• 제목/요약/키워드: Binding Potential

검색결과 931건 처리시간 0.028초

In vitro에서 발암물질에 의한 발암진행에 미치는 천궁약침액의 영향 (Effect of Cnidium officinale Makino Aqua-acupuncture Solution on Carcinogen-induced Carcinogenesis in In vitro)

  • 한상훈;노동일;이기택;손윤희;백태선;남경수;임종국
    • Korean Journal of Acupuncture
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    • 제19권1호
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    • pp.7-13
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    • 2002
  • 1. 천궁약침액은 1${\times}$에서 15.1%의 cytochrome P4501A1 저해효과를 나타냈으며 그 억제효과는 약침액의 농도가 높을수록 증가하였다. 2 천궁약침액은 benzo[a]pyrene과 세포의 DNA 결합을 유의성있게 억제시켰다. 이상의 결과를 종합해 볼때 천궁약침액은 효과적으로 cytochrome P4501A1 효소를 저해했으며, 발암물질과 DNA의 결합을 억제시켜 외부 물질 또는 대사물에 의해 일어날 수 있는 돌연변이와 암 발생을 억제할 것으로 사료된다.

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난소절제 흰쥐에서 엉겅퀴 추출물의 골다공증 보호 효과 (Osteoprotective Effect of Extract from Cirsium japonicum var. ussuriense in Ovariectomized Rats)

  • 김영옥;김진성;이상원;조익현;나세원
    • 한국약용작물학회지
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    • 제23권1호
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    • pp.1-7
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    • 2015
  • This study was carried out to investigate the effects of the Cirsium japonicum var. ussuriense (C. japonicum) extract on serum level of hormones from induced osteoporosis by ovariectomized rats. Two month-old rats were ovariectomized (OVX), remained untreated for 8 weeks, and were subsequently administered C. japonicum (200 mg/kg) every day for 8 weeks. We examined the effects of treated C. japonicum on ovariectomy-related changes in Insulin-like Growth Factors (IGF), Insulin-like Growth Factor binding protein-3 (IGBF-3), Estrogen, Calcium, and Phosporus. After 8 weeks, the serum levels of IGF-I, -II, and IGFBP-3 were higher presented as compared to the other two groups (P < 0.05), in the C. japonicum extract treatment on OVX rats. There were differences between OVX and C. japonicum extract treated OVX rats in serum levels of $Ca^{2+}$, but $Ca^{2+}$ levels for the normal group was higher than for the other two groups. The C. japonicum extract increased both serum IGFs and IGFBP-3 levels on induced osteoporotic rat by ovariectomized. Thus, these results revealed that the C. japonicum extract is a possible role for improvement of osteoporosis induced-ovariectomized rats and has a great potential as an alternative tool for the treatment of osteoporosis.

Stabilization of Quinonoid Intermediate E-Q by Glu32 of D-Amino Acid Transaminase

  • Ro Hyeon-Su;Jeon Che-Ok;Kim Hak-Sung;Sung Moon-Hee
    • Journal of Microbiology and Biotechnology
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    • 제16권9호
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    • pp.1434-1440
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    • 2006
  • The stable anchorage of pyridoxal 5'-phosphate (PLP) in the active site of D-amino acid transaminase (D-AT) is crucial for the enzyme catalysis. The three-dimensional structure of D-AT revealed that Glu32 is one of the active site groups that may playa role in PLP binding. To prove the role of Glu32 in PLP stability, we firstly checked the rate of the potential rate-limiting step. The kinetic analysis showed that the rate of the ${\alpha}$-deprotonation step reduced to 26-folds in E32A mutant enzyme. Spectral analyses of the reaction of D-AT with D-serine revealed that the E32A mutant enzyme failed to stabilize the key enzyme-substrate intermediate, namely a quinonoid intermediate (E-Q). Finally, analysis of circular dichroism (CD) on the wild-type and E32A mutant enzymes showed that the optical activity of PLP in the enzyme active site was lost by the removal of the carboxylic group, proving that Glu32 is indeed involved in the cofactor anchorage. The results suggested that the electrostatic interaction network through the groups from PLP, Glu32, His47, and Arg50, which was observed from the three-dimensional structure of the enzyme, plays a crucial role in the stable anchorage of the cofactor to give necessary torsion to the plane of the cofactor-substrate complex.

Can denosumab be a substitute, competitor, or complement to bisphosphonates?

  • Kim, Su Young;Ok, Hwoe Gyeong;Birkenmaier, Christof;Kim, Kyung Hoon
    • The Korean Journal of Pain
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    • 제30권2호
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    • pp.86-92
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    • 2017
  • Osteoblasts, originating from mesenchymal cells, make the receptor activator of the nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in order to control differentiation of activated osteoclasts, originating from hematopoietic stem cells. When the RANKL binds to the RANK of the pre-osteoclasts or mature osteoclasts, bone resorption increases. On the contrary, when OPG binds to the RANK, bone resorption decreases. Denosumab (AMG 162), like OPG (a decoy receptor), binds to the RANKL, and reduces binding between the RANK and the RANKL resulting in inhibition of osteoclastogenesis and reduction of bone resorption. Bisphosphonates (BPs), which bind to the bone mineral and occupy the site of resorption performed by activated osteoclasts, are still the drugs of choice to prevent and treat osteoporosis. The merits of denosumab are reversibility targeting the RANKL, lack of adverse gastrointestinal events, improved adherence due to convenient biannual subcutaneous administration, and potential use with impaired renal function. The known adverse reactions are musculoskeletal pain, increased infections with adverse dermatologic reactions, osteonecrosis of the jaw, hypersensitivity reaction, and hypocalcemia. Treatment with 60 mg of denosumab reduces the bone resorption marker, serum type 1 C-telopeptide, by 3 days, with maximum reduction occurring by 1 month. The mean time to maximum denosumab concentration is 10 days with a mean half-life of 25.4 days. In conclusion, the convenient biannual subcutaneous administration of 60 mg of denosumab can be considered as a first-line treatment for osteoporosis in cases of low compliance with BPs due to gastrointestinal trouble and impaired renal function.

Preparation and Characterization of Self-assembled Glycol Chitosan Hydrogels Containing Palmityl-acylated Exendin-4 for Extended Hypoglycemic Action

  • Lee, Ju-Ho;Lee, Chang-Kyu;Bae, Sung-Ho;Yoon, Jeong-Hyun;Choi, Eun-Joo;Oh, Kyung-Taek;Lee, Eun-Seong;Lee, Kang-Choon;Youn, Yu-Seok
    • Journal of Pharmaceutical Investigation
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    • 제41권3호
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    • pp.173-178
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    • 2011
  • Injectable chitosan hydrogels have attracted great potential due to sustained-release property and safety. Here, palmityl-acylated glycol chitosan (Pal-GC) was used to generate physically cross-linked hydrogels by virtue of hydrophobic attraction of linear fatty carbons. Glycol chitosan was chemically modified with N-hydroxysuccinimide-activated palmitic acid in dimethylsulfoxide (DMSO) containing dimethylaminopyridine. Through a series of preparation steps of (i) dialysis with DMSO, (ii) addition of palmityl-acylated exendin-4 (Ex4-C16), and (iii) dialysis with water, Pal-GC was self-assembled to form physically cross-linked hydrogels entrapped with Ex4-C16. The Pal-GC derivative was analyzed by using 1H NMR, and the surface morphology of Pal-GC hydrogels formed was examined by scanning electron microscopy. Also, the hypoglycemic effect induced by Pal-GC hydrogels containing Ex4-C16 (250 nmol/kg) was evaluated in non-fasted type 2 diabetic db/db mice and compared with GC hydrogels containing native Ex4 at the same dose. Results showed that palmityl group was successfully conjugated with the amines of glycol chitosan, and that Pal-GC efficiently generated the hydrogels formation. Moreover, Pal-GC hydrogels containing Ex4-C16 was found to greatly prolong the hypoglycemia duration (~ 4 days). This was due to the dual-functions of the palmityl groups present in both GC and exendin-4 such as hydrophobic attraction and plasma albumin-binding. We consider this new type of self-assembled GC hydrogels loaded with Ex4-C16 would be a promising long-acting sustained-release system with anti-diabetic property.

The Anti-Adipogenic Activity of a New Cultivar, Pleurotus eryngii var. ferulae 'Beesan No. 2', through Down-Regulation of PPAR γ and C/EBP α in 3T3-L1 Cells

  • Kang, Min-Jae;Kim, Keun Ki;Son, Byoung Yil;Nam, Soo-Wan;Shin, Pyung-Gyun;Kim, Gun-Do
    • Journal of Microbiology and Biotechnology
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    • 제26권11호
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    • pp.1836-1844
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    • 2016
  • Adipogenesis is one of the cellular processes and a highly controlled program. Nowadays, inhibition of adipogenesis has received attention as an effective way to regulate obesity. In the current study, we investigated the inhibition effect of a chloroform extract of Pleurotus eryngii var. ferulae 'Beesan No. 2' (CEBT) on adipogenesis in 3T3-L1 murine preadipocytes. Pleurotus eryngii var. ferulae is one of many varieties of King oyster mushroom and has been reported to have various biological activities, including antitumor and anti-inflammation effects. Biological activities of 'Beesan No. 2', a new cultivar of Pleurotus eryngii var. ferulae, have not yet been reported. In this study, we found that CEBT suppressed adipogenesis in 3T3-L1 cells through inhibition of key adipogenic transcription factors, such as peroxisome proliferatoractivated receptor ${\gamma}$ and CCAAT/enhancer binding protein ${\alpha}$. Additionally, CEBT reduced the expression of the IRS/PI3K/Akt signaling pathway and its downstream factors, including mammalian target of rapamycin and p70S6 kinase, which stimulate adipogenesis. Furthermore, ${\beta}-catenin$, a suppressor of adipogenesis, was increased in CEBT-treated cells. These results indicate that Pleurotus eryngii var. ferulae 'Beesan No. 2' effectively inhibited adipogenesis, so this mushroom has potential as an anti-obesity food and drug.

Characterization of CYP125A13, the First Steroid C-27 Monooxygenase from Streptomyces peucetius ATCC27952

  • Rimal, Hemraj;Subedi, Pradeep;Kim, Ki -Hwa;Park, Hyun;Lee, Jun Hyuck;Oh, Tae-Jin
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1750-1759
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    • 2020
  • The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated KD value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min-1 nmol-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

Surface Topographical Cues for Regulating Differentiation of Human Neural Stem Cells

  • Yang, Kisuk;Lee, Jong Seung;Lee, Jaehong;Cheong, Eunji;Lee, Taeyoon;Im, Sung Gap;Cho, Seung-Woo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2016년도 추계학술대회 논문집
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    • pp.122.2-122.2
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    • 2016
  • Surface topographical cues has been highlighted to control the fate of neural stem cells (NSCs). Herein we developed a hierarchically patterned substrate (HPS) platform for regulating NSC differentiation. The HPS induced cytoskeleton alignment and highly activated focal adhesion in hNSCs as indicated by enhanced expression of focal adhesion proteins such as focal adhesion kinase (FAK) and vinculin. hNSCs cultured on HPS exhibited enhanced neuronal differentiation compared to flat group. We also developed a graphene oxide (GO)-based hierarchically patterned substrates (GPS) that promote focal adhesion formation and neuronal differentiation of hNSCs. Enhanced focal adhesion and differentiation of hNSCs on the HPS was reversed by blocking the ${\beta}1$ integrin binding and mechanotransduction-associated signals including Rho-associated protein kinase (ROCK) and extracellular-regulated kinase (ERK) pathway, which may suggest a potential mechanism of beneficial effects of HPS. In addition, hNSCs on the HPS differentiated into functional neurons exhibiting sodium currents and action potentials as confirmed by whole cell patch-clamping analysis. The hierarchical topography can direct differentiation of NSCs towards functional neurons, and therefore would be an important element for the design of functional biomaterials for neural tissue regeneration applications.

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Korean Red Ginseng attenuates ethanol-induced steatosis and oxidative stress via AMPK/Sirt1 activation

  • Han, Jae Yun;Lee, Sangkyu;Yang, Ji Hye;Kim, Sunju;Sim, Juhee;Kim, Mi Gwang;Jeong, Tae Cheon;Ku, Sae Kwang;Cho, Il Je;Ki, Sung Hwan
    • Journal of Ginseng Research
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    • 제39권2호
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    • pp.105-115
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    • 2015
  • Background: Alcoholic steatosis is the earliest and most common liver disease, and may precede the onset of more severe forms of liver injury. Methods: The effect of Korean Red Ginseng extract (RGE) was tested in two murine models of ethanol (EtOH)-feeding and EtOH-treated hepatocytes. Results: Blood biochemistry analysis demonstrated that RGE treatment improved liver function. Histopathology and measurement of hepatic triglyceride content verified the ability of RGE to inhibit fat accumulation. Consistent with this, RGE administration downregulated hepatic lipogenic gene induction and restored hepatic lipolytic gene repression by EtOH. The role of oxidative stress in the pathogenesis of alcoholic liver diseases is well established. Treatment with RGE attenuated EtOH-induced cytochrome P450 2E1, 4-hydroxynonenal, and nitrotyrosine levels. Alcohol consumption also decreased phosphorylation of adenosine monophosphate-activated protein kinase, which was restored by RGE. Moreover, RGE markedly inhibited fat accumulation in EtOH-treated hepatocytes, which correlated with a decrease in sterol regulatory element-binding protein-1 and a commensurate increase in sirtuin 1 and peroxisome proliferator-activated receptor-a expression. Interestingly, the ginsenosides Rb2 and Rd, but not Rb1, significantly inhibited fat accumulation in hepatocytes. Conclusion: These results demonstrate that RGE and its ginsenoside components inhibit alcoholic steatosis and liver injury by adenosine monophosphate-activated protein kinase/sirtuin 1 activation both in vivo and in vitro, suggesting that RGE may have a potential to treat alcoholic liver disease.

The Efficiency of Deer Antler Herbal Acupuncture on Modulation and Prevention of IL-1 Mediated Activation in Rat Chondrocytes at a Receptor Level

  • Kim, Woo-Young;Lee, Seung-Deok;Kim, Kyung-Ho;Baek, Seung-Tae;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • 제23권2호
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    • pp.113-123
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    • 2006
  • Objectives : Deer antler Herbal-Acupuncture (DHA) solution represents one of the most commonly used medicine to treat rheumatoid arthritis. But, mechanisms of its antiarthritic activities are still poorly understood. Identification of common DHA aqua-acupuncture capable of affording protection or modulating the onset and severity of arthritis may have important human health implications. Results : We determined if DHA could prevent the binding of $IL-1{\beta}$ to its cellular receptors. DHA addition to rat chondrocytes treated with $IL-1{\beta}$ or with reactive oxygen species(ROS) prevents the activation of proteoglycan synthesis. After treatment with $IL-1{\beta}$, DHA increased the expression of mRNA encoding the type II $IL-1{\beta}$ receptor. These results emphasize the potential role of two regulating proteins of the $IL-1{\beta}$ signaling pathway that could account for the beneficial effect of DHA in osteRArthritis. The present study also identifies a novel mechanism of DHA-mediated anti-inflammatory activity. Conclusion : It is shown that DHA inhibits both $IL-1{\beta}-$ and $TNF-{\alpha}-induced$ NO production in normal human articular chondrocytes. The observed suppression of IL-1-induced NO production is associated with inhibition of inducible NO synthase(iNOS) mRNA and protein expression. In addition, DHA also suppresses the production of IL-1-induced cyclooxygenase-2 and IL-6. The constitutively expressed cyclooxygenase-1, however, was not affected by the sugar. These results demonstrate that DHA expresses a unique range of activities and identifies a novel mechanism for the inhibition of inflammatory processes.

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