• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.398-406
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• 2022

The outer membrane of Gram-negative bacteria is the outermost layer of cellular environment in which numerous biophysical and biochemical processes are in action sustaining viability. Advances in cell engineering enable modification of bacterial genetic information that subsequently alters membrane physiology to adapt bacteria to specific purposes. Surface display of a functional molecule on the outer membranes is one of strategies that directs host cells to respond to a specific extracellular matter or stimulus. While intracellular expression of a functional peptide or protein fused to a membrane-anchoring motif is commonly practiced for surface display, the method is not readily applicable to exogenous or large proteins inexpressible in bacteria. Chemical conjugation at reactive groups naturally occurring on the membrane might be an alternative, but often compromises fitness due to non-specific modification of essential components. Herein, we demonstrated two distinct approaches that enable site-specific decoration of the outer membrane with a fluorescent agent in Escherichia coli. An unnatural amino acid genetically incorporated in a surface-exposed peptide could act as a chemoselective handle for bioorthogonal dye labeling. A surface-displayed α-helical domain originating from a part of a selected heterodimeric coiled-coil complex could recruit and anchor a green fluorescent protein tagged with a complementary α-helical domain to the membrane surface in a site- and hetero-specific manner. These methods hold a promise as on-demand tools to confer new functionalities on the bacterial membranes.

• Food Science and Preservation
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• v.21 no.3
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• pp.388-395
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• 2014

Six types of mixed cereals powder were prepared using different mixing ratios of barley, proso millet, sorghum, and adlay, and their nutritional components and functionalities were analyzed. The mixed cereals powders contained high levels of crude protein. The free amino acid and mineral contents of Sample E were the highest among all the samples. Fructose, glucose, sucrose, and maltose were detected as the four major free sugars in all the mixed cereals powders, and Sample D had the highest amount of reducing sugar among all the samples. The total polyphenol and total flavonoid contents of Sample F were significantly higher than those of the other samples. Sample C showed the highest level of DPPH radical scavenging activity and reducing power. As for the ABTS radical scavenging activity, the $IC_{50}$ of Sample D was the lowest among all the samples, but did not significantly differ from that of Sample C. Therefore, we suggest 2:2:1:1 (in Sample D) as the best mixing ratio of barley, proso millet, sorghum, and adlay to produce a mixed cereals powder with excellent nutritional value and antioxidant activities.

• Food Science and Preservation
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• v.23 no.6
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• pp.839-847
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• 2016

The changes of approximate composition, antioxidant activity and melatonin content in rapeseed were monitored during 10 days germination to choose the optimum sprouts with beneficial functionalities. The moisture content of seeds increased from 3.23% to 17.50% during 10 days germination period, while ash content was similar (4.03~4.91%). The fat content was reduced from 38.18% to 22.65%, however, protein content increased from 21.43% to 26.72%. The carbohydrate content increased from 32.71% to 35.84% at 8th day. The reducing sugar and fiber contents reached 10.47% and 15.12% at 6th day from 4.04% and 12.82%, respectively. Eighth day sprouts contained highest level of polyphenol (gallic acid equivalent, 19.2 g/kg). Germination increased antioxidant activities (trolox equivalent, mmol/kg) of seeds with slight difference depending on assay. That is, antioxidant activity was highest at 6th day in DPPH radical scavenging (55.9), 10th day both in ABTS radical scavenging (71.6) and Fe(III) reducing (125.3), and 4th day in peroxy radical scavenging (116.7) assay. Melatonin content of seeds ($0.85{\mu}g/kg$) also increased and reached up to $14.93{\mu}g/kg$ at 6th day. In conclusion, germination more than 4 days raised antioxidant activity of seeds highly, and 6th day sprouts had additional benefit in terms of melatonin, reducing sugar and crude fiber contents.

• Food Science and Preservation
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• v.18 no.6
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• pp.844-852
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• 2011

In this study, various antioxidant propertieswere evaluated by analyzing the proximate composition and free-sugar and DNJ contents of the Bombyx mori L., Mori fructus, Morus ramulus, Mori folium, Dioscoreae rhizome and Inonotus obliquus extracts, and the antidiabetic effect was evaluated through an in-vivo experiment. Product evaluation was conducted after preparing a beverage for the easy use of the mixed extract for biological activity, as a functional resource. The biochemical composition of the extracts was 0.31% crude protein, 0.114 g/100 mL free sugar and 161.02 mg/gdw DNJ, all of which showed excellent results in all the antioxidant ability and ${\alpha}$-glucosidase inhibition ability experiments. The beverage showed the following functionalities. The total-polyphenol content was 71.93%, but the electron-donating ability was highest in the 5% extract concentration. Moreover, when the TBARS values were experimented on, KO2 showed an especially high scavenging ability. During the five-week beverage supply after inducing diabetes with streptozotocin (STZ), the change in the blood sugar was measured, and the STZ-induced diabetes+oral-beverage group (C) showed a lower blood sugar level than the diabetes comparative group (B) in the second week. In the STZ-induced diabetes+free-diet/beverage group (D), the blood glucose level also slowly decreased in the second week. The lowest blood glucose level among the STZ-induced diabetes groups was shown in the fifth week.

• Food Science and Preservation
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• v.21 no.6
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• pp.885-891
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• 2014

This study investigated the physiochemical properties of Kanjang (soy sauce) contaning Astragalus memyranaceus to improve the acceptability and functionalities of Kanjang during its six-month ripening period. Kanjang was fermented in the traditional manner, and then 5 and 10% Astragalus memyranaceus (AM) were added to two samples of it, respectively. The pH, salinity, sugar content, crude protein, amino nitrogen, optical density, total polyphenol content, total flavonoid content, and sensory test results of Kanjang contaning Astragalus memyranaceus (AK) were then investigated. The pH remained the same in the two samples. The salinity was slowly increased, and the sugar content ($^{\circ}Brix$) was highest after 3 months. The crude protein and amino nitrogen contents increased with time. The optical density showed significant differences according to the rate of addition of AM. The total polyphenol contents were highest in the AK 5% sample aged for six months (up to 25.01 mg/mL). The flavonoid contents of the AK 5% sample was higher at five months (up to 200.15 mg/mL). Finally, the sensory test results of the AK 5% sample was higher than that of the other sample. These results suggest that Kanjang containing 5% Astragalus memyranaceus can be used as a functional Kanjang.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.226-233
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• 2007

Purpose: Dual reporter gene imaging has several advantages for more sophisticated molecular imaging studies such as gene therapy monitoring. Herein, we have constructed hepatoma cell line expressing dual reporter genes of sodium iodide symporter (NIS) and enhanced green fluorescence protein (EGFP), and the functionalities of the genes were evaluated in vivo by nuclear and optical imaging. Materials and Methods: A pRetro-PN vector was constructed after separating NIS gene from pcDNA-NIS. RSV-EGFP-WPRE fragment separated from pLNRGW was cloned into pRetro-PN vector. The final vector expressing dual reporter genes was named pRetro-PNRGW. A human hepatoma (HepG2) cells were transfected by the retrovirus containing NIS and EGFP gene (HepG2-NE). Expression of NIS gene was confirmed by RT-PCR, radioiodine uptake and efflux studies. Expression of EGFP was confirmed by RT-PCR and fluorescence microscope. The HepG2 and HepG2-NE cells were implanted in shoulder and hindlimb of nude mice, then fluorescence image, gamma camera image and I-124 microPET image were undertaken. Results: The HepG2-NE cell was successfully constructed. RT-PCR showed NIS and EGFP mRNA expression. About 50% of cells showed fluorescence. The iodine uptake of NIS-expressed cells was about 9 times higher than control. In efflux study, $T_{1/2}$ of HepG2-NE cells was 9 min. HepG2-NE xenograft showed high signal-to-background fluorescent spots and higher iodine-uptake compared to those of HepG2 xenograft. Conclusion: A hepatoma cell line expressing NIS and EGFP dual reporter genes was successfully constructed and could be used as a potential either by therapeutic gene or imaging reporter gene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1302-1309
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• 2009

This study was carried out to investigate physicochemical and functional properties of dried Brassica campestris ssp rapa (BR) sprouts. The proximate compositions of BR sprouts as dry matter basis were 2.35% of moisture content, 22.51% of crude protein, 21.60% of crude lipid, 4.35% of crude ash, and 49.19% of carbohydrate, respectively. The free sugars were identified as glucose and fructose. Analyzing total amino acids, 18 kinds of components were isolated from BR sprouts. The essential amino acid contained in BR sprouts accounted for 47.00% of total amino acid, while the non-essential amino acid accounted for 53.00%. The contents of vitamin A and vitamin E were 0.09 mg% and 3.06 mg%, respectively. Tartaric acid was the major organic acid. Among the minerals in dried BR sprouts, the content of potassium was the highest (882.50 mg%) and those of magnesium and calcium were comparatively high (342.85 mg%, 274.30 mg%). BR sprouts ethanol extract significantly inhibited the HMG-CoA reductase activity in a concentration-dependent manner in vitro. Furthermore, nitrite scavenging ability and DPPH radical scavenging activity of the ethanol extract of BR sprouts were 64.25% and 69.29% at a concentration of 1,000 ${\mu}g$/mL, respectively. These results suggest that BR sprouts possess potential antioxidative capacity and HMG-CoA reductase inhibitory activity.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.261-267
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• 2022

The purpose of this study is to investigate the various functionalities of the peels, pulps, and seeds of passion fruit. Proximate composition, mineral contents, phenolic acid contents, total polyphenols, total flavonoids, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, reducing power, α-glucosidase, and α-amylase inhibitory activities were measured for each part of passion fruit. Proximate composition analysis of the passion fruit indicated that moisture content contained (4.78-8.20%), carbohydrate (68.33-73.23%), protein (8.78-13.63%), fat (1.19-11.60%), and ash (1.51-8.80%). K, Ca, Na and Fe were the predominant mineral in the peels. P and Mg were the predominant mineral in the pulps. All the antioxidant activities (total polyphenols, total flavonoids, DPPH radical scavenging, ABTS radical scavenging, and reducing power) showed high results in the seeds. α-Glucosidase and α-amylase inhibitory activities IC₅₀ were in the peels (5.59 and 63.16 mg/mL), in the pulps (3.80 and 31.90 mg/mL), and in the seeds (0.06 and 1.02 mg/mL). These results indicated that the pulps, peels, and seeds of passion fruit have value as natural antioxidants with the high quality functional components.