• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.26-30
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• 2002

A droplet fractionation method was previously developed to concentrate a dilute nonfoaming protein solution. In that earlier study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a nonfoaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of 5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet fractionation experiment.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.3
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• pp.167-172
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• 2003

Foam fractionation can be used to enrich a hydrophobic protein such as bromelain from an aerated dilute protein solution because the protein foams. On the other hand, a protein such as invertase, which is hydrophilic, is not likely to foam under similar aerated conditions. While a foam fractionation process may not be appropriate for recovering a hydrophilic protein alone, it is of interest to see how that non-foaming protein affects the foaming protein when the two are together in a mixture. The bromelain enrichment, activity and mass recovery were observed as a function of the solution pH in order to explore how invertase can affect the recovery of bromelain in a foam fractionation process.

• Agricultural and Biosystems Engineering
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• v.6 no.2
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• pp.77-82
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• 2005

The fractionation of green juice could be one of the ways to treat the green juice for saving the bio re-sources by using the basic processes of protein coagulation and separating juice coagulation into protein paste and brown juice and storing the final products. The fractionation of Chinese cabbage juice can be accomplished by applying the combine method of the formic acid with rate of 0.3% and the propionic acid with rate of 0.1 % added 4 hours later in the juice with maximum recovery of protein coagulation. The separation of coagulation into the protein paste and the brown juice completed in 6.5 hours by set up method in a special designed storage. The protein paste could be stored safely for 30days in anaerobic condition.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.515-518
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• 2002

The method of foam fractionation can be applied to enrich proteins from a dilute protein solution if the proteins are hydrophobic and foam. If a protein, such as invertase, is hydrophilic, a dilute solution containing this protein may not foam. In that case, a batch foam fractionation process may not be appropriate for recovering a concentrated solution of that protein. In this paper, various concentrations of invertase were added to a dilute solution containing bromelain (a hydrophobic protein), in order to determine how the presence of a hydrophilic protein can affect the recovery of the desired hydrophobic protein. The effect of invertase on bromelain recovery was studied here at an initial bulk solution pH of 5 and an air superficial velocity of 4.6 cm/s.

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.103-110
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• 2007

The protein profiles among Korean rice cultivars were assessed by total protein determination, solubility fractionation, SDS-PAGE analysis and scanning densitometry. In the extraction of protein, the SDS/urea system at a neutral pH was more efficient than that at alkaline pH. The determination of total protein showed that the protein content was similar among cultivars, ranging from 87.9 to 92.7 mg/g dry weight. Additionally, the water/NaCl-soluble protein fraction, containing 14${\sim}$16 kDa albumin and 22 kDa globulin ${\alpha}$-globulin, was also similar among cultivars, with a range of 9.94 to 11.98 mg/g dry weight. The SDS-PAGE/densitometry of total protein showed that there was no discernable difference in proteins of higher molecular weights among various cultivars, whereas the amount of lower molecular weight proteins (14${\sim}$16 kDa) is somewhat variable among cultivars. Furthermore, SDS-PAGE analysis of water/NaCl-soluble and propanol-soluble fractions indicates that there is a discernible change in the content of albumin, globulin or prolamin among cultivars. Thus, the PAGE/densitometry method, preceded by solubility fractionation, is useful for examining differences in protein profiles of rice cultivars.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1315-1320
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• 2011

Whey protein (WP) is a mixture of proteins, and is of high nutritional values. WP has become an important source of functional ingredients in various health-promoting foods. In this study, size-exclusion chromatography (SEC) and asymmetrical flow field-flow fractionation (AsFlFFF) were used for separation and analysis of whey proteins. It was found that a lab-prepared WP from raw milk is mostly of ${\beta}$-lactoglobulin with small amount of higher molecular weight components, while a commercial whey protein isolate (WPI) powder contains relatively larger amount of components other than ${\beta}$-lactoglobulin, including IgG and protein aggregates. Results suggest that AsFlFFF provides higher resolution for the major whey proteins than SEC in their normal operation conditions. AsFlFFF could differentiate the BSA and Albumin, despite a small difference in their molecular weights, and also was able to separate much smaller amount of aggregates from monomers. It is noted that SEC was able to show the presence of low molecular weight components other than the major whey proteins in the WP samples, which AsFlFFF could not show, probably due to the partial loss of those low molecular weight species through the membrane.

• YAKHAK HOEJI
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• v.22 no.1
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• pp.42-50
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• 1978

The plasma proteins of fresh water fishes have been fractionated by disc electrophoresis in acrylamide gels utilized as an electrophoretic supporting medium. The species of fishes examined in this experiment were Anguilla japonica, Misgurnus mizolepis, Parasilurus asotus, Siniperca scherzeri, Pelteobagrus fulvidra, Carassius carassius, Cyprinus carpio, and Hemibarbus labeo, obtained in the Han River. Disc electrophoresis was performed as described by Ornstein and Davis. Gels and buffer solution were prepared by the method developed by W.J.Kim. The separation gels were 7% acrylamide gel. The fractionation of plasma proteins showed 13 bands in Anguilla japonica, 10 in Misgurnus mizolepis, 15 in Parasilurus asotus, 12 in Siniperca scherzeri, 11 in Pelteobagrus fulvidra, 13 in Carassius carassius, 9 in Cyprinus carpio, and 13 in Hemibarbus labeo. The patterns of plasma protein on the each species of fishes were different in the number of bands, ratio of contents, relative mobilities, and forms of fractionation.

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1339-1344
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• 2003

Flow field-flow fractionation (FlFFF) is a technology to separate the molecules by size in an open channel. Molecules with different size have different diffusivities and are located vertically in different positions when passing through an open channel. In this study, hollow fiber membranes instead of conventional rectangular channels have been used as materials for the open channel and this change would decrease the cost of manufacturing. FlFFF is a useful technique to characterize the biopolymeric materials. Retention time, diffusion coefficients and Stokes radius of analysis can be calculated from the related simple equations. Hollow-fiber flow field-flow fractionation (HF-FlFFF) has been used for the characterization and separation of protein mixture in a phosphate buffer solution and has demonstrated the potential to be developed into a disposable FlFFF channel. The important indexes for the analytical separation are selectivity, resolution and plate height. The optimized separation condition for protein mixture of Ovalbumin, Alcohol dehydrogenase, Apoferritin and Thyroglobulin is ${\dot V}_{out}/{\dot V}_{rad}=0.65/0.85\;mL/min$.

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.123-125
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• 2002

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.87-91
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• 2005

Although 2D-PAGE has been widely used as the primary method for protein separation, difficulties in displaying proteins with an extreme values of isoelectric paint (pI), molecular size and hydrophobicity limit the technique. In addition, time consuming steps involving protein transfer and extraction from the gel-pieces can result in sample loss. Here, we describe a novel protein separation technique with capillary size-exclusion chromatography (CSEC) for rapid protein identification from human plasma. The method includes protein fractionation along with molecular size followed by in-solution tryptic digestion and peptide analysis through reversed phase liquid chromatography (RPLC) coupled to nanoflow electrospray-tandem mass spectrometry (ESI-MS/MS). Tryptic peptides are applied an a $100\;{\mu}m\;i.d.{\times}10mm$ length pre-column and then separated on a $75\;{\mu}m{\times}200mm$ analytical column at -100 nL/min flaw rate. Proteins were identified over the wide ranges of pI (3.7-12.3) when this technique was applied to the analysis of $1-2\;{\mu}L$ of human plasma. This gel-free system provides fast fractionation and may be considered a complementary technique to SDS-PAGE in proteomics.