• Title/Summary/Keyword: Ligand effect

Search Result 423, Processing Time 0.029 seconds

Condensation-Decondensation Structural Transition of DNA Induced by Reversible Ligand Binding : Effect of Urea on Anomalous Absorbance-Temperature Profile of Spermine-DNA Complex (可逆的 리간드 結合에 의하여 誘發되는 DNA의 응축-풀림 構造變移 : Spermine-DNA 複合體의 異例的 吸光度-溫度 樣相에 미치는 Urea의 影響)

  • Thong-Sung Ko;Chan Yong Lee
    • Journal of the Korean Chemical Society
    • /
    • v.29 no.5
    • /
    • pp.533-538
    • /
    • 1985
  • To investigate the importance of the hydrophobic interaction in the spermine-induced collapse of DNA to a compact structure, the effect of urea on the anomalous absorbance-temperature profile of calf thymus DNA has been investigated. With the increase of the urea concentration, the trough phase of the anomalous absorbance-temperature profile was eliminated eventually. The cooperativity, enthalpy, and the midpoint of the transition to the trough region are more sensitive to urea than those of the Tm-region transition. The present data of the adverse effect of urea, a hydrophobic environmental reagent, on the thermal stabilization of the condensed state of DNA, suggest that hydrophobic interaction may play an important role in the stabilization of the tertiary structure of the collapsed state of DNA.

  • PDF

Inhibitory Effects on Bone Resorption and osteoblast proliferation of Kyungok-go (경옥고와 경옥고가연자육의 조골세포 증식과 골흡수 억제효과)

  • Kim, Ju-Ho;Lee, Jung-Ho;Oh, Jae-Min;Kim, Yun-Kyung
    • Herbal Formula Science
    • /
    • v.19 no.2
    • /
    • pp.61-71
    • /
    • 2011
  • Objectives : Kyungok-go(KOG), the first herbal formulation of donguibogam, has been used for treating of many symptoms of yin deficiency. In this study, we examined the effect of KOG on bone resorption. Methods : We determined the effects of water extract of KOG in RANKL(Receptor Activator for Nuclear Factor ${\kappa}B$ Ligand)-induced osteoclast differentiation culture system and osteoblast proliferation. In addition, we determined the effects of water extract of ABR on LPS-induced bone-loss with mice. Results : Water extract of KOG showed proliferation effect on osteoblast without cytotoxicity and no effect on RANKL-treated osteoclast differentiation. KOG rescued bone erosion by LPS induction in vivo study. Conclusions : These results demonstrated that KOG can be a useful remedy for treating of bone-loss disease such as osteoporosis.

Effect of Sochungryong-tang Extract on Osteoclast Differentiation and Bone-pit Formation (소청룡탕이 파골세포 분화억제와 골흡수에 미치는 영향)

  • Ahn, Min-Youn;Lim, Hyung-Ho
    • The Journal of Korean Medicine
    • /
    • v.38 no.3
    • /
    • pp.59-72
    • /
    • 2017
  • Objectives: This study was performed to evaluate effects of Sochungryong-tang Extract(SRE) on osteoclast differentiation and bone resorptionin order to find out the possibility for clinical use in preventing and treating osteoporosis. Methods: To evaluate the effect of SRE on osteoclast differentiation, we induced RAW 264. 7 cells to be differentiated to osteoclasts by RANKL (receptor activator of nuclear $factor-{\kappa}B$ ligand). We measured effect on TRAP (Tartrate-resistant acid phosphatase), NFATc, cathepsin K, MMP-9, inflammation related factors, histogenesis factors and bone resorption. Results: SRE decreased osteoclast differentiation, and also decreased expression of bone resorbing factors such as MMP-9, cathepsin K, TRAP, NFATc1, MITF, c-Fos, osteoclast stimulatory transmembrane protein, calcitonin receptor in RANKL-induced osteoclast. SRE also decreased Cyclooxygenase-2, indusible nitric oxide synthase, $TNF-{\alpha}$, which are thought to be related with the inflammatory bone destruction. Conclusion: SRE inhibits osteoclast differentiation and bone resorption. The results indicate that the BHT extract can potentially be applied for preventing and treating osteoporosis.

Anti-osteoporotic Effects of Unripe Fructus of Rubus coreanus Miquel in Osteoblastic and Osteoclastic Cells

  • Kim, Hyo Jin;Sim, Dong-Soo;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
    • /
    • v.27 no.6
    • /
    • pp.593-600
    • /
    • 2014
  • Osteoporosis is a progressive bone disease characterized by low bone mass which is caused by disturbance in the balance between the activities of osteoblasts and osteoclasts. Postmenopausal osteoporosis is one of the most common disorders in women after menopause, which is linked to an estrogen deficiency and characterized by an excessive loss of trabecular bone. Rubus coreanus has been used for their various pharmacological properties in Asia as a traditional medicine. To investigate the effect of unripe fruits of R. coreanus 30% ethanol extract (RCE) on osteoblast-like cells (MG63) differentiation, we examined the effects of RCE on in vitro osteoblastic differentiation markers, alkaline phosphatase (ALP) activity and receptor activator of nuclear factor ${\kappa}$-B ligand (RANKL) and osteoprotegerin (OPG) expression. The high concentration (50 and $100{\mu}g/mL$) of RCE markedly increased ALP activity, whereas decreased the RANKL/OPG. We also investigated the effect of RCE on M-CSF plus RANKL-induced differentiation of pre-osteoclast cells (RAW 264.7). RCE treatment remarkably inhibited M-CSF/RANKL-induced formation of osteoclast-like multinuclear cells from RAW 264.7 cells. Moreover, the inhibitory effect of RCE was reduced by selective estrogen receptor-${\alpha}$ antagonist. Our research suggests that suggested that unripe fruits of R. coreanus may act beneficial effects on bone mass by regulating both osteoblast and osteoclast.

Inhibitory Effects of Wogonin Mixed with Hydrogel on Osteoclast Differentiation (우고닌-하이드로젤 지지체의 파골세포 분화 억제 효과)

  • Yang, Na-Rae;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.24 no.4
    • /
    • pp.1-9
    • /
    • 2011
  • Purpose: Wogonin is an active component isolated from scutellariae radix. This study was conducted to evaluate the inhibitory effect of wogonin mixed with hydrogel on osteoclast differentiation. Methods: It was performed to estimate cytotoxicity of Wogonin alginate hydrogel disk(WHD) in BMMs stimulated with RANKL, M-CSF. ROS synthesis and actin ring formation were analysed to observe the effect of WHD. Results: WHD has no cytotoxicity at the concentration of 0.1 ${\mu}g/ml$ or lower. 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the synthesis of ROS and 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the formation of actin ring. Conclusions: WHD has the inhibitory effect of osteoclast differentiation and bone resorption. Further studies are needed to treat osteoporosis by herbal medicine.

17O Solid-State NMR Study of the Effect of Organic Ligands on Atomic Structure of Amorphous Silica Gel: Implications for Surface Structure of Silica and Its Dehydration Processes in Earth's Crust (유기 리간드와 비정질 실리카겔의 상호 작용에 대한 17O 고상핵자기공명 분광분석 연구: 실리카 표면 구조 및 지각의 탈수반응에 대한 의의)

  • Kim, Hyun Na;Lee, Sung Keun
    • Journal of the Mineralogical Society of Korea
    • /
    • v.25 no.4
    • /
    • pp.271-282
    • /
    • 2012
  • We explore the effect of removal of organic ligand on the atomic configurations around oxygen in hydroxyl groups in amorphous silica gel (synthesized through hydrolysis of $SiCl_4$ in diethyl-ether) using high resolution $^{17}O$ solid state NMR spectroscopy. $^1H$ and $^{29}Si$ MAS NMR spectra for amorphous silica gel showed diverse hydrogen environments including water, hydroxyl groups (e.g., hydrogen bonded silanol, isolated silanol), and organic ligands (e.g., alkyl chain) that may interact with surface hydroxyls in the amorphous silica gel, for instance, forming silica-organic ligand complex (e.g., Si-$O{\cdots}R$). These physically and chemically adsorbed organic ligands were partly removed by ultrasonic cleaning under ethanol and distilled water for 1 hour. Whereas $^{17}O$ MAS NMR spectra with short pulse length ($0.175{\mu}s$) at 9.4 T and 14.1 T for as-synthesized amorphous silica gel showed the unresolved peak for Si-O-Si and Si-OH structures, the $^{17}O$ MAS NMR spectra with long pulse length ($2{\mu}s$) showed the additional peak at ~0 ppm. The peak at ~0 ppm may be due to Si-OH structure with very fast relaxation rate as coupled to liquid water molecules or organic ligands on the surface of amorphous silica gel. The observation of the peak at ~0 ppm in $^{17}O$ MAS NMR spectra for amorphous silica gel became more significant as the organic ligands were removed. These results indicate that the organic ligands on the surface of amorphous silica gel interact with oxygen atoms in Si-OH and provide the information about atomic structure of silanol and siloxane in amorphous silica gel. The current results could enhance the understanding of dehydration mechanism of diverse silicates, which is known as atomic scale origins of intermediate depth (approximately, 70~300 km) earthquakes in subduction zone.

Studies on the Effect of Picolines on the Stereochemistry of Lanthanide(III) Nitrate Coordination Compounds of 4[N-Furfural)amino]antipyrine Semicarbazone and Antibacterial Activities (4[N-Furfural)amino]antipyrine Semicarbazone의 질산 란탄(III) 배위화합물의 입체화학에 미치는 Picolines의 영향과 항박테리아 활성)

  • Agarwal, Ram K.;Agarwal, Himanshu;Prasad, Surendra;Kumar, Anil
    • Journal of the Korean Chemical Society
    • /
    • v.55 no.4
    • /
    • pp.594-602
    • /
    • 2011
  • The effect of ${\alpha}$-, ${\beta}$- and ${\gamma}$-picolines on the stereochemistry of the coordination compounds of lanthanide(III) nitrates derived from 4[N-(furfural)amino]antipyrine semicarbazone (FFAAPS) has been studied. The general composition of the present coordination compounds is [Ln(FFAAPS)$(NO_3)_3$Pic] (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy or Ho and Pic=${\alpha}$-, ${\beta}$- or ${\gamma}$-picolines). All these coordination compounds have been characterized by elemental analyses, molecular weight, molar conductance, magnetic susceptibility, infrared and electronic spectra. The infrared studies suggest that the FFAAPS behaves as a neutral tridentate ligand with N, N, O donor while ${\alpha}$-, ${\beta}$- or ${\gamma}$-picoline is coordinated to the lanthanide(III) ions via heterocyclic N-atom. Nitrates are bicovalently bonded in these compounds. From the electronic spectral data, nephelauxetic effect (${\beta}$), covalence factor ($b^{1/2}$), Sinha parameter (${\delta}%$) and the covalence angular overlap parameter (${\eta}$) have been calculated. Thermal stabilities of these complexes have been studied by thermogravimetric analysis. The coordination number of lanthanide(III) ions in the present compound is found to be ten. The antibacterial studies screening of the primary ligand FFAAPS and the complexes showed that the present complexes have moderate antibacterial activities.

Radiotherapy and immune checkpoint blockades: a snapshot in 2016

  • Koo, Taeryool;Kim, In Ah
    • Radiation Oncology Journal
    • /
    • v.34 no.4
    • /
    • pp.250-259
    • /
    • 2016
  • Immune checkpoint blockades including monoclonal antibodies (mAbs) of cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) have been emerged as a promising anticancer therapy. Several immune checkpoint blockades have been approved by US Food and Drug Administration (FDA), and have shown notable success in clinical trials for patients with advanced melanoma and non-small cell lung cancer. Radiotherapy is a promising combination partner of immune checkpoint blockades due to its potent pro-immune effect. This review will cover the current issue and the future perspectives for combined with radiotherapy and immune checkpoint blockades based upon the available preclinical and clinical data.

Rheumatoid Fibroblast-like Synoviocytes Downregulate Foxp3 Expression by Regulatory T Cells Via GITRL/GITR Interaction

  • Kim, Sung Hoon;Youn, Jeehee
    • IMMUNE NETWORK
    • /
    • v.12 no.5
    • /
    • pp.217-221
    • /
    • 2012
  • Fibroblast-like synoviocytes (FLS) colocalize with leukocyte infiltrates in rheumatoid synovia. Proinflammatory leukocytes are known to amplify inflammation by signaling to FLS, but crosstalk between FLS and regulatory T cells (Tregs) remains uncharacterized. To address this possibility, we cocultured FLS lines derived from arthritic mice with Tregs. FLS that expressed the ligand for glucocorticoid-induced TNF receptor family-related gene (GITR) decreased expression of Foxp3 and GITR in Tregs in a contact-dependent manner. This effect was abolished by blocking antibody to GITR. On the other hand, the Tregs caused the FLS to increase IL-6 production. These results demonstrate that inflamed FLS license Tregs to downregulate Foxp3 expression via the GITRL/GITR interaction while the Tregs induce the FLS to increase their production of IL-6. Our findings suggest that the interaction between FLS and Tregs dampens the anti-inflammatory activity of Tregs and amplifies the proinflammatory activity of FLS, thereby exacerbating inflammatory arthritis.

Adsorption Characteristic and Elution Behavior of Rare Earth Metals by Cryptand 22 Synthetic Resin (Cryptand 22 합성수지에 의한 희토류 금속들의 흡착특성과 용리행동)

  • 노기환;김준태
    • Journal of environmental and Sanitary engineering
    • /
    • v.11 no.1
    • /
    • pp.17-25
    • /
    • 1996
  • Resins with cryptand 22 macrocyclic ligand attached to chloromethylated styrene-1,4-divinylbenzene by substitution reaction were prepared and the effect of pH, metal concentration and cross-linkage of the matrix on the adsorption for $UO_2^{2+}$, $Cd^{2+}$ and $Sm^{3+}$ was investigated. The metal ion was not adsorbed on the resins pH range below 3 but above pH 4 fast adsorption behavior was showed. The resin selectivity determined in ethanol matrix was in increasing order $UO_2^{2+}{\;}>Cd^{2+}{\;}Sm^{3+}$. In addition, these metal ion could be separated on the column packed with 1% crosslinked resin by pH 2.5 $HNO_3$ as an eluent.

  • PDF