• Journal of Microbiology and Biotechnology
• /
• 제20권12호
• /
• pp.1711-1716
• /
• 2010

A gene encoding the ${\beta}$-xylosidase/${\alpha}$-arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium ${\beta}$-xylosidase/${\alpha}$-N-arabinosidase and Bacillus cellulosilyticus ${\alpha}$-arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a C-terminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on para-nitrophenyl-${\alpha}$-arabinofuranoside (pNPA) as well as para-nitrophenyl-${\beta}$-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

• 한국식품영양과학회지
• /
• 제33권6호
• /
• pp.1013-1016
• /
• 2004

토란으로부터 polyphenol oxidase를 추출하여 Maillard reation products(MRPs)가 토란 PPO에 미치는 영향을 조사하였다. 토란 PPO에 대한 MRPs의 저해 효과는 사용한 기질이 (+)-catechin, catechol인 경우에 높게 나타났다. 그리고 MRPs의 토란 PPO 저해 효과는 당의 종류를 달리하여 생성한 MRPs 중에서 fructose와 glucose로 제조한 MRPs의 첨가시 가장 높았으며, glycine과 glucose의 농도가 높아질수록 저해 효과가 증가하였다. 반응 시간에 따른 MRPs의 저해 효과를 조사한 결과, 반응 시간이 길어질수록 MRPs의 변색 정도가 높아졌으며, 이에 따라서 토란 PPO에 대한 저해 효과도 증가하였다.

• 한국식품영양과학회지
• /
• 제39권7호
• /
• pp.953-959
• /
• 2010

본 연구에서는 청각으로부터 생리활성물질을 추출하기 위해서 친환경적인 효소적 방법을 이용하여, 이들 효소 가수 분해물의 TPC, TFC, 항산화 활성, acetylcholinesterase(AChE) 저해 활성 및 항염증 활성을 측정하였다. 청각의 단백질 및 탄수화물 가수분해물의 TPC는 TFC보다 높은 함량을 나타내었으며, 단백질 가수분해물이 탄수화물 가수분해물보다 높은 TPC를 나타내었다. 청각 가수분해물의 항산화 활성은 DPPH radical 소거 활성으로 측정하였고, 단백질 가수분해물에서는 Flavourzyme 가수분해물이 활성이 높았고, 탄수화물 가수분해물에서는 Promozyme 가수분해물이 높은 DPPH radical 소거 활성을 나타내었다. 따라서 두가지 가수분해물을 이용하여 hydrogen peroxide 소거능, $Fe^{2+}$ 킬레이팅 및 reducing power를 측정한 결과 두 가수분해물 모두 우수한 항산화 활성을 나타냄을 알 수 있었다. 또한, hydroxyl radical로 유도된 DNA 손상을 효과적으로 억제하였다. AChE 저해 활성에서는 Flavourzyme 및 Dextrozyme 가수분해물이 각각 우수한 AChE 저해 활성을 나타내었다. 청각 가수분해물의 RAW264.7 세포주에 대한 세포독성을 검토한 결과 세포독성을 나타내지 않았으며, lipopolysaccharide(LPS)로 유도된 nitric oxide(NO) 생성 억제능에서는 모든 가수분해물이 유의적(p<0.05)으로 NO의 생성을 억제하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권11호
• /
• pp.1612-1619
• /
• 2017

Objective: The objective of this study was to optimize ultrasonic-assisted enzymatic hydrolysis conditions, including enzyme-to-substrate (E/S) ratio, pH, and temperature, for producing porcine liver hydrolysates (PLHs) with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity by using response surface methodology (RSM). Methods: The study used RSM to determine the combination of hydrolysis parameters that maximized the antioxidant activity of our PLHs. Temperature ($40^{\circ}C$, $54^{\circ}C$, and $68^{\circ}C$), pH (8.5, 9.5, and 10.5), and E/S ratio (0.1%, 2.1%, and 4.1%) were selected as the independent variables and analyzed according to the preliminary experiment results, whereas DPPH free radical scavenging activity was selected as the dependent variable. Results: Analysis of variance showed that E/S ratio, pH, and temperature significantly affected the hydrolysis process (p<0.01). The optimal conditions for producing PLHs with the highest scavenging activity were as follows: E/S ratio, 1.4% (v/w); temperature, $55.5^{\circ}C$; and initial pH, 10.15. Under these conditions, the degree of hydrolysis, DPPH free radical scavenging activity, ferrous ion chelating ability, and reducing power of PLHs were 24.12%, 79%, 98.18%, and 0.601 absorbance unit, respectively. The molecular weight of most PLHs produced under these optimal conditions was less than 5,400 Da and contained 45.7% hydrophobic amino acids. Conclusion: Ultrasonic-assisted enzymatic hydrolysis can be applied to obtain favorable antioxidant hydrolysates from porcine liver with potential applications in food products for preventing lipid oxidation.

• Natural Product Sciences
• /
• 제11권3호
• /
• pp.155-159
• /
• 2005

The aqueous extract of Coscinium fenestratum was studied for its antioxidant status in STZ-nicotinamide induced type 2 diabetic rats at two dose levels of 250 mg/kg and 500 mg/kg. At the end of the experimental period, diabetic rats treated with aqueous extract at both dose levels showed a significant increase in the levels of enzymatic antioxidants such as glutathione peroxidase, glutathione synthetase, peroxidase, superoxide dismutase and catalase as compared to the untreated control. Similarly, a significant increase was also observed in the levels of the non enzymatic antioxidants ceruloplasmin, ascorbic acid and tocopherol. The results suggest that the aqueous stem extract of C. fenestratum prevents type 2 diabetes mellitus induced oxidative stress.

• 한국식품영양과학회지
• /
• 제35권7호
• /
• pp.919-925
• /
• 2006

양식 굴을 효율적으로 이용할 목적으로 6가지의 상업적 효소(Alcalase, Flavourzyme, Neutrase, Protamex, pepsin, trypsin)를 이용하여 굴 효소 가수분해물을 제조하고, 그 특성에 대하여 살펴보았다. 상업적 효소 굴 가수분해물의 항산화능 및 ACE 저해능은 모두 Protamex로 1시간동안 가수분해시킨 것이 가장 우수하였고, 이 때 이들의 $IC_{50}$값은 각각 1.16 mg/mL 및 14 mg/mL이었다. 하지만 항균성은 모든 효소 가수분해물에서 인정되지 않았다. 또한, ACE 저해능 및 항산화능은 가수분해 시간에 따른 의존성이 인정되지 않았다. Protamex로 1시간동안 처리한 굴 가수분해물의 경우 가수분해 처리하지 않은 대조구에 비하여 $29{\sim}66\;kDa$ 획분과 6.5 kDa 부근의 획분이 모두 감소하여 저분자화 하는 경향을 나타내었다.

• Fisheries and Aquatic Sciences
• /
• 제5권4호
• /
• pp.263-270
• /
• 2002

The Pacific oysters, Crassostrea gigas, were stressed with different concentrations of benzo(a) pyrene and depurated to determine the hemocyte lysosomal membrane stability and hydrolytic enzymatic activity as a biomarker candidate to the chemical, using NRR (neutral red retention) and API ZYM System, respectively. The membrane damage measured as NRR decrease was significant with the increase of chemical concentration and exposure time (P<0.05), providing a possible tool for biomarker. Interestingly, the control showed intrinsic stress probably due to captive life in the laboratory, and a recovering trend was also found during the depuration. The benzo(a)pyrene-exposed oysters showed increased enzyme activities in alkaline phosphatase, esterase (C4), acid phosphatase, naphthol-AS-BI-phospho­hydrolase, $\beta$-galactosidase, $\beta$-glucuronidase, and N-acetyl- $\beta$-glucosaminidase. Of them, only two enzymes, acid phosphatase and alkaline phosphatase, showed some potential available for the generation of enzymatic biomarker in the oyster. The results are suggestive of the potential availability of the cellular and enzymatic properties as a biomarker. However, considering that a robust biomarker should be insensitive to natural stress coming from normal physiological variation, but sensitive to pollutants, a concept of intrinsic stress the animal possesses should be taken into consideration. This reflects the necessity of further research on the intrinsic stress affecting the cellular and enzymatic properties of the chemical­stressed oysters prior to using the data as a biomarker.

• Archives of Plastic Surgery
• /
• 제34권1호
• /
• pp.13-17
• /
• 2007

Purpose: To understand the pathogenesis of the disease that presents abnormally proliferated vascular endothelial cells, a model of DMH(1,2-dimethylhydrazine)-induced abnormal proliferation of HUVECs(Human Umbilical Vein Endothelial Cells) was made. We indirectly determined that Protein Kinase C(PKC) restricts the cellular proliferation and inhibits the manifestation of growth factor by using several inhibiting substances of the transmitter through our previous studies. Thereupon, we attempted to observe direct enzymatic activities of PKC and its correlation with the abnormal proliferation of vascular endothelial cells. Methods: $10^5$ HUVECs cells were applied to 6 individual well plates in three different groups; A control group cultured without treatment, a group concentrated with $0.75{\times}10^{-8}M$ DMH only, and a group treated with DMH & $5{\times}10^{-9}M$ Calphostin C, inhibitor of PKC. In analyzing the formation of intracellular PKC enzyme, protein separation was performed, and separated protein was quantitatively measured. PKC enzyme reaction was analyzed through Protein Kinase C Assay System (Promega, USA), and the results were analyzed according to Beer's law. Results: Enzymatic activity of PKC presented the highest in all reaction time of a group concentrated only with DMH, and the lowest in the control group. The group treated with DMH and the inhibitor revealed statistically lower enzymatic activity than group only with DMH in all reaction time, although higher than the control group. Conclusion: From the enzymatic aspect, most active and immediate reaction of the PKC was observed in the group concentrated with DMH only. The group treated with DMH & PKC inhibitor showed meaningful decrease. Accordingly, PKC holds a significant role in DMH-induced abnormal proliferation of vascular endothelial cells.

• Journal of Applied Biological Chemistry
• /
• 제64권1호
• /
• pp.97-102
• /
• 2021

본 연구에서는 들깨(Perilla frutescens)박으로부터 효소분해물을 제조하기 위한 효소를 선별하여 최적의 반응조건을 확립하였다. Alcalase와 Ceremix의 동시 처리가 들깨박의 단백질과 탄수화물의 가용화에 효과적이었으며, 효소 사용량은 들깨박 중량의 2% (w/w), pH는 7.0, 반응 시간은 2시간이 적당하였다. 최적의 반응조건에서 들깨박을 Alcalase와 Ceremix로 처리한 결과 환원당, 가용성 단백질 및 총 폴리페놀 함량이 크게 증가하였다. 유리 라디칼과 양이온 라디칼에 대한 소거활성으로 확인한 결과 들깨박 효소분해물의 항산화 활성은 대조군에 비해 우수하였다. 또한 젖산균인 Leuconostoc mesenteroides 310-12 균주를 들깨박 효소분해물에서 배양한 결과 대조군에 비해 생육과 산의 생성이 우수하였다. 결론적으로 들깨박 효소분해물은 항산화 생리활성 소재로서뿐만 아니라 유산균 배양 배지로서도 활용 가능성이 있음을 확인하였다.

• 대한수의학회지
• /
• 제43권1호
• /
• pp.139-144
• /
• 2003

A chitinase cDNA named CHT1 was cloned from the hard tick, Haemaphysalis longicornis, and the enzymatic properties of its recombinant proteins were characterized. The CHT1 cDNA encodes 930 amino-acid (aa) residues including a 22 aa putative signal peptide, with the calculated molecular mass of the putative mature protein 104 kDa. The E coli-expressed rCHT1 exhibited weak chitinolytic activity against $4MU-(GlcNAc)_3$. The rCHT1 protein with higher activity was obtained using recombinant Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which expresses rCHT1 under polyhedrin promoter. These findings suggest that the rCHT1 expressed in baculovirus-mediated Sf 9 cells has a high activity than E coli-expressed rCHT1.