• Fisheries and Aquatic Sciences
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• 제14권3호
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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.

• 한국축산식품학회지
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• 제36권4호
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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.

• 한국식품조리과학회지
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• 제13권5호
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• pp.623-626
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• 1997

뽕나무는 옛날 가정에서 질긴 쇠고기를 조리할 때 사용하였다고 하였는데, 실제로 육류 조리에의 이용 가능성을 모색하기 위하여 우선 뽕나무 줄기의 속껍질에서 추출한 단백질 분해효소의 활성 및 특성을 알아 본 결과는 다음과 같다. 시료 2,800 g으로부터 조효소 분말 2.25 g을 회수하였는데, 회수율은 0.08% (wet basis)이었다. 뽕나무에서 추출한 단백질 분해효소 활성은 2,358 unit/g을 나타내었다. 효소의 특성 중 기질 특이성은 다른 단백질 기질에 대한 뽕나무에서 추출한 조효소의 효소활성을 조사해 본 결과 casein 100에 대하여 hemoglobin 44, collagen 34, egg white 20, gelatin 13의 비율로 가수분해하는 것으로 나타났다. 이 결과 뽕나무에서 추출한 조효소의 기질 특이성은 육류에 주로 함유된 단백질인 hemoglobin과 collagen을 비교적 잘 가수분해하는 것으로 나타났다. 뽕나무에서 추출한 조효소의 활성 온도는 30~6$0^{\circ}C$였고, 최적온도는 5$0^{\circ}C$로 나타났으며, 7$0^{\circ}C$ 이상의 온도에서는 그 활성이 급격히 감소하였다. 또한 pH를 달리한 역가 실험은 pH 5.0~7.0에서 안정하였고, 최적 pH는 6.0으로 관찰되어졌으며 8.0이상의 pH에서는 그 활성이 급격히 떨어졌다. 또한 뽕나무에서 추출한 조효소의 단백질 함량은 7.2%였고, specific activity는 32.75 unit/mg이었다.

• 한국축산식품학회지
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• 제37권4호
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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.

• 미생물학회지
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• 제37권4호
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• pp.239-244
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• 2001

충남 대둔산의 토양으로부터 분리한 점액세균을 ARJ라 명명하고 그 특성을 알아보았다. CT 배지에서 swarming을 하며 성장한 이 균주는 slime을 형성하였고, 액체 및 고체배지 상에서 황록색의 색소를 방출하였으며 swarming 부분을 파장이 366 nm인 자외선으로 조사하였을 때 초록색의 형광을 띄었다. 또한 이 균주는 영양분이 고갈되었을 때 fruiting body를 형성하는 것으로 보아 Myxobacteria라고 생각되었으며 주사전자 현미경 관찰 결과 이 균주가 형성한 fruiting body는 stalk이 없었고 naked myxospore를 가지고 있었다. Myxobacteria의 분류에 있어서 가장 중요한 이러한 형태학적 특성들로 볼때 이 균주는 Myxococcus virescens와 가장 유사한 것으로 밝혀졌다. 한편 이 균주는 특히 gram 양성 세균에 대해 antimicrobial activity가 있는 것으로 나타났는데, 여과한 배양 여액에서도 이렇ㄴ activity가 있었지만 비변성 polyacrylamide 전기영동을 하여 본 결과 이 물질이 단백질은 아닌 것으로 밝혀졌다. 또한 이 배양 여액은 상당한 proteolytic activity가 있었으며 최소한 2개의 proteolytic enzyme이 있는 것으로 비변성 polyacrylamide 전기영동을 통하여 밝혀졌다.

• 한국어병학회지
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• 제21권3호
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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.

• 한국축산식품학회지
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• 제37권1호
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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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• 제13권1호
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• pp.92-97
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• 1989

인삼엽을 강광(100 KLuw) 및 고온($45^{\circ}C$, 암상태)에 처리하여 효소(glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase)의 활성도를 조사한 결과 두 처리구에서 공히 감소하는 경향이었으나, 특기 강광에서 활성도가 현저히 감소하였다. 이와 같은 활성도 감소는 효소의 thermal stabilities나 coagulation 등과 같은 광에 의한 2차적인 엽온상승 효과에 따른 inactivation이 아니며, proteolytic activity 증가로 인한 효소단백질의 함량감소로 확인되었다. 인삼엽에서 proteolytic activity가 강광에 의해 급속히 증가하는 것으로 보아 정상엽(normal leaf)에 inactive 상태로 내재(compartmentation)되어 있는 proteinase가 타 식물에 비해 많은 것으로 사료된다. 또한 chlorphyll bleaching과 효소의 inactivation을 유발시킬 수 있는 superoxide radical(${O_2}^{-}$)의 광화학적 생성율이 비교식물(Solanum nigrum)보다 높게 나타나고 crude saponin이 superoxide의 생성율을 촉진하는 것으로 보아 superoxide에 의한 pigment system의 광산화율이 타 식물에 비해 높을 것으로 사료된다.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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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.

• 한국동물학회지
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• 제33권1호
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• pp.53-62
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• 1990

양서류의 여포난자를 생체외에서 배양하면서 호르몬을 처리하면 난자의 성숙(핵붕괴)을 일으킨다. 본 연구는 북방산개구리의 여포난자를 배양하면서 난자내 단백질 분해효소들의 활성변화를 유도하여 이것이 난자의 성숙에 어떠한 영향을 미치는가를 조사하였다. chymotrypsin의 저해제로 알려진 N$\alpha$ -tosyl-L-phenylalanine-chloromethyl-ketone(TPCK)을 배양액에 처리하면 비교적 낮은 농도(0.001-1 $\mu$M)에서는 호르몬의 도움없이도 난자의 성숙을 유도하나 높은 농도 (100 $\mu$M)에서는 호르몬에 의한 난자의 성숙까지도 억제하는 이중적인 효과를 나타내었다. Trypsin의 저해제인 N$\alpha$ -tosyl-L-phenylalanine-chloromethyl-ketone(TPCK)은 성숙유도능력이 없을 뿐 아니라 progesterone에 의한 난자의 성숙을 억제하였다. Trypsin을 직접 처리했을 때에는 농도에 의존하여(0.001-1$\mu$g/2ml) 호르몬의 도움없이도 난자의 성숙을 유도함을 발견하였다. TLCK나 TPCK의 억제효과는 성숙 초기에만 나타났다. 본 결과는 양서류 난자의 성숙조절 과정에 몇종의 단백질 분해효소들이 참여한다는 것을 시사해주고 있다.