• 대한화학회지
• /
• 제36권4호
• /
• pp.523-535
• /
• 1992

ECEPP/2 및 MM2 방법을 이용하여 고리형 헥사펩티드의 형태 및 알칼리 금속 양이온과의 착물형성 그리고 DPH에 의한 양이온 전달방해를 이론적으로 살펴보았다. 착물을 형성하지 않은 고리형 펩티드에 대하여 여러 가지 안정한 형태가 얻어졌으며, 대부분의 아미드 수소원자는 카르보닐 산소와 분자내 수소결합을 이루고 있어 조밀한 구조를 나타내었다. 펩티드와 Na$^+$ 이온 및 DPH간의 착물형성에너지는 각각 -60kcal/mol 및 -18kcal/mol이었다. 그러나 헥사펩티드의 국부최소에너지 구조들에는 금속 양이온을 결합할 수 있는 공동이 존재하지 않았고 공동이 존재하는 헥사펩티드의 에너지는 본 연구의 최저에너지 구조보다 10kcal/mol 정도 높은 에너지를 주었으며, 이러한 에너지 차이와 금속 양이온의 탈수 과정을 고려하면 DPH에 의한 양이온 전달방해를 설명할 수 있었다. 또한 DPH와 결합하는데 있어서의 가장 중요한 아미노산 잔기는 글리신이었으며 이를 사코신(N-메틸 글리신) 으로 치환할 때 양이온 전달이 저해되는 실험적 사실을 설명할 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제21권9호
• /
• pp.867-874
• /
• 2000

Two new azobenzene crown ether calix[4]arenes, 10 and 11, were synthesized by two pathways. In the first pathway,two ethoxy nitrobenzene groups were attached to t-butylcalix[4]arenes in a 1,3 position. Subsequent reduction ofthe nitrobenzene group s by metallic zinc in an alkaline solution afforded 10 and 11 in8% and 12%,respectively. In the second pathway,an azobenzene containing two glycolic units was prepared prior connect-ing to t-butylcalix[4]arenes. The yields from the second approach (5%, 8% for 10 and 11, respectively) were lower than those from the former approach. Single crystals of 10 suitable for X-ray crystallography was ob-tained by recrystallization in methanol.Both the X-ray structure and the 1H-NMR spectrum of 10 indicated that the stereoisomer of the azobenzene moiety was trans and the calixarene platform was in cone conformation. 1H NMR spectroscopy suggested that 10 underwent an observable cis-trans isomerization in CDCl3 under room light and upon UV irradiation with cis:trans ratios of 33:67 and 36:64,respectively. Compound 6 which was the precursor of 11showed fluxional behavior and was found to have mixed conformations ofcone and partial cone with a ratio of 47:53 at -30 $^{\circ}C.$ 1H NMR spectrum of 11 suggested that 11 was initially isolated as cis azobenzene with calix[4]arene in cone conformation and underwent conformational interconversion through calix[4]arene annulas in a similar fashion to 6 upon exposing to light. The complexation studies of 10 with picrate salts of Na+ and K+ using 1H NMR spectroscopysuggested that Na+ preferred to bind the cis form of 10 while K+ preferred to bind the trans form. The stereoisomer of the azobenzene unit in 11 changed partially from cis to trans upon complexing with K+.

• Molecules and Cells
• /
• 제44권5호
• /
• pp.310-317
• /
• 2021

Cluster of differentiation 1 (CD1) is a family of cell-surface glycoproteins that present lipid antigens to T cells. Humans have five CD1 isoforms. CD1a is distinguished by the small volume of its antigen-binding groove and its stunted A' pocket, its high and exclusive expression on Langerhans cells, and its localization in the early endosomal and recycling intracellular trafficking compartments. Its ligands originate from self or foreign sources. There are three modes by which the T-cell receptors of CD1a-restricted T cells interact with the CD1a:lipid complex: they bind to both the CD1a surface and the antigen or to only CD1a itself, which activates the T cell, or they are unable to bind because of bulky motifs protruding from the antigen-binding groove, which might inhibit autoreactive T-cell activation. Recently, several studies have shown that by producing T_H2 or T_H17 cytokines, CD1a-restricted T cells contribute to inflammatory skin disorders, including atopic dermatitis, psoriasis, allergic contact dermatitis, and wasp/bee venom allergy. They may also participate in other diseases, including pulmonary disorders and cancer, because CD1a-expressing dendritic cells are also located in non-skin tissues. In this mini-review, we discuss the current knowledge regarding the biology of CD1a-reactive T cells and their potential roles in disease.

• 대한한방내과학회지
• /
• 제41권6호
• /
• pp.1078-1088
• /
• 2020

Objective: The purpose of this study was to investigate the effect of amorfrutin of licorice for Type2 diabetes mellitus. Method: The PubMed, CNKI, Wanfang, OASIS, NDSL, J-STAGE, and CiNii databases were searched from the beginning of the search to September 20, 2020, with no limits on language. Extractions and selections from the literature were made by two authors. The study included in vivo experiments with amorfrutins in high-fat diet-induced obesity C57BL/6 mice and leptin receptor-deficient db/db mice and in silico studies. Results & Conclusion: Four studies were finally selected. We confirmed that amorfrutin treatment considerably improved insulin sensitivity and glucose tolerance and reduced plasma insulin and glucose. Amorfrutins bind to and selectively activate Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), which plays an important role in glucose metabolism. Amorfrutins also strongly bind to the glucagon receptor (GCGR) and work as antagonist. Using the amorfrutins from licorice could therefore be helpful in treating type2 diabetes mellitus.

• 한국식품위생안전성학회지
• /
• 제35권6호
• /
• pp.561-566
• /
• 2020

참돔은 등쪽에 푸른 반점이 흩어져 있고, 홍민어는 꼬리 쪽에 검은 점이 있어 원물 형태는 쉽게 구분할 수 있다. 그러나 횟감이나 필렛으로 이용 시 참돔과 홍민어를 구분하기 어려워, 참돔의 종 특이 primer를 개발 및 검증하고 모니터링을 통해 참돔의 위변조 사례를 조사하고자 하였다. 시료에서 gDNA를 추출하여 PCR을 진행하였으며 참돔 primer의 product size는 468 bp, 홍민어 primer의 product size는 181 bp으로 설계하였다. Multiplex PCR 결과 참돔과 홍민어에 대한 종 특이적 증폭이 확인되었다. 또한, 참돔과 홍민어 PCR 민감도 실험 결과 참돔 primer는 1 ng, 홍민어 primer는 0.1 ng 까지 밴드가 확인되었다. 모니터링 결과 참돔으로 구매한 시료 19건 모두 참돔으로 판정되었다. 따라서 본 연구에서 제작된 참돔과 홍민어 종에 대한 종 특이적 primer는 횟감 등 수산물에도 적용할 수 있어 현재 유통 및 판매되고 있는 참돔 및 홍민어 판별에 적합성을 확인하였다.

• Journal of Ginseng Research
• /
• 제46권3호
• /
• pp.376-386
• /
• 2022

Background: Brain-derived neurotrophic factor (BDNF)-tropomyosin-related kinase B (TrkB) plays a critical role in the pathogenesis of depression by modulating synaptic structural remodeling and functional transmission. Previously, we have demonstrated that the ginsenoside Rb1 (Rb1) presents a novel antidepressant-like effect via BDNF-TrkB signaling in the hippocampus of chronic unpredictable mild stress (CUMS)-exposed mice. However, the underlying mechanism through which Rb1 counteracts stress-induced aberrant hippocampal synaptic plasticity via BDNF-TrkB signaling remains elusive. Methods: We focused on hippocampal microRNAs (miRNAs) that could directly bind to BDNF and are regulated by Rb1 to explore the possible synaptic plasticity-dependent mechanism of Rb1, which affords protection against CUMS-induced depression-like effects. Results: Herein, we observed that brain-specific miRNA-134 (miR-134) could directly bind to BDNF 30 UTR and was markedly downregulated by Rb1 in the hippocampus of CUMS-exposed mice. Furthermore, the hippocampus-targeted miR-134 overexpression substantially blocked the antidepressant-like effects of Rb1 during behavioral tests, attenuating the effects on neuronal nuclei-immunoreactive neurons, the density of dendritic spines, synaptic ultrastructure, long-term potentiation, and expression of synapse-associated proteins and BDNF-TrkB signaling proteins in the hippocampus of CUMS-exposed mice. Conclusion: These data provide strong evidence that Rb1 rescued CUMS-induced depression-like effects by modulating hippocampal synaptic plasticity via the miR-134-mediated BDNF signaling pathway.

• Journal of Veterinary Science
• /
• 제21권5호
• /
• pp.79.1-79.12
• /
• 2020

Background: Recently, the pork industry of Thailand faced an epidemic of highly virulent strains of porcine reproductive and respiratory syndrome virus (PRRSV), which spread throughout Southeast Asia, including the Lao People's Democratic Republic and Cambodia. Hence, the rapid and on-site screening of infected pigs on a farm is essential. Objectives: To develop the new aptamer as a biosensor for detection PRRSV which are rapid and on-site screening of infected pig. Methods: New aptamers against PRSSV were identified using the combined techniques of capillary electrophoresis, colorimetric assay by gold nanoparticles, and quartz crystal microbalance (QCM). Results: Thirty-six candidate aptamers of the PRRSV were identified from the systematic evolution of ligands by exponential enrichment (SELEX) by capillary electrophoresis. Only 8 out of 36 aptamers could bind to the PRSSV, as shown in a colorimetric assay. Of the 8 aptamers tested, only the 1F aptamer could bind specifically to the PRSSV when presented with the classical swine fever virus and a pseudo rabies virus. The QCM was used to confirm the specificity and sensitivity of the 1F aptamer with a detection limit of 1.87 × 10¹⁰ particles. Conclusions: SELEX screening of the aptamer equipped with capillary electrophoresis potentially revealed promising candidates for detecting the PRRSV. The 1F aptamer exhibited the highest specificity and selectivity against the PRRSV. These findings suggest that 1F is a promising aptamer for further developing a novel PRRSV rapid detection kit.

• 한국미생물·생명공학회지
• /
• 제50권3호
• /
• pp.328-336
• /
• 2022

Aptamers are short, chemically synthesized, single-stranded DNA or RNA oligonucleotides that fold into unique three-dimensional structures. In this study, we aim to determine the antibiofilm activity and binding specificity of the six polyclonal DNA aptamers (S15K3, S15K4, S15K6, S15K13, S15K15, and S15K20) on Staphylococcus aureus BPA-12 and Escherichia coli EPEC 4. Aptamer S15K6 showed the highest percentage of antibiofilm activity against S. aureus BPA-12 (37.4%) as shown by the lowest OD570 value of 0.313. Aptamer S15K20 showed the highest percentage of antibiofilm activity against E. coli EPEC 4 (15.4%) as shown by the lowest OD570 value of 0.515. Aptamers S15K13 and S15K20 showed antibiofilm activities against both S. aureus BPA-12 and E. coli EPEC4, and thus potentially have broad reactivity. Furthermore, based on the binding capacity and Kd values from our previous study, the binding specificity assay of selected polyclonal DNA aptamers (S15K3 and S15K15) against S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, S. agalactiae, E. coli MHA-6, and Listeria monocytogenes were performed using qPCR. Aptamers S15K3 and S15K15 showed specific binding to S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, and S. agalactiae, but could not bind to E. coli MHA-6 and L. monocytogenes. Therefore, this study showed that the polyclonal DNA aptamers have antibiofilm activity and were able to bind to S. aureus BPA-12 and E. coli EPEC 4 bacteria.

• Journal of Veterinary Science
• /
• 제24권5호
• /
• pp.67.1-67.15
• /
• 2023

Background: Feline immunodeficiency virus (FIV) causes an acquired immunodeficiency-like syndrome in cats. FIV is latent. No effective treatment has been developed for treatment the infected cats. The first and second generations non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, nevirapine (NVP) and efavirenz (EFV), and rilpivirine (RPV), were used to investigate the potential of NNRTIs for treatment of FIV infection. Objective: This study aims to use experimental and in silico approaches to investigate the potential of NNRTIs, NVP, EFV, and RPV, for inhibition of FIV reverse transcriptase (FIV-RT). Methods: The FIV-RT and human immunodeficiency virus reverse transcriptase (HIV-RT) were expressed and purified using chromatography approaches. The purified proteins were used to determine the IC₅₀ values with NVP, EFV, and RPV. Surface plasmon resonance (SPR) analysis was used to calculate the binding affinities of NNRTIs to HIV-RT and FIV-RT. The molecular docking and molecular dynamic simulations were used to demonstrate the mechanism of FIV-RT and HIV-RT with first and second generation NNRTI complexes. Results: The IC₅₀ values of NNRTIs NVP, EFV, and RPV against FIV-RT were in comparable ranges to HIV-RT. The SPR analysis showed that NVP, EFV, and RPV could bind to both enzymes. Computational calculation also supports that these NNRTIs can bind with both FIV-RT and HIV-RT. Conclusions: Our results suggest the first and second generation NNRTIs (NVP, EFV, and RPV) could inhibit both FIV-RT and HIV-RT.

• 식물조직배양학회지
• /
• 제24권1호
• /
• pp.1-35
• /
• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.