• Fisheries and Aquatic Sciences
• /
• v.19 no.10
• /
• pp.42.1-42.10
• /
• 2016

The objectives of this study were to identify the histamine-forming bacteria and bacteriocin- producing lactic acid bacteria (LAB) isolated from Myeolchi-jeot according to sequence analysis of the 16S rRNA gene, to evaluate the inhibitory effects of the bacteriocin on the growth and histamine accumulation of histamine-forming bacteria, and to assess the physico-chemical properties of the bacteriocin. Based on 16S rRNA gene sequences, histamine-forming bacteria were identified as Bacillus licheniformis MCH01, Serratia marcescens MCH02, Staphylococcus xylosus MCH03, Aeromonas hydrophila MCH04, and Morganella morganii MCH05. The five LAB strains identified as Pediococcus acidilactici MCL11, Leuconostoc mesenteroides MCL12, Enterococcus faecium MCL13, Lactobacillus sakei MCL14, and Lactobacillus acidophilus MCL15 were found to produce an antibacterial compound with inhibitory activity against the tested histamine-producing bacteria. The inhibitory activity of these bacteriocins obtained from the five LAB remained stable after incubation at pH 4.0-8.0 and heating for 10 min at $80^{\circ}C$; however, the bacteriocin activity was destroyed after treatment with papain, pepsin, proteinase K, ${\alpha}$-chymotrypsin, or trypsin. Meanwhile, these bacteriocins produced by the tested LAB strains also exhibited histamine-degradation ability. Therefore, these antimicrobial substances may play a role in inhibiting histamine formation in the fermented fish products and preventing seafood-related food-borne disease caused by bacterially generated histamine.

• Food Science and Biotechnology
• /
• v.16 no.4
• /
• pp.572-575
• /
• 2007

The angiontensin converting enzyme (ACE) inhibitory peptides were separated from beef sarcoplasmic protein extract and their amino acid sequences were identified as GFHI, DFHINQ, FHG, and GLSDGEWQ. The 4 peptides were synthesized in a laboratory and the ACE inhibitory activities of pep tides was measured after 2 months of storage at $4^{\circ}C$ under different pH conditions (6.0, 6.5, 7.0, 7.5, and 8.0) and the exposure of different temperatures (70, 80, 90, and $100^{\circ}C$) for 20 min to evaluate industrial use. No significant difference was detected by pH and temperature abuse for 20 min during storage. When the synthetic peptides were digested by pepsin, trypsin, and chymotrypsin, the ACE inhibitory activity was not changed. These results indicated that the 4 synthetic peptides with ACE inhibitory activity were pH-stable, heat-stable, and resistant to proteinases in gastro-intestinal tracts. Therefore, those 4 peptides can be used as a source for functional food product with various applications.

• Fisheries and Aquatic Sciences
• /
• v.19 no.7
• /
• pp.29.1-29.6
• /
• 2016

In the present study, we investigated to the antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of the northern shrimp (Pandalus borealis) by-products (PBB) hydrolysates prepared by enzymatic hydrolysis. The antioxidant and ACE inhibitory activities of five enzymatic hydrolysates (alcalase, protamex, flavourzyme, papain, and trypsin) of PBB were evaluated by the 2, 2'-azino-bis [3-ethylbenzothiazoline-6-sulfonic acid] ($ABTS^+$) radical scavenging and superoxide dismutase (SOD)-like activities, reducing power and Li's method for ACE inhibitory activity. Of these PBB hydrolysates, the protamex hydrolysate exhibited the most potent ACE inhibitory activity with $IC_{50}$ value of $0.08{\pm}0.00mg/mL$. The PBB protamex hydrolysate was fractionated by two ultrafiltration membranes with 3 and 10 kDa (below 3 kDa, between 3 and 10 kDa, and above 10 kDa). These three fractions were evaluated for the total amino acids composition, antioxidant, and ACE inhibitory activities. Among these fractions, the < 3 kDa and 3-10 kDa fractions showed more potent $ABTS^+$ radical scavenging activity than that of > 10 kDa fraction, while the > 10 kDa fraction exhibited the significant reducing power than others. In addition, 3-10 kDa and > 10 kDa fractions showed the significant ACE inhibitory activity. These results suggested that the high molecular weight enzymatic hydrolysate derived from PBB could be used for control oxidative stress and prevent hypertension.

• Food Science of Animal Resources
• /
• v.37 no.1
• /
• pp.62-70
• /
• 2017

The aim of this study was identifying a suitable food grade enzymes to hydrolyze whey protein concentrates (WPCs), to give the highest bioactivity. WPCs from ultrafiltration retentate were adjusted to 35% protein (WPC-35) and hydrolyzed by enzymes, alcalase, ${\alpha}-chymotrypsin$, pepsin, protease M, protease S, and trypsin at different hydrolysis times (0, 0.5, 1, 2, 3, 4, and 5 h). These 36 types of hydrolysates were analyzed for their prominent peptides ${\beta}-lactoglobulin$ (${\beta}-Lg$) and ${\alpha}-lactalbumin$ (${\alpha}-La$), to identify the proteolytic activity of each enzyme. Protease S showed the highest proteolytic activity and angiotensin converting enzyme inhibitory activity of IC50, 0.099 mg/mL (91.55%) while trypsin showed the weakest effect. Antihypertensive and antioxidative peptides associated with ${\beta}-Lg$ hydrolysates were identified in WPC-35 hydrolysates (WPH-35) that hydrolyzed by the enzymes, trypsin and protease S. WPH-35 treated with protease S in 0.5 h, responded positively to usage as a bioactive component in different applications of pharmaceutical or related industries.

• Journal of the Korean Chemical Society
• /
• v.34 no.3
• /
• pp.288-296
• /
• 1990

Antielastic fragment in GBⅠ-Ⅱ differ on $P_1$ site with that of antitryptic fragment in LBI. To obtain further understanding of the role of amino acid residue near the reactive site, specificity of $P_1$ site and loop size, Tyr substituted cyclic nonapeptide and cyclic pentapeptide were synthesized and the inhibition constants for some proteinases were calculated by Dixon method. Cyclic nonapeptide showed no inhibition for chymotrypsin but appeared low inhibitory activity for trypsin and elastase and that of cyclic pentapeptide possessed inhibitory activity for chymotrypsin.

• BMB Reports
• /
• v.29 no.1
• /
• pp.58-62
• /
• 1996

The structural changes in the electron donor side of the PSII reaction center have been monitored since heat treatment ($45^{\circ}C$ for 5 min) of thylakoids is known to decrease the oxygen evolving activity. In heat-treated spinach chloroplast thylakoids, the inhibitory effect of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the electron transport activity of the PSII reaction center from diphenyl carbazide to dichlorophenolindophenol became reduced approximately 3.8 times and [$^{14}C$]-labeled DCMU binding on the D1 polypeptide decreased to 25~30% that of intact thylakoid membranes, implying that the conformational changes of the DCMU binding pocket, residing on the D1 polypeptide, occur by heat treatment. The accessibility of trypsin to the $NH_2$-terminus of the cytochrome b-559 ${\alpha}$-subunit, assayed with Western blot using an antibody generated against the synthetic peptide (Arg-68 to Arg-80) of the COOH-terminal domain, was also increased, indicating that heat-treatment caused changes in the structural environments near the stromal side of the cytochrome b-559 ${\alpha}$-subunit, allowing trypsin more easily to cleave the $NH_2$-terminal domain. Therefore, the structural changes in the electron donor side of the PSII reaction center complexes could be one of the reasons why the oxygen evolving activity of the heat-treated thylakoid membranes decreased.

• Fisheries and Aquatic Sciences
• /
• v.19 no.5
• /
• pp.25.1-25.8
• /
• 2016

The fractionation of serine protease inhibitor (SPI) from fish roe extracts was carried out using polyethylene glycol-4000 (PEG4000) precipitation. The protease inhibitory activity of extracts and PEG fractions from Alaska pollock (AP), bastard halibut (BH), skipjack tuna (ST), and yellowfin tuna (YT) roes were determined against target proteases. All of the roe extracts showed inhibitory activity toward bromelain (BR), chymotrypsin (CH), trypsin (TR), papain-EDTA (PED), and alcalase (AL) as target proteases. PEG fractions, which have positive inhibitory activity and high recovery (%), were the PEG1 fraction (0-5 %, w/v) against cysteine proteases (BR and PA) and the PEG4 fraction (20-40 %, w/v) against serine proteases (CH and TR). The strongest specific inhibitory activity toward CH and TR of PEG4 fractions was AP (9278 and 1170 U/mg) followed by ST (6687 and 2064 U/mg), YT (3951 and 1536 U/mg), and BH (538 and 98 U/mg). The inhibitory activity of serine protease in extracts and PEG fractions from fish roe was stronger than that of cysteine protease toward common casein substrate. Therefore, SPI is mainly distributed in fish roe and PEG fractionation effectively isolated the SPI from fish roes.

• YAKHAK HOEJI
• /
• v.47 no.5
• /
• pp.325-330
• /
• 2003

Solanum melongena L. (Solanaceae) has anti-oxidant, analgesic, and hypolipidemic effects. We previously showed that Solanum melongena (SM) aqueous extract inhibits mast cell-mediated allergic reactions. The activation of protease-activated receptor-2 (PAR-2) induces acute inflammation in rat hindpaw. In the present study, we investigated the effects of the SM aqueous extract on mouse paw edema induced by PAR2 agonists. Trypsin or trans-cinnamoyl-LIGRLO-NH$_2$ (tc-NH$_2$), PAR-2 agonists, was injected into the hind paw of mice to induce paw edema. SM aqueous extract (1, 5, 10, and 100 mg/kg) was orally administered 1 hr before induction of paw edema. SM aqueous extract (5, 10, and 100 mg/kg) significantly inhibited both paw edema and vascular permeability in the dose-dependent manner. Furthermore, SM aqueous extract (10 mg/kg) significantly inhibited PAR-2 agonist-induced myeloperoxidase (MPO) activity and tumor necrosis factor (TNF)-$\alpha$ expression in paw tissue compared to that of saline. These results suggest that SM aqueous extract may be useful for treatment of PAR-2-mediated inflammation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.7
• /
• pp.919-925
• /
• 2006

The study was carried out to prepare oyster hydrolysates by using Alcalase, Flavourzyme, Neutrase, Protamex, pepsin and trypsin, and to investigate its functional properties. The ACE inhibitory activity and antioxidant activity of enzymatic oyster hydrolysates did not increase with hydrolysis time. Among enzymatic oyster hydrolysates, oyster hydrolysates incubated with Protamex for 1 hr (OHP) showed the most excellent ACE inhibitory activity and antioxidant activity, and their $IC_{50}$ values were 1.16 mg/mL and 1.49 mg/mL, respectively. However, all enzymatic oyster hydrolysates were not detected in antimicrobial activity.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.25 no.4
• /
• pp.635-640
• /
• 2011

Betulae Cortex of Betula platyphylla Suk. var. japonica Hara (Betulaceae) has long been used for treatment of various inflammation, fever and cough in Eastern Asia. In order to investigate antibacterial activity of the Betulae Cortex against Streptococcus mutans or Porphyromonas gingivalis, MIC (minimal inhibitory concentration) and pH were checked, and for anti-inflammation activity, the experiments about trypsin-induced paw edema, vascular permeability and myeloperoxidase activity in rat's hind-paw tissue, were carried out with various extracts of Betulae Cortex (BCXs) respectively. The BCXs showed significant antibacterial activity, and at the dose of over 50 mg/kg, BCX showed significant inhibition on the paw edema, vascular permeability and myeloperoxidase activity. These results indicate that BCXs have antibacterial activity against oral cariogenic bacteria and anti-inflammatory effect.