• The Korean Journal of Zoology
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• v.37 no.4
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• pp.524-530
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• 1994

An Arpase complex has been purified to apparent homogeniety from the extract of chick skeletal muscle using conventional column chromatographies and glycerol density gradient centrifugation. This eWe has a sedimentation coefficient of 15S as determined by the gradient centrifugation and therefore is referred to as the 15S ATPase. It behaves as a 600-kOa molecule upon gel filtration analysis using a Superose-6 column. However, the ATPase runs as a 95-kDa polvpeptide when analyzed by polvacrvlamide gel electrophoresis in the presence of sodium dodecyl sulfate. Thus, the Arpase is likely to consist of six identical subunits of 95 KDa. It has a Km value of 0.6 mM for ATP and is maximally active at pH 9.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.441-445
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• 1987

The subcellular distribution of lipoxygenase in germinating soybean seeds (Glycine max[L.] AmSoy) was investigated by using differential centrifugation and sucrose density gradient fractionation. Most of lipoxygenase -1 and -2/3 activities was present in the supernatant fraction after differential centrifugation of homogenates prepared from three-day-old seedlings; only 1.5% of lipoxygenase activity remained in particulate fractions. The results of a sucrose density gradient fractionation (three-day-old) showed that the lipoxygenase activity coincided with acid phosphatase at the densities of 1.19, 1.23, $1.25g/cm^3$, even though most of lipoxygenase and acid phosphatase activities appeared in supernatant fractions. There was no indication that mitochondria contained any lipoxygenase activity, and it does not appear that glyoxysomes and ER contained any lipoxygenase activity either.

• KSBB Journal
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• v.8 no.2
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• pp.97-103
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• 1993

This study was investigated as a step for the purpose of successful introduction of cytoplasmic inherited characters between the different plants. Cytoplasts were separated from the protoplasts of CMS(cytoplasmic male sterility) line such as MS Burley 21 which carried from Nicotiana megalosiphon. The cytoplasts were fused to protoplasts derived from Nicotiana tabacum Br 64 with PEG(polyethylene g1yco1). The cytoplasts were separated by density gradient centrifugation. Efficient separation of cytoplasts depended on the difference of specific density of gradient solution. However, the iso-osmolality of gradient solution was not important to separate the cytoplasts. The cells for a cybrid were fused with 50% concentration of PEG.

• Korean Journal of Veterinary Research
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• v.11 no.2
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• pp.123-136
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• 1971

(1) The non-specific inhibitors (NSI) in normal chicken sera were active against all the tested group A and group B arboviruses, but the group B arbovirus were more sensitive than group A arboviruses. (2) The titres of the NSI were distributed nearly uniformly among chickens from seven different age groups to group A arboviruses. In contrast, the NSI titres to group A arboviruses were found to increase with age. (3) No significant difference could be demonstrated between acetone-ether extraction and kaolin adsorption for removal of the NSI in normal chicken sera. (4) After heating, the NSI titres in chicken sera were increased for both group A and group B arboviruses. (5) After heating the sera at $80^{\circ}C$ and $100^{\circ}C$, kaolin adsorption was less efficient for removing the NSI than it, was in unheated serum. Acetone-ether extraction of the NSI was unimpaired after heating at $80^{\circ}C$ but was less efficient after heating at $100^{\circ}C$. (6) The NSI activity was found mainly in the first peak (IgM) and diffused to a part of second peak (IgG) by fractionation of chicken serum by gel filtration through Sephadex G200. After zonal centrifugation of chicken serum in a linear ten to 40 percent sucrose gradient all of the NSI activities were found on the top of the centrifugal tubes. These properties of large molecular size and low density indicated that the NSI in chicken serum were probably lipoproteins. (7) The natural agglutinins for goose erythrocytes in chicken sera were partially destroyed by acetone-ether extraction but not by kaolin adsorption, and were efficiently adsorbed with ten percent goose erythrocytes. No difference of the NA titre was demonstrated with diluents of different pH. (8) The NA in chicken serum was found to possess the properties of IgM by gel filtration through Sephadex G200 and zonal centrifugation in linear ten to 40 percent sucrose gradient.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.4
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• pp.199-206
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• 2016

Objective: This study was carried out to investigate the correlations of the sperm DNA fragmentation index (DFI) with semen parameters and apoptosis, and to investigate the effects of density-gradient centrifugation (DGC) and magnetic-activated cell sorting (MACS) on reducing the proportion of sperm with DNA fragmentation and protamine deficiency. Methods: Semen analysis and a sperm DNA fragmentation assay were performed to assess the correlations between semen parameters and the DFI in 458 semen samples. Sperm with progressive motility or non-apoptosis were isolated by DGC or MACS, respectively, in 29 normozoospermic semen samples. The effects of DGC or MACS alone and of DGC and MACS combined on reducing the amount of sperm in the sample with DNA fragmentation and protamine deficiency were investigated. Results: The sperm DFI showed a significant correlation (r=-0.347, p< 0.001) with sperm motility and morphology (r=-0.114, p< 0.05) but not with other semen parameters. The DFI ($11.5%{\pm}2.0%$) of semen samples was significantly reduced by DGC ($8.1%{\pm}4.1%$) or MACS alone ($7.4%{\pm}3.9%$) (p< 0.05). The DFI was significantly further reduced by a combination of DGC and MACS ($4.1%{\pm}1.3%$, p< 0.05). Moreover, the combination of DGC and MACS ($1.6%{\pm}1.1%$, p< 0.05) significantly reduced the protamine deficiency rate of semen samples compared to DGC ($4.4%{\pm}3.2%$) or MACS alone ($3.4%{\pm}2.2%$). Conclusion: The combination of DGC and MACS may be an effective method to isolate high-quality sperm with progressive motility, non-apoptosis, high DNA integrity, and low protamine deficiency in clinical use.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.597-604
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• 1994

Membranes obtained from the normal human RBC population were separated by continuous sucrose density gradient centrifugation and the density-fractionated membranes were then examined for changes in molecular markers. This study focuses on changes of (i) the membrane protein profile, (ii) differences in membrane-associsted enzyme activities, and (iii) the amount of autologous IgG bound. The following observations were made: (i) ratios for band 4. la over the sum of bands (4. la + 4.Ib) ranged from 0.58 to 0.79 for membranes of lowest density; (ii) significant changes in bound glyceraldehyde-3-phosphate dehydrogenase and acetvlcholinesterase activities were found; (iii) the amounts of autolosous IgG's attached to the red blood cells was highest in the membrane fraction of lowest density.

• Journal of Plant Biology
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• v.28 no.3
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• pp.225-232
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• 1985

Intracellular localization and the developmental changes in activities of uricase and allantoinase during germination were investigated with the cotyledons of rape(Brassica napus L.) seedlings. The development anddisappearance of uricase activity took place independently of light, but allantoinase activity was increased by light. The temporal pattern of uricase activity showed that uricolysis was actively taking place in the cotyledons during their early stages of germination. While uricase can be localized in the microbody fraction isolated from crude organelle extracts of the cotyledons by density gradient centrifugation, most of the allantoinase activity found in the microbody fraction did not appear to be an integral part of the microbody.

• Journal of Plant Biology
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• v.30 no.3
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• pp.201-203
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• 1987

Total RNA was isolated from two months old wheat, rice, tobacco and sweet potato. The procedure used was simple and provided pure RNA preparation. Lysis of plant tissue in a buffer with guanidine thiocyanate and CsCl density gradient centrifugation separated RNA from the rest of the cellular components. Subsequent cholroform/1-butanol extraction and ethanol precipitation were necessary to ensure contaminant-free RNA preparation. Storage of the lysed plant tissue in the buffer with guanidine thiocyanate preserved the sample for two months without noticeable RNA degradation.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.611-618
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• 2007

We demonstrate the sol-gel coating technique of colloidal clusters for producing hollow micro-particles with complex morphologies. Cross-linked amidine polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion copolymerization of styrene and divinylbenzene. The amidine PS particles were self-organized inside toluene-in-water emulsion droplets to produce large quantities of colloidally stable clusters. These clusters were coated with thin silica shell by sol-gel reaction of tetraethylorthosilicate (TEOS) and ammonia, and the organic polystyrene cores were removed by calcination at high temperature to generate nonspherical hollow micro-particles with complex morphologies. This process can be used to prepare hollow particles with shapes such as doublets, tetrahedra, icosahedra, and others.