• 한국축산식품학회지
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• 제34권6호
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• pp.769-776
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• 2014

The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than $70^{\circ}C$. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.

• 한국정보통신학회논문지
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• 제22권1호
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• pp.125-130
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• 2018

선형판별분석(LDA) 기법은 특징벡터의 차원을 줄이거나 클래스 식별에 이용되는 통계적 분석 방법이다. 그러나 선형 분리가 불가능한 데이터 집합의 경우에는 비선형 함수를 이용하여 특징벡터를 고차원의 공간으로 사상(mapping) 시켜줌으로써 선형 분리가 가능하도록 만들 수 있는데, 이러한 기법을 일반화된 판별분석(GDA) 또는 커널판별분석(KDA) 기법이라고 한다. 본 연구에서는 인터넷에 공개되어 있는 능동소나 표적신호에 LDA 및 GDA 기법을 이용하여 표적식별 실험을 수행하고, 그 결과를 비교/분석하였다. 실험 결과 104개의 테스트 데이터에 대해 LDA 기법으로는 73.08% 인식률을 얻었으나 GDA 기법으로는 95.19%로 기존의 MLP 또는 커널 기반 SVM에 비해 나은 성능을 보였다.

• 생명과학회지
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• 제9권3호
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• pp.253-261
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• 1999

Leptin gene, an obesity gene, has been known to involve in the regulation of food intake and body weight. It is also thought to be related to the glucose metabolism, insulin secretion and type II diabetes mellitus. Recently, the production of recombinant leptin protein has been attempted for the application in the treatment of obesity and the correction of hereditary obesity and type II diabetes. In the present study, leptin cDNA was cloned from mouse fat cells by RT-PCR and prokaryotic expression of leptin was attempted in order ot prepare a leptin-specific antigen. Immunization of a rabbit with the leptin-specific antigen into a rabbit resulted in the generation of leptin-specific antiserum that could be useful in the detection of leption expressed in various tissues. The sequence of leptin cDNA prepared in the present study wa identical to the previously reported one. Transformation of E. coli(DH5a) cells with the leptin cDNA-inserted translation vector, pGEX-4T-3-leptin followed by treatment with IPTG (0.1mM) resulted in the expression of a large amount of GST-leptin fusion protein with a molecular weight of 44 KDa as an inclusion body. Denaturation of the insoluble fusion protein by 8M urea, 6M guanidium-HCI or 0.1% 2-mercaptoethanol followed by a slow oxidation could not solubilize the inclusion body. The cell extract was subjected to SDS-PAGE and GST-leptin protein electroeluted from the gel was then injected into a rabbit subcutaneously for the immunization. Anti-GST-leptin rabbit antiserum which had a cross reactivity to the GST-leptin protein was generated. Leptin protein expressed in mouse brain and fat tissues was detected by Western blot immunodetection system using the antiserum generated in the present study.

• 생명과학회지
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• 제16권1호
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• pp.44-48
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• 2006

L-alanine의 산업적 생산을 위한 신규의 L-aspartate $\beta-carboxylase$ 유전자를 Enterococcus faecalis에서 검색하고 이를 대장균에 형질전환시켰다. E. faecalis 유래의 ADC유전자 는 1611 bp의 염기서열로 구성되어 있으며 형질전환된 대장균에서 59 KDa의 효소를 생산하며 L-aspartate $\beta-carboxylase$의 촉매활성을 나타내는 것을 확인하였다. 본 연구결과로 기능은 모르고 유전체 서열만 아는 균체에서 신규 효소를 개발하는 방법을 확립하였으며 저가의 aspartate를 이용한 고부가가치 L-alanine을 생산할 수 있는 신규효소를 개발할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제6권5호
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• pp.269-274
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• 2002

A large number of factors such as osteotropic hormones, cytokines, or growth factors are related to the bone remodeling which is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Recent investigations have indicated that cytokines such as $interleukin-1{\beta}\;(IL-1{\beta})$ and tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ play a potential role in the bone resorption associated with a variety of pathological conditions such as inflammatory osteolytic disease. Collagen is the most abundant protein of the extracellular matrix of bone, and the participation of collagenase in bone resorption has been widely investigated. In this study, effects of $IL-1{\beta}$ and $TNF-{\alpha}$ on the release of collagenase from osteoblastic cells were measured. The gelatinase activity was also measured by gel substrate analysis (zymography) after electrophoresis of conditioned media of osteoblastic cell culture. $IL-1{\beta}$ increased the collagenase activity in ROS17/2.8 and HOS cell culture. $TNF-{\alpha}$ also increased the collagenase activity of osteoblastic cells. When two kinds of cytokines were treated simultaneously in the culture of osteoblastic cells, synergistic increase of collagenase activity was seen in ROS17/2.8 cells. $IL-1{\beta}$ and $TNF-{\alpha}$ significantly increased the collagenase activity after 6 hour treatment in the osteoblastic cell culture, and there was no additional increase according to the culture period. Osteoblastic cells released the gelatinase and molecular weight of this enzyme was measured about 70 KDa as assessed by zymogram. $IL-1{\beta}$ and $TNF-{\alpha}$ showed increase of the gelatinase activity produced by ROS17/2.8 and HOS cells. Taken together, this study suggested that $IL-1{\beta}$ and $TNF-{\alpha}$ can modulate bone metabolism, at least in part, by increased release of collagenase and gelatinase from osteoblasts.

• 한국어병학회지
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• 제25권3호
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• pp.165-172
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• 2012

Vibrio alginolyticus (V. alginolyticus) 는 우리나라 전 연안에서 높은 빈도로 발견되며 인간 및 어패류에 감염을 유발시키는 박테리아의 일종이다. 본 연구는 서해안 양식장의 해수와 어패류에서 V. alginolyticus와 이에 대한 특이적인 용균성 파아지를 분리하였으며 분리된 파아지의 형태학적 특성을 전자현미경으로 확인 하였다. 또한 파아지의 핵산의 종류 및 구조 단백질의 특성 대한 연구가 수행되었다. 분리된 파아지는 형태학적으로 60 nm의 육각형 두부와 20 nm의 짧은 미부를 가진 podoviridae과로 분류되었다. 핵산을 분리한 결과 23 Kb 크기의 DNA로 판명 되었으며 구조 단백질은 37.8 kDa과 198 kDa 사이에 7종류의 단백질 분획이 존재함을 확인 하였다.

• 한국식품영양과학회지
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• 제26권4호
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• pp.669-674
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• 1997

면역활성, 항균성 등의 기능성을 보여 식품첨가물로 전량 수입에 의존하여 사용되는 human lactoferrin을 진핵세포에서의 생산을 시도하였다. 우선, 항균성을 보이는 lactoferrin에 대하여 생육저해가 없는 host cell에 lactoferrin 유전자를 발현시키고자 lactoferrin에 대한 항균력을 실험한 결과 Pichia pastoris는 생육저해를 일으키지 않아 이를 lactoferrin 생산균주로 선정하였다. Pichia를 숙주로 하는 pHIL-SI expression vector에 lactoferrin 유전자를 삽입 하였을 때 genomic DNA에 유전자가 integration 되었다. 즉, transformant JY-1, JY-2는 PCR(polymerase chain reaction)과 southern blotting에 의하여 2.4Kb의 크기의 HLF(human lactoferrin) 유전자가 삽입되었음을 확인하였다. 유전자 발현을 검토한 결과 transformant JY-1는 immunoblotting에 의하여 lactoferrin 단백질 생산을 확인하였다. 배양시간에 따른 HLF의 생산성을 알아본 결과 48시간 이후에 75KDa의 HLF단백질이 분비됨을 확인하였다

• 한국축산식품학회지
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• 제41권2호
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• pp.185-195
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• 2021

The objective of this study was to determine the effects of high pressure to investigate the technical functional properties of the protein solution extracted from an edible insect, Protaetia brevitarsis seulensis. High pressure processing was performed at 0 (control), 100, 200, 300, 400, and 500 MPa at 35℃. The essential amino acid index of the control was lower (p<0.05) than that of the P. brevitarsis seulensis extract treated with 100 MPa. The SDS-PAGE patterns tended to become faint at approximately 75 kDa and thicker at approximately 37 KDa after high pressure treatment. The protein solubility and pH of the protein tended to increase as the hydrostatic pressure levels increased. The instrument color values (redness and yellowness) of the P. brevitarsis seulensis protein treated with high pressure were lower (p<0.05) than those of the control. The forming capacity of the protein solution with P. brevitarsis seulensis treated with high pressure was higher (p<0.05) than that of the control. In conclusion, we confirmed that the technical functional properties of edible insect proteins extracted under high pressure of 200 MPa are improved. Our results indicate that high pressure can improve the technical functional properties of proteins from edible insects.

• 한국미생물·생명공학회지
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• 제51권3호
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• pp.257-267
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• 2023

The potential polyhydroxyalkanoates (PHA)-producing bacteria, Bacillus megaterium PP-10, was successfully isolated and studied its feasibility for utilization of pineapple peel waste (PPW) as a cheap carbon substrate. The PPW was pretreated with 1% (v/v) H₂SO₄ under steam sterilization and about 26.4 g/l of total reducing sugar (TRS) in pineapple peel hydrolysate (PPH) was generated and main fermentable sugars were glucose and fructose. A maximum cell growth and PHA concentration of 3.63 ± 0.07 g/l and 1.98 ± 0.09 g/l (about 54.58 ± 2.39%DCW) were received in only 12 h when grown in PPH. Interestingly, PHA productivity and biomass yield (Y_x/s) in PPH was about 4 times and 1.5 times higher than in glucose. To achieve the highest DCW and PHA production, the optimal culture conditions e.g. carbon to nitrogen ratios of 40 mole/mole, incubation temperature at 35℃ and shaking speed of 200 rpm were performed and a maximum DCW up to 4.24 ± 0.04 g/l and PHA concentration of 2.68 ± 0.02 g/l (61% DCW) were obtained. The produced PHA was further examined its monomer composition and found to contain only 3-hydroxybutyrate (3HB). This finding corresponded with the presence of class IV PHA synthase gene. Finally, certain thermal properties of the produced PHA i.e. the melting temperature (T_m) and the glass transition temperature (T_g) were about 176℃ and -4℃, respectively whereas the M_w was about 1.07 KDa ; therefore, the newly isolated B. megaterium PP-10 is a promising bacterial candidate for the efficient conversion of low-cost PPH to PHA.

• 한국수산과학회지
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• 제27권2호
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• pp.107-113
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• 1994

우리나라 남해연안 어패류에서 V. vulnificus, V. cholerae non O1 균을 분리하여 이들 균이 생산한 용혈독소의 활성을 검토하고 특히 치사율이 높은 패혈증 원인균인 V. vulnificus균이 생산한 균체외 단백독소인 hemolysin을 분리정제하고 얻어진 독소를 이용하여 항혈청을 만들었다. 1. V. vulnificus hemolysin(VVH)은 HI broth에서 $37^{\circ}C,\;15{\sim}24hr$ 진탕배양으로 잘 생산되었으며 V. cholerae non O1 균의 경우는 배양 15시간까지는 hemolysin 생산이 증가되었으나 15시간 경과 후에는 균종에 따라 증가되는 것도 있었고 경과 시간에 따라 오히려 감소하는 균주도 있었다. 2. V. vulnificus가 생산한 hemolysin은 면양적혈구에 대한 용혈활성이 강하고 토끼적혈구에 대하여는 약하였으나 V. cholerae non O1 균주는 토끼적혈구에 대한 용혈활성이 면양이나 말 적혈구에 대한 활성보다 2배정도 강하였다. 3. VVH는 hydrophobic Phenyl-Sepharose HP column을 이용하여 washing buffer와 elution buffer의 성분과 pH를 조정하면서 $1\%$ CHAPS를 이용하여 2차에 걸쳐 column chromatography한 결과 정제도와 수율이 매우 좋아졌다. 본 방법으로 다섯 차례에 걸쳐 정제한 결과 정제된 VVH의 specific activity는 $16900{\sim}52300$배로 평균 27,000배 이상 증가하였으며 수율도 $18.2{\sim}33.0\%$로 평균 $23.4\%$나 되었다. 실제로, V. vulnificus 배양액 2400ml로 부터 정제된 hemolysin을 $250{\mu}g$정도 만들 수 있어서 패혈증 비브리오균 연구에 크게 이바지 할수 있을 것으로 사료된다. 4. 정제된 VVH를 SDS-PAGE한 결과 분자량은 50KDa이었으며 토끼를 이용해서 만든 항혈청의 항체가는 $2000{\sim}8500$이었다.