• Title/Summary/Keyword: binding agent

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Development of a Novel Short Synthetic Antibacterial Peptide Derived from the Swallowtail Butterfly Papilio xuthus Larvae

  • Kim, Seong Ryul;Choi, Kwang-Ho;Kim, Kee-Young;Kwon, Hye-Yong;Park, Seung-Won
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1305-1309
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    • 2020
  • Insects possess biological defense systems that can effectively combat the invasion of external microorganisms and viruses, thereby supporting their survival in diverse environments. Antimicrobial peptides (AMPs) represent a fast-acting weapon against invading pathogens, including various bacterial or fungal strains. A 37-residue antimicrobial peptide, papiliocin, derived from the swallowtail butterfly Papilio xuthus larvae, showed significant antimicrobial activities against several human pathogenic bacterial and fungal strains. Jelleines, isolated as novel antibacterial peptides from the Royal Jelly (RJ) of bees, exhibit broad-spectrum protection against microbial infections. In this study, we developed a novel antimicrobial peptide, PAJE (RWKIFKKPFKISIHL-NH2), which is a hybrid peptide prepared by combining 1-7 amino acid residues (RWKIFKK-NH2) of papiliocin and 1-8 amino acid residues (PFKISIHL-NH2) of Jelleine-1 to alter length, charge distribution, net charge, volume, amphipaticity, and improve bacterial membrane interactions. This novel peptide exhibited increased hydrophobicity and net positive charge for binding effectively to the negatively charged membrane. PAJE demonstrated antimicrobial activity against both gram-negative and gram-positive bacteria, with very low toxicity to eukaryotic cells and an inexpensive process of synthesis. Collectively, these findings suggest that this novel peptide possesses great potential as an antimicrobial agent.

Synthesis of [18F]-Labelled Nebivolol as a β1-Adrenergic Receptor Antagonist for PET Imaging Agent (베타1-아드레날린 수용체를 표적으로 하는 심근영상제로서 18F 표지된 nebivolol의 합성)

  • Kim, Taek-Soo;Park, Jeong Hoon;Lee, Jun Young;Yang, Seung Dae;Chang, Dong-Jo
    • Journal of Radiation Industry
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    • v.10 no.4
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    • pp.181-187
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    • 2016
  • Selective ${\beta}_1$-agonist and antagonists are used for the treatment of cardiac diseases including congestive heart failure, angina pectoris and arrhythmia. Selective ${\beta}_1$-antagonists including nebivolol have high binding affinity on ${\beta}_1$-adrenergic receptor, not ${\beta}_2$-receptor mainly expressed in smooth muscle. Nebivolol is one of most selective ${\beta}_1$-blockers in clinically used ${\beta}_1$-blockers including atenolol and bisoprolol. We tried to develop clinically useful cardiac PET tracers using a selective ${\beta}_1$-blocker. Nebivolol is $C_2$-symmetric and has two chromane moiety with a secondary amino alcohol and aromatic fluorine. We adopted the general synthetic strategy using epoxide ring opening reaction. Unlike formal synthesis of nebivolol, we prepared two chromane building blocks with fluorine and iodine which was transformed to diaryliodonium salt for labelling of $^{18}F$. Two epoxide building blocks were readily prepared from commercially available chromene carboxylic acids (1, 8). Then, the amino alcohol building block (15) was prepared by ammonolysis of epoxide (14) followed by coupling reaction with the other building block, epoxide (7). Diaryliodonium salt, a precursor for $^{18}F$-aromatic substitution, was synthesized in moderate yield which was readily subjected to $^{18}F$-aromatic substitution to give $^{18}F$-labelled nebivolol.

Inhibitory effect of ethanolic extract of Abeliophyllum distichum leaf on 3T3-L1 adipocyte differentiation

  • Thomas, Shalom Sara;Eom, Ji;Sung, Nak-Yun;Kim, Dong-Sub;Cha, Youn-Soo;Kim, Kyung-Ah
    • Nutrition Research and Practice
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    • v.15 no.5
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    • pp.555-567
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    • 2021
  • BACKGROUND/OBJECTIVES: Abeliophyllum distichum is a plant endemic to Korea, containing several beneficial natural compounds. This study investigated the effect of A. distichum leaf extract (ALE) on adipocyte differentiation. MATERIALS/METHODS: The cytotoxic effect of ALE was analyzed using cell viability assay. 3T3-L1 preadipocytes were differentiated using induction media in the presence or absence of ALE. Lipid accumulation was confirmed using Oil Red O staining. The mRNA expression of adipogenic markers was measured using RT-PCR, and the protein expressions of mitogen-activated protein kinase (MAPK) and peroxisome proliferator-activated receptor gamma (PPAR𝛾) were measured using western blot. Cell proliferation was measured by calculating the incorporation of Bromodeoxyuridine (BrdU) into DNA. RESULTS: ALE reduced lipid accumulation in differentiated adipocytes, as indicated by Oil Red O staining and triglyceride assays. Treatment with ALE decreased the gene expression of adipogenic markers such as Ppar𝛾, CCAAT/enhancer binding protein alpha (C/ebp𝛼), lipoprotein lipase, adipocyte protein-2, acetyl-CoA carboxylase, and fatty acid synthase. Also, the protein expression of PPAR𝛄 was reduced by ALE. Treating the cells with ALE at different time points revealed that the inhibitory effect of ALE on adipogenesis is higher in the early period treatment than in the terminal period. Furthermore, ALE inhibited adipocyte differentiation by reducing the early phase of adipogenesis and mitotic clonal expansion. This was indicated by the lower number of cells in the Synthesis phase of the cell cycle (labeled using BrdU assay) and a decrease in the expression of early adipogenic transcription factors such as C/ebp𝛽 and C/ebp𝛿. ALE suppressed the phosphorylation of MAPK, confirming that the effect of ALE was through the suppression of early phase of adipogenesis. CONCLUSIONS: Altogether, the results of the present study revealed that ALE inhibits lipid accumulation and may be a potential agent for managing obesity.

Study on the Effects of Phenyldiazenylanilines on the Activation of Arylhydrocarbon Receptor (Phenyldiazenylaniline 유도체가 방향족탄화수소 수용체의 활성에 미치는 영향)

  • Lee, Hyosung
    • Journal of the Korea Convergence Society
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    • v.10 no.1
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    • pp.285-290
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    • 2019
  • AHR regulates the expression of xenobiotics metabolizing enzymes (XMEs) as a transcription fact upon binding of ligands that are mainly aryl hydrocarbons. The role of AHR in human physiology has been intensively investigated for the past decades, however our understanding on AHR yet to be elucidated largely due to the lack of proper chemical agents. It has been demonstrated that AHR correlates to pathogenesis for some diseases in recent studies suggesting that the study on the AHR may provide a valid therapeutic target. Classical antagonists in current use are reported to be partially agonistic whereas a pure antagonist is yet to be found. In this study, phenyldiazenylaniline has been designed based on the structure of two known AHR antagonist, Resveratrol and CH223191. The derivatives of phenyldiazenylaniline have been prepared and subjected to assessment as an AHR antagonist in order to optimize the AHR antagonistic activity of the designed structure by means of convergence study of organic synthesis and molecular biology.

Synergistic anticancer effects of timosaponin AIII and ginsenosides in MG63 human osteosarcoma cells

  • Jung, Okkeun;Lee, Sang Yeol
    • Journal of Ginseng Research
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    • v.43 no.3
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    • pp.488-495
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    • 2019
  • Background: Timosaponin AIII (TA3) is a steroidal saponin extracted from Anemarrhena asphodeloides. Here, we investigated the anticancer effects of TA3 in MG63 human osteosarcoma cells. TA3 attenuates migration and invasion of MG63 cells via regulations of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are involved with cancer metastasis in various cancer cells. TA3 reduced enzymatic activities and transcriptional expressions of MMP-2 and MMP-9 in MG63 cells. TA3 also inhibited Src, focal adhesion kinase, extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), p38, ${\beta}-catenin$, and cAMP response element binding signaling, which regulate migration and invasion of cells. TA3 induced apoptosis of MG63 cells via regulations of caspase-3, caspase-7, and poly(ADP-ribose) polymerase (PARP). Then, we tested several ginsenosides to be used in combination with TA3 for the synergistic anticancer effects. We found that ginsenosides Rb1 and Rc have synergistic effects on TA3-induced apoptosis in MG63 cells. Methods: We investigated the anticancer effects of TA3 and synergistic effects of various ginseng saponins on TA3-induced apoptosis in MG63 cells. To test antimetastatic effects, we performed wound healing migration assay, Boyden chamber invasion assays, gelatin zymography assay, and Western blot analysis. Annexin V/PI staining apoptosis assay was performed to determine the apoptotic effect of TA3 and ginsenosides. Results: TA3 attenuated migration and invasion of MG63 cells and induced apoptosis of MG63 cells. Ginsenosides Rb1 and Rc showed the synergistic effects on TA3-induced apoptosis in MG63 cells. Conclusions: The results strongly suggest that the combination of TA3 and the two ginsenosides Rb1 and Rc may be a strong candidate for the effective antiosteosarcoma agent.

Gastroprokinetic agent, mosapride inhibits 5-HT3 receptor currents in NCB-20 cells

  • Park, Yong Soo;Sung, Ki-Wug
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.5
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    • pp.419-426
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    • 2019
  • Mosapride accelerates gastric emptying by acting on 5-hydroxytryptamine type 4 ($5-HT_4$) receptor and is frequently used in the treatment of gastrointestinal (GI) disorders requiring gastroprokinetic efficacy. We tested the effect of mosapride on 5-hydroxytryptamine type 3 ($5-HT_3$) receptor currents because the $5-HT_3$ receptors are also known to be expressed in the GI system and have an important role in the regulation of GI functions. Using the whole-cell voltage clamp method, we compared the currents of the $5-HT_3$ receptors when 5-HT was applied alone or was co-applied with mosapride in cultured NCB-20 cells known to express $5-HT_3$ receptors. The $5-HT_3$ receptor current amplitudes were inhibited by mosapride in a concentration-dependent manner. Mosapride blocked the peak currents evoked by the application of 5-HT in a competitive manner because the $EC_{50}$ shifted to the right without changing the maximal effect. The rise slopes of $5-HT_3$ receptor currents were decreased by mosapride. Pre-application of mosapride before co-application, augmented the inhibitory effect of mosapride, which suggests a closed channel blocking mechanism. Mosapride also blocked the opened $5-HT_3$ receptor because it inhibited the $5-HT_3$ receptor current in the middle of the application of 5-HT. It accelerated desensitization of the $5-HT_3$ receptor but did not change the recovery process from the receptor desensitization. There were no voltage-, or use-dependency in its blocking effects. These results suggest that mosapride inhibited the $5-HT_3$ receptor through a competitive blocking mechanism probably by binding to the receptor in closed state, which could be involved in the pharmacological effects of mosapride to treat GI disorders.

Mediation of antiinflammatory effects of Rg3-enriched red ginseng extract from Korean Red Ginseng via retinoid X receptor α-peroxisome-proliferating receptor γ nuclear receptors

  • Saba, Evelyn;Irfan, Muhammad;Jeong, Dahye;Ameer, Kashif;Lee, Yuan Yee;Park, Chae-Kyu;Hong, Seung-Bok;Rhee, Man Hee
    • Journal of Ginseng Research
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    • v.43 no.3
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    • pp.442-451
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    • 2019
  • Background: Ginseng has a wide range of beneficial effects on health, such as the mitigation of minor and major inflammatory diseases, cancer, and cardiovascular diseases. There are abundant data regarding the health-enhancing properties of whole ginseng extracts and single ginsenosides; however, no study to date has determined the receptors that mediate the effects of ginseng extracts. In this study, for the first time, we explored whether the antiinflammatory effects of Rg3-enriched red ginseng extract (Rg3-RGE) are mediated by retinoid X receptor ${\alpha}$-peroxisome-proliferating receptor ${\gamma}$ ($RXR{\alpha}-PPAR{\gamma}$) heterodimer nuclear receptors. Methods: Nitric oxide assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay, quantitative reverse transcription polymerase chain reaction, nuclear hormone receptor-binding assay, and molecular docking analyses were used for this study. Results: Rg3-RGE exerted antiinflammatory effects via nuclear receptor heterodimers between $RXR{\alpha}$ and $PPAR{\gamma}$ agonists and antagonists. Conclusion: These findings indicate that Rg3-RGE can be considered a potent antiinflammatory agent, and these effects are likely mediated by the nuclear receptor $RXR{\alpha}-PPAR{\gamma}$ heterodimer.

Surface Modification of Nanofiltration Membrane with Silane Coupling Agents for Separation of Dye (실란 표면 개질된 나노복합막의 염료 분리 특성)

  • Park, Hee Min;Lim, Jee Eun;Kim, Seong Ae;Lee, Yong Taek
    • Membrane Journal
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    • v.28 no.6
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    • pp.414-423
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    • 2018
  • In this study, the commercial nanofiltration membranes were modified with octyltrimethoxysilane(OcTMS) and (3-aminopropyl)trimethoxysilane (APTMS) to improve fouling resistance and to separate dye. The chemical structure and binding energy of elements of silane-deposited surface were analyzed using XPS analysis. And the morphology and hydrophilicity property of silane-modified NF membrane were analyzed using FE-SEM, EDX, AFM, and contact angle. The surface charge of silane-modified NF membrane was characterized by zeta potentiometer analyzer. As a result, silane-modified NF membrane improved fouling resistance about 2 times as compared with that of the commercial membrane. And the silane-modified NF membranes effectively were removed cation dye over 98%.

Study on the Antagonistic Activity on Arylhydrocarbon Receptor of Phenyldiazenylphenylpicolinamides (Phenyldiazenylphenylpicolinamide 유도체들의 방향성탄화수소 수용체의 길항 활성에 대한 연구)

  • Yoon, Wan-Young;Lee, Hyosung
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.443-447
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    • 2019
  • Aryl hydrocarbon receptor (AhR) is the master regulator of xenobiotics metabolizing enzymes (XMEs). AhR is activated by aryl hydrocarbons upon binding then goes into the cell nucleus and acts as a transcription factor. Despite the role of AhR in human physiology has been investigated for a long while, it is yet to be understood mainly due to the lack of appropriate chemical agents. Furthermore, it has been reported that AhR is related to a wide range of pathogenesis. In addition, recent studies suggest that the study on the development of AhR antagonist may provide a valid therapeutic agent. Some known antagonists in current use are partially agonistic whereas a pure antagonist is still absent. In this study, two phenyl-ring structures of phenyldiazenylphenylpicolinamide has been modified into various structures and evaluated its impact on the AhR antagonistic activity to elucidate the structure-activity relationship.

Effects of a Mixture of Cynanchi Wilfordii Radix and Humuli Lupuli Flos Extract on Estrogenic Activities and Anti-Osteoclastogenesis (백수오(白首烏)와 비주화(啤酒花) 복합물의 에스트로겐 활성과 파골세포 분화 억제효과)

  • Park, Dongjun;Lee, Hong Gu;Min, Kyoungin;Park, Hyoungkook;Jin, Mu Hyun;Cho, Ho Song
    • The Korea Journal of Herbology
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    • v.37 no.5
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    • pp.1-8
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    • 2022
  • Objectives : This study aimed to investigate the synergistic effect of combining Cynanchi Wilfordii Radix extract with Humuli Lupuli Flos extract on estrogenic and anti-osteoclastogenic activity. Methods : Estrogenic effect of a mixture of Cynanchi Wilfordii Radix extract and Humuli Lupuli Flos extract (CWHL), Cynanchi Wilfordii Radix extract, Humuli Lupuli Flos extract, caudatin (an active ingredient of Cynanchi wilfordii Radix extract) and 8-prenylnaringenin (an active ingredient of Humuli Lupuli Flos extract) were examined by proliferation E-screen assay and expression of estrogen inducible gene, pS2 via Real Time-PCR (RT-PCR) in MCF-7 estrogen responsive cells. And their estrogenic activities were investigated how to modulate Estrogen receptor 𝛽 by binding affinity assay. Inhibitory effect of CWHL, Cynanchi Wilfordii Radix extract, Humuli Lupuli Flos extract, caudatin and 8-prenylnaringenin on RANKL-induced osteoclast differentiation were tested by TRAP (Tartrate-resistant acid phosphatase) staining in osteoclastogenic RAW 264.7 cells. Results : CWHL, Humuli Lupuli Flos extract and 8-prenylnaringenin accelerated the proliferation of MCF-7 and the expression of pS2 in MCF-7. CWHL, Cynanchi Wilfordii Radix extract, Humuli Lupuli Flos extract, caudatin and 8-prenylnaringenin bind to estrogen receptor 𝛽. CWHL, Cynanchi Wilfordii Radix extract, Humuli Lupuli Flos extract, caudatin and 8-prenylnaringenin inhibited RANKL-induced osteoclastogenesis in osteoclastogenic RAW 264.7. CWHL is more effective for all markers than Cynanchi Wilfordii Radix extract or Humuli Lupuli Flos extract alone. Conclusions : CWHL may a potential therapeutic agent for menopause and osteoporosis as a natural food resource. CWHL as a natural food source has therapeutic potential in cases of menopause and osteoporosis.