• KSBB Journal
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• v.13 no.2
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• pp.195-202
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• 1998

The cholesterol oxidase was purified from the culture broth of Rhodococcus sp. 3T6-5Mj strain by procedures involving filtration, acetone precipitation, DEAE-Sephadex A-50, and cholesterol affinity column chromatography with a recovery of 15% to specific activity of 25.6 units/mg. The molecular weight of the enzyme was estimated to be 52,000 daltons by SDS-PAGE. Optimum pH and temperature for the enzyme activity were approximately pH 7.0 and $50^{\circ}C$ respectively. The Michaelis constant (Km) for cholesterol was found to be $3.2{\times}10^{-4}$ M. The enzyme showed a high substrate specificity for $3{\beta}$-hydroxysterols and the relative oxidation rates were 100% for cholesterol, 89% for campesterol, 55% for stigmasterol, etc. Amino acid analysis showed that the enzyme protein was composed of 440 amino acid residues without cystein and tryptophan.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.660-664
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• 2023

In this study, a new system to determine the concentration of cholesterol using a color change was developed. The system comprised diacetylene vesicles and cholesterol oxidase (ChOx). 10,12-Pentacosadiynoic acid (PCDA) was used as the diacetylene compound, and PCDA vesicles were formed using sonication. The H₂O₂ produced during the reaction between cholesterol and ChOx was used to initiate the polymerization of the PCDA in the vesicles. During polymerization, the vesicles changed from colorless to blue. Therefore, the cholesterol concentration was proportional to the intensity of the blue color. The absorption at 665 nm indicated that the blue color was directly proportional to the cholesterol concentration. This indicates that the system can be used for cholesterol detection. The minimum cholesterol concentration detected using this system was 1.0 mM.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.226-232
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• 2002

This study was carried out to investigate the effect of mixture of Gastrodiae rhizoma (GM) on blood amelioration in high cholesterol-diet rats. Sprague-Dawley male rats were randomly assigned to one normal diet and three high cholesterol-diet groups which contained 1 % (w/w) cholesterol diet. The groups of high cholesterol-diet were classified to control (high cholesterol-diet only), GM-1 (high cholesterol-diet and GM) and ST-1 (high cholesterol-diet and Statin drug). The body and organs weight were not significantly changed among the tested groups. Contents of serum total cholesterol and LDL-cholesterol were significantly increased in cholesterol-diet groups compared with normal diet group but significantly decreased in the group of GM-1. Morphology of red blood cell in GM-1 group was similar to normal diet group but the control group had many crystals of cholesterol. Hepatic xanthine oxidase activity in the rats of high cholesterol-diet was decreased up to the levels of normal diet group according to oral administration of GM. The results of the present study demonstrate that the orally injection of GM can ameliorate the status of total cholesterol and LDL-cholesterol, and repress xanthine oxidase in liver in high cholesterol-diet rats. These finding suggest that GM is expected to be an effective tea for the blood amelioration in high cholesterol-diet rats.

• Transactions on Electrical and Electronic Materials
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• v.15 no.3
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• pp.136-138
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• 2014

In this study, cholesterol sensors consisting of a mixture of cholesterol oxidase (ChOx) and zinc oxide (ZnO) nanoparticles (NPs) are constructed on plastic substrates and their sensing characteristics are examined in air. The current of the ChOx-ZnO NP film decreases in magnitude as cholesterol molecules are adsorbed on the film, due to the resulting increase in the number of electrons generated by the reaction between the cholesterol and the ChOx. The cholesterol sensor shows a high sensitivity of $1.08{\mu}A/mM$ and a wide detection range from 10 nM to 1 mM.

• KSBB Journal
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• v.11 no.2
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• pp.140-150
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• 1996

To develop a home-version assay system for plasma lipoprotein cholesterol, variables that can control the assay performance were optimized. The system was constructcd by using two major components: nitrocellulose membrane strip with immobilized enzymes (cholesterol esterase, cholesterol oxidase, and horseradish peroxidase); and sample carrier solution containing non-ionic detergent (Triton X-100) and chromogen (3,3'-diaminobenzidine). Once a sample combined with the carrier was absorbed from the bottom of the strip, cholesterol was delivered by capillary action to the immobilized enzymes and a sequential reactions took place. In the final reaction, the chromogen was oxidized and then generated a color as signal that was proportional to the concentration of cholesterol. The signal intensity was enhanced by optimizing conditions for the immobilization of enzymes and the chemical composition of carriel. Under these conditions, a dose-response curve was obtained and revealed a high sensitivity enough to measure the cholesterol in blood.

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.373-381
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• 1994

An actinomycete strain, HSL-613 was isolated -from soil and identified by International Streptomyces Project (ISP) and chemotaxonomic methods. The spore chain of the strain HSL-613 appears in a spiral shape, and its spores are spherical shape with smooth surface. The cell wall contains LL-diaminopimelic acid (DAP). Menaquinone MK-9 (H$_{6}$, H$_{8}$) and iso- and anteiso-branched fatty acids were detected from whole cell extract. Sugars identified from whole cell extract include galactose, glucose, mannose and ribose, which are distinct from general sugar patterns of Streptomyces. Average G+C content in the chromosome is 59%. 5S rRNA of HSL-613 consists of 120 nucleotides as determined by comparing with that of a type strain Streptomyces griseus subsp. KCTC 9080. Through morphological, physiological, and chemical characterization, HSL-613 was identified and named as Streptomyces sp. HSL-613.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.241-247
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• 2016

Natamycin is a widely used antifungal antibiotic. For natamycin biosynthesis, the gene pimE encodes cholesterol oxidase, which acts as a signalling protein. To confirm the positive effect of the gene pimE on natamycin biosynthesis, an additional copy of the gene pimE was inserted into the genome of Streptomyces gilvosporeus 712 under the control of the ermE* promoter (p_ermE*) using intergeneric conjugation. Overexpression of the target protein engendered 72% and 81% increases in the natamycin production and cell productivity, respectively, compared with the control strain. Further improvement in the antibiotic production was achieved in a 1 L fermenter to 7.0 g/l, which was a 153% improvement after 120 h cultivation. Exconjugants highly expressing pimE and pimM were constructed to investigate the effects of both genes on the increase of natamycin production. However, the co-effect of pimE and pimM did not enhance the antibiotic production obviously, compared with the exconjugants highly expressing pimE only. These results suggest not only a new application of cholesterol oxidase but also a useful strategy to genetically engineer natamycin production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1355-1363
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• 1999

The purpose of this study was to investigate the effects of vitamin E on liver microsomal cytochrome P450 contents and xanthine oxidase activity in acute cadmium poisoned rats. Sprague Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal and three cadmium injected groups. Cadmium injected groups were fed vitamin E free diet(0E Cd group), 40mg vitamin E per kg diet(40E Cd group) or 400mg vitamin E per kg diet(400E Cd group). Vitamin E level of normal group was 40mg per kg diet. Animals were injected intraperitoneally with 2.0mg Cd2+/kg bw for 4 days after the rats were fed diets with three different levels of vitamin E for 2 and 4 weeks. Body weight, food intake and feed efficiency ratio of cadmium injected animals, were decreased compared with those of normal group. The weights of liver and kidney in cadmium injected groups were not different from those of normal group. Cadmium contents of liver in cadmium groups were 160 fold higher those that of normal group. Accumulation of cadmium poisoned rat liver was reduced by vitamin E supplementation. Contents of blood hemoglobin and hematocrit in 0E Cd groups were decreased to 2~ 14% of those of the other groups. Contents of serum triglyceride in all experimental groups were not significantly different each other. Levels of serum total cholesterol, LDL cholesterol and antherogenic index in 0E Cd and 40E Cd groups were higher than those of normal group, while the contents of HDL cholesterol in 0E Cd and 40E Cd groups were lower than those of normal group. Xanthine oxidase(XOD) activity and cytochrome P450 contents in the liver were significantly increased in cadmium injected groups but these were reduced by vitamin E supplementations. The present results indicate that acute cadmium poisoning in rats causes increasing free radical generation systems in the liver and that leads to liver tissue damage. But these abnormalities can be reduced by dietary vitamin E supplementations.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1212-1220
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• 2013

Because the cholesterol oxidase from Brevibacterium sp. M201008 was not as stable as the free enzyme form, it had been covalently immobilized onto chemically modified Sepharose particles via N-ethyl-N'-3-dimethylaminopropyl carbodiimide. The optimum immobilization conditions were determined, and the immobilized enzyme activity obtained was 12.01 U/g Sepharose-ethylenediamine. The immobilization of the enzyme was characterized by Fourier transform infrared spectroscopy. The immobilized enzyme exhibited the maximal activity at $35^{\circ}C$ and pH 7.5, which was unchanged compared with the free form. After being repeatedly used 20 times, the immobilized enzyme retained more than 40.43% of its original activity. The immobilized enzyme showed better operational stability, including wider thermal and pH ranges, and retained 62.87% activity after 20 days of storage at $4^{\circ}C$, which was longer than the free enzyme.

• Journal of Food Hygiene and Safety
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• v.24 no.2
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• pp.148-153
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• 2009

In this study, we have developed a fluorescence chromatographic assay for the quantification of total cholesterol in serum, which is a well-known risk predictor for cardiovascular diseases. The new assay system consists of a chromatographic strip in a cartridge, enzyme buffer containing cholesterol esterase, cholesterol oxidase, horseradish peroxidase, and color developer AEC, and a laser fluorescence scanner. The correlation coefficient (r) between cholesterol concentration and relative fluorescence units was 0.968 in the new assay, showing a reliable linearity through the tested range of cholesterol. Recovery test and comparability with a Hitachi 747 instrument showed 106.5-94% and r = 0.939 (p<0.001), respectively. The new assay system for cholesterol was developed as a pre-POCT platform conducted in clinics since it is fast (8 min) and uses a small volume of sample ($5\;{\mu}l$), and it may be applied for on-site diagnostics to replace expensive automated biochemical analyzer.