• Title/Summary/Keyword: Binding Mechanism

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Study on ShangHanLun BianMaiFa (1) ("상한론(傷寒論)-변맥법(辨脈法)"에 관한 연구(1))

  • Cho, Eun-Kyung;Choi, Jong-Moon;Kim, Yun-Ju;Hong, Jin-Woo;Shin, Sang-Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.6
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    • pp.945-960
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    • 2011
  • The BianMaiFa chapter, which is the first chapter of SongBon ShangHanLun, is the scholarly description(專論) of the pulse and pathological mechanism but has not been studied and published yet. This study is about article 1-10 which is the first part of The BianMaiFa chapter. We compared the original texts within the editions, comparing and analyzing the annotations of successive dynastic medical group. The articles of The SongBon ShangHanLun BianMaiFa chapter 1-10 is consisted as is shown: article 1 discriminates pulse by yin-yang and states about the prognosis of disease according to pulse, article 2 states about binding in yin and binding in yang which is from abnormal exuberance of yin and yang, article 3 states about the pulse and pathological mechanism of chills with fever, article 4 states about pathological mechanism and symptom of nutrient and defense through pulse, article 5 distinguishes within binding in yang(陽結), binding in yin(陰結), yang faintness(陽微), yang debilitation(陽衰), blood collapse(亡血) by the pulse which was in article 2 3 4, article 6 7 8 9 10 states states about the shape or pathological mechanism of bound pulse(結脈) skipping pulse(促脈) stirred pulse(動脈) moderate pulse(緩脈) string-like pulse(弦脈) tight pulse(緊脈) drumskin pulse(革脈). Article 4 could be understood that inch pulse is floating and deficient shape and cubit pulse is sunken and weak shape(寸脈浮虛, 尺脈沈弱) related to article 3, article 5 could be understood as binding in yin and yang is aggregation shape related to article 2, yang-qi faintness is floating and debilitation shape, yang-qi debilitation is sunken and faint shape, blood collapse is deficient and stasis shape related to article 3 4.

Ginsenoside F2 Restrains Hepatic Steatosis and Inflammation by Altering the Binding Affinity of Liver X Receptor Coregulators

  • Kyurae Kim;Myung-Ho Kim;Ji In Kang;Jong-In Baek;Byeong-Min Jeon;Ho Min Kim;Sun-Chang Kim;Won-Il Jeong
    • Journal of Ginseng Research
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    • v.48 no.1
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    • pp.89-97
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    • 2024
  • Background: Ginsenoside F2 (GF2), the protopanaxadiol-type constituent in Panax ginseng, has been reported to attenuate metabolic dysfunction-associated steatotic liver disease (MASLD). However, the mechanism of action is not fully understood. Here, this study investigates the molecular mechanism by which GF2 regulates MASLD progression through liver X receptor (LXR). Methods: To demonstrate the effect of GF2 on LXR activity, computational modeling of protein-ligand binding, Time-resolved fluorescence resonance energy transfer (TR-FRET) assay for LXR cofactor recruitment, and luciferase reporter assay were performed. LXR agonist T0901317 was used for LXR activation in hepatocytes and macrophages. MASLD was induced by high-fat diet (HFD) feeding with or without GF2 administration in WT and LXRα-/- mice. Results: Computational modeling showed that GF2 had a high affinity with LXRα. LXRE-luciferase reporter assay with amino acid substitution at the predicted ligand binding site revealed that the S264 residue of LXRα was the crucial interaction site of GF2. TR-FRET assay demonstrated that GF2 suppressed LXRα activity by favoring the binding of corepressors to LXRα while inhibiting the accessibility of coactivators. In vitro, GF2 treatments reduced T0901317-induced fat accumulation and pro-inflammatory cytokine expression in hepatocytes and macrophages, respectively. Consistently, GF2 administration ameliorated hepatic steatohepatitis and improved glucose or insulin tolerance in WT but not in LXRα-/- mice. Conclusion: GF2 alters the binding affinities of LXRα coregulators, thereby interrupting hepatic steatosis and inflammation in macrophages. Therefore, we propose that GF2 might be a potential therapeutic agent for the intervention in patients with MASLD.

Characterization of αX I-Domain Binding to Receptors for Advanced Glycation End Products (RAGE)

  • Buyannemekh, Dolgorsuren;Nham, Sang-Uk
    • Molecules and Cells
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    • v.40 no.5
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    • pp.355-362
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    • 2017
  • The ${\beta}2$ integrins are cell surface transmembrane proteins regulating leukocyte functions, such as adhesion and migration. Two members of ${\beta}2$ integrin, ${\alpha}M{\beta}2$ and ${\alpha}X{\beta}2$, share the leukocyte distribution profile and integrin ${\alpha}X{\beta}2$ is involved in antigen presentation in dendritic cells and transendothelial migration of monocytes and macrophages to atherosclerotic lesions. ${\underline{R}}eceptor$ for ${\underline{a}}dvanced$ ${\underline{g}}lycation$ ${\underline{e}}nd$ ${\underline{p}}roducts$ (RAGE), a member of cell adhesion molecules, plays an important role in chronic inflammation and atherosclerosis. Although RAGE and ${\alpha}X{\beta}2$ play an important role in inflammatory response and the pathogenesis of atherosclerosis, the nature of their interaction and structure involved in the binding remain poorly defined. In this study, using I-domain as a ligand binding motif of ${\alpha}X{\beta}2$, we characterize the binding nature and the interacting moieties of ${\alpha}X$ I-domain and RAGE. Their binding requires divalent cations ($Mg^{2+}$ and $Mn^{2+}$) and shows an affinity on the sub-micro molar level: the dissociation constant of ${\alpha}X$ I-domains binding to RAGE being $0.49{\mu}M$. Furthermore, the ${\alpha}X$ I-domains recognize the V-domain, but not the C1 and C2-domains of RAGE. The acidic amino acid substitutions on the ligand binding site of ${\alpha}X$ I-domain significantly reduce the I-domain binding activity to soluble RAGE and the alanine substitutions of basic amino acids on the flat surface of the V-domain prevent the V-domain binding to ${\alpha}X$ I-domain. In conclusion, the main mechanism of ${\alpha}X$ I-domain binding to RAGE is a charge interaction, in which the acidic moieties of ${\alpha}X$ I-domains, including E244, and D249, recognize the basic residues on the RAGE V-domain encompassing K39, K43, K44, R104, and K107.

Effects of Allicin on the Gene Expression Profile of Mouse Hepatocytes in vivo with DNA Microarray Analysis

  • Park, Ran-Sook
    • Nutritional Sciences
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    • v.8 no.1
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    • pp.23-27
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    • 2005
  • The major garlic component, Allicin [diallylthiosulfinate, or (R, S)-diallyldissulfid-S-oxide] is known for its medicinal effects, such as antihypertensive activity, microbicidal activity, and antitumor activity. Allicin and diallyldisulfide, which is a converted form of allicin, inhibited the cholesterol level in hepatocytes, in vivo and in vitro. The metabolism of allicin reportedly occurs in the microsomes of hepatocytes, predominantly with the contribution of cytochrome P-450. However, little is known about how allicin affects the genes involved in the activity of hepatocytes in vivo. In the present study, we used the short-term intravenous injection of allicin to examine the in vivo genetic profile of hepatocytes. Allicin up-regulate ten genes in the hepatocytes. For example, the interferon regulator 1 (IRF-I), the wingless-related MMTV (mouse mammary tumor virus) integration site 4 (wnt-4), and the fatty acid binding protein 1. However, allicin down-regulated three genes: namely, glutathione S-transferase mu6, a-2-HS glycoprotein, and the corticosteroid binding globulin of hepatocytes. The up-regulated wnt-4, IRF-1, and mannose binding lectin genes can enhance the growth factors, cytokines, transcription activators and repressors that are involved in the immune defense mechanism. These primary data, which were generated with the aid of the Atlas Plastic Mouse 5 K Microarray, help to explain the mechanism which enables allicin to act as a therapeutic agent, to enhance immunity, and to prevent cancer. The data suggest that these benefits of allicin are partly caused by the up-regulated or down-regulated gene profiles of hepatocytes. To evaluate the genetic profile in more detail, we need to use a more extensive mouse genome array.

Study on the Mechanism of P-glycoprotein Inhibitory Activity of Silymarin in Human Breast Cancer Cell

  • Kwon, Young-Joo;Jung, Ho-Jin;Lee, Hwa-Jeong
    • Journal of Pharmaceutical Investigation
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    • v.36 no.5
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    • pp.315-320
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    • 2006
  • Silymarin showed P-glycoprptein(P-gp) inhibitory activity as much as verapamil, a well-known P-gp inhibitor, by decreasing $IC_{50}$ value of daunomycin(DNM)($16.0{\pm}0.7{\mu}M$), increasing the DNM accumulation($224.9{\pm}3.2%$), and decreasing DNM efflux($58.5{\pm}6.7%$), concurrently. In this study, we clarified the mechanism of action of silymarin for P-gp inhibitory function. First, silymarin may bind to the ATP-binding site and thus, prevent ATP hydrolysis. Second, the P-gp inhibitory activity of silymarin is not related to changing the cellular P-gp level. Third, the cytotoxicity of silymarin was increased in the presence of verapamil, reflecting that silymarin is a competent P-gp substrate against verapamil in the P-gp-overexpressed adriamycin-resistant MCF-7 breast cancer(MCF-7/ADR) cells. Conclusively, silymarin had the P-gp inhibitory activity through the action of competent binding to the P-gp substrate-binding site. Therefore, silymarin can be a good candidate for safe and effective MDR reversing agent in clinical chemotherapy by administering concomitantly with anticancer drugs.

Effect of 3-Methylcholanthrene on Rat Uterus: Uterine Growth and Mechanism of Action of 3-Methylcholanthrene

  • Sheen, Yhun-Y.;Kim, Sun-S.;Yun, Hea-C.
    • Archives of Pharmacal Research
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    • v.16 no.4
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    • pp.276-282
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    • 1993
  • This study has been undertaken to examine the effect of 3-methylcholanthrene (3MC) on rat uterine growth and to understand the mechanism of action of 3MC in rat uterus. After diethylstilbesterol(DES) or tamoxifen(TAM) or 3MC or DES plus TAM or DES plus 3MC was administered into immature female rats, uterine weight over corn oil-treated uteri. 3MC treatment had no effect on uterine weight but, DES stimulated uterine weight was inhibited by 3MC concomitant tratment. While TAM alone treatment showed slight increase in uterine wieght, inhibited uterine growth simulated by DES when it was adiministrated with DES condirect binding assay with $[^3H]$ estradiol and the relative binding affinities of 3MC and TAM were estimated by competetion assy. Estradiol tumed out to have high affinity for rat uterine estrogen receptor (kd = 0.4 nM). The relative binding affinities of TAM and 3MC were 1% and 4.7% that of DES for rat uterine estrogen receptor, respectively. 3MC was shown to have similar affinity for eat uterine estrogen receptor to that of TAM. Effects of DES 3MC and TAM administration in vivo on rat uterine estrogen recptor level were examined. It was confirmed that the estrogen, DES and antiestrogen, TAM decreased estrogen receptor levels from rat ulterus and also 3MC decreased rat uterine estrogen receptor level when rats were treated with DES, TAM and 3MC in vivo. Data indicates that 3MC acts as an antiestrogen mediated through estrogen receptor system.

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The linker connecting the tandem ubiquitin binding domains of RAP80 is critical for lysine 63-linked polyubiquitin-dependent binding activity

  • Cho, Hyun-Jung;Lee, Sang-Ho;Kim, Hong-Tae
    • BMB Reports
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    • v.42 no.11
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    • pp.764-768
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    • 2009
  • The tandem ubiquitin-interacting motif (UIM) domain located at the N-terminus of Receptor Associated Protein 80 (RAP80) plays a crucial role in ionizing radiation (IR)-induced DNA damage response. RAP80 translocates to sites of IR-induced DNA damage through interaction of its UIM domain with ubiquitinated H2A and Lys63-linked polyubiquitin chains. The exact mechanism, however, through which RAP80 associates with Lys63-linked polyubiquitin chains is not clear. Here, we show by in vitro GST-pull down assays that modifying the linker region between the tandem ubiquitin binding domains of RAP80 changes the binding affinity for Lys63-linked polyubiquitin chains and affects translocation to sites of DNA breaks. Based on these findings, we suggest that the length of the linker region between the tandem ubiquitin binding domains of RAP80 may be a key factor in the binding of RAP80 with Lys63-linked polyubiquitin chains as well as in the translocation of RAP80 to DNA break sites.

Protection of Metal Stress in Saccharomyces cerevisiae: Cadmium Tolerance Requies the Presence if Two ATP-Binding Domains of Hsp 104 Protein

  • Lee, Gyeong Hui;Eom, Jeong Hun
    • Bulletin of the Korean Chemical Society
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    • v.22 no.5
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    • pp.514-518
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    • 2001
  • We have explored the importance of two ATP binding domains of Hsp104 protein in protection of yeast cells from cadmium exposure. In the previous study we have discovered that the presence of two ATP binding sites was essential in providing heat sh ock protection as well as rescuing cells from oxidative stress. In this paper we first report wild type cell with functional hsp104 gene is more resistant to cadmium stress than hsp104-deleted mutant cell, judging from decrease in survival rates as a result of cadmium exposure. In order to demonstrate functional role of two ATP binding sites in cadmium defense, we have transformed both wild type (SP1) and hyperactivated ras mutant (IR2.5) strains with several plasmids differing in the presence of ATP binding sites. When an extra copy of functional hsp104 gene with both ATP binding sites was overexpressed with GPD-promoter, cells showed increased survival rate against cadmium stress than mutants with ATP binding sites changed. The degree of protection in the presence of two ATP binding sites was similarly observed in ira2-deleted hyperactivated ras mutant, which was more sensitive to oxidative stress than wild type cell. We have concluded that the greater sensitivity to cadmium stress in the absence of two ATP binding sites is attributed to the higher concentration of reactive oxygen species (ROS) produced by cadmium exposure based on the fluorescence tests. These findings, taken all together, imply that the mechanism by which cadmium put forth toxic effects may be closely associated with the oxidative stress, which is regulated independently of the Ras-cAMP pathway. Our study provides a better understanding of cadmium defense itself and cross-talks between oxidative stress and metal stress, which can be applied to control human diseases due to similar toxic environments.

Molecular Mechanism of R1162 Plasmid Incompatibility Exerted by Direct Repeat in the Replicative Origin

  • Kim, Yung-Jin
    • BMB Reports
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    • v.29 no.1
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    • pp.63-67
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    • 1996
  • In order to elucidate the molecular mechanism of plasmid incompatibility of broad host-range plasmid R1162, the plasmid-encoded replication protein RepIB was purified and tested for binding to the 20 bp direct repeat (DR) DNA sequence which is reiterated 3 and 1/2 times within the replicative origin of the plasmid. The RepIB protein specifically binds to the DR DNA. Point mutations in the DR which affect expression of plasmid incompatibility also coordinately affect binding. These results indicate that the incompatibility of broad host-range plasmid R1162 is exerted by the DR DNA by titrating the essential replication protein RepIB.

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A Method Enforcing Dependencies between ID Certificates and Attribute Certificates in Inter-domain (속성인증서와 신분인증서 사이의 바인딩 메카니즘에 관한 연구)

  • Park Chong-Hwa
    • The Journal of Information Technology
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    • v.5 no.4
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    • pp.81-88
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    • 2002
  • An ID certificate is digitally signed by a certificate authority for authentication and a attribute certificate is digitally signed by an attribute certificate authority for authorization. In many applications in web, there should be a mechanism to bind attributes to proper identities. So we analyzed some known binding methods, selective revocation methods and cryptographic binding methods and we proposed the new mechanism in order to solve their problems.

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