• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.379-386
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• 2014

크로마틴은 DNA 구조를 다시 결정해주는 것과 같은 존재로 각종 신호에 폭넓게 반응한다. 크로마틴의 중요한 변화는 이러한 조절을 위한 히스톤의 변이이다. 이러한 변화들에 대한 지식이 점점 축적되고 있으며 이러한 반응의 복잡성이 점점 더 명확히 이해되고 있다. 히스톤의 변화가 대부분의 생명체의 반응에 있어서 DNA 의 발현 또는 억제를 통하여 중요한 역할을 한다는 사실이 명확해지고 있다. Nucleosome 의 표면은 각종 변화를 수용할 수 있다. 크로마틴 변화는 크로마틴 수축을 제거하거나 또는 비히스톤 단백질들을 불러 모으는 과정을 통하여 작용될 수 있다. 히스톤 변이를 매개로 하는 이러한 많은 조절들이 유전적으로 보존되어 전달되는 것으로 추측된다. 따라서 히스톤 변이는 동물, 식물 또는 미생물 세계의 기본적인 생물학적 반응과 상당히 밀접한 관계가 있다. 히스톤 변이가 제대로 이루어지지 않을 경우 크로모좀의 응축 또는 이완이 제대로 않되며 결국은 발생, 성숙, 생물체 방어 등 다방면에 대해 기능을 제대로 수행하지 못한다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2012년도 정기총회 및 춘계학술발표회
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• pp.8-8
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• 2012

Ginseng have been traditionally used for strengthening immunity, providing nutrition and recovering health from fatigue. Recently, pharmaceutical activities of ginseng roots have been proven by many researches, and ginseng has become a world-famous medicinal plant. Ginseng saponin, ginsenoside, is one of the most important secondary metabolite in ginseng which has various pharmacological activities. Many studies have aimed to convert major ginsenosides to the more active minor ginsenoside Rg3 for consumer demand ginseng product. Microbial strain GS514 strain was isolated from soil around ginseng roots for enzymatic preparation of ginsenoside Rg3, which strain shows strong ability of converting ginsenoside Rb1and Rd into Rg3 in the solution with NaCl. The gene encoding a ${\beta}$-glucosidase from this GS514 was cloned and expressed in the BL21 (DE3) strain of Escherichia coli. The recombinant enzyme was purified and characterized. The molecular mass of purified was 87.5 kDa, as determined by SDS-PAGE. The gene sequence revealed significant homology to the family 3 glycoside hydrolases. The purified single enzyme also catalyzed the conversion of ginsenoside Rb1 into Rg3. This target enzyme will be able to produce as much saponin for consumer demand ginseng product. Anti-apoptotic proteins bind with pro-apoptotic proteins to induce apoptosis mechanism. Over expression of these anti-apoptotic proteins lead to several cancers by preventing apoptosis. Docking simulations were performed for anti-apoptotic proteins with several ginsenosides from Panax ginseng. Our finding shows ginsenosides particularly Rg3, Rh2 and Rf have more binding affinity with apoptotic proteins. Further, these docking system of each ginsenosides can be extended to experimental screen system for further brief confirmations of several diseases.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 제2회 추계심포지움
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• pp.69-80
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• 1994

Although ureases play important roles in microbial nitrogen metabolism and in the pathogenesis of several human diseases, little is known of the mechanism of metallocenter biosynthesis in this Ni-Containing enzyme. Klebsiella aerogenes urease apo-protein was purified from cells grown in the absence of Ni. The purified apo-enzyme showed the same native molecular weight, charge, and subunit stoichiometry as the holo-enzyme. Chemical modification studies were consistent with histidinyl ligation of Ni. Apo-enzyme could not be activated by simple addition of Ni ions suggesting a requirement for a cellular factor. Deletion analysis showed that four accessory genes (ureD, ureE, ureF, and ureG) are necessary for the functional incorporation of the urease metallocenter. Whereas the $\Delta$ureD, $\Delta$ureF, and $\Delta$ureG mutants are inactive and their ureases lack Ni, the $\Delta$ureE mutants retain partial activity and their ureases possess corresponding lower levels of Ni. UreE and UreG peptides were identified by SDS-polyacrylamide gel comparisons of mutant and wild type cells and by N-terminal sequencing. UreD and UreF peptides, which are synthesized at ve교 low levels, were identified by using in vitro transcription/translation methods. Cotransformation of E. coli cells with the complementing plasmids confirmed that ureD and ureF gene products act in trans. UreE was purified and characterized. immunogold electron microscopic studies were used to localize UreE to the cytoplasm. Equilibrium dialysis studies of purified UreE with $^{63}$ NiC1$_2$ showed that it binds ～6 Ni in a specific manner with a $K_{d}$ of 9.6 $\pm$1.3 $\mu$M. Results from spectroscopic studies demonstrated that Ni ions are ligated by 5 histidinyl residues and a sixth N or O atom, consistent with participation of the polyhistidine tail at the carboxyl termini of the dimeric UreE in Ni binding. With these results and other known features of the urease-related gene products, a model for urease metallocenter biosynthesis is proposed in which UreE binds Ni and acts as a Ni donor to the urease apo-protein while UreG binds ATP and couples its Hydrolysis to the Ni incorporation process.ouples its Hydrolysis to the Ni incorporation process.s.

• Journal of Applied Biological Chemistry
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• 제64권4호
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• pp.375-382
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• 2021

조록나무는 제주도 및 일본 혼슈 이남, 중국 동남부, 타이완 등에 분포하는 조록나무과의 상록 교목으로, 항산화 및 tyrosinase, elastase의 억제에 효과적인 것으로 알려져 있지만 NO에 대한 억제 효능은 미미한 것으로 보고되었다. 이에 본 연구는 조록나무 잎 추출물(DL)에 biorenovation 생물 전환 기법을 적용하여 항 염증 활성을 증진 시키고자 수행되었다. 이들의 활성은 LPS로 자극된 RAW264.7 염증 모델에서 평가 되었으며 NO, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) 및 전 염증성 사이토카인에 대한 억제 실험이 수행되었다. 그 결과, biorenovation을 적용한 조록나무 잎 추출물(DLB)는 독성이 없는 농도에서 DL대비 향상된 NO와 prostaglandin E2 억제효능을 나타내었으며, 이들의 합성 효소인 iNOS 및 COX-2의 발현에도 유의한 억제 경향을 나타내었다. 또한 대표적인 전 염증성 사이토 카인인 tumor necrosis factor-α, Interleukin 6, Interleukin-1β 에서도 향상된 억제 효능을 확인 하였다. 이러한 결과를 근거로 우리는 biorenovation을 통해 DL의 항염증 효능이 개선될 수 있으며, DLB가 효과적인 천연 항염증 소재로 적용될 수 있음을 제시한다.

• 한국식품영양과학회지
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• 제34권9호
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• pp.1434-1442
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• 2005

수입산 밀가루(ASW+AH)와 쌀가루(오대)를 첨가한 혼합된에 transglutaminase를 첨가하여 반죽 물성 및 가공적 싶을 조사한 결과는 다음과 같다. Mixograph의 결과에서, 수입산 밀가루(ASW+AH)에 transglutaminase를 첨가한 mixograph 특성은 transglutaminase를 첨가할수록 각각 stability가 증가하다가 5,000 ppm 이상에서 감소하는 것으로 나타났다. 수입산 밀가루에 쌀가루(오대)를 첨가할수록 mixograph 패턴은 매우 불규칙하고 불안정한 패턴을 보여주고 있으며, stability, midline peak time, midline peak height, width at peak등의 파라메터 측정치와 특정한 관련성을 보이지 않았다. 그러나 수입산 밀가루(ASW+AH)와 쌀가루(오대)의 혼합분에 transglutaminase를 첨가함에 따라 이러한 불규칙성이 감소하였다. Farinograph의 결과에서, 수입산 밀가루(ASW+AH)에 첨가한 쌀가루(오대) 함량이 증가할수록 stability와 valormeter value는 급격히 감소하고 weakness는 크게 증가하여 매우 약하고 안정성이 낮은 반죽을 형성하였다. 그러나 transglutaminase를 첨가함에 따라 수입산 밀가루(ASW+AH)에 쌀가루(오대)를 첨가한 복합분의 stability와 valormeter value는 증가하였고, weakness는 감소하였다. 수분 흡수량은 대조군인 수입산 밀가루(ASW+AH)의 반죽에 비하여 쌀가루(오대) 혼합비율이 커질수록 증가하였으며, transglutaminase를 첨가함에 따라 수분 흡수량이 감소하는 경향을 가졌다. Peak time은 수입산 밀가루(ASW+AH)와 쌀가루(오대)를 첨가할수록 짧은 경 향을 나타내었으며, 두 반죽 모두 ttansglutaminase 를 첨가할수록 길어지는 경향을 나타내었다 조리면의 기계적 조직감을 Texture profile analysis(TPA)로 측정한 결과, 쌀가루(오대)를 첨가하여 제조한 혼합분(10, 30, $50\%$)에 transglutaminase(3000, 1000, 7000 ppm)를 첨가함에 따라 검성, 씹힘성, 견고성 등 TPA 파라메터 값이 증가하였고, 10,000 ppm 첨가시에는 비슷한 수치를 나타내거나 감소하였다. 관능평가 결과에서는 쌀가루를 $30\%$ 첨가한 혼합분으로 제조한 조리면의 조직감(씹힘성, 견고성)은 수입산 밀가루에 비해서 낮게 평가되었으나, transglutaminase를 7,000 ppm 첨가한 쌀 혼합분 조리면의 씹힘성이 향상되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• KSBB Journal
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• 제24권3호
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• pp.217-226
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• 2009

p53은 전사인자로서 세포의 사멸이나 세포주기 조절 등 다양한 세포 활성을 보이기 때문에 일반적인 환경에서는 매우 낮은 수준으로 단백질 양이 확인된다. p53의 단백질 양과 활성은 다양한 세포 내 신호에 의하여 이루어지는 후전사 변형을 통하여 조절 받는다. 이중 유비퀴틴화는 세포 내에서 p53 단백질의 발현 수준이 낮게 유지되는 것이 가능하게 하는 대표적인 기전이다. 이러한 기전을 일으키는 대표적인 p53의 E3 ligase로는 mdm2, Pirh2, COP1, ARF-BP1 등이 보고되어 있으며, 각각 negative feedback loop나 다른 기전을 통하여 p53 단백질의 분해를 유도하여 세포의 항상성을 조절한다. 이 밖에도 p53은 mdm2나 WWP1, UBC13, MSL2와 같은 E3 ligase로 인해서 모노 유비퀴틴화 되고, p53의 세포 내 위치가 조절되어 전사인자로서의 활성이 억제된다. p53의 세포 내 위치와는 관계없이 p53의 전사인자로써의 활성 또한 아세틸화와 유비퀴틴화의 경쟁적 반응으로 인해 조절 될 수 있다. E4F1에 의한 유비퀴틴화는 세포주기와 관련된 유전자의 발현을 증가시키되 세포사멸 관련 유전자의 발현은 감소시키는 것으로 보아 p53의 수많은 downstream gene의 발현 또한 유비퀴틴화를 통해 조절 될 수 있음이 제시되었다. 앞으로의 연구는 신규 E3 ligase에 의한 p53의 유비퀴틴화 기전 연구 뿐 아니라 이와 관련된 다른 변형과의 관계에 대한 연구 또한 매우 중요하게 부각되어 질 것으로 예상된다.

• 대한환경공학회지
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• 제28권7호
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• pp.752-756
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• 2006

최근 수계의 총질소(T-N) 규제가 강화되면서 기존 BAF 공정의 개선을 위해 독립적인 무산소조가 추가로 도입되었다. 본 연구에 사용된 공정은 유기물과 질산화 중심으로 개발 된 기술인 $Biobead^{(R)}$공법으로 상용화된 상향류의 BAF공정의 하나이다. 독립적인 무산소조의 도입의 타당성을 검토하기 위해 분자생물학적 방법의 하나인 PCR-DGGE기법이 수행되었다. 두 가지 type의 nitrite reductase genes를 통해 진행되었는데, nirS로 암호화된 cytocrome $cd_1$ nitrite reductase gene과 nirK로 암호화된 Cu를 함유한 nitrite reductase gene이다. 이러한 탈질 기능유전자를 이용하여 PCR-DGGE를 통해 탈질 목적으로 순화된 독립적인 무산소조의 탈질미생물의 군집을 해석하였다. PCR 증폭결과, 탈질을 수행하는 무산소조 내에서는 nirS와 nirK유전자 가운데 nirS유전자만 검출되었고, DGGE 분석결과, 최초 식종원으로 이용된 활성슬러지에서는 상대적으로 많은 band들이 검출되는 반면, 무산소조 내에서는 운전일수와 nitrate 부하량이 증가할수록 단일 band로 우점화 하는 경향을 나타내었다. DGGE band에 대한 염기서열 분석결과, 식종 슬러지의 경우 다양한 uncultured bacteria가 나타났으나, nitrate 제거율이 높은 안정화된 무산소조에서는 alcaligenes faecalis 등 특정 탈질미생물이 우점화 되는 것으로 확인되었다. 결론적으로 이러한 탈질미생물 군집특성을 가지는 무산소조의 도입은 96%이상의 안정적인 탈질을 가능하게 하였으며, BAF 공정 개선을 위한 독립적인 무산소조의 도입은 적절한 것으로 판단되었다.

• Journal of Periodontal and Implant Science
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• 제31권2호
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• pp.371-388
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• 2001

A novel glucanhydrolase(DXAMase) from a mutant of Lipomyces starkeyi(KSM 22) has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependentadherent microbial film and DXAMase has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi DXAMase are desirable for its application as a dental plaque control agent. This study was performed to determine the adjunctive oral hygiene benefits and safety of dextranase(Lipomyces starkeyi KSM 22 DXAMase)-containing mouthwash when used alongside normal tooth-brushing. This 6-month clinical trial was placebo-controlled double-blind design evaluating 1U/ml dextranase mouthwash and 0.12% chlorhexidine mouthwash. A total 39 systemically healthy subjects, who had moderate levels of plaque and gingivitis were included. At baseline, 1, 3 and 6 months, subjects were scored for plaque accumulation(Turesky modification of Quingley-Hein's plaque index), gingivitis status($L\ddot{o}e$ and Silness gingival index), and tooth stain(Area and severity index system by Lang et al). Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Two weeks after pre-experiment examinations and a professional prophylaxis, the subjects provided with allocated mousewash and instructed to use 20-ml volumes for 30s twice daily after toothbrushing. All the groups showed significant increase in plaque accumulation since 1 month of experiment. During 6 months' period, the Dextranase mouthwash group showed the least increase in plaque accumulation, compared to the Chlorhexidine mouthwash and placebo groups. As for gingival inflammation, all the groups showed significant increase during 6 months of experiment. The Experimental group(Dextranase mouthwash) also showed the least increase in gingival index score, compared to the Positive control(Chlorhexidine mouthwash)as well as the Negative control(placebo)groups. Whereas the tooth stain was increased significantly in the Positive control group, compared to the baseline score and the Negative controlgroup since 3 months of mouthrinsing. It was significantly increased after 6 months in the Experimental group, still less severe than the Positive control group. As for the oral side effect, the Experimental group showed less tongue accumulation, bad taste, compared to the Positive control group. From these results, mouthrinsing with Lipomyces starkeyi KSM 22 dextranase provided adjunctive benefits to toothbrushing, comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effects were if anything less frequent and less intense than chlorhexidine, with long-term use of the mouthwash. All data had provided positive evidence for Lipomyces starkeyi KSM 22 dextranase as an antiplaque agent and suggested that further development of dextranase formulations for plaque control are warranted.

• Animal Bioscience
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• 제35권2호
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• pp.184-195
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• 2022

Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle. Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0%, 0.05%, 0.075%, 0.1%, 0.125%, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9, and 12 h post-feeding on 30 d. Results: After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and Megasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion: The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be an important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.