CaCl$_2$, and was inhibited by CuSO$_4$, ZnSO$_4$, HgCl$_2$, EDTA and EGTA. Also, the enzyme was found to be a metaloenzyme requiring Mn$\^$2+/ as cofactor. The NH$_2$-terminal amino acid of alkaline protease was alanine. The Km and Vmax values of this enzyme for casein was 4.0 mg/$m\ell$ and 5,500 unit/$m\ell$, respectively.

• Korean Journal of Microbiology
• /
• v.35 no.3
• /
• pp.231-236
• /
• 1999

The fuugus(Penicil1ium oralicum; HCLF-34) secreted the cyanobacteria lytic enzyme which had a molecular weight of about 22 kDa, a optimum temperature of $20^{\circ}C$, a optimum pH of 3.5, and a temperature-stable up to $50^{\circ}C$. The chemical ions such as sodium, potassium, barium, magnesium. and mangan ions appeared positive activity. but calcium, iron, copper ions, EDTA, and PMSF displayed negative activity: this results were the same as the characterilics of other cell wall lytic enzymes. This extracellular enzyme showed lytic aclivily against SDS-insoluble peptidoglycan of Anabaenrr cylinrlrica. The cell wall lylic enzyme of Penicilliurn oxalicum(HCLF-34) seemed to be glycosidase-like enzyme in the fact that ihe concentration of rcducing sugar was increased when the peptidoglycan of Anabaena qlinrlricn md Micrococcus luteus reacted with this enzyme

• Journal of the Korean Chemical Society
• /
• v.33 no.6
• /
• pp.601-606
• /
• 1989

The effects of temperature and retaining ion on the separation factor (${\alpha}$) and distribution ratio (D) of some lanthanides ($Pr^{3+},\;Nd^{3+},\;Sm^{3+},\;and\;Er^{3+}$) have been studied in the EDTA solution as an elutant by using Amberite IR 120 + resin. The retaining ions on the resin were ${NH_4}^+,\;Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+},\;Zn^{2+}$and $Ce^{3+}$. Separation factor of Nd/Pr is much improved by using $Ce^{3+}$ as retaining ion. The distribution ratios were decreased with the increase of temperature, but separation factors did not always increase with the increase of temperature. However, in the case of $Ce^{3+}$ as retaining ion, separation factors of Nd/Pr and Sm/Nd were increased with the increasing of temperature. And also in the case of $Zn^{2+}$ as retaining ion, separation factor of Er/Sm was increased with the increasing of temperature.

• Childhood Kidney Diseases
• /
• v.12 no.2
• /
• pp.239-244
• /
• 2008

Calcification in patients with endstage renal disease on renal replacement therapy can occur in extraskeletal area such as conjunctiva and cornea. Conjunctival and corneal calcification(CCC) has mostly has been reported in adults with endstage renal disease on hemodialysis. CCC seems to be associated with the duration of renal replacement therapy, and high Ca$\times$P value. We report a 10-year-old girl who was on peritoneal dialysis for 31 months and presented with CCC on both eyes. Her corneal calcification was resolved after the epithelial debridement and ethylenediaminetetraacetic acid(EDTA) soaking therapy.

• Korean Journal of Microbiology
• /
• v.37 no.1
• /
• pp.15-20
• /
• 2001

In this study, we have isolated bacterial cell wall lytic enzyme in the culture supernatant of Aspergillus sp. HCLF-4. This hydrolase showed cell wall lytic activity against Anabaena cylindrica. The extracellular enzyme was produced by Aspergillus sp. HCLF-4 when it was grown in a PDB media containing 0.05% heat killed Micrococcus luteus cells. The molecular weight of lytic enzyme was about 14.3 kDa. The optimal pH and temperature for the activity of this enzyme were 3.0~4.0 and $30^{\circ}C$, respectively. This hydrolase activity was reduced by $Na^{+}$, $Li^{+}$, $Ca^{2+}$, $Cu^{2+}$, $Fe^{3+}$, EDTA, and PMSF, whereas it was increased by $Mg^{2+}$, $Mn^{2+}$>. The enzyme has N-acetylmuramyl-L-amidase or endopeptidase activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.18 no.3
• /
• pp.348-355
• /
• 1989

This experiment was conducted to investigate the characteristics of alkaline protease from Aspergillus fumigatus which was isolated from soil as a superior strain for the production of the alkaline protease. The optimum temperature for enzyme activity was $50^{\circ}C$ and optimum pH was 9.0. The enzyme was stable at pH 8.0 to 10.0 and thermal inactivation was shown $30^{\circ}C$. The activity of the enzyme was increased by the addition of $Mn^{++},\;Cu^{++},\;Ba^{++},\;Mg^{++},\;$wheras it was inhibitied by $K^+,\;Fe^{+++},\;Ag^+,\;Pb^{++},\;Na^+,\;Ca^{++},\;Hg^+,\;Zn^{++}$. EDTA. 2, 4-DNP, ${\varepsilon}-amino$ caproic acid did not show inhibitory effect on the proteolytic activity of alkaline protease but P-chloromercuribenzoic acid inhibited the enzyme activity, indicating that reactive sulfhydryl group is required for the enzymatic activity. The reaction of this enzyme followed typical Michael-Menten Kinetics with the Km value of $8.33{\times}10^{-4}mole/{\ell}$ with the Vmax of $47.62{\mu}g/min$. This enzyme had stronger proteolytic activity than trypsin on substrate such as casin and hemoglibin.

• Korean Journal of Food Science and Technology
• /
• v.21 no.5
• /
• pp.606-612
• /
• 1989

A New lectin from baby clam, Tapes japonica, was isolated and purified through the following procedures; acetone powder, 0.15M NaCl extraction, ammonium sulfate fractionation, N-acetyl-D-galactosamine-agarose affinity column, and ion exchange Mono Q of FPLC. This lectin nonspecifically agglutinated human erythrocytes but didn't agglutinate mouse and rabbit erythrocytes. And the lectin neither stimulated human lymphocytes nor agglutinated Sarcoma 180 cells. On polyacrylamide gel electrophoresis, the lectin migrated as a major single band indicating homogeneous. A molecular weight was estimated to be about 131,000 daltons by Biogel P-300 and 125,000 daltons by SDS-PAGE without ${\beta}-mercaptoethanol$. This lectin is supposed to be a tetramer composed of heterogeneous subunits, about 30,000 and 33,000 daltons. Baby clam lectin was inhibited by EDTA and recovered agglutinating activity by $Ca^{++}\;and\;Mn^{++}$. This lectin is revealed as glycoprotein that contained about 4.2% neutral sugar.

• Korean Journal of Microbiology
• /
• v.32 no.4
• /
• pp.291-296
• /
• 1994

A bacterial strain NO. AM-28, showing proteolytic activity against defatted soybean was isolated from domestic soil. The isolated strain was identified as Aeromonas hydrophila by both the biochemical tests using API kit and the analysis of cellular fatty acid profile with MIDI system. The protease production from A. hydrophila AM-28 was highly enhanced when it was cultivated in the medium containing glycerol as a carbon source, tryptone or $(NH_4)_2HPO_4$ as a nitrogen source, and $CaCl_2$ as a mineral source. The optimal pH and temperature for the enzyme was 8.0 and $65^{\circ}C$, respectively. The enzyme was stable up to $55^{\circ}C$ and at pH values ranging from 7.0 to 13.0. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride and EDTA, indicating that serine residue and metal ions be involved in enzyme activity.