• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.63-72
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• 2000

Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.320-325
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• 2021

Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) methods are conventional analytical methods to analyze water quality. Both of these methods are technically indirect measurement methods, require complicated preconditions, and are time-consuming. On the other hand, the total organic carbon (TOC) method is a direct and fast measurement method which is more intuitive and accurate than the BOD and COD methods. However, general TOC analysis methods involve complicated processes and high power consumption owing to the process of phase transition from liquid to gas by a high-temperature heater. Furthermore, periodic consumables are also required for the removal of inorganic carbon (IC). Titanium dioxide (TiO₂) is one of the most suitable photocatalysts for simple processes. Its usage involves low power consumption because it only reacts with the organic carbon (OC) without the requirement of any other reagents and extra processes. We investigated a TiO₂ photocatalyst-based TOC analysis for simple and affordable products. TiO₂-coated fiber substrate maintained under carbon included water was exposed to ultraviolet (UV) radiation of wavelength 365 nm. This method is suitable for the real-time monitoring of water pollution because of its fast reaction time. Its linear property is also sufficient to match the real value.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.41-46
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• 1980

Low molecular weight endo-glucanase was partially purified from cellulase complex using Sephadex G-100 gel chromatography. Biochemical properties of the purified component was investigated. Optimum pH and temperature determined were 6.0 and 5$0^{\circ}C$, respectively. Enzymatic hydrolysis of four cellulosic substrates having varying crystallinity was evaluated. It was found that hydrolysis of amorphous region was followed by the hydrolysis of crystalline region. In order to examine the effect of adsorption of the enzyme onto the cellulosic substrates on the hydrolysis kinetics, adsorption studies were carried out. Time course of adsorption of low molecular weight endo-glucanase onto various cellulostances was observed for 25 min. The rate and amount of adsorption to amorphous cellulose was greater than those to the crystalline cellulose. This result suggested that the role of endo-glucanasc was more important to the hydrolysis of amorphous cellulose than to the crystalline region of the cellulose.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.66-74
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• 2005

Three experiments were conducted to study the property of xylanase and the effects of xylanase in wheat-based diets on growth performance of broilers, respectively. Experiment 1 was performed in vitro to evaluate the effect of different pH and temperature on xylanase activity, and to evaluate the enzymic stability under different conditions. The results indicated that the optimum temperature and pH for xylanase activity were $50^{\circ}C$ and 4.5, respectively. The activity of enzyme solution was reduced rapidly after the treatment of water bath above $60^{\circ}C$ for 10 min. The enzyme was relatively stable at pH 3.5 to 8.0 and deteriorated when incubated at pH below 3.5. In Experiment 2, a total of 378 d-old male Arbor Acres broilers were randomly distributed to 7 different treatments with 6 replicates (9 birds) in each treatment. The treatments were as follows: (1) corn based diet (CS), (2) wheat based diet (WS), (3) WS+ 0.05% xylanase, (4) WS+0.15% xylanase, (5) WS+0.25% xylanase, (6) WS+0.35% xylanase, (7) WS+0.45% xylanase. The results showed that the body weight and feed/gain ratio of the broilers fed wheat-based diets have been significantly improved (p<0.05) compared to that fed corn-based diet in the first 3 wk. With regard to the wheat-based diets, the xylanase supplementation had a tendency to improve the growth performance in first 3 wk. After 3 wk, no significant difference (p>0.05) was found among all these different treatments. The supplementation of xylanase and the type of diets did not affect the feed intake but increased the concentration of triglyceride in serum. In Experiment 3, a total of 360 d-old male Arbor Acres broilers were assigned to 30 groups with 12 birds in each group randomly. These groups were then randomly distributed to 5 different treatments with 6 replicates within each treatment. The broilers of each treatment were fed one of the diets as follows: (1) Corn based diet, (2) White wheat based diet (WW) (3) White wheat based diet+0.25% xylanase, (4) Red wheat based diet, (5) Red wheat based diet+0.25% xylanase. The results showed that the body weight and feed/gain ratio had been significantly improved (p<0.05) by xylanase supplementation in the first 2 or 3 wk. The effect of xylanase in red wheat diet is a little higher than that used in white wheat diet. From the results of the present experiments, it can be concluded that the supplementation of Aspergillar xylanase can improve the performance of the broilers fed the wheat-based diet.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.195-203
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• 2015

Two bacterial strains, Bacillus licheniformis YB-1413 and YB-1414, producing extracellular α-galactosidase, were obtained from homemade Doenjang. On the basis of their biochemical properties, 16S rRNA sequences and random amplified polymorphic DNA patterns by polymerase chain reaction, they were found to be somewhat different from one another. α-Galactosidase productivities of the two isolates were increased by wheat bran, but drastically decreased by melibiose, raffinose and sucrose which were used as carbon sources. The enzyme productivities were increased by yeast extract as a nitrogen source with maximum levels of 1.87 U/ml for YB-1413 and 1.69 U/ml for YB-1414, respectively. The enzymes of both isolates exhibited maximum activity for hydrolysis of para-nitrophenyl-α-D-galactopyranoside (pNP-αGal) under reaction conditions of pH 6.0 and 45℃. Their hydrolyzing activities for pNP-αGal were drastically decreased by the addition of low concentrations of ribose and galactose. They were capable of hydrolyzing completely α-1,6 linked galactosyl residue in melibiose, raffinose and stachyose, which are known to be anti-nutritional factors in products of soybean and legume. In relation to the latter, the isolates YB-1413 and YB-1414 have potential applicability in improving soybean-fermented foods and the nutritional value of soybean feed.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.79-85
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• 1974

To obtain further information concerning the nature myofibrillar proteins in a food system, an investigation has been conducted to compare the change in the biochemical property of the myofibril with the changes in the morphological structure of the myofibril. When myofibrils were prepared with 0.16 M KCl-0.04 M Tris-HCl, the band pattern was clear and distinct. There was a uniform thickening of A-band, a sharp appearence of Z-lines and a wide I-band. The band pattern of myofibrils was changed as the composition of extraction solution was changed. Also the ATPase activity of myofibril changed as the length of sarcomere changed. When myofibrils were treated with a low concentration of trypsin, myofibrils turned in the contracted state. With the progress of prolonged trypsin treatment, most of myofibrils exhibited a pattern of alternating light and dark bands, supercontracted pattern. Although myofibrils exhibited a supercontracted band pattern, the ATPase activity of myofibril continued to increase with the progress of trypsin treatment. An assumption was made that tropomyosin may be located in Z-line and that troponin-tropomyosin complex can inhibit the ATPase activity of myofibrils through the structural alternation of myofibril.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.347-356
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• 1992

In oriental medicine, Artemisia Iwayomogi(Compositae) has been used clinically for jaundice, hepatitis, liver cirrhosis etc. The purposes of present study were to examine pharmacological effects of Artemisia lwayomogi water extract(AIWE) on weights of body, liver, kidney, spleen and adrenal, and on biochemical parameters (activities of AST, ALT and LDH, contents of cholesterol and triacylglycerol, and levels of hepatic lipid peroxide) against hepatic injury by carbon tetrachloride($CCl_4$) in rats. The results were as follow; 1. Body weights were reduced by $CCl_4$. In AIWE pretreatment groups, reduction of body weights was inhibited at 48 hours. Increased liver weights by $CCl_4$ were reduced in proportion to numbers of treatment of AIWE in AIWE pre- and posttreatment groups. Increased kidney weights by $CCl_4$ were reduced in AIWE pretreatment groups at 72 hours. Increased weights of spleen and adrenal by $CCl_4$ were not affected by AIWE treament. 2. Increased AST activities by $CCl_4$ were significantly (p<0.05) decreased in AIWE posttreatment groups at 48 and 72 hours. Increased ALT activities by $CCl_4$ were significantly(p<0.05) decreased in AIWE posttreatment groups at 48 hours. Increased LDH activities by $CCl_4$ were very significantly (p<0.01, p<0.001) decreased in AIWE posttreatment groups at 48 and 72 hours, respectively. 3. Increased cholesterol contents by $CCl_4$ were significantly (p<0.05) decreased in AIWE posttreatment groups at 24 and 48 hours. Decreased triacylglycerol contents by $CCl_4$ were significantly (p<0.05) increased in AIWE posttreatment at 48 and 72 hours. 4. Increased hepatic lipid peroxide levels by $CCl_4$ were significantly (p<0.05, p<0.01) decreased in AIWE posttreatment groups at 48 and 72 hours, respectively. In conclusion, AIWE did not affect normal liver function and had property of antioxidant, due to reduced lipid peroxidation by $CCl_4$. AIWE seems to have hepatoprotective effects rather than direct preventive effects to $CCl_4$-induced necrotic degeneration of liver cell, cholestasis and damages in metabolism of lipid.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.8-14
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• 2014

The objective of this work is to investigate and compare several functional properties of lactic acid bacteria (LAB), Lactobacillus casei SK-7 isolated from home-made yogurt and Lactobacillus bulgaricus YK-11 from commercial yogurt. Initially, physiological and biochemical properties of SK-7 and YK-11 were characterized. Phylogenetic analysis using 16S rRNA sequencing were performed to identify the strains, and the strain could be assigned to Lactobacillus casei and Lactobacillus bulgaricus, designated as L. casei SK-7 and L. bulgaricus YK-11. Phylogenetic tree of SK-7 and YK-11 was plotted based on 16S rRNA sequence comparisons. Production of lactic acid and organic acid, and pH changes in the cultures of SK-7 and YK-11 were monitored during 72 h. During the incubation period, several functional properties of L. casei SK-7 and L. bulgaricus YK-11 were examined. L. casei SK-7 and L. bulgaricus YK-11 cultures eliminated 93.9% and 88.2% of nitrite, respectively. Antioxidant activity of cultural supernatants of SK-7 and YK-11 were 62.6%, 54.9%, and activity of ${\beta}$-galactosidase were 14.9 units/mg and 13.1 units/mg, respectively. The antimicrobial activities were examined with 20-fold concentrated culture supernatants from the cultures of SK-7 and YK-11. The activities of SK-7 supernatants were clearly observed against all microorganisms in this work, whereas no activities were observed in YK-11 supernatants. Although it might be conducted additional functional research, functional properties of LAB isolated from home-made yogurt have been shown to be better than those of commercial yogurt in this work.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.131-137
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• 1993

Human neutrophil elastase (HNE, EC 3,4,21, 11), a mediator of tissue breakdown, was inhibited by tetracycline, oxytetracycline and demeclocycline. Among them, oxytetracycline showed the most potent inhibitory effect on the activity of HNE. IC50 of this drug at our specific condition was less than 1 mM. Tetracycline inhibited human neutrophil elastase non-competitively, and oxytetracycline inhibited competitively. Ki values of tetracycline and oxytetracycline were 4.9 mM and 0.39 mM, respectively. Structural modified tetracycline, de-dimethylaminotetracycline, which showed no antibiotic activity since the active dimethylamino radical was removed from the position #4 of the tetracycline, showed similar inhibition effect on the activity of human neutrophil elastase to that of tetracycline. Thus, we speculated that inhibition of human neutrophil elastase by tetracyclines was not depended on the dimethylamino radical which is a critical active site for antibiotic effect, rather it was depended on the hydoxyl radical of tetracyclines. Therefore, the property of inhibiting elastase may be an additional molecular biochemical mechanism of action of these drugs at the inflammatory sites.

• Resources Recycling
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• v.22 no.5
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• pp.20-28
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• 2013

This study was carried out to evaluate the possibility of resource recovery for municipal solid waste(MSW) that sorted by a MBT system. First, physical property of MSW was similar to wastes carried into Sudokown landfill site. However, moisture of MSW was little higher than that. As a result of BMP test using organic fraction of MSW(OFMSWs), approximately 60 ~ 80 mL $CH_4/g$-VS of methane was occurred. Compared to the other studies, the value of methane is lower. It seems to be caused that high ratio of vinyl/plastic in OFMSWs. The other BMP test using sample of MBT system located in Sudokwon landfill was conducted each physical properties. According to the result of experiment, food waste makes 193 mL $CH_4/g$-VS, and paper is 102 mL $CH_4/g$-VS. However, there was not methane production in vinyl and rubber. Additionally, others that can't sort no more show 30 m $CH_4L/g$-VS of methane production. From the result of experimental data OFMSWs has high fraction of vinyl, rubber and other substance that difficult for biodegradation. Therefore it is need to sort of them.