• Biomolecules & Therapeutics
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• 제28권4호
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• pp.311-319
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• 2020

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a newly emerging viral disease with fatal outcomes. However, no MERS-CoV-specific treatment is commercially available. Given the absence of previous structure-based drug discovery studies targeting MERS-CoV fusion proteins, this set of compounds is considered the first generation of MERS-CoV small molecule fusion inhibitors. After a virtual screening campaign of 1.56 million compounds followed by cell-cell fusion assay and MERS-CoV plaques inhibition assay, three new compounds were identified. Compound numbers 22, 73, and 74 showed IC₅₀ values of 12.6, 21.8, and 11.12 µM, respectively, and were most effective at the onset of spike-receptor interactions. The compounds exhibited safe profiles against Human embryonic kidney cells 293 at a concentration of 20 µM with no observed toxicity in Vero cells at 10 µM. The experimental results are accompanied with predicted favorable pharmacokinetic descriptors and drug-likeness parameters. In conclusion, this study provides the first generation of MERS-CoV fusion inhibitors with potencies in the low micromolar range.

• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.78-84
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• 2008

EGFR has been intensively investigated as a target to block the signal transduction pathway which stimulates cancer growth and metastasis. Studies about structure-activity relationship for tricyclic azepine derivatives were performed with topomer-CoMFA. The derived topomer-CoMFA model with steric and electrostatic field parameters based on fragment units gave reasonable statistics ($q^2$=0.561, $r^2$=0.679). The model explains why a halogen atom at the meta position of aniline is important to increases inhibitory activity. This comes from an electrostatically negative groups are favored near this region. The model also shows that there are sterically favored regions around methoxy group extended from oxazepine derivatives. The findings about steric and electrostatic effects can be utilized for designing new inhibitors.

• Molecular & Cellular Toxicology
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• 제3권3호
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• pp.159-164
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• 2007

Stimulation of epidermal growth factor receptor (EGFR) is essential in signaling pathway of tumor cells. Thus, EGFR has intensely studied as an anticancer target. We developed hologram quantitative structure activity relationship (HQSAR) models for data set which consists of tricyclic azepine derivatives showing inhibitory activities for EGFR. The optimal HQSAR model was generated with fragment size of 6 to 7 while differentiating fragments having different atom and connectivity. The model showed cross-validated $q^2$ value of 0.61 and non-cross-validated $r^2$ value of 0.93. When the model was validated with an external set excluding one outlier, it gave predictive $r^2$ value of 0.43. The contribution maps generated from this model were used to interpret the atomic contribution of each atom to the overall inhibition activity. This can be used to find more efficient EGFR inhibitors.

• Biomolecules & Therapeutics
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• 제29권3호
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• pp.282-289
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• 2021

A novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), caused a worldwide pandemic. Our aim in this study is to produce new fusion inhibitors against SARS-CoV-2, which can be the basis for developing new antiviral drugs. The fusion core comprising the heptad repeat domains (HR1 and HR2) of SARS-CoV-2 spike (S) were used to design the peptides. A total of twelve peptides were generated, comprising a short or truncated 24-mer (peptide #1), a long 36-mer peptide (peptide #2), and ten peptide #2 analogs. In contrast to SARS-CoV, SARS-CoV-2 S-mediated cell-cell fusion cannot be inhibited with a minimal length, 24-mer peptide. Peptide #2 demonstrated potent inhibition of SARS-CoV-2 S-mediated cell-cell fusion at 1 µM concentration. Three peptide #2 analogs showed IC50 values in the low micromolar range (4.7-9.8 µM). Peptide #2 inhibited the SARS-CoV-2 pseudovirus assay at IC50=1.49 µM. Given their potent inhibition of viral activity and safety and lack of cytotoxicity, these peptides provide an attractive avenue for the development of new prophylactic and therapeutic agents against SARS-CoV-2.

• Bulletin of the Korean Chemical Society
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• 제29권3호
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• pp.647-655
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• 2008

Microsomal prostaglandin E2 synthase (mPGES-1) is a potent target for pain and inflammation. Various QSAR (quantitative structure activity relationship) analyses used to understand the factors affecting inhibitory potency for a series of MK886 analogues. We derived four QSAR models utilizing various quantum mechanical (QM) descriptors. These QM models indicate that steric, electrostatic and hydrophobic interaction can be important factors. Common pharmacophore hypotheses (CPHs) also have studied. The QSAR model derived by best-fitted CPHs considering hydrophobic, negative group and ring effect gave a reasonable result (q2 = 0.77, r2 = 0.97 and Rtestset = 0.90). The pharmacophore-derived molecular alignment subsequently used for 3D-QSAR. The CoMFA (Comparative Molecular Field Analysis) and CoMSIA (Comparative Molecular Similarity Indices Analysis) techniques employed on same series of mPGES-1 inhibitors which gives a statistically reasonable result (CoMFA; q2 = 0.90, r2 = 0.99. CoMSIA; q2 = 0.93, r2 = 1.00). All modeling results (QM-based QSAR, pharmacophore modeling and 3D-QSAR) imply steric, electrostatic and hydrophobic contribution to the inhibitory activity. CoMFA and CoMSIA models suggest the introduction of bulky group around ring B may enhance the inhibitory activity.

• BMB Reports
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• 제32권6호
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• pp.594-598
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• 1999

The Jun and Fos families of eukaryotic transcription factors form heterodimers capable of binding to their cognate DNA enhancer elements. We are interested in searching for inhibitors or antagonists of the binding of the Jun-Fos heterodimer to the activator protein-1 (AP-1) site. The basic-region leucine zipper (bZIP) domain of c-Fos was expressed as a fusion protein with glutathione S-transferase, and allowed to form a heterodimer with the bZIP domain of c-Jun. The heterodimer was bound to glutathione-agarose, to which were added radiolabeled AP-1 nucleotides. After thorough washing, the gel-bound radioactivity was counted. The assay is faster than the coventional electrophoretic mobility shift assay because the gel electrophoresis step and the autoradiography step are eliminated. Moreover, the assay is very sensitive, allowing the detection of picomolar quantities of nucleotides, and is not affected by up to 50% dimethylsulfoxide, a solvent for hydrophobic inhibitors. Curcumin and dihydroguaiaretic acid, recently known inhibitors of Jun-Fos-DNA complex formation, were applied to this Jun-GST-fused Fos system and revealed to decrease the dimer-DNA binding.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3025-3033
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• 2016

Chronic myeloid leukaemia (CML) is a clonal myeloproliferative hematopoietic stem cell disorder. Deregulated BCR-ABL fusion tyrosine kinase activity is the main cause of CML disease pathogenesis, making BCR-ABL an ideal target for inhibition. Current tyrosine kinase inhibitors (TKIs) designed to inhibit BCR-ABL oncoprotein activity, have completely transformed the prognosis of CML. Interruption of TKI treatment leads to minimal residual disease reside (MRD), thought to reside in TKI-insensitive leukaemia stem cells which remain a potential reservoir for disease relapse. This highlights the need to develop new therapeutic strategies for CML either as small molecule master TKIs or phytopharmaceuticals derived from nature to achieve chronic molecular remission. This review outlines the past, present and future therapeutic approaches for CML including coverage of relevant mechanisms, whether ABL dependent or independent, and epigenetic factors responsible for developing resistance against TKIs. Appearance of mutant clones along the course of therapy either pre-existing or induced due to therapy is still a challenge for the clinician. A proposed in-vitro model of generating colony forming units from CML stem cells derived from diagnostic samples seems to be achievable in the era of high throughput technology which can take care of single cell genomic profiling.

• Molecules and Cells
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• 제19권1호
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• pp.54-59
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• 2005

Deoxyribonuclease I (DNase I) is a divalent cation dependent endonuclease and thought to be a significant barrier to effective gene delivery. The only known DNase I-specific inhibitor is monomeric actin which acts by forming a 1:1 complex with DNase I. Its use, however, is restricted because of tendency to polymerize under certain conditions. We screened two random phage peptide libraries of complexity $10^8$ and $10^9$ for DNase I binders as candidates for DNase I inhibitors. A number of DNase I-binding peptide sequences were identified. When these peptides were expressed as fusion proteins with Escherichia coli maltose binding protein, they inhibited the actin-DNase I interaction ($IC_{50}=0.1-0.7{\mu}M$) and DNA degradation by DNase I ($IC_{50}=0.8-8{\mu}M$). Plasmid protection activity in the presence of DNase I was also observed with the fusion proteins. These peptides have the potential to be a useful adjuvant for gene therapy using naked DNA.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.81-89
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• 2004

Tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and lymphotoxin-$\alpha$ (LT-$\alpha$, TNF-$\beta$) can initiate and perpetuate human diseases such as multiple sclerosis (MS), rheumatoid arthritis (RA), and insulin-dependent diabetes mellitus (IDDM). TNFs can be blocked by the use of soluble TNF receptors. However, since monomeric soluble receptors generally exhibit low affinity or function as agonists, the use of monomeric soluble receptors has been limited in the case of cytokines such as TNF-$\alpha$, TNF-$\alpha$, interleukin (IL)-1, IL-4, IL-6, and IL-13, which have adapted to a multi component receptor system. For these reasons, very high-affinity inhibitors were created for the purpose of a TNFs antagonist to bind the TNFR and trigger cellular signal by using the multistep polymerase chain reaction method. First, recombinant simple TNFR-Ig fusion proteins were constructed from the cDNA sequences encoding the extracellular domain of the human p55 TNFR (CD120a) and the human p75 TNFR (CD120b), which were linked to hinge and constant regions of human $IgG_1$ heavy chain, respectively using complementary primers (CP) encoding the complementary sequences. Then, concatameric TNFR-Ig fusion proteins were constructed using recombinant PCR and a complementary primer base of recombinant simple TNFR-Ig fusion proteins. For high level expression of recombinant fusion proteins, Chinese hamster ovary (CHO) cells were used with a retroviral expression system. The transfected cells produced the simple concatameric TNFR-Ig fusion proteins capable of binding TNF and inactivating it. These soluble versions of simple concantameric TNFR-Ig fusion proteins gave rise to multiple forms such as simple dimers and concatameric homodimers. Simple TNFR-1g fusion proteins were shown to have much more reduced TNF inhibitory activity than concatameric TNFR-Ig fusion proteins. Concatameric TNFR-Ig fusion proteins showed higher affinity than simple TNFR-Ig fusion proteins in a receptor inhibitor binding assay (RIBA). Additionally, concatameric TNFR-Ig fusion proteins were shown to have a progressive effect as a TNF inhibitor compared to the simple TNFR-Ig fusion proteins and conventional TNFR-Fc in cytotoxicity assays, and showed the same results for collagen induced arthritis (CIA) in mice in vivo.

• 순환기질환의공학회:학술대회논문집
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• 순환기질환의공학회 2006년도 제6회 학술대회
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• pp.10-13
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• 2006

Inflammation plays an important role in the progression of atherosclerosis and plaque destabilization converting a chronic process into an acute disorder with ensuing thromboembolism. Current therapeutic effective in preventing atherosclerosis and stroke such as statins, ASS and RAS inhibitors my exert part of their effects by modulating inflammatory responses in the vessel walls. As alternative approaches, discovery to find having inhibitory action of MMP activity, COX-2, macrophage infiltration, such as APE1/ref-1 and fusion technology for cell permeable protein may provide a new antiatherosclerotic therapy in the future.