• BMB Reports
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• v.31 no.6
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• pp.565-571
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• 1998

The expression of the endogenous human apolipoprotein(apo)E gene was significantly induced when HepG2 cells were treated with exogenous 25-hydroxy-cholesterol. This sterol-mediated apoE gene upregulation appears to require the participation of a positive element for the apoE gene transcription (PET) ( -169/ -140), a core sequence of upstream regulatory element (URE)1 enhancer of the human apoE gene. This PET was renamed as sterol regulatory element (SRE)4 based on its new role as a sensor for the level of intracellular sterol. Furthermore, a gel mobility shift analysis showed that binding activity of the SRE4 binding protein (BP) obtained from HepG2 cells was induced by sterol treatment, while that from either MCF7 or BT20 cells remained unchanged. Binding activity of SRE4BP was also induced in mouse macrophage cells, J774A.1, by sterol treatment, but it was drastically reduced when cells were subjected to treatment of AY-9944, a potent inhibitor for sterol synthesis. However, binding activity of Spl, which is a co-binding protein to the SRE4 region, remained the same in either condition, suggesting that SRE4BP (formally known as PETBP) may be mainly responsible for the sterol-mediated regulation of the apoE gene expression. Deletion analysis of the core binding site of SRE4BP by gel mobility shift assays showed that the minimal sequence of the SRE4BP binding appears to reside between -157 and -140, confirming the identity of SRE4 with the previously determined core sequence of URE1.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3429-3443
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• 2013

Chemokine receptor (CCR2) is a G protein-coupled receptor that contains seven transmembrane helices. Recent pharmaceutical research has focused on the antagonism of CCR2 and candidate drugs are currently undergoing clinical studies for the treatment of diseases like arthritis, multiple sclerosis, and type 2 diabetes. In this study, we analyzed the time dependent behavior of CCR2 docked with a potent 4-azetidinyl-1-aryl-cyclohexane (4AAC) derivative using molecular dynamics simulations (MDS) for 20 nanoseconds (ns). Homology modeling of CCR2 was performed and the 4AAC derivative was docked into this binding site. The docked model of selected conformations was then utilized to study the dynamic behavior of the 4AAC enzyme complexes inside lipid membrane. MDS of CCR2-16b of 4AAC complexes allowed us to refine the system since binding of an inhibitor to a receptor is a dynamic process and identify stable structures and better binding modes. Structure activity relationships (SAR) for 4AAC derivatives were investigated and reasons for the activities were determined. Probable binding pose for some CCR2 antagonists were determined from the perspectives of binding site. Initial modeling showed that Tyr49, Trp98, Ser101, Glu291, and additional residues are crucial for 4AAC binding, but MDS analysis showed that Ser101 may not be vital. 4AAC moved away from Ser101 and the hydrogen bonding between 4AAC and Ser101 vanished. The results of this study provide useful information regarding the structure-based drug design of CCR2 antagonists and additionally suggest key residues for further study by mutagenesis.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.55-63
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• 2001

In macrophages, lipopolysaccharide (LPS) alone or in combination with $interferon-{\gamma}\;(IFN-{\gamma})$ has been shown to release a nitric oxide (NO) through the increase of the transcription of the inducible nitric oxide synthase (iNOS) gene. To investigate the exact intracellular signaling pathway of the regulation of iNOS gene transcription by LPS plus $IFN-{\gamma},$ the effects of protein tyrosine kinase (PTK) inhibitor and protein kinase C (PKC) inhibitors on NO production, iNOS mRNA expression, nuclear $factor-_{\kappa}B\;(NF-_{\kappa}B)$ binding activity and the promoter activity of iNOS gene containing two $NF-_{\kappa}B$ sites have been examined in a mouse macrophage RAW 264.7 cells. LPS or $IFN-{\gamma}$ stimulated NO production, and their effect was enhanced synergistically by mixture of LPS and $IFN-{\gamma}.$ The PTK inhibitor such as tyrphostin reduced LPS plus $IFN-{\gamma}-induced$ NO production, iNOS mRNA expression and $NF-_{\kappa}B$ binding activity. In contrast, PKC inhibitors such as H-7, Ro-318220 and staurosporine did not show any effect on them. In addition, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that tyrphostin inhibited the iNOS promoter activity through the $NF-_{\kappa}B$ binding site, whereas PKC inhibitors did not. Taken together, these suggest that PTK, but not PKC pathway, is involved in the regulation of the iNOS gene transcription through the $NF-_{\kappa}B$ sites of iNOS promoter in RAW 264.7 macrophages by LPS plus $IFN-{\gamma}$.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.277-286
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• 2020

Polycystic kidney disease 2-like-1 (PKD2L1), also known as polycystin-L or TRPP3, is a non-selective cation channel that regulates intracellular calcium concentration. Calmodulin (CaM) is a calcium binding protein, consisting of N-lobe and C-lobe with two calcium binding EF-hands in each lobe. In previous study, we confirmed that CaM is associated with desensitization of PKD2L1 and that CaM N-lobe and PKD2L1 EF-hand specifically are involved. However, the CaM-binding domain (CaMBD) and its inhibitory mechanism of PKD2L1 have not been identified. In order to identify CaM-binding anchor residue of PKD2L1, single mutants of putative CaMBD and EF-hand deletion mutants were generated. The current changes of the mutants were recorded with whole-cell patch clamp. The calmidazolium (CMZ), a calmodulin inhibitor, was used under different concentrations of intracellular. Among the mutants that showed similar or higher basal currents with that of the PKD2L1 wild type, L593A showed little change in current induced by CMZ. Co-expression of L593A with CaM attenuated the inhibitory effect of PKD2L1 by CaM. In the previous study it was inferred that CaM C-lobe inhibits channels by binding to PKD2L1 at 16 nM calcium concentration and CaM N-lobe at 100 nM. Based on the results at 16 nM calcium concentration condition, this study suggests that CaM C-lobe binds to Leu-593, which can be a CaM C-lobe anchor residue, to regulate channel activity. Taken together, our results provide a model for the regulation of PKD2L1 channel activity by CaM.

• BMB Reports
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• v.43 no.11
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• pp.711-719
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• 2010

Kinomics is an emerging and promising approach for deciphering kinomes. Chemical kinomics is a discipline of chemical genomics that is also referred to as "chemogenomics", which is derived from chemistry and biology. Chemical kinomics has become a powerful approach to decipher complicated phosphorylation-based cellular signaling networks with the aid of small molecules that modulate kinase functions. Moreover, chemical kinomics has played a pivotal role in the field of kinase drug discovery as it enables identification of new molecular targets of small molecule kinase modulators and/or exploitation of novel functions of known kinases and has also provided novel chemical entities as hit/lead compounds. In this short review, contemporary chemical kinomics technologies such as activity-based protein profiling, T7 kinasetagged phages, kinobeads, three-hybrid systems, fluorescenttagged kinase binding assays, and chemical genomic profiling are discussed along with a novel allosteric Bcr-Abl kinase inhibitor (GNF-2/GNF-5) as a successful application of chemical kinomics approaches.

• Preventive Nutrition and Food Science
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• v.4 no.1
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• pp.75-78
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• 1999

Acetylcarnitine, a metabilite of carnitine, has been porven to be a potent inhibitor of ethanol oxidation in hepatocytes. It inhibits the activity of alcohol dehydrognase (ADH), but not the microsomal ethanol oxidizing system. which was significatly inhibited by acetylcarnitine at NAD ; acetylcarnitine $\leq$1. the main objectives of his study were to ascertain the interaction between acetylcarnitine and NAD on ADH activity and to elucidate whether different species have different effects. Tehpost-mocrosomal supernatant (PMS) was prepared from normal rat, guinea pig, mouse and broilers by differential centrifugation . Horse and yeast ADH were purchased from the Sigma Chemical Co. Prepared and purchased ADH are used for determination of ADH activity in the presence or absence of carnitine and acetylcar- nitine. Binding studies showed that acetylcarnitine did bind to ADH in a dose realted manner when low NAD ; acetylcar- nitine ratio was provided. It was found that the inhibitionof ADH activity occurred only when NAD concentration was less than the inhibitor concentration . Crystalline and crude ADH preparation from different vertebrate species wer inhibited by acetylcarnitine, whereas the yeast ADH was not affected by acetylcarnitine.

• Molecules and Cells
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• v.20 no.2
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• pp.167-172
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• 2005

Ceruloplasmin (Cp) is a copper protein with important functions in iron homeostasis and in inflammation. Cp mRNA expression is induced by interferon (IFN)-${\gamma}$ in U937 monocytic cells, but synthesis of Cp protein is halted after about 12 h by transcript-specific translational silencing. The silencing mechanism requires binding of a 4-component cytosolic inhibitor complex, IFN-gamma-activated inhibitor of translation (GAIT), to a defined structural element (GAIT element) in the Cp 3'-UTR. Translational silencing of Cp mRNA requires the essential proteins of mRNA circularization, suggesting that the translational inhibition requires end-to-end mRNA closure. These studies describe a new mechanism of translational control, and may shed light on the role that macrophage-derived Cp plays at the intersection of iron homeostasis and inflammation.

• Archives of Pharmacal Research
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• v.9 no.2
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• pp.81-86
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• 1986

The effect of imperatorin on hepatic microsomal mixed function oxidases (MF0) was investigated. On acute treatment, imperatorin (30 mg/kg, i.p) caused a significant reduction in activities of hepatic aminopyrine N-demethylase, hexobarbital hydroxylase and aniline hydroxylase as well as cytochrome p0450 content in rats and mice. Kinetic studies on rat liver enzymes revealed that imperatorin appeared to be a competitive inhibitor of aminopyrine N-demethylase (Ki,0.007 mM), whereas a non-competitive inhibitor of hexobarbital hydroxylase (Ki, 0.0148 mM). Imperatorin also inhibited non-competitively aniline metabolism (Ki 0.2 mM). Imperatorin binds to phenobarbital-induced cytochrome p-450 to give a typical type 1 binding sepctrum (max. 388nm, min 422 nm). Multiple administrations of imperatorin (30 mg/kg. i. p. daily for 7 days) to mice shortended markedly the duration of hexobarbital narcosis and increased activities of hepatic aminopyrine N-demethylase and hexobarbital hydroxylase and the level of cytochrome p-450 where as aniline hydroxylase activity was unaffected.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.86-89
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• 2016

The Zika virus, which is a member of the flavivirus genus, poses a serious threat to humanity because there is no vaccine or cure. Zika is suspected to cause microcephaly, and it is rapidly spreading throughout parts of Brazil. Surprisingly, there are no known protein structures for the virus which are essential for drug and vaccine development. This paper investigates the Zika virus's nonstructural proteins with template-based modeling by using GalaxyTBM/Refine/SC. GalaxyDock was used to examine the effectiveness of various known serine protease inhibitors in inhibiting the Zika viral protease. In testing five inhibitors, Kunitz soybean trypsin inhibitor showed the strongest binding affinity (-10.082 kcal/mol). This paper provides a rudimentary foundation for further drug discovery research regarding the Zika virus.

• Biomolecules & Therapeutics
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• v.30 no.4
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• pp.299-308
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• 2022

T cells are attractive targets for the development of immunotherapy to treat cancer due to their biological features, capacity of cytotoxicity, and antigen-specific binding of receptors. Novel strategies that can modulate T cell functions or receptor reactivity provide effective therapies, including checkpoint inhibitor, bispecific antibody, and adoptive transfer of T cells transduced with tumor antigen-specific receptors. T cell-based therapies have presented successful pre-clinical/clinical outcomes despite their common immune-related adverse effects. Ongoing studies will allow us to advance current T cell therapies and develop innovative personalized T cell therapies. This review summarizes immunotherapeutic approaches with a focus on T cells. Anti-cancer T cell therapies are also discussed regarding their biological perspectives, efficacy, toxicity, challenges, and opportunities.