• Journal of Plant Biology
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• v.38 no.3
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• pp.251-258
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• 1995

The soluble acid invertase ($\beta$-D-fructofuranoside fructohydrolase, EC 3.2.1.26) was isolated and characterized from the hypocotyls of mung bean (Phaseolus radiatus L.). The enzyme was purified to apparent homogeneity by consecutive step using diethylaminoethyl (DEAE)-cellulose anion exchange, Concanavalin (Con) A affinity and Sephacryl S-300 chromatography. The overall purification was about 148-fold with a yield of about 15%. The finally purified enzyme exhibited a specific activity of about 139 $\mu$mol of glucose produced mg-1 protein min-1 at pH 5.0 and appeared to be a single protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing PAGE. The enzyme had the native molecular weight of 70 kD and subunit molecular weight of 70 kD as estimated by Sephadex G-200 chromatography and SDS-PAGE, respectively, suggesting that the enzyme was composed of a monomeric protein. On the other hand, the enzyme appeared to be a glycoprotein containing N-linked high mannose oligosaccharide chain on the basis of its ability to bind to the immobilized C on A. The enzyme had a Km for sucrose of 1.8 mM at pH 5.0 and maximum activity around pH 5.0. The enzyme showed highest enzyme activity with sucrose as substrate, but the activity was slightly measured with raffinose and cellobise. No activity was measured with maltose and lactose. These results indicate the soluble acid invertase is a $\beta$-fructofuranosidase.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.197-205
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• 1996

The $\beta$-xylosidase was purified 99- fold from the culture supernatant of Pseudo onas sp. CB-33 by ammonium sulfate precipitation, PEI precipita- tion, DEAE-Sephadex column chromatography, Sephadex G-75 gel filtration chromatography and preparative disc gel electrophoresis. Molecular weight of the enzyme was estimated to be 44,000 by SDS polyacrylamide gel electrophoresis. The enzyme has a pH optimum for activity at 7.0 and is stable over pH 6.5-9.0. The optimal temperature of the enzyme was 45$\circ$C, and its enzymatic activity was completely inactivated at 55$\circ$C for 30 min. Km value of the enzyme for p-nitrophenyl-$\beta$-D-xylopyranoside was calculated to be 4.6 mM. The effect of various reagents on the $\beta$-xylosidase activity was investigated. The enzyme activity was completely inhibited by Hg$^{2+}$, Cu$^{2+}$ and Zn$^{2+}$. The $\beta$-xylosidase was inactivated by tryptophan-specific reagent, N-bromosuccinimide and tyrosine-specific reagent, iodine. The enzyme could degrade xylo-oligosaccharides to xylose and the enzyme was competitively inhibited by xylose. The $\beta$-xylosidase and endoxylanase from Psedomonas sp. CB-33 hydrolized xylan synergically. The purified enzyme also showed $\alpha$-L-arabinofuranosidase activity.

• Nutritional Sciences
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• v.7 no.1
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• pp.35-40
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• 2004

This study was performed to evaluate the effect of iron supplementation on iron-deficiency-related indices, oxidative stress and antioxidative enzyme activity in female marathoners. Fourteen teenage female marathoners participated in the study. Subjects were divided into two groups: mild anemic and control, depending on their hemoglobin (Hb) level. The mild anemic group had significantly lower RBC count and hematocrit (Hct) and Hb levels compared to the control group. The mild anemic group (〈12.5g Hb/dI, n=7) was given iron supplements (60mg Fe/day) for four weeks during the summer training period. RBC count, Hct and Hb levels showed an increasing tendency through iron supplementation, and significant differences in these variables between the anemic and control groups disappeared in the post-period. There was no difference in plasma malondialdehyde (MDA) between the anemic and control groups. However, catalase (CAT) and glutathione peroxidase (GPx) activity were significantly higher in the anemic group. The significant difference in enzyme activity between the groups disappeared in the post-period. In addition, superoxide dismutase activity significantly decreased after iron supplementation. In conclusion, antioxidative enzyme activity was up-regulated in an anemic condition and mild iron supplementation decreased the antioxidant enzyme activity of female marathoners while improving their anemic condition.

• YAKHAK HOEJI
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• v.29 no.4
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• pp.165-175
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• 1985

It has been reported that clonidine is $\alpha_2$-adrenergic agonist, potnet new hypotensive drug in human with low dose. The change in blood pressure is implicated in the concentration, release, uptake and metabalism of catecholamine and activity of catecholamine synthesizing enzyme in specific brain areas. Thus the experiment was set up to investigate the effect on the enzyme activity of clonidine alone and that of clonidine pretreated with imipramine or tranylcypromine by measuring activity of the Dopa-forming enzyme, tyrosine hydroxylase (TH) and epinephrine forming enzyme, phenylethanolamine-N-methyl transferase (PNMT) in brain and adrenal gland. The TH activity in brainstem and substantia nigra is decreased by intraperitoneally administered clonidine 0.1mg/kg twice a day for 5 days, but increased in the rats pretreated with imipramine 10mg/kg intraperitoneally given 26 hrs and 5 hrs before decaptitation. However the TH activity in all regions of brain is increased in rats pretreated with tranylcypromine 10mg/kg intraperitoneally twice a day for 5 days. The effect of clonidine on TH activity is due to inhibition release of norepinephrine by activation of presynaptic $\alpha_2$-adrenoreceptor, axon terminal result in the decrease of TH activity in brain. The increasing of TH activity in brain results in attenuation of the role of clonidine by pretreated with imipramine or tranylcypromine in rats. The activity of PNMT was not significantly affected by clonidine, imipramine and tranylcypromine in adrenal gland.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.389-396
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• 2013

The antioxidant enzyme and DPPH radical scavenging activity with variations in drying methods of diploid and tetraploid in Platycodon grandiflorum were determined. Antioxidant enzyme activities were measured as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX). The roots of Platycodon grandiflorum were freeze-dried, indoor-dried, hot-air dried, and microwave dried. The root extract of P. grandiflorum have shown the highest SOD enzyme activity of 92% in tetraploid of freeze-dried and indoor-dried while diploid of microwave dried showed the lowest SOD enzyme activity of 47.5%. The activity of CAT showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all drying methods. The APX activity showed relatively higher values in the root extract of freeze-dried both the diploid and tetraploid, but the difference in comparison with other extracts was not significant. The POX activities according to drying methods of diploid and tetraploid in P. grandiflorum showed relatively high values in freeze-dried and indoor-dried compared with other drying methods, and the POX activity between the diploid and tetraploid was not significant difference in each drying method. The DPPH radical scavenging activity with variation in drying methods of diploid and tetraploid in P. grandiflorum was the highest in the freeze-dried, and was higher in tetraploid than diploid in all the concentrations. In conclusion, the root of P. grandiflorum had the potent biological activities in both diploid and tetraploid. In particular, the tetraploid root of P. grandiflorum showing high antioxidant enzyme activity could be good materials for development of source of functional healthy food.

• Korean Journal of Microbiology
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• v.17 no.4
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• pp.187-192
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• 1979

Dennis (1972) reported that Trichosporon cutaneum FRI-425 from the petioles of Pheum rhamponticum var, had showed the celluloytic activity. Chun (1977) also suggested that Trichoporon pullulons 225 isolated from the saline water of the Yeoung San River had a similar properties. However, the assay conditions for enzyme activity were not yet investigated. Thus, the present work was undertaken to examine some conditions for CMCase activity and at the same time to compare the activities of crude enzyme produce from above two species of Trichosporon pullulans. The results are as follows; 1. The maximum production of total reducing sugar by crude enzyme of Tr. pululans was after 30 minutes, whereas that of Tr. cutanuem FRI-425 was after 90 minutes. This fact showed that the reaction velocity of enzyme from Tr. pullulans 225 was more faster than that of Tr. cutaneum FRI-425. 2. Two species showed a similar trend to increase the production of reducing sugar in proportion to the increment in substrate concentration and to arrive at maximum level at lmg/ml of substrate concentration. However, Tr. pullulans 225 produced more $50{\mu}g$ of reducing sugar compared to Tr. cutaneum. 3. The optimum PH for CMCase activity is 5.0 for Tr. pullulans 225 as well as Tr. cutaneum FRI-425, and PH stability lie within the range of 6 and 8. In the activity and stability of enzyme on PH changes, enzyme of Tr. cutaneum FRI-425 was more unstable than that of TY. pullulans 225. 4. The optimum temperature for CMCase activity was $40^{\circ}C$, and enzyme activity from Tr. pullulans 225 was more sensitive to temperature changes compared with that of TY. cutaneum. The heat stability was within $40^{\circ}C$, but that was rapidly decreased above $40^{\circ}C$. In comparison of the heat stability for enzyme of Tr. cutaneum FRI-425 with that of Tr. pullulans 225 at the same temperature of $80^{\circ}C$, the former was some 10 percent more stable than the latter.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.407-413
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• 1996

A novel type of extracellular phospholipase $A_1$ was isolated from Serratia sp. MK1 and purified to homogeneity by ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The purified enzyme was a monomer with a molecular mass of about 43, 000 Da. This enzyme showed the highest lipolytic activity toward phosphatidylserine among the phosphoglycerides tested, and preferentially catalyzed the hydrolysis of the ester bond in phosphatidic acid to lyso-phosphatidic acid. Enzyme activity was completely inhibited by the addition of a chelating agent such as EDTA, and inhibited enzyme activity was fully recovered by the presence of $Ca^{2+}$. This implies that the enzyme requires $Ca^{2+}$ for activity. The enzyme was stable up to $70^{\circ}C$ when incubated for 1 h at pH 8.5, and the optimal pH and temperature were 8.5 and $50^{\circ}C$, respectively.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.53-59
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• 1995

A protease isolated and purified 51 fold from the culture filtrate of a soil bacterium, Bacillus sp. KUN-17, which was appeared to be a monomeric protein with molecular weight of 38, 000 daltons, was suggested to be involved in the serine (-alkaline) protease (E.C 3.4.21.14) since its activity was selectively inhibited by phenylmethylsulfonyl fluoride (PMSF) and required 40$\circ$C and pH 10.5 for optimal condition. The half-life of the enzyme activity was 1 hr at 55$\circ$C, and the activity was maintained even under high concentrations of SDS or urea. The enzyme was indicated to perform random proteolysis from the fact that most of the chromogenic substrates employed were hydrolyzed by the enzyme. The affinity of the enzyme for natural proteins was approximately 10-times higher than ester compounds, and both substrates showed mutual inhibitory effect competitively for the enzyme activity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.66-73
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• 2003

Alkaline cellulolytic enzymes are prepared from Coprinus cinereus 2249. Recovery method of enzyme protein from cultured medium and effect factors on enzyme activity of protein were investigated. The results could summarized as follows, \circled1 Amount of enzyme protein from cultured medium was highest in incubation with shaking and addition of skim milk. \circled2 Protein from cultured medium was alkaline enzymatic protein which shows the highest activity at pH 9.0. \circled3 The most effective recovery method of enzyme protein was the precipitation of protein by addition of cultured medium of protein in ethanol. \circled4 The enzyme activity was enhanced by tween-80 and decreased with $Al_2(SO_4)_3$, $H_2O_2$et al, and was little changed with metal ions except $Hg^{++}$.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.318-322
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• 1994

Upon gel filtration, the commercial bovine milk xanthine oxidase preparation was fractionated into two preparations showing enzyme activity. Native polyacrylamide gel electrophoresis showed that one was in a dimeric form and the other was a monomer having molecular weight of 150 kDa. It was also found that this commercial enzyme existed mostly in an active monomeric form without loss of enzyme activity. The rabbit antisera produced against two enzyme preparations cross-reacted well each other. In SDS-polyacrylamide gtel electro-phoresis, however, both enzyme preparations yielded two smaller protein bands below 150 kDa, which appeared to bind with both antisera with high affinity but not to retain enzyme activity. It implies that bovine milk xanthine oxidase can lose its activity when monomeric subunit is further degraded.