• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.542-547
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• 2016

The thermal properties of ramie leaf ${\beta}$-amylase (RBA) were examined to develop a novel process for enzyme purification. The thermostability of RBA extract prepared from ramie leaf powder was examined at various temperatures. RBA activity decreased slightly, whereas other carbohydrate-active enzymes, such as $\small{D}$-enzyme, were rapidly inactivated during 30 min incubation at $60^{\circ}C$. When the heat-treated extract was incubated with various substrates, maltose was produced exclusively as the major product, whereas the untreated crude extract produced maltose and other maltooligosaccharides. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, fewer protein bands were observed for the heat-treated extract than the untreated extract, indicating that the thermostable RBA was partially purified and other thermolabile enzymes were eliminated. Thus, the treatment of the RBA extract at $60^{\circ}C$ for 30 min resulted in 5.4-fold purification with a recovery yield of 90%.

• Korean Journal of Pharmacognosy
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• v.25 no.3
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• pp.238-248
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• 1994

The hypoglycemic and metabolic effects of Commelina communis L. extract were investigated in alloxan induced diabetic rats. The increased blood glucose level in the diabetic rats was significantly reduced and the loss of body weight was recovered with the treatment of the plant protein fractions($30{\sim}70%$ ammonium sulfate precipitates). Administration of the plant protein fractions elicited the significant increase of glucose-6-phosphate dehydrogenase (G-6-P DH) activity and liver weight which were decreased in the diabetic rat liver. G-6-P DH was partially purified from extract- or insulin-treated diabetics, diabetic control, and normal rat liver and studied for the biochemical properties. The $K_m$ value(9.002 mM) of diabetic rat liver enzyme was greatly higher than that (0.033 mM) of normal enzyme indicating the affinity of enzyme for the substrate was significantly reduced in the diabetic rat liver. This reduced affinity of enzyme for the substrate in the diabetic rat was recovered in the extract- or insulin-treated rat liver enzyme having 0.164 or 0.208 mM of their $K_m$ values, respectively. Although there was no significant difference in the optimum pH(6.0) and optimum temperature($37^{\circ}C$) of enzyme among the experimental groups, the dependence of their activities on pH appeared to be slightly resistant in the extract- or insulin-treated group compared to the diabetic group. In order to investigate the antigenicity of rat liver enzyme among experimental groups, enzyme-linked immunosorbent assay was carried out by using anti-G-6-P DH anti-serum. Absorbance(0.102) shown in the normal rat liver was reduced even below zero in the alloxan-diabetic rat liver, but increased again in the extract- or insulin-treated rat liver(0.096 or 0.118, respectively). The result of this study suggested that G-6-P DH may be used as a marker enzyme to diagnose and to indicate the progress of the diabetics, and the hypoglycemic effect of the extracts of Commelina communis L. was certainly associated with action or mode of G-6-P DH on the rat liver.

• Textile Coloration and Finishing
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• v.13 no.4
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• pp.227-233
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• 2001

Wool fabrics were pre-treated with corona prior to treating with enzyme for shrinkage resistance. Commercial protease and cellulase were used for degradation of wool and the treatment conditions such as enzyme amount, treating time, and assistant chemicals. Friction coefficient and zeta-potential were measured to certificate an effect of treatment condition on the handle of wool fabric. Corona pretreatment make the wool fabric soft, which result in the decrease of friction coefficient and zeta-potential. Scale removal of wool surface was observed by scanning electron microscope. Amino acid analysis shows the effectiveness of enzyme, and corona pretreatment does not cause severe internal damage.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.206.4-206
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• 1978

By utilizillg whole cell enzyme of the Xantho-monas citri IFO 3835, cephalexin is synthesized directly from 7-amino-deacetoxy cephalosporanic acid (7-ADCA) and phenyl glycine methyl ester (PGM). To date, cephalexin has been manufactu-red by chemical process involving fairly large number of steps to protect the amino group of phenly glycine and carboxyl group of 7-ADCA. However, the enzymatic process involves only a single step with 85％ conversion in 90 minutes. The fermentation variables studied indicate that oxygen transfer is limiting step in the enzyme production. Optimum conditions for enzymatic reaction were 37 C, pH 6.0, and the optimum substrate molar ratio of PGM to 7-ADCA was 2. Other variables that are related to the biochemical properties of whole cell enzyme temperature stability, pH stability, kinetic constants, reusing effect, enzyme loading effect were also evaluated.

• Korean Journal of Microbiology
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• v.18 no.1
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• pp.7-14
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• 1980

A thermostrable ${\beta}-galactosidase$ (${\beta}-galactoside$ galactohydorlase, EC 3.2.1.23) was inducible in Bacillus coagulans by lactose and D-glactose. The enzyme was purified 87 fold, and the optimum temeprature and pH for actiivity were determined to be $60^{\circ}C$ and pH 7.5, respectively. Kinetic determinations at $55^{\circ}C$ established a Km of 3.3mM for the chromogenic substrate onitorphenyl ${\beta}-D-galactopyranoside$ (ONPG). Galactose and lactose were competitive inhibitors with Ki of 6.1mM and 4.9mM, respectively. The enzyme ws relatively thermostable. The crude enzyme was inactivated about 20% after 20 min of exposure at $60^{\circ}C$ and the purified was about 50%. Maximal enzyme activity required $Mn^{++}$, and for the thermal stabilization $Fe^{++}\;and\;Ca^{++}$ were necessary.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.144-149
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• 1992

Invertase was extracted from Korean ginseng(Panax ginseng C. A. Meyer) leaf with deionized water, and then prepared by ammonium sulfate(0.4~0.6 Sat.) fractionation, the enzymological properties of the invertase were investigated, and the results obtained were as follows. The optimum pH and temperature of the enzyme were pH 6.0 and 4$0^{\circ}C$ respectively. The enzyme was stable in the pH range of pH 6.0 to 8.0, and at the temperature below 4$0^{\circ}C$. The enzyme was inactivated completely by the treatment with some proteases(pepsin, trypsin, papain and ficin) and protein denaturants(8M urea and 6M guanidine-HCI), but not with glycosidases (a-amylase, $\beta$-amylase and glucoamylase). The enzyme catalyzed specifically the hydrolization of the $\beta$-fructofuranosides such as sucrose and inulin.

• Journal of Life Science
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• v.8 no.3
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• pp.326-332
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• 1998

Cyclodextrin glucanotransferase from B. stearothermophilus KJ16 that can produce both cyclodextrin glucanotransferase and cyclodextrinase was purified by ammonium sulfate precipitation, DEAE-cellulose chromatography, Sephadex G-100 chromatography, and FPLC. The molecular weight of the purifice enzyme was about 65,000 dalton by SDS-PAGE. The optimal pH and temperature were 6.0 and $60^{\circ}C$, respectively. The enzyme was stable at $50^{\circ}C$ for 1 hr and in the pH range of 5.5 and 8.5. Mercaptoethanol and dithiothreitol inhibited the enzyme activity strongly. The enzyme produced 60% cyclodextrin(CD) from 5% soluble starch with the $^{\alpha}$, $^{\beta}$, $^{\gamma}$-CD ratio of 42:46:12. Amylopectin was the most suitable substrate with 67% conversion to CD.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.123-136
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• 1996

IPSKCDNA gene(1.8 kbp) encoding rat brain IP3K enzyme contained Not I restric site in open reading frame. The Not I sequence, GCGGCCGC, was converted to GCAGCCGC by site-directed mutagenesis. The mutated IP3KcDNA was digested with EcoR I and ligated with EcoR I-restricted psp72·Not2 vector. The resulting psp72 · Not2-IP3KCDNA was digested with the Not I restriction enzyme and then subcloned into the Not I -digested PZIP · NeoSV(X) mammalian expression vector. The PZIP · NeoSV(X) -IPSKCDNA was transfected into CCL39 hamster lung fibroblast cells. The efficiency of the expressed IPSKCDNA gene was significantly higher than expected generally, not only a mean 5-fold increase in the amount of enzyme, but also 16-fold increase in enzyme activity from tractsfected CCL39 cells by the method of Western blot using anti-lP3K antibodies. Both distribution of IPSK in various rat tissues and biochemical properties were discussed.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.175-181
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• 1977

Lysosomal enzyme latency was demonstrated for hydrolases from porcine leukocyte by suspending sediment sfrom differential centrifugation in 0.125 to 0.250 M sucrose. Specific activities pH optima and activation energies were determined for hydrolases distributed in various sedimentation fractions and for enzymes solubilized by n-butyl alcohol extraction. Specific activities of the hydrolases revealed the heterogeneity of the Iysosomal fractions relative to enzyme content. pH optima identified the enzyme as acid hydrolases with optima for cathepsin D and aryl sulfatase also at pH 6.8. Activation energies of some hydrolases were low revealing that these enzymes could function efficiently during low temperature aging of meat.

• KSBB Journal
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• v.13 no.1
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• pp.1-5
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• 1998

A $\beta$-fructofuranosidase of garlic (Allium sativum L. ; Seosan) was purified by ammonium sulfate fractionation and gel filtration chromatography with a recovery of 8.3%. The molecular mass of the purified enzyme was estimated to be 79kDa by SDS-PAGE, which revealed two subunits of 41kDa and 38kDa. Maximum enzyme activity was observed at pH 5.0 and 40$^\circ C$ and the enzyme was stable over the pH range of 4.0-6.0 and below 50$^\circ C$. The Km value for sucrose was 15.5mM and the enzyme activity was significantly inhibited by bivalent metal ions(Hg$^2+$, Cu$^2+$, Cd$^2+$) and EDTA.