• Archives of Pharmacal Research
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• v.28 no.1
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• pp.55-60
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• 2005

Leukocyte adhesion to the vascular endothelium is a critical initiating step in inflammation and atherosclerosis. We have herein studied the effect of manassantin A (1) and S (2), dineolignans, on interaction of THP-1 monocytic cells and human umbilical vein endothelial cells (HUVEC) and expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in HUVEC. When HUVEC were pretreated with 1 and 2 followed by stimulation with $TNF-{\alpha}$, adhesion of THP-1 cells to HUVEC decreased in dose-dependent manner with $IC_{50}$ values of 5 ng/mL and 7 ng/mL, respectively, without cytotoxicity. Also, 1 and 2 inhibited $TNF-{\alpha}-induceda$ up-regulation of ICAM-1, VCAM-1 and E-selectin. The present findings suggest that 1 and 2 prevent monocyte adhesion to HUVEC through the inhibition of ICAM-1, VCAM-1 and E-selectin expression stimulated by $TNF-\alpha$, and may imply their usefulness for the prevention of atherosclerosis relevant to endothelial activation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5586-5590
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• 2015

In this paper, the directed alignment methode of the DNA molecule between the Au electrodes was suggested for the application of nano devices. To fabricate the nano device coated DNA, 2-Aminoethanthiol(AET) was coated on Au electrodes which was formed using photo-lithography process on $SiO_2/Si$ substrates. In general, the AET that was a positive charge with $NH^{3+}$ was strongly combined under the electrostatic interaction with DNA molecule which had to be a negative charge. The DNA molecules could be easily aligned between Au electrodes coated with AET. The structures of the DNA molecules were investigated using AFM(Atomic force microscope), they were changed from single types to bundle according to the AET concentrations.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3199-3205
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• 2013

The inclusion behavior of sulfobutylether-${\beta}$-cyclodextrin (SBE-${\beta}$-CD) with perphenazine (PPH) was first studied by flow injection (FI)-chemiluminescence (CL) analysis with proposed $lg[(I_0-I_s)/I_s]=lgK_{P-CD}+nlg[C_{PPH}]$ model and molecular docking. Results showed that a 1:1 complex of SBE-${\beta}$-CD/PPH could online form, with the formation constant $K_{P-CD}$ of $2.57{\times}10^7Lmol^{-1}$ at 298 K. The thermodynamic parameters showed that the inclusion behavior of SBE-${\beta}$-CD/PPH was a spontaneous process by hydrophobic interaction. The molecular docking results revealed PPH entered into the larger cavity of SBE-${\beta}$-CD with two hydrogen bonds. Based on the linear relationship of the decrement of luminol/SBE-${\beta}$-CD/PPH CL intensity against the logarithm of PPH concentration ranging from 0.03 to 30.0 ng $mL^{-1}$, the present FI-CL analysis using luminol/SBE-${\beta}$-CD/PPH system was successfully applied to PPH determination in biological fluids and tablets with recoveries from 94.5 to 105.6% and RSDs less than 2.6% (n = 5).

• Bulletin of the Korean Chemical Society
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• v.17 no.3
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• pp.239-244
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• 1996

Mastoparan B (MP-B) that is a novel MP isolated from the hornet Vespa basalis, was studied as compared with MP, in terms of interaction with phospholipid bilayer and antimicrobial activity. MP-B has more hydrophilic amino acid residues in hydrophilic face of amphiphilic α-helical structure than MP. The both peptides exhibited considerably different effect on interaction with lipid bilayers, e.g. their conformation in the presence of acidic and neutral liposomes, dye-release ability from encapsulated liposomes, but on the whole the interaction mode was similar. On antimicrobial activity, MP had a strong activity against Gram-positive bacteria but no against Gram negative ones. Contrary to this, MP-B had a strong activity against Gram-positive and potent against Gram-negative ones. Since both peptides have almost same residues on the hydrophobic side, such more hydrophilic surface on the molecule seems to lead to the subtle change in its interaction with membranes, resulting in the alternation in its biological activity.

• International Journal of Oral Biology
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• v.47 no.3
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• pp.33-40
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• 2022

Store-operated Ca²⁺ entry (SOCE) represents one of the major Ca²⁺ entry routes in non-excitable cells. It is involved in a variety of fundamental biological processes and the maintenance of Ca²⁺ homeostasis. The Ca²⁺ release-activated Ca²⁺ (CRAC) channel consists of stromal interaction molecule and Orai; however, the role and action of Homer proteins as an adaptor protein to SOCE-mediated Ca²⁺ signaling through the activation of CRAC channels in non-excitable cells still remain unknown. In the present study, we investigated the role of Homer2 in the process of Ca²⁺ signaling induced by the interaction between CRACs and Homer2 proteins in non-excitable cells. The response to Ca²⁺ entry by thapsigargin-mediated Ca²⁺ store depletion remarkably decreased in pancreatic acinar cells of Homer2^-/- mice, as compared to wild-type cells. It also showed critical differences in regulated patterns by the specific blockers of SOCE in pancreatic acinar cells of Homer2^-/- mice. The response to Ca²⁺ entry by the depletion in Ca²⁺ store markedly increased in the cellular overexpression of Orai1 and STIM1 as compared to the overexpression of Homer2 in cells; however, this response was remarkably inhibited by the overexpression of Orai1, STIM1, and Homer2. These results suggest that Homer2 has a critical role in the regulatory action of SOCE activity and the interactions between CRAC channels.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3338-3342
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• 2012

Covalent functionalization of a $B_{12}N_{12}$ nano-cage with $CO_2$ molecule has been investigated using density functional theory in terms of energetic, geometric, and electronic property analyses. Results show that besides two physisorption configurations, $CO_2$ preferably tends to perform [2+2] addition on B-N bonds of the cluster which are shared between six-membered and four-membered rings, releasing energy of 14.99 kcal/mol for adsorption of the first $CO_2$ and of 15.45 kcal/mol for the second one (per each molecule). On the basis of calculated density of states, we have found that the electronic properties of the physisorbed $B_{12}N_{12}$ by $CO_2$ have not changed, while slight changes have been predicted in the functionalized cases. Present results might be helpful to provide an effective way to modify the $B_{12}N_{12}$ properties for further purifications and applications.

• BMB Reports
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• v.33 no.5
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• pp.379-384
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• 2000

The native conformation of serpins (serine protease inhibitors) is strained. Upon cleavage of the reactive center loop of serpins by a protease, the amino terminal portion of the cleaved loop is inserted into the central ${\beta}-sheet$, A sheet, as the fourth strand, with the concomitant release of the native strain. We questioned the role of protease in this conformational switch from the strained native form into a stable relaxed state. Chemical cleavage of the reactive center loop of ${\alpha}_1-antitrypsin$, a prototype serpin, using hydroxylamine dramatically increased the stability of the serpin. A circular dichroism spectrum and peptide binding study suggests that the amino terminal portion of the reactive center loop is inserted into the A sheet in the chemically-cleaved ${\alpha}_1-antitrypsin$, as in the enzymatically-cleaved molecule. These results indicate that the structural transformation of a serpin molecule does not require interaction with a protease. The results suggest that the serpin conformational switch that occurred during the complex formation with a target protease is induced by the cleavage of the reactive center loop per se.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.160-165
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• 1989

Binding of sulfaethidole to bovine serum albumin was studied by equilibrium dialysis, fluorescence probe technique, uv difference spectrophotometry and circular dichroism. Equilibrium dialysis method enabled us to estimate the total number of drug binding sites of albumin molecule. For sulfaethidole, albumin had 6 primary and 40 secondary binding sites. The primary and secondary binding constants were 0.9 * 10/sup 5/ M/sup -1/ and 0.2 * 10/sup 6/ M/sup -1/, respectivitely. 1-Anilino-8-naphthalenesulfonate (ANS) and 2-(4-hydroxylbenzeneazo)- benzoic acid (HBAB) were used as the fluorescence probe and the uv spectrophotometric probe, respectively. In fluorescence probe technique, results indicated that the number of higher affinity drug binding site of albumin was 1 and the number of lower affinity drug binding sites of albumin was 3, and the primary and secondary drug binding constants for bovine serum albumin were 2.15 * 10/sup 5/M/sup -1/ and 1.04 * 10/sup 5/ M/sup -1/, respectively. In uv difference spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above results suggest that several different methods should be used in ompensation for insufficient information about drug binding to albumin molecule given by only one method.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2473-2479
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• 2013

The kinetics of the radical-polar molecule reaction $CH_3+HBr{\rightarrow}CH_4+Br$ has been studied at temperatures between 150 and 1000 K using classical dynamics procedures. Potential energy surfaces constructed using analytical forms of inter- and intramolecular interaction energies show a shallow well and barrier in the entrance channel, which affect the collision dynamics at low temperatures. Different collision models are used to distinguish the reaction occurring at low- and high-temperature regions. The reaction proceeds rapidly via a complex-mode mechanism below room temperature showing strong negative temperature dependence, where the effects of molecular attraction, H-atom tunneling and recrossing of collision complexes are found to be important. The temperature dependence of the rate constant between 400 and 1000 K is positive, the values increasing in accordance with the increase of the mean speed of collision. The rate constant varies from $7.6{\times}10^{-12}$ at 150 K to $3.7{\times}10^{-12}$ at 1000 K via a minimum value of $2.5{\times}10^{-12}\;cm^3\;molecule^{-1}\;s^{-1}$ at 400 K.