• Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.174-178
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• 2011

This study aimed to determine the degree of hydrolysis and angiotensin-I-converting enzyme (ACE)-inhibitory activity of Giant Jellyfish Nemopilema nomurai (jellyfish) hydrolysates. The degree of hydrolysis using six proteolytic enzymes (Alcalase, Flavozyme, Neutrase, papain, Protamex, and trypsin) ranged from 13.1-36.8% and the inhibitory activities from 20.46-79.58%. Using papain hydrolysate, we newly isolated and characterized ACE-inhibitory peptides with a molecular weight of 3,000-5,000 Da that originated from jellyfish collagen. The purified peptide (FII-b) was predicted to be produced from an alpha-2 fragment of the type IV collagen of jellyfish. The N-terminal sequence of FII-b was Asp-Pro-Gly-Leu-Glu-Gly-Ala-His-Gly- and showed 87% identity to the collagen type IV alpha-2 fragment of Rattus norvegicus and a predicted protein from Nematostella vectensis, indicating that the ACE-inhibitory peptide originated from the collagen hydrolysate and had an $IC_{50}$ value of 3.8 ${\mu}g$/mL. The primary structure of the fragment is now being studied; this peptide represents an interesting new type of ACE inhibitor and will provide knowledge of the potential applications of jellyfish components as therapies for hypertension.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.558-565
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• 2016

The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.623-626
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• 1997

The purpose of this study was to investigate the properties of proteolytic enzymes extracted from mulberry (Morus alba L.). The protease activity of the enzymes from mulberry was 2,358 unit/g. The enzymes showed strong activities toward hemoglobin and collagen. The optimum temperature and pH of the enzymes were 50$^{\circ}C$ and 6.0, respectively. The enzymes were stable at the temperature range of 30$^{\circ}C$ to 60$^{\circ}C$ and the pH from 5.0 to 7.0 for 1 hr at 37$^{\circ}C$ of incubation and also retained whole activity after incubation for 1 hr at 60$^{\circ}C$.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.535-541
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• 2017

This study investigated the psychrotrophic bacteria isolated from chicken meat to characterize their microbial composition during refrigerated storage. The bacterial community was identified by the Illumina MiSeq method based on bacterial DNA extracted from spoiled chicken meat. Molecular identification of the isolated psychrotrophic bacteria was carried out using 16S rDNA sequencing and their putrefactive potential was investigated by the growth at low temperature as well as their proteolytic activities in chicken meat. From the Illumina sequencing, a total of 187,671 reads were obtained from 12 chicken samples. Regardless of the type of chicken meat (i.e., whole meat and chicken breast) and storage temperatures ($4^{\circ}C$ and $10^{\circ}C$), Pseudomonas weihenstephanensis and Pseudomonas congelans were the most prominent bacterial species. Serratia spp. and Acinetobacter spp. were prominent in chicken breast and whole chicken meat, respectively. The 118 isolated strains of psychrotrophic bacteria comprised Pseudomonas spp. (58.48%), Serratia spp. (10.17%), and Morganella spp. (6.78%). All isolates grew well at $10^{\circ}C$ and they induced different proteolytic activities depending on the species and strains. Parallel analysis of the next generation sequencing and culture dependent approach provides in-depth information on the biodiversity of the spoilage microbiota in chicken meat. Further study is needed to develop better preservation methods against these spoilage bacteria.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.239-244
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• 2001

We isolated a Myxobacteria strain from a soil sample obtained from Mt. Daedoon located in Choongnam, Korea. This strain, ARJ, secreted slime while swarmed on the surface of CT medium. It produced greenish yellow pigment in liquid or solid media, and the swarming edge showed green florescence under U. V. at 366 nm. It formed fruiting bodies when nutrient was exhausted, which is one of the most imkportant characteristics of Myxobacteria. The fruiting bodies did not have a stalk and consisted of naked myxospores when examined under the scanning electron microscope. These traits lead us to believe that this strain is very close to Myxococcus virescens. It showed antimicrobial activity, especially against Gram positive bacteria. Culture filtrate showed the activity but this was not due to protein. The culture filtrate also had proteolytic activity in which at least two enzymes are involved.

• Journal of fish pathology
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• v.21 no.3
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• pp.247-257
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• 2008

To understand the activity of non-specific defence factors in cultured Sebastes, the antibacterial effect of the serum, skin mucus and homogenate of various organs from cultured oblong rockfish (Sebastes oblongus) and rockfish(Sebastes schlegeli) against pathogenic bacteria, Aeromonas hydrophila, Edwardsiella tarda, Vibrio anguillarum, and Streptococcus sp. was compared with that of flounder(Paralichthys olivaceus) and seabass(Leteolabrax japonicus). And the activities of proteolytic enzyme, chitinolytic enzyme and haemolycin as non-specific defence factor were investigated on the oblong rockfish and rockfish. Samples from oblong rockfish showed the highest antibacterial activity by lysoplate assay on agar plate mixed with pathogens, followed in descending order by rockfish, seabass, and flounder. Turbidimetric assay was carried to evaluate the lysozyme activity of fish samples against lyophilized cells of Micrococcus lysodeiktikus. The serum, kidney, liver, stomach, intestine and eyeball of oblong rockfish and the mucus and gill of rockfish appeared to have the highest lysozyme activity among the fish strains investigated. All samples except skin mucus, liver, and eyeball of oblong rockfish and rockfish showed proteolytic enzyme activity. Chitinolytic enzyme activity was showed in random sampling and haemolytic activity was remarkable in oblong rockfish. Therefore, Sebastes strain was proved to have effective defense mechanisms based on the antibacterial activities, and lysozyme, proteolytic enzyme, chitinolytic enzyme, and haemolycin were considered to act as the non-specific defence factor of Sebastes.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.62-70
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• 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 Ginseng Research
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• v.13 no.1
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• pp.92-97
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• 1989

This study investigated the effects of high light intensity (100 KLw) and high temperature (45 ℃, dark) on enzyme (glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase, and proteinase) activities and characteristics of Panax ginseng C.A. Meyer leaves. Enzyme activity and protein content decreased rapidly under treatment with high light intensity In P ginseng the thermal stabilities of catalase and peroxidase were high (above 70%), and the coagulation rates of soluble proteins were low (below 17%). Therefore, the decrease in enzyme activity and protein content was not caused by increase in leaf temperature due to the high light intensity, but by increase in proteolytic activities. The photochemical formation rate of superoxide radical (O-2) was higher in the P ginseng leaf extracts than in Solanum nigmm, and was accelerated by addition of crude saponin to the buffer extracts.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.25-25
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• 2002

CodWX, encoded by the cod operon in Bacillus subtilis, is a member of the ATP-dependent protease complex family, and is homologous to the eukaryotic 26S proteasome. It consists of two multimeric complexes: two hexameric ATPase caps of CodX and a protease chamber consisting of CodW dodecamer. Prior structural studies have shown that the N-terminal threonine residue is solely functional as a proteolytic nucleophile in ATP-dependent proteases such as HslV and certain β-type subunits of 20S proteasome, which have a primary sequence similarity of -50% and -20% with CodW respectively. Here we present a 3.0 Å resolution crystal structure of CodW, which is the first N-terminal serine protease among the known proteolytic enzymes. In spite of the same fold and the conserved contacts between subunits with HslV in E. coli and H. influenza, this structure shows the five additional residues extending from conserved Thr1 among the other ATP-dependent pretense and extraordinary basic proteolytic chamber.

• 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.