• Fisheries and Aquatic Sciences
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• v.22 no.10
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• pp.22.1-22.7
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• 2019

The functional peptides from protein hydrolysates of various fishery sources have been identified such as antioxidant activity. The main intention of this study was purification and characterization of antioxidative peptide from black eelpout muscle. The antioxidative peptides were purified from black eelpout (Lycodes diapterus) muscle using different proteases. Antioxidant activity of black eelpout hydrolysates was evaluated using DPPH radical scavenging activity. Among six hydrolysates, the pepsin hydrolysate had the highest antioxidant activity compared to the other hydrolysates. Therefore, it was further purified and a peptide with seven amino acid residues of DLVKVEA (784 Da) was identified by amino acid sequence analysis. The EC₅₀ value for scavenging DPPH radicals by purified peptide was 688.77 μM. Additionally, the purified peptide exhibited protective effect against DNA damage induces by oxidation in mouse macrophages (RAW 264.7 cells). The results of this study suggest that black eelpout muscle protein hydrolysate could potentially contribute to development of bioactive peptides in basic research.

• Korean Journal of Plant Resources
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• v.30 no.1
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• pp.1-7
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• 2017

In this study, we produced the recombinant lunasin peptide using E. coli and P. pastoris, and evaluated biological activity of the recombinant lunasin peptide. Lunasin peptide was produced from E. coli transfected with pPGEX-lunasin expression vector and P. pastoris GS115 transfected with pPIC-lunasin expression vector. These recombinant lunasin peptides were similar to the synthetic lunasin peptide in the identification by LC-ESI-MS. In addition, the recombinant lunasin peptide from E. coli and P. pastoris was bound in the chromatin, and inhibited histone acetylation and the activity of histone acetyltransferase. These findings suggest that the production of the lunasin peptide using E. coli and P. pastoris will be useful for industrial utilization of lunasin peptide.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.284-292
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• 2018

Receptor for advanced glycation end-products (RAGE) is overexpressed in various cancer cells. In this study, a RAGE-binding peptide (RBP) was conjugated to polyethylenimine (25 kDa, PEI). RBP-conjugated PEI (PEI-RBP) was characterized as a dual-functional reagent, a RAGE-mediated gene carrier and an anti-angiogenic reagent. As a gene carrier, PEI-RBP had higher transfection efficiency to the C6 glioblastoma cells than PEI. As an anti-angiogenic reagent, the pEmpty/PEI-RBP complex reduced RAGE expression on the surface of the C6 glioblastoma cells. Also, the complex reduced the VEGF expression and tube formation of endothelial cells. Therefore, PEI-RBP may be useful for development of glioblastoma therapy.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2386-2388
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• 2010

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.1
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• pp.1-8
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• 2018

The objective of this study was to purify and characterize the ${\beta}-secretase$ inhibitor from enzymatic hydrolysates of blackfin flounder muscle, for development of a novel anti-dementia agent that may be used in the drug or functional food industries. ${\beta}-secretase$ inhibitory peptide was purified from various enzymatic hydrolysates of blackfin flounder muscle. Among six enzymatic hydrolysates, the Alcalase hydrolysate revealed highest ${\beta}-secretase$ inhibitory activity. Consecutive purification of the blackfin flounder muscle hydrolysate using Sephadex G-25 column chromatography and octadecylsilane C18 reversed phase HPLC techniques were used to isolate a potent ${\beta}-secretase$ inhibitory peptide composed of 5 amino acids, Leu-Thr-Gln-Asp-Trp (MW: 526.7 Da). The $IC_{50}$ value of purified ${\beta}-secretase$ inhibitory peptide was $126.93{\mu}M$. Results of this study suggest that peptides derived from blackfin flounder muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• Rapid Communication in Photoscience
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• v.4 no.3
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• pp.59-62
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• 2015

We investigated photo-induced electron transfer (PET) in a dye-labeled peptide, fluorophore-Ala-Gly-Gln-Tyr, employing time-resolved fluorescence. As an effort to develop new functional dyes, we studied an acriflavine derivative for the electron-acceptor in the excited state from tyrosine, an electrondonor in the ground-state. The pH dependence of the fluorescence lifetime of the model peptide indicates that electron transfer between the excited dye and tyrosine occurs when the tyrosine is deprotonated. The proton-coupled electron transfer appears to be sequential rather than concerted. We also report direct time measurements on the end-to-end loop formation processes of the peptide in water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1124-1129
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• 2005

Functional activities of low molecular weight substances purified from pepsin hydrolysates of four different seaweeds; Costaria costata, Enteromorpha prolifera, Grateloupia filicina and Porphyra tenera, were inves-tigated. Each pepsin hydrolysate of Costaria costata, Enteromorpha prolifera, and Grateloupia filicina resulted in three peptide peaks on Bio-Rad P2 gel chromatography pattern, while that of Porphyra tenera showed 2 peaks. Peak 1 of Porphyra tenera showed the highest antioxidative activity followed by peak 2 of Porphyra tenera and peak 2 of Costaria costata in order Peak 1 of Porphyra tenera showed the highest ACE inhibitory activity followed by peak 3 and peak 2 of Enteromorpha prolifera in order. Peak 1 and peak 2 of Porphyra tenera, and peak 2 of Enteromorpha prolifera showed the highest antityrosinase activity followed by peak 3 of Enteromorpha prolifera. Peak 1 of Enteromorpha prolifera showed the highest antitumor activity followed by peak 2 of Costaria costata, peak 3 of Enteromorpha prolifera, and peak 3 of Grateloupia filicina in order. Porphyra tenera showed the highest functional activities, which is thought to be due to its high protein content. Structure and amino acid sequence of low molecular weight peptide of Porphyra tenera should be analyzed in the further study.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.257-264
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• 2003

Carnitine, hydroxycitric acid, and soy peptide have been known to be anti-obesity agents. The purpose of this study was to evaluate the combined effects of carnitine, hydroxycitric acid, and soy peptide mixture as a potential anti-obesity supplement in overweight women. Overweight premenopausal women (n=33; PIBW>110; 20 to 39 years) were randomized into two groups: the placebo group and the functional beverage group (the test group). Functional beverage was composed of 2000 mg soy peptide, 20 mg L-carnitine and 300 mg garcinia(40% hydroxycitric acid). Body weight and 3 day food dimes, biochemical measurements and computerized tomography were measured at baseline and 8-week. After 8-week consumption of functional beverage with usual diet and exercise, body weight fell an average of 1.4 kg (2.1%). Visceral fat area reduced an average of 7.8% at L1($69.6{\pm}8.7\;vs\;64.2{\pm}7.5\;\textrm{cm}^2$) and 5.1% ($60.7{\pm}4.9\;vs\;57.6{\pm}4.8\;\textrm{cm}^2$, p<0.05) at L4level after weight loss in the test group. Calf fat area in the test group showed about 10% reduction ($31.0{\pm}2.7\;vs=\;27.7{\pm}1.7\;\textrm{cm}^2$, p<0.05) after weight loss. These reductions in fat areas were not shown in the placebo group. There were tendencies of increase in serum levels of $\beta-hydroxybutyrate$, acetoacetate, and total ketones in the test group. There were 7% and 17% insignificant increase in fasting free fatty acid (FFA) and response area of FFA during oral glucose tolerance test(OGTT), respectively, in this group. ill addition, little weight loss in the test group showed 8% but not significant reduction in insulin response area during OGTT. In conclusion, this study shows that taking a mixture of carnitine, hydroxycitric acid, and soy peptide as a potential anti-obesity supplement for 8-week produced advantageous changes in the weight and visceral fat accumulation of overweight women.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.88-89
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• 2003

A series of novel spinning acrylic polymer containing silk protein were synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) modified by acryloyl chloride (AC) with vinyl groups. The viscosity values of these copolymers showed that the copolymers have good spinnability, which are synthesized under the condition of putting a micro amount of metal ions into synthesizing solvent. The fiber based on the poly (AN-co-SFP) was prepared and characterized by SEM, FTIR measurement of its shell and core flakes, and moisture absorption. The fiber appeared a smooth surface and could be assumed to have excellent adhesive between SFP and PAN. Furthermore, these fibers showed a shell-core structure and excellent moisture absorption.