• Title/Summary/Keyword: Receptor complex

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Glycogen synthase kinase 3β in Toll-like receptor signaling

  • Ko, Ryeojin;Lee, Soo Young
    • BMB Reports
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    • v.49 no.6
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    • pp.305-310
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    • 2016
  • Toll-like receptors (TLRs) play a critical role in the innate immune response against pathogens. Each TLR recognizes specific pathogen-associated molecular patterns, after which they activate the adaptor protein MyD88 or TRIF-assembled signaling complex to produce immune mediators, including inflammatory cytokines and type I IFNs. Although the activation of TLR is important for host defense, its uncontrolled activation can damage the host. During the past decade, numerous studies have demonstrated that GSK3β is a key regulator of inflammatory cytokine production in MyD88-mediated TLR signaling via TLR2 and TLR4. Recently, GSK3β has also been implicated in the TRIF-dependent signaling pathway via TLR3. In this review, we describe current advances on the regulatory role of GSK3β in immune responses associated with various TLRs. A better understanding of the role of GSK3β in TLR signaling might lead to more effective anti-inflammatory interventions.

High-Contrast Imaging of Biomolecular Interactions Using Liquid Crystals Supported on Roller Printed Protein Surfaces

  • Park, Min-Kyung;Jang, Chang-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3269-3273
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    • 2012
  • In this study, we report a new method for the high contrast imaging of biomolecular interactions at roller printed protein surfaces using thermotropic liquid crystals (LCs). Avidin was roller printed and covalently immobilized onto the obliquely deposited gold surface that was decorated with carboxylic acid-terminated self-assembled monolayers (SAMs). The optical response of LCs on the roller printed film of avidin contrasted sharply with that on the obliquely deposited gold surface. The binding of biotin-peroxidase to the roller printed avidin was then investigated on the obliquely deposited gold substrate. LCs exhibited a non-uniform and random orientation on the roller printed area decorated with the complex of avidin and biotin-peroxidase, while LCs displayed a uniform and planar orientation on the area without roller printed proteins. The orientational transition of LCs from uniform to non-uniform state was triggered by the erasion of nanometer-scale topographies on the roller printed surface after the binding of biotin-peroxidase to the surface-immobilized avidin. The specific binding events of protein-receptor interactions were also confirmed by atomic force microscopy and ellipsometry. These results demonstrate that the roller printing of proteins on obliquely deposited gold substrates could provide a high contrast signal for imaging biomolecular interactions using LC-based sensors.

Estrogen Regulate Neuroprotection and PDI Gene Expression in Ischemic Rat Brain

  • Yu, Seong-Jin;Kim, Do-Rim;Kim, Jee-Yun;Youm, Mi-Young;Lee, Chae-Kwan;Kang, Sung-Goo
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.69-69
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    • 2003
  • Neuroprotective strategies have been appeared to be effective in a variety of stroke models. One of the major focuses has been related to the activities of estrogen. $17\beta$-estradiol valerate(EV) has been reported to exert neuroprotective effects when administered before an ischemic insult. The purpose of this study was to determine whether EV can protect against brain injury via estrogen receptor. Chronic and acute pretreatment can reduce the ischemic damage of focal cerebral ischemia in OVX rat, indicating that EV may be a new therapeutic class of drugs to prevent neuronal damage associated with cerebral ischemia. RNAs were extracted from the hippocampus of ovariectomized female rat with or without EV. Differential gene expression profiles were revealed(Bone morphogenetic protein type 1A receptor, Protein disulphide isomerase, cytochrome bc-1 complex core P, thiol-specific antioxidant protein). RT-PCR and in situ hybridization were used to validate the relative expression pattern obtained by the cDNA array. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) through the Biohealth Products Research Center(BPRC), Inje University, Korea

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Essential role of tryptophan residues in toxicity of binary toxin from Bacillus sphaericus

  • Kunthic, Thittaya;Promdonkoy, Boonhiang;Srikhirin, Toemsak;Boonserm, Panadda
    • BMB Reports
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    • v.44 no.10
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    • pp.674-679
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    • 2011
  • Bacillus sphaericus produces mosquito-larvicidal binary toxin composed of BinA and BinB. While BinB is expected to bind to a specific receptor on the cell membrane, BinA interacts to BinB or BinB receptor complex and translocates into the cytosol to exert its activity via unknown mechanism. To investigate functional roles of aromatic cluster in BinA, amino acids at positions Y213, Y214, Y215, W222 and W226 were substituted by leucine. All mutant proteins were highly produced and their secondary structures were not affected by these substitutions. All mutants are able to insert into lipid monolayers as observed by Langmuir-Blodgett trough and could permeabilize the liposomes in a similar manner as the wild type. However, mosquito-larvicidal activity was abolished for W222L and W226L mutants suggesting that tryptophan residues at both positions play an important role in the toxicity of BinA, possibly involved in the cytopathological process after toxin entry into the cells.

Isolation of Grb2-Shc Domain Binding Inhibition Component from Agastache rugosa (배초향으로부터 Grb2-Shc domain 결합저해 물질의 분리)

  • Lee, Eun-Sook;Ahn, Byung-Tae;Lee, Sae-Bom;Kim, Hyae-Kyeong;Bok, Song-Hae;Jeong, Tae-Sook
    • Korean Journal of Pharmacognosy
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    • v.30 no.4
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    • pp.404-408
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    • 1999
  • SH2 domains and their associated catalytic or noncatalytic proteins constitute critical signal transduction targets for drug discovery. Grb2 associates with phosphotyrosine sites of the activated receptors or Shc via their SH2 domain to link receptor tyrosine kinases to ras signalling. Blocking of the Grb2-Shc complex may be to intervene the oncogenic signal transduction pathways and to develop a new antitumor drug. In the search for blockers of Grb2 SH2-Shc interaction, Lutein, a family of carotenoids, was isolated from the extract of the leaf of Agastache rugosa O. Kuntze as SH2 domain antagonists. The $IC_{50}$ of Lutein against Grb2-Shc binding was $6.8\;{\mu}M$.

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Direct radio-iodination of folic acid for targeting folate receptor-positive tumors

  • Huynh, Phuong Tu;Lee, Woonghee;Ha, Yeong Su;Yoo, Jeongsoo
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.4 no.1
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    • pp.3-10
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    • 2018
  • The folate receptor (FR) is a promising cell membrane-associated target for nuclear imaging of various cancers (via imaging $FR-{\alpha}$) and potentially also inflammatory diseases (via imaging $FR-{\beta}$), through the use of folic acid-based radioconjugates. However, there have been several drawbacks of previously reported radioconjugates, such as a short half-life of the radiolabel ($^{68}Ga\;t_{1/2}$ 68 min), a complex and time-consuming multistep radiosynthesis, and a high renal uptake of radiolabeled folate derivatives. The goal of this study was to develop an imaging probe by directly labeling folate with radioactive iodine without using an extra prosthetic group. The radiolabeling of folate was optimized using various labeling conditions and the labeled tracers were isolated by high-performance liquid chromatography. The in vitro stability of labeled folate was checked in phosphate-buffered saline and serum. The tumor-targeting efficacy of the probe was also evaluated by biodistribution studies using a murine 4T1 tumor model.

Use of Conformational Space Annealing in Molecular Docking

  • Lee, Kyoung-Rim;Czaplewski, Cezary;Kim, Seung-Yeon;Lee, Joo-Young
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2004.11a
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    • pp.221-233
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    • 2004
  • Molecular docking falls into the general category of global optimization problems since its main purpose is to find the most stable complex consisting of a receptor and its ligand. Conformational space annealing (CSA), a powerful global optimization method, is incorporated with the Tinker molecular modeling package to perform molecular docking simulations of six receptor-ligand complexes (3PTB, 1ULB, 2CPP, 1STP, 3CPA and 1PPH) from the Protein Data Bank. In parallel, Monte Carlo with minimization (MCM) method is also incorporated into the Tinker package for comparison. The energy function, consisting of electrostatic interactions, van der Waals interactions and torsional energy terms, is calculated using the AMBER94 all-atom empirical force field. Rigid docking simulations for all six complexes and flexible docking simulations for three complexes (1STP, 3CPA and 1PPH) are carried out using the CSA and the MCM methods. The simulation results show that the docking procedures using the CSA method generally find the most stable complexes as well as the native -like complexes more efficiently and accurately than those using the MCM, demonstrating that CSA is a promising search method for molecular docking problems.

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Estradiol Valerate Exerts Neuroprotective Effects in Ischemic Rat Brain when Administered after Middle Cerebral Artery Occlusion

  • Yoo, Seong-Jin;Yu, Jeong-Min;Youm, Mi-Young;Kim, Do-Rim;Kim, Jee-Yun;Kang, Sung-Goo
    • Proceedings of the Korean Society of Embryo Transfer Conference
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    • 2002.11a
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    • pp.111-111
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    • 2002
  • Stroke occurs when local thrombosis, embolic particle or the rupture of blood vessele interrupts the blood floe to the brain. $\beta$-estradiol 17-valerate has been reported to exert neuroprotective effects when administered before an ischemic insult. Recently, the pathophysiology of cerebral ischemia has been studied extensively in rat with various methods. In the present study, we investigates whether $\beta$-estrodiol 17-valerate can protect against brain injury. RNA sample were extracted from the hippocampus of female rat, reverse-transcription in the presence of [$\alpha$32p] dATP. Differential gene express-ion profiles were revealed (Bone morphogenetic protein type 1A receptor, Protein disulphide isomerase, Leukemia inhibitor factor receptor, cytochrome bc- 1 complex-x core P, thiol-specific antioxidant protein). RT-PCR was used to validate the relative expression pattern obtained by the cDNA array. The precise relationship between the early expression of recovery genes and stroke is a matter of luther investigation. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) through the Biohealth Products Research Center(BPRC), Inje University, Korea.

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[ $GABA_A$ ]-Benzodiazepine Receptor and Anxiety Disorder ($GABA_A$-Benzodiazepine 수용체 이상과 불안장애)

  • Lee Sang-Yeol;Park Min-Cheol;Kang He-Ja
    • Anxiety and mood
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    • v.1 no.1
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    • pp.25-30
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    • 2005
  • In the 40 years since the first benzodiazepine was brought into clinical use there has been a substantial growth in understanding the molecular basis of action of these drugs and the role of their receptors in anxiety disorders. Benzodiazepine receptors are present throughout the brain with the highest concentration in cortex, and it potentiate and prolong the synaptic action of the inhibitory neurotransmitter GABA. Central benzodiazepine receptors and $GABA_A$ receptors are part of the same macromolecular complex. Abnormalities of these $GABA_A$-benzodiazepine receptors as a result of drug challenge tests and neuroimaging studies may underlie some anxiety disorders. The role of $GABA_A$-benzodiazepine receptors in the action of benzodiazepine and as a factor in anxiety disorder, in both animal and humans including knock-out and knock in technique, may lead to new anxiolytics that have potentially significant therapeutic gains without unwanted side effects.

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Protonation and Energetical Investigations of Calix[4]-cyclen-benzo-crown-6 and Its Complexes with Zinc and Copper

  • Boonchoo, Thanaporn;Pulpoka, Buncha;Ruangpprnvisuti, Vithaya
    • Bulletin of the Korean Chemical Society
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    • v.25 no.6
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    • pp.819-822
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    • 2004
  • Protonation constants of calix[4]-cyclen-benzo-crown-6, L in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ determined by potentiometric titration are log $K_1$ = 10.91, log $K_2$ = 10.30, log $K_3$ = 6.24 and log $K_4$ = 2.55. Stability constants for the receptor L complexes with Cu(II) and Zn(II) in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ were determined by UV-VIS spectrometric titration. Stability constants of the CuL and ZnL complexes as log $\beta$ are 4.37 and 3.45, respectively. Stabilization energies for protonations of receptor L, derived from ab initio Hartree-Fock method with 6-31G basis set, are ${\Delta}E_1$ = -290.1, ${\Delta}E_2$ = -205.0, ${\Delta}E_3$ = -124.9 and ${\Delta}E_4$ = -26.9 kcal/mol and complexation energy of ZnL complex is -370.3 kcal/mol.