• Natural Product Sciences
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• v.26 no.3
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• pp.207-213
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• 2020

Characterization and in vitro inhibition studies of protease inhibitor from the mushroom Pleurotus floridanus (PfTI) towards the pest Papilio demoleus is studied. The addition of 1 mM Mn²⁺, Na²⁺, Ba²⁺ and Ni ²⁺ enhanced the PfTI activity. The ICP-atomic emission spectrum showed the presence of Ca²⁺, Mg²⁺ and Zn²⁺ in the PfTI. Surfactants SDS and CTAB at a concentration of 1% reduced the PfTI activity whereas, the nonionic detergents Triton X and Tween 80 increased the activity. The inhibitory activity gradually decreased with increase in concentration of DMSO and H₂O₂. The activity was increased by dithiothreitol up to a concentration of 80 μM and inactivated at 140 μM. The activity of PMSF modified PfTI was drastically reduced to 0.234 U/mL at 4 mM concentration and similar results were obtained for modification of cysteine by N-Ethylmaleimide at slightly higher concentrations. The complex of trypsin and PfTI showed complete loss in fluorescence intensity at 343 nm compared with control. In vitro inhibition studies of PfTI with midgut proteases isolated from citrus pest P. demoleus with protease activity of 1.236 U was decreased to 0.613 U by 50 μL (0.1 mg/mL) of the inhibitor. Inhibitor was stable up to 0.04 M concentration of HCl.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2003.11a
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• pp.46-46
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• 2003

Hypocholesterolemic peptide isolated from glycimin (11S protein) hydrolyzate by trypsin was purified and identified as LPYP and IAVPGEVA. To investigate the effects of phyiscal properties of side chains of the hypocholesterolemic activity, some of mutant peptides were designed and synthesized chemically. The structure related structures of each peptide were simulated and constructed and their conformations were observed by using spectropolarimeter. The hypocholesterolemic activities were monitored by assaying the inhibition of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase) in vitro and by the determination of cholesterol content in mice serum. For LPYP derivatives, Hypocholesterolemic activity was lost when hydrophobic leucine residue at N-terminus was not so critical for maintaining hypocholesterolemic activity. For idealogical design of hypocholesterolemic peptides, the structure of HMG-CoA reductase are shown and inhibition mechanism of some peptides or inhibitors will be presented. For IAVPGEVA derivative inhibition of HMG-CoA reductase has been studied. For detail study of hypocholesterolemic activity, kinetic study of inhibition of peptides on HMG-CoA reductase and structural view of ligand binding should be investigated.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.436-441
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• 1994

To investigate the lowering effects of in vitro enzymatic hydrolysis by the treatment of chymotrypsin, trypsin, pancreatin, or protease from Aspergillus oryzae on the antigenicity of whey protein isolate (WPI) against rabbit anti ${\alpha}-LA$ antiserum, competitive inhibition ELISA (cELISA) and passive cutaneous anaphylaxis (PCA) test using guinea pig were performed. The results of cELISA showed that the monovalent antigenicity of the whey protein hydrolysates (WPH) to the antiserum was decreased to $10^{-2.5}-10^{-5.5}$ and less by the hydrolysis. The monovalent antigenicity of the WPH hydrolyzed by trypsin, or protease from Asp. nryzae was much lowered by the pretreatment of heat denaturation. The antigenicity of the WPH hydrolyzed by chymotrypsin, trypsin, or pancreatin was much lowered by the pretreatment of pepsin. Especially, the antigenicity of TDP (trypic hydrolysate with pretreatment of heat and pepsin) was found almost to be removed. However, there was not consistency between degree of hydrolysis(DH) and the monovalent antigenicity of the WPH. By the heterologous PCA it was found that all of the PGPH lost the polyvalent antigenicity regardless of the pretreatments although WPI and ${\alpha}-LA$ had the positive high antigenicity. The results suggested that the peptides derived from ${\alpha}-LA$ in WPH could bind specific antibodies but they could not induce allergy. Therefore, it was elucidated that the allergenicity of ${\alpha}-LA$ in whey protein could be destroyed easily by the enzymatic hydrolysis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.110-113
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• 2004

The Baenong-san has long been used for treatment of inflammatory in Korea. In this study, the anti-inflammatory effects of Baenong-san water extract (BWX) were investigated in proteinase-activated receptor-2 (PAR2)-mediated rat paw edema. Paw edema was induced by injection of trypsin or trans-cinnamoyl-LIGRLO-NH₂ (to-NH₂) into hindpaw of rats. BWX (10, 50, 100 and 200mg/kg) was orally administered 1 h before induction of inflammation. At doses of 50, 100 and 200 mg/kg, BWX showed significant inhibition of both change in paw volume and vascular permeability. BWX(100mg/kg) significantly also inhibited PAR2 agonist-induced myeloperoxidase (MPO) activity in paw tissue. This study demonstrated that BWX has an anti-inflammatory action for PAR2-mediated paw edema.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.366-371
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• 2003

Biological efficacy assays, including antimicrobial, tyrosinase inhibition and anticancer activities of Chlorella hydrolysate, were carried out. In tyrosinase inhibition assay of Chlorella hydrolysate, $IC_{50}$(inhibitory concentration) was measured as 12%. Chlorella hydrolysate showed high anti-lung cancer activity of 88.2% at a concentration of 0.15%.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.161-165
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• 2008

The trypsin inhibitor activities (TIA) of various potato cultivars were evaluated by measuring the inhibition of trypsin inhibitor activity using N-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. The TIA values of 5 potato cultivars (1.99 to 2.88 mg/g) were significantly different among cultivars (p<0.05). When the TIA values of commercially processed potatoes were determined, no TIA was detected. During cooking, the $IT_{50}$ (time required to reach 50% inhibition of TIA) values were decreased as heating temperature and time increased. The ITso of moist heating was estimated to be 0.34 min at $100^{\circ}C$, whereas for deep-fat frying the $IT_{50}$ was 0.13 min at $180^{\circ}C$ and 5.28 min for oven baking at $100^{\circ}C$. The $IT_{50}$ value of microwave cooking was 0.194 min at medium heat, and which was similar to that of pressure cooking at $120^{\circ}C$ (0.185 min). Moreover, there was a negative relationship between temperature (${\geq}80^{\circ}C$) and $IT_{50}$ values ($R^2=0.99$, p<0.01). The TIA of potato was completely inactivated by moist heating at $100^{\circ}C$ within 5 min, whereas the pressure cooking at $120^{\circ}C$ and deep-fat frying at $180^{\circ}C$ within 60 and 30 sec, respectively. Based on our results, deep-fat frying is the most effective cooking method to reduce TIA in potatoes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.783-788
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• 2010

The purpose of this study is to investigate the antioxidative activity and digestive enzyme inhibition of grape seed extract (GSE). The GSE was tested for its effect on various antioxidative potentials (scavenging activities of DPPH radical, superoxide anion radical and hydroxyl radical) and inhibitory effect of various digestive enzymes (trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\beta$-glucosidase and lipase). DPPH radical scavenging activity ($SC_{50}$, 50% scavenging concentration) of GSE was 4.76${\pm}$0.27 ppm while those of positive controls (EGCG and vitamin C) were 2.22${\pm}$0.12 ppm and 9.50${\pm}$0.72 ppm, respectively. $SC_{50}$ value of GSE against superoxide anion radical and hydroxyl radical were 3.82${\pm}$0.07 ppm and 803.23${\pm}$27.16 ppm, respectively. In addition, $IC_{50}$ values of GSE against trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\alpha$-glucosidase and lipase were 2.17${\pm}$0.59 ppm, 7.46${\pm}$1.25 ppm, 18.25${\pm}$3.54 ppm, 12.30${\pm}$1.12 ppm, and 653.23${\pm}$79.34 ppm, respectively. These results suggest that GSE may be useful for the prevention or treatment of obesity.

• Journal of Life Science
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• v.24 no.6
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• pp.633-641
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• 2014

This study investigated the antioxidant and antiobesity activity of extract powders from the following natural color resources: Polygonum indigo, Black locust, Cochineal, Catechu, Grape, Tesu flower, Henna, Chrysanthemum, Sandalwood Red, Himalayan Rhubarb, and Madder. Total phenol content was the highest in Catechu extract, at 348.25 mg/g. DPPH, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP) were also higher in Catechu extract. Bleaching inhibition activity in the ${\beta}$-carotene linoleic acid system was the highest in Black locust extract, as was ${\alpha}$-Glucosidase inhibition activity. ${\alpha}$-Amylase inhibition activity was the highest in Catechu extract. Trypsin inhibition activity of Black locust extract was greater than 60%, and ${\alpha}$- chymotrypsin inhibition activity of Catechu extract was greater than 40%. Lipase inhibition activity was the highest Black locust extract, at 52.73%. Viability of 3T3-L1 cells was not affected by treatment with extracts at concentrations of $1.25{\sim}25{\mu}g/ml$. Lipid accumulation in the 3T3-L1 cells was the lowest following treatment with Catechu extract, at 55.8%, and this extract also inhibited adipocyte differentiation. These results suggest that the Catechu and Black locust extracts have high antioxidant and antiobesity activities and can be useful ingredients in functional foods.

• BMB Reports
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• v.42 no.11
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• pp.713-718
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• 2009

Apoptotic DNA fragmentation, the hallmark of apoptosis, is mediated primarily by caspase-activated DFF40 (CAD) nuclease. DFF40 exists as a heterodimer with DFF45 (ICAD), which is a specific chaperone and inhibitor of DFF40 under normal conditions. To understand the mechanism through which the DFF40/DFF45 system is regulated, we analyzed the structural and biochemical properties of apoptotic DNA fragmentation mediated by DFF40/DFF45. Using limited proteolysis, we show that residues 1-281 of DFF45 form a rigid, crystallized domain, whereas the loop formed by residues 277-281 is accessible by trypsin. These results show that the C-terminal helix formed by residues 281-300 is dynamic and necessary for the chaperone activity of DFF45, but not for inhibition of DFF40.