• 한국식품조리과학회지
• /
• 제20권6호
• /
• pp.658-666
• /
• 2004

In order to develop and commercialize high quality frozen soy yogurt, the effects of industrial proteases and commercial mixed cultures were examined on the functional properties and the sensory attributes of frozen soy yogurt. For quality improvement, soy protein isolates were primarily hydrolyzed by either Flavourzyme or Neurtrase, industrial Proteases, to reduce the beany flavor and increase the functional properties of the protein. The viable cell count of lactic acid bacteria was higher in the soy protein hydrolysates than whenuntreated. ABT-5 (L. acidophilus, Bifidobacterium lactis, and S. thermophilus) resulted in higher acid tolerance, bile acid tolerance and melt-down percent values than those with YC-X11 (Lactobacillus bulgaricus and Streptococci thermophilus). The overrun of frozen soy yogurt was improved by both Flavourzyme $(193.3\%)$ and Neurtrase $(156.7\%)$ treatments. With regard to thesensory characteristics, Flavourzyme improved the beany flavor, astringency taste, mouth feel and overall quality of frozen soy yogurts fermented with ABT-5. Further studies onproduct formulation will be needed to commercialize the frozen soy yogurt for the market.

• BMB Reports
• /
• 제41권2호
• /
• pp.102-107
• /
• 2008

Extracellular proteases play an important role in a wide range of host physiological events, such as food digestion, extracellular matrix degradation, coagulation and immunity. Among the large extracellular protease family, serine proteases that contain a "paper clip"-like domain and are therefore referred to as CLIP-domain serine protease (clip-SP), have been found to be involved in unique biological processes, such as immunity and development. Despite the increasing amount of biochemical information available regarding the structure and function of clip-SPs, their in vivo physiological significance is not well known due to a lack of genetic studies. Recently, Drosophila has been shown to be a powerful genetic model system for the dissection of biological functions of the clip-SPs at the organism level. Here, the current knowledge regarding Drosophila clip-SPs has been summarized and future research directions to evaluate the role that clip-SPs play in Drosophila immunity are discussed.

• Journal of Microbiology
• /
• 제34권2호
• /
• pp.198-205
• /
• 1996

Two proteases were partially characterized from culture filtrate of Mycobacterium, tuberculosis KIT110. Their molecular weights were approximately 200 and 180 kDa, respectively and they exhibited similar enzymatic characteristics. These enzymes were inhibited significantly by EDTA and to some extent by EGTA. Their activity was enhanced by $Ca^{2+}$ and $Mg^{2+}$ to some degree. However, $Cu^{2+}$ and $Ag^{2+}$ completely inhibited the enzyme activity at the concentration of 2.5 and 5 mM, respectively. The optimal pH was 7.0 and optimal temperature was around $40^{\circ}C$. These enzymes were rapidly inactivated at $80^{\circ}C$. Therefore, they were heat-labile, neutral metalloproteases. These enzymes exhibited antigenicity shown by their reacting with sera from the partients with pulmonary tuberculosis. These enzymes were able to degrade serum proteins including hemoglobin, bovine serum albumin, lysozyme and immunoglobulin G and structural matrix protein such as type I collagen. Therefore, these enzymes may be thought to contribute to tissue necrosis and pathogenesis during infection.

• Animal cells and systems
• /
• 제16권6호
• /
• pp.431-437
• /
• 2012

Calpains are a class of proteins that belong to the calcium-dependent, non-lysosomal cysteine proteases. There are three major types of calpains expressed in the skeletal muscle, namely, ${\mu}$-calpain, m-calpain, and calpain 3, which show proteolytic activities. Skeletal muscle fibers possess all three calpains, and they are $Ca^{2+}$-dependent proteases. The functional role of calpains was found to be associated with apoptosis and myogenesis. However, calpain 3 is likely to be involved in sarcomeric remodeling. A defect in the expression of calpain 3 leads to limb-girdle muscular dystrophy type 2A. Calpain 3 is found in skeletal muscle fibers at the N2A line of the large elastic protein, titin. A substantial proportion of calpain 3 is activated 24 h following a single bout of eccentric exercise. In vitro studies indicated that calpain 3 can be activated 2-4 fold higher than normal resting cytoplasmic [$Ca^{2+}$]. Characterization of the calpain system in the developing muscle is essential to explain which calpain isoforms are present and whether both ${\mu}$-calpain and m-calpain exist in differentiating myoblasts. Information from such studies is needed to clarify the role of the calpain system in skeletal muscle growth. It has been demonstrated that the activation of ubiquitous calpains and calpain 3 in skeletal muscle is very well regulated in the presence of huge and rapid changes in intracellular [$Ca^{2+}$].

• 한국동물학회지
• /
• 제33권1호
• /
• pp.119-125
• /
• 1990

Trypsin을 비롯한 여러 serine protease를 저해하는 단백질을 계골격근으로부터 여러 chromatography 방법을 이용하여 순수하게 분리하였다. 이 저해제의 분자량은 젤 여과법을 이용하여 측정한 결과 66,000 달톤이었으며 sodium dodecyl sulfate 존지하에서 전기영동하였을 때 66,000과 64,000 달톤의 두 단백질로서 나타났다. 이 중 64,000 달톤의 단백질은 순수분리과정 혹은 생체 내에서 일어난 부분 절제현상에 기인한 66,000 달톤 단백질의 부산물인 것으로 사료된다. 이 저해제는 약 7.4의 등전점을 가진 당 단백질임을 알 수 있었으며, 다량의 cysteine잔기를 포함하고 있다.

• Journal of Microbiology
• /
• 제37권1호
• /
• pp.14-20
• /
• 1999

Two extracellular proteases, EP I and EP II, from cells of Oligotropha carboxydovorans (formerly Pseudomonas carboxydovorans) DSM 1227 grown in nutrient broth were purified to greater than 95% homogeneity in five steps using azocasein as a substrate. The final specific activities of EPs I and II were 214.9 and 667.4 units per mg of protein. The molecular weights of native EPs I and II were determined to be 23,000. Sodium dodecyl sulfate-gel electrophoresis revealed the two enzymes to be monomers. The enzymes were found to be serine-type proteases. The activity of EP I was stimulated by Ca2+, Mg2+, and Ba2+, but that of EP II was not. The enzymes were completely inhibited by Fe2+, Hg2+, Co2+, Zn2+, and Cd2+. EDTA and EGTA exhibited a strong inhibitory effect on EP I. The optimal pH for the two enzymes was pH 9.0. The optimal temperatures for EP I and II were 60 and 50$^{\circ}C$, respectively. The enzymes were stable under alkaline conditions. The thermal stability of EP I was higher than that of EP II. Cell-free extracts did not inhibit the purified enzymes. The enzymes were active on casein, azocasein, azocoll, and carbon monoxide dehydrogenase, but weakly active with bovine serum albumin.

• 미생물학회지
• /
• 제33권2호
• /
• pp.136-141
• /
• 1997

한국의 전통 발효식품인 된장에서 단백질 분해효소를 분비하는 미생물의 존재를 규명하기 위해, skim milk 한천배지를 이용하여 투명환을 보이는 균주들을 얻었고, 각종 생리 및 생화학적 검사, VITEK system, MIDI system을 통해 이들 중, JH-1, SH-5, SH-7의 3 strain이 Bacillus cereus임을 동정하였다. JH-1과 SH-5 균주가 분비하는 단백질 분해효소는 pH 9와 40^{\circ}C.$에서 최적활성을 보였으며, SH-7 균주는 pH 8과 50^{\circ}C.$에서 최적활성을 보였다. 또한 이들 3균주는 blood agar plate에서 용혈능력을 보였다.

• 한국식품과학회지
• /
• 제43권6호
• /
• pp.729-734
• /
• 2011

쌀부산물인 탁주박을 상업적으로 사용되는 8가지 protease를 최적화된 조건에서 단일 혹은 혼합 처리하여 수용성 단백질을 분리하였다. 이렇게 분리된 단백질을 Lowry, Kjeldahl 그리고 건조 방법 등 총 3가지 방법으로 분석을 한 결과 Protamex, Alcalase, Protease N이 가장 높은 분해율을 나타냈으며 이것을 이용하여 3가지 protease를 혼합하여 처리하였을 때 단일처리와 큰 차이가 없는 것을 알 수 있었다. 효소처리를 하여 얻어진 단백질의 사이즈를 알아보기 위해 SDS PAGE를 한 결과 어떠한 밴드도 형성이 되지 않았고 이는 단백질이 마커의 최소사이즈 15 kDa보다 작은 것을 의미한다. 즉 일단 단백질보다 사이즈가 작은 polypeptide나 amino acid로써 분해된 것을 뜻하고 실제로 섭취하였을 때는 trypsin이나 chymotrypsin의 효소적인 분해 없이도 흡수할 수 있는 식품첨가물로써 활용도가 높은 단백질로 분해 되었음을 알 수 있었다. 또한 아미노산의 경우 lysine의 함량이 적기 때문에 단백질의 유래가 탁주박에 존재하는 효모가 아닌 쌀이라는 것을 알 수 있었으며 총 아미노산의 함량은 효소 3개를 모두 혼합하였을 때 가장 높은 것을 알 수 있었다. 전체적으로 필수아미노산 8가지 중 4가지의 함량이 일반 쌀보다 높은 것을 알 수 있었는데 이것은 각 효소마다 작용하는 기질이 정해져 있고 효소의 개수가 많을수록 아미노산의 생성확률이 높아져서 총 아미노산의 함량이 효소를 모두 혼합하였을 때 가장 높아진 것으로 생각된다. 상대적으로 효소를 두 개 혹은 세 개로 혼합하였을 때 생성된 총 단백질 함량은 비슷하였지만 총 아미노산의 함량은 적었기 때문에 두 개의 효소를 혼합한 샘플들은 효소에 의해 아미노산으로 분해되지 못한 polypeptide가 모든 효소를 혼합한 샘플에 비해 더 많이 존재 할 것으로 생각된다.

• 한국식품영양학회지
• /
• 제16권4호
• /
• pp.388-396
• /
• 2003

녹용각질을 protease와 염산으로 가용화시킬 수 있는 최적 조건을 조사하였다. 녹용을 5$0^{\circ}C$에서 물로 추출하고 난 각질에 세균 protease를 가하여 5$0^{\circ}C$에서 5시간 추출한 것은 32.8%(흡광도 3.61), 파파인 추출액은 23.8%(흡광도 0.94), 펜신 추출액은 31.2%(흡광도 2.96)가 녹았다. 녹용을 끓여서 추출하고 남은 각질에 세균 protease를 가하여 5$0^{\circ}C$에서 5시간 반응시킨 것은 45.0%(흡광도 3.61), 파파인 추출액은 30.4%(흡광도 0.33), 펜신 추출액은 51.2%(홉광도 2.77)가 녹았다. HPLC로 분석한 결과, 저온 물추출 각질과 열수 추출각질은 protease에 의하여 모두 분자량 1,000 이하의 펩티드로 작아졌다. 녹용 각질에 염산을 가하여 5$0^{\circ}C$에서 5시간 반응시킨 결과, 염산 0.1N농도에서 45%(흡광도 0.78), 0.2N에서 61%(흡광도 1.82), 0.4N에서는 81.0%(흡광도 2.29), 2.0N에서 82.0%(흡광도 3.28) 녹았다. HPLC로 분석한 결과, 0.8N 염산으로 추출한 것은 분자량 7만 정도의 피크가 58%였다. 녹용을 0.8N 염산으로 추출하여 동결 건조한 분말의 단백질 함량은 8.2%, 아미노산 함량은 81.6%, 회분 함량은 1.3%를 나타냈고, 무기물 함량은 Ca 0.1%, P 2.3%, Mg 0.8%, Na 3,4%, F 0,02%를 나타냈다. 녹용각질 가용화의 최적조건은 세균 pretense를 작용시켜서 5$0^{\circ}C$에서 5시간 반응시킨 다음, 0.8N 염산으로 5시간 추출하는 것이었다.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
• /
• pp.195-195
• /
• 2003