• Journal of Pharmaceutical Investigation
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• v.26 no.3
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• pp.169-174
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• 1996

Inclusion complexes of diclofenac sodium with ${\beta}-cyclodextrin$ were prepared in aqueous solution, alkaline solution and solid phase. The interaction of diclofenac sodium with ${\beta}-cyclodextrin$ in pH 9.0 alkaline solution was evaluated by the solubility method and the instrumental analysis such as thermal analysis, infrared spectroscopy, X-ray diffractometry. The solubility of diclofenac sodium was increased linearly with the increase in the concentration of ${\beta}-cyclodextrin$up to 0.15 mol and showed that the aqueous solubility rate of diclofenac sodium was significantly increased by complex with ${\beta}-cyclodextrin$. The optimum composition of this complex was one molecule of ${\beta}-cyclodextrin$ included 1.59 molecular weight of diclofenac sodium as a guest molecule. The pharmacokinetic parameters of the diclofenac sodium and the complex with ${\beta}-cyclodextrin$ were studied in rats by oral route. $T_{max}$ between drug alone and inclusion complex showed significant difference to be 120 minute and 20 minute respectively. Both of $C_{max}$ and AUC of inclusion complex was about 40% higher than drug alone. It is estimated from the data in this study that complexation of diclofenac sodium with ${\beta}-cyclodextrin$ increased the absorption rate and improved the bioavalability of the diclofenac sodium by the formation of a water-soluble complexes.

• Elastomers and Composites
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• v.50 no.2
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• pp.110-118
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• 2015

In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethylaminoethyl methacrylate (DEAEMA) was introduced to the SBR molecule as a third monomer, was synthesized by cold emulsion polymerization. It is expected that amine group introduced to a rubber molecule would improve dispersion of silica by the formation of hydrogen bond (or ionic coupling) between the amine group and silanol groups of silica surface. The chemical structure of DEAEMA-SBR was analyzed using proton nuclear magnetic resonance spectroscopy (H-NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Then, various properties of DEAEMA-SBR/silica composite such as crosslink density, bound rubber content, abrasion resistance, and mechanical properties were evaluated. As a result, bound rubber content and crosslink density of DEAEMA-SBR/silica compound were higher than those of the SBR 1721 composite. Abrasion resistance and moduli at 300% elongation of the DEAEMA-SBR/silica composite were better than those of SBR 1721 composite due to the high bound rubber content and crosslink density. These results are attributed to high affinity between DEAEMA-SBR and silica. The proposed study suggests that DEAEMA-SBR can help to improve mechanical properties and abrasion resistance of the tire tread part.

• Journal of the Korean Chemical Society
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• v.50 no.4
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• pp.291-297
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• 2006

The equilibrium structures, relative energies and NBO analyses for the possible conformations and transition states which can exist on the internal rotation of CPDFB and CPCFB molecules have been investigated using DFT and ab initio methods with various basis sets. The interaction between bonding orbital ((C1-C3, C2-C3)) and antibonding orbital (n*(B9) and *(B9-Cl11)) was the main characteristic hyperconjugation in both molecules. In addition, the stabilization energy of CPDFB was 6.63kcal/mol and that of CPCFB was 6.97(E-form)/6.79(Z-form) kcal/mol for each conformation. The rotational barriers by internal rotation of BF2- and BFCl- functional groups were evaluated to be 5.3~6.7kcal/mol and 5.7~6.5kcal/mol respectively, which showed good agreement with the experimental values reported by previous dynamic NMR study. Finally, Z-form was more stable than E-form by 0.2 kcal/mol in CPCFB molecule and therefore Z-form was confirmed as global minimum.

• Journal of Nutrition and Health
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• v.30 no.6
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• pp.658-668
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• 1997

Path of a small hydrophobic molecule through the aqueous cytoplasma is not linear. Partition may favor membrane binding by several orders of magnitude : thus significant membrane association will markedly decrease the cytosolic transport rate. The presence of high concentration of soluble binding proteins for these hydrophobic molecules would compete with membrane association and thereby increase transport rate. For long chain fatty acid molecules, a family of cytosolic binding proteins collectively known as the fatty acid binding proteins(FABP), are thought to act as intracellular transport proteins. This paper examines the mechanism of transfer of fluorescent antyroyloxy-labeled fatty acids(AOFA) from purified FABPs to phosholipid membranes. With the exception of the liver FABP, AOFA is transferred from FABP by collisional interaction of the protein with a acceptor membrane. The rate of transfer increased markedly when membranes contain anionic phospholipids. This suggests that positively charged residues on the surface of the FABP may interact with the membranes. Neutralization of the surface lysine residues of adipocyte FABP decreased fatty acid transfer rate, and transfer was found to proceed via aqueous diffusion rather than collisional interaction. Site specific mutagenesis has further shown that the helix-turn-helix domain of the FABP is critical for interaction with anionic acceptor membranes. Thus cytosolic FABP may function in intracellular transport of fatty acid to decrease their membranes association as well as to target fatty acid to specific subcellular sites of utilization.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1752-1756
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• 2006

This study explores and interprets in a new way the complex solvent and the temperature dependence of the NMR shifts for the N-$CH_2$ protons in tris(N,N-diethyldithiocarbamato) iron(III) in acetone, benzene, carbon disulfide, chloroform, dimethylformamide and pyridine. The NMR shifts are interpreted in terms of the Fermi contact interaction and the dipolar term from the multipole expansion of the interaction of the electron orbital angular momentum and the electron spin dipolar-nuclear spin angular momentum. This analysis yields a direct measure of the effect of the solvent system on the environment of the transition metal ion. The results are analysed in terms of the crystal field environment of the transition metal ion with contributions from (a) the dithiocarbamate ligand (b) the solvent molecules and (c) the interaction of the effective dipole moment of the polar solvent molecule with the transition metal ion complex.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.87-92
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• 2006

Fas-associated death domain protein (FADD) recruits and activates procaspase-8 through interactions between the death effector domains of these two proteins. Cellular FLICE-inhibitory protein (c-FLIP) was identified as a molecule with sequence homology to caspase-8. It has been postulated that c-FLIP prevents formation of the competent death-inducing signaling complex in a ligand-dependent manner, through its interaction with FADD and/or caspase-8. However, the interaction of FADD and $c-FLIP_s$ (short form) in apoptosis signaling has been controversially discussed. We show the purification and the characterization of human full-length FADD and $c-FLIP_s$ expressed in Escherichia coli. The purified FADD and $c-FLIP_s$ are shown as homogeneity, respectively, in SDS-PAGE analysis and light-scattering measurements. The folding properties of the $\alpha$-helical structure of FADD and the super-secondary structure of $c-FLIP_s$ proteins were characterized by circular dichroism spectroscopy. Furthermore, we report here a series of biochemical and biophysical data for FADD-$c-FLIP_s$ binding in vitro. The binding of both FADD and $c-FLIP_s$ proteins was detected by BIAcore biosensor, fluorescence measurement, and size-exclusion column (SEC).

• Bulletin of the Korean Chemical Society
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• v.4 no.5
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• pp.223-227
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• 1983

A molecular dynamic computer experiment was performed on a system of 108 particles composed of a single polymer chain and solvent molecules. The state considered was in the immediate neighborhood of the triple point of the system. The polymer itself is an analog of a freely jointed chain. The Lennard-Jones potential was used to represent the interactions between all particles except for that between the chain elements forming a bond in the polymer chain, for which the interaction was expressed by a harmonic potential. The self-diffusion coefficient and velocity autocorrelation function (VACF) of a polymer were calculated at various chain lengths $N_p$, and various interaction strengths between solvent molecules and a polymer chain element. For self-diffusion coefficients D, the Einstein relation holds good; as chain length $N_p$ increases the D value decreases, and D also decreases as ${\varepsilon}_{cs}$ (the interaction parameter between the chain element and solvent molecules) increases. The relaxation time of velocity autocorrelation decreases as ${\varepsilon}_{cs}$ increases, and it is constant for various chain lengths. The diffusion coefficients in various conditions reveal that our systems are in a free draining limit as is well known from the behavior of low molecular weight polymers, this also agrees with the Kirkwood-Riesman theory.

• Journal of Life Science
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• v.28 no.4
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• pp.488-495
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• 2018

The p53 gene plays a critical role in the transcriptional regulation of cellular response to stress, DNA damage, hypoxia, and tumor development. Keeping in mind the recently discovered manifold physiological functions of p53, its involvement in the regulation of cancer is not surprising. In about 50% of all human cancers, inactivation of p53's protein function occurs either through mutations in the gene itself or defects in the mechanisms that activate it. This disorder plays a crucial role in tumor evolution by allowing the evasion of a p53-dependent response. Many recent studies have focused on directly targeting p53 mutants by identifying selective, small molecular compounds to deplete them or to restore their tumor-suppressive function. These small molecules should effectively regulate various interactions while maintaining good drug-like properties. Among them, the discovery of the key p53-negative regulator, MDM2, has led to the design of new small molecule inhibitors that block the interaction between p53 and MDM2. Some of these small molecule compounds have now moved from proof-of-concept studies into clinical trials, with prospects for further, more personalized anti-carcinogenic medicines. Here, we review the structural and functional consequences of wild type and mutant p53 as well as the development of therapeutic agents that directly target this gene, and compounds that inhibit the interaction between it and MDM2.

• BMB Reports
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• v.49 no.6
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• pp.337-343
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• 2016

Understanding of trafficking, processing, and degradation mechanisms of amyloid precursor protein (APP) is important because APP can be processed to produce β-amyloid (Aβ), a key pathogenic molecule in Alzheimer's disease (AD). Here, we found that APP contains KFERQ motif at its C-terminus, a consensus sequence for chaperone-mediated autophagy (CMA) or microautophagy which are another types of autophagy for degradation of pathogenic molecules in neurodegenerative diseases. Deletion of KFERQ in APP increased C-terminal fragments (CTFs) and secreted N-terminal fragments of APP and kept it away from lysosomes. KFERQ deletion did not abolish the interaction of APP or its cleaved products with heat shock cognate protein 70 (Hsc70), a protein necessary for CMA or microautophagy. These findings suggest that KFERQ motif is important for normal processing and degradation of APP to preclude the accumulation of APP-CTFs although it may not be important for CMA or microautophagy.

• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.151-155
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• 2015

The interfacial electronic structure between zinc phthalocyanine (ZnPc) and aluminumdoped zinc oxide (AZO) substrates has been evaluated by ultraviolet photoemission spectroscopy and angle-dependent x-ray absorption spectroscopy to understanding the molecular orientation of a ZnPc layer on the performance of small molecule organic photovoltaics (OPVs). We find that the ZnPc tilt angle improves the ${\pi}-{\pi}$ interaction on the AZO substrate, thus leading to an improved short-circuit current in OPVs based on phthalocyanine. Furthermore, the molecular orientation-dependent energy level alignment has been analyzed in detail using ultraviolet photoemission spectroscopy. We also obtained complete energy level diagrams of ZnPc/AZO and ZnPc/indium thin oxide.