• 한국해양바이오학회지
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• 제1권4호
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• pp.305-310
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• 2006

Wnt/${\beta}$-catenin 신호전달계의 비정상적인 활성화는 ${\beta}$-catenin response transcription (CRT)를 증가시킬 뿐 아니라 대장암의 발생과 밀접한 관련이 있다. 따라서 Wnt/${\beta}$-catenin 신호전달계는 대장암에 대한 항암제 개발 및 대장암 치료에 중요한 표적이 된다. 본 연구에서는 세포기반 초고속 스크리닝 기법을 사용하여 Wnt/${\beta}$-catenin 신호를 저해하는 참그물 바탕말 추출물을 발굴하였다. 참그물 바탕말 추출물은 세포내 ${\beta}$-catenin 단백질 수준에는 영향을 미치지 않았으며 ${\beta}$-catenin/TCF에 의해 조절되는 유전자 중의 하나인 cyclin D1의 발현을 저해하였다. 또한 참그물 바탕말 추출물은 다양한 대장암의 증식을 저해하였다. 본 연구의 결과들로부터 참그물 바탕말 추출물이 잠재적으로 대장암을 포함하는 새로운 암 예방 및 치료제로 사용될 수 있을 것이다.

• KSBB Journal
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• 제17권4호
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• pp.376-380
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• 2002

항암, 항콜레스테롤, 항산화 및 면역증강 효과와 피부재생 효과 등 여러 가지 생리활성이 밝혀지고 있는 $\beta$-1,3/1,6-글루칸은 크게 식물성 유래, 효모 및 곰팡이 유래, 버섯 유래의 것으로 등으로 분류할 수 있다. 풀루란을 생산하는 Aureobasidum pullulans ATCC 42023에 자외선을 조사하여 얻은 변이주인 Aureobasidum puiluian SM-2001 균주가 생산하여 체외로 분비하는 고분자 중합체를 핵자기 공명분석기로 분석한 결과, $\beta$-1,3- 및 $\beta$-1,6- 결합이 서로 혼재되어 있는 $\beta$-1,3/1,6-글루칸의 전형적인 구조임을 확인하였으며, 평균 분자량은 2.6$\times$$10^{5}$ 임을 확인하였다. 또한, $\beta$-1,3/1,6-글루칸의 생산에 최적인 탄소원이 설탕임을 확인하였으며, 0.5% (w/v)의 설탕을 탄소원으로 사용하였을 경우 약 50%의 변환율로 $\beta$-1,3/l,6-글루칸을 생산할 수 있었다. 이는 생물공학적인 방법으로 $\beta$-1,3/l,6-글루칸의 생산을 의미하며 저렴한 생산비로 대량 생산할 수 있는 방법의 개발을 의미한다한다

• The Korean Journal of Physiology and Pharmacology
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• 제7권6호
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• pp.349-355
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• 2003

We previously shown that LES contraction depends on $M_3$ receptors linked to PTX insensitive $G_q$ protein and activation of PLC. This results in production of $IP_3$, which mediates calcium release, and contraction through a CaM dependent pathway. In the esophagus ACh activates $M_2$ receptors linked to PTX sensitive $G_{i3}$ protein, resulting in activation of PLD, presumably, production of DAG. We investigated the role of PLC isozymes which can be activated by $G_q$ or $G{\beta}$ protein on ACh-induced contraction in LES and esophagus. Immunoblot analysis showed the presence of 3 types of PLC isozymes, $PLC-{\beta}1$, $PLC-{\beta}3$, and $PLC-{\gamma}1$, but not $PLC-{\beta}2$, $PLC-{\beta}4$, $PLC-{\gamma}2$, $PLC-{\delta}1$, and $PLC-{\delta}2$ from both LES and esophageal muscle. ACh produced contraction in a dose dependent manner in LES and esophageal muscle cells obtained by enzymatic digestion with collagenase. $PLC-{\beta}1$ or $PLC-{\beta}3$ antibody incubation reduced contraction in response to ACh in LES but not in esophageal permeabilized cells, but $PLC-{\gamma}1$ antibody incubation did not have an inhibitory effect. The inhibition by $PLC-{\beta}1$ or $PLC-{\beta}3$ antibody on Ach-induced contraction was antibody concentration dependent. The combination with $PLC-{\beta}_1$ and $PLC-{\beta}_3$ antibody completely abolished the contraction, suggesting that $PLC-{\beta}1$ and $PLC-{\beta}3$ have a synergism to inhibit the contraction in LES. $PLC-{\beta}1$, -${\beta}3$ or -${\gamma}1$ antibody did not reduce the contraction of LES cells in response to DAG ($10^{-6}$ M), suggesting that this isozyme of PLC may not activate PKC. When $G_{q/11}$ antibody was incubated, the inhibitory effect of the incubation of PLC ${\beta}3$, but not of PLC ${\beta}_1$ was additive (Fig. 6). In contrast, when $G_{\beta}$ antibody was incubated, the inhibitory effect of the incubation of PLC ${\beta}_1$, but not of PLC ${\beta}_3$ was additive. This data suggest that $G_{q/11}$/11 or $G{\beta}$ may activate cooperatively different PLC isozyme, $PLC{\beta}_1$ or $PLC{\beta}_3$ respectively.

• 한국축산식품학회지
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• 제22권4호
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• pp.343-347
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• 2002

TGF-$\beta$l은 여러 가지 생리활성 기능을 가지고 있기에 기능성식품 및 의약품 소재로 이용될 수 있다. 본 연구에서는 bovine colostrum milk로부터 TGF-$\beta$l을 분리 정제하기 위해 Cel-filtration chromatography, AF-heparin column chromatography 및 AF-heparin column rechromatography를 수행하여 TGF-$\beta$l을 정제하였다. 정제된 TGF-$\beta$1은 비환원조건하에서 전기영동을 수행하여 표준 TGF-$\beta$l과 같은 위치에 단일 band가 나타남으로 TGF-$\beta$l임을 확인하였다. 또한 환원 조건하에서 Western blot을 수행한 결과 TGF-$\beta$l 단일클론 항체와 결합하는 monomer 형태의 밴드를 확인하였다. 정제 TGF-$\beta$1의 회수율은 21%였다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.69-69
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• 2003

Although effect of TGF$\beta$$_1$ on preimplantation embryo development was reported at mice, little information relevant to this subject is known in bovine. The objectives of this study were to investigate TGF$\beta$$_1$, and TGF$\beta$$_1$ receptors type I and II expression, known as important factors in the embryo development, at unfertilized oocytes and fertilized embryos that will be used as basic data to be compared to NT embryos. We postulated that TGF$\beta$$_1$ may have a beneficial effect on the preimplantation embryo and show different expression patterns as embryo stages change. We have used immunocytochemistry to investigate the presence in unfertilized oocytes and preimplantation embryos of TGF$\beta$$_1$ and the essential components of the TGF$\beta$$_1$ signalling pathway, TGF$\beta$$_1$ receptors type I and II. We found that both receptors, as well as TGF$\beta$$_1$, were present in the unfertilized oocytes. This indicates that TGF$\beta$$_1$, is a maternally expressed protein. At the morulae and blastocyst stages the TGF$\beta$$_1$ receptor type II was not present, but the TGF$\beta$$_1$ receptor type I was present at both stages and we can confirm the TGF$\beta$$_1$ expression of high level at 8-cell stage. These findings support our hypothesis that the TGF$\beta$$_1$, and TGF$\beta$$_1$ receptors may interact with the oocyte and preimplantation embryo, and that TGF$\beta$$_1$ signalling may be important for the development of the oocyte and the preimplahtation embryo.

• Molecules and Cells
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• 제26권1호
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• pp.100-105
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• 2008

Glycogen synthase kinase $3{\beta}$ (GSK $3{\beta}$) is a serine/threonine kinase that phosphorylates substrates such as ${\beta}$-catenin and is involved in a variety of biological processes, including embryonic development, metabolism, tumorigenesis, and cell death. Here, we present evidence that human GSK $3{\beta}$ is associated with Fe65, which has the characteristics of an adaptor protein, possessing a WW domain, and two phosphotyrosine interaction domains, PID1 and PID2. The GSK $3{\beta}$ catalytic domain also contains a putative WW domain binding motif ($^{371}PPLA^{374}$), and we observed, using a pull down approach and co-immunoprecipitation, that it interacts physically with Fe65 via this motif. In addition, we detected co-localization of GSK $3{\beta}$ and Fe65 by confocal microscopy, and this co-localization was disrupted by mutation of the putative WW domain binding motif of GSK $3{\beta}$. Finally, in transient transfection assays interaction of GSK $3{\beta}$ (wt) with Fe65 induced substantial cell apoptosis, whereas interaction with the GSK $3{\beta}$ AALA mutant ($^{371}AALA^{374}$) did not, and we noted that phosphorylation of the Tyr 216 residue of the GSK $3{\beta}$ AALA mutant was significantly reduced compared to that of GSK $3{\beta}$ wild type. Thus, our observations indicate that GSK $3{\beta}$ binds to Fe65 through its $^{371}PPLA^{374}$ motif and that this interaction regulates apoptosis and phosphorylation of Tyr 216 of GSK $3{\beta}$.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.239-248
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• 2017

Desensitization and acute tolerance are terms used to describe the attenuation of receptor responsiveness by prolonged or intermittent exposure to an agonist. Unlike desensitization of G protein-coupled receptors (GPCRs), which is commonly explained by steric hindrance caused by the ${\beta}$-arrestins that are translocated to the activated receptors, molecular mechanisms involved in the acute tolerance of GPCRs remain unclear. Our studies with several GPCRs and related mutants showed that the acute tolerance of GPCRs could occur independently of agonist-induced ${\beta}$-arrestin translocation. A series of co-immunoprecipitation experiments revealed a correlation between receptor tolerance and interactions among receptors, ${\beta}$-arrestin2, and $G{\beta}{\gamma}$. $G{\beta}{\gamma}$ displayed a stable interaction with receptors and ${\beta}$-arrestin2 in cells expressing GPCRs that were prone to undergo tolerance compared to the GPCRs that were resistant to acute tolerance. Strengthening the interaction between $G{\beta}{\gamma}$ and ${\beta}$-arrestin rendered the GPCRs to acquire the tendency of acute tolerance. Overall, stable interaction between the receptor and $G{\beta}{\gamma}$ complex is required for the formation of a complex with ${\beta}$-arrestin, and determines the potential of a particular GPCR to undergo acute tolerance. Rather than turning off the signal, ${\beta}$-arrestins seem to contribute on continuous signaling when they are in the context of complex with receptor and $G{\beta}{\gamma}$.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.555-562
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• 2012

PCR was performed to analyze the ${\beta}$-lactamase genes carried by ampicillin-resistant Vibrio spp. strains isolated from marine environments in Korea between 2006 and 2009. All 36 strains tested showed negative results in PCR with the primers designed from the nucleotide sequences of various known ${\beta}$-lactamase genes. This prompted us to screen new ${\beta}$-lactamase genes. A novel ${\beta}$-lactamase gene was cloned from Vibrio alginolyticus KV3 isolated from the aquaculture water of Geoje Island of Korea. The determined nucleotide sequence (VAK-3 ${\beta}$-lactamase) revealed an open reading frame (ORF) of 852 bp, encoding a protein of 283 amino acids (aa), which displayed low homology to any other ${\beta}$-lactamase genes reported in public databases. The deduced 283 aa sequence of VAK-3, consisting of a 19 aa signal peptide and a 264 aa mature protein, contained highly conserved peptide segments specific to class A ${\beta}$-lactamases including the specific amino acid residues STFK (62-65), SDN (122-124), E (158), and RTG (226-228). Results from PCR performed with primers specific to the VAK-3 ${\beta}$-lactamase gene identified 3 of the 36 isolated strains as V. alginolyticus, Vibrio cholerae, and Photobacterium damselae subsp. damselae, indicating the utilization of various ${\beta}$-lactamase genes including unidentified ones in ampicillin-resistant Vibrio spp. strains from the marine environment. In a mating experiment, none of the isolates transfered the VAK-3 ${\beta}$-lactamase gene to the Escherichia coli recipient. This lack of mobility, and the presence of a chromosomal acyl-CoA flanking sequence upstream of the VAK-3 ${\beta}$-lactamase gene, led to the assumption that the location of this new ${\beta}$-lactamase gene was in the chromosome, rather than the mobile plasmid. Antibiotic susceptibility of VAK-3 ${\beta}$-lactamase was indicated by elevated levels of resistance to penicillins, but not to cephalosporins in the wild type and E. coli harboring recombinant plasmid pKV-3, compared with those of the host strain alone. Phylogenetic analysis showed that VAK-3 ${\beta}$-lactamase is a new and separate member of class A ${\beta}$-lactamases.

• 한국산학기술학회논문지
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• 제20권2호
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• pp.286-293
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• 2019

알츠하이머 질환은 대표적인 신경퇴행성 질환으로, 뇌 내에서 $A{\beta}$ 단백질 축적은 알츠하이머 질환의 원인으로 알려져 있다. 본 연구에서는 amyloid beta ($A{\beta}$)로 손상을 유도한 SH-SY5Y 신경세포에서 kaempferol, kaempferol-3-O-glucoside, quercetin, quercetin-3-${\beta}$-D-glucoside의 신경세포 보호 효과에 대해 검토하였다. SH-SY5Y 신경세포에 $A{\beta}_{25-35}$ ($25{\mu}M$)를 처리하였을 때, 처리하지 않은 normal군에 비해 세포생존율이 유의적으로 감소하였다. 반면, kaempferol, quercetin 및 그 배당체들을 각각 처리하였을 때 $A{\beta}_{25-35}$만을 처리한 control군에 비해 유의적으로 세포생존율의 증가를 나타내었다. 또한, apoptosis에 관여하는 cleaved caspase9, Bcl-2-associated X protein (Bax) 단백질 발현을 측정한 결과, normal군에 비해 control군에서 유의적으로 cleaved caspase9 및 Bax 단백질 발현의 증가를 나타내어 $A{\beta}$ 유도 신경세포 손상으로 인한 apoptosis가 유발됨을 확인 하였으며, kaempferol, quercetin 및 그 배당체들의 처리 시 apoptosis 관련 단백질 발현이 감소함으로써 신경세포 보호 효능이 나타냄을 확인하였다. 이러한 결과는 kaempferol, quercetin 및 그 배당체들이 apoptosis 조절을 통해 신경세포 보호 효과를 나타내며, 신경세포 손상으로 인한 알츠하이머 질환을 예방하는 유용한 소재로써 사용 가능성이 있음을 보여준다.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1505-1509
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• 2008

Comparative molecular simulations were performed to establish molecular interaction and inhibitory effect of flavonoid myricetin on formation of amyloid fibris. For computational comparison, the conformational stability of myricetin with amyloid $\beta$ -peptide (A$\beta$ ) and $\beta$ -amyloid fibrils (fA$\beta$) were traced with multiple molecular dynamics simulations (MD) using the CHARMM program from Monte Carlo docked structures. Simulations showed that the inhibition by myricetin involves binding of the flavonoid to fA$\beta$ rather than A$\beta$ . Even in MD simulations over 5 ns at 300 K, myricetin/fA$\beta$ complex remained stable in compact conformation for multiple trajectories. In contrast, myricetin/A$\beta$ complex mostly turned into the dissociated conformation during the MD simulations at 300 K. These multiple MD simulations provide a theoretical basis for the higher inhibitory effect of myricetin on fibrillogenesis of fA$\beta$ relative to A$\beta$ . Significant binding between myricetin and fA$\beta$ observed from the computational simulations clearly reflects the previous experimental results in which only fA$\beta$ had bound to the myricetin molecules.