• Title/Summary/Keyword: Binding state

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Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

  • Park, Hea Jung;Sung, Nam Kyung;Kim, Su Rhan;Ahn, So Hyun;Yoon, Ung Chan;Cho, Dae Won;Mariano, Patrick S.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3681-3689
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    • 2013
  • This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation $Hg^{2+}$ and $Pb^{2+}$ showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals.

Expression Profiles of Cellular Retinol-binding Protein, Type II (CRBP II) in Erlang Mountainous Chickens

  • Yin, H.D.;Tian, K.;Li, D.Y.;Gilbert, E.R.;Xiao, L.H.;Chen, S.Y.;Wang, Y.;Liu, Y.P.;Zhao, X.L.;Zhu, Q.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.3
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    • pp.310-315
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    • 2014
  • Cellular retinol-binding protein II (CRBP II) belongs to the family of cellular retinol-binding proteins and plays a major role in absorption, transport, and metabolism of vitamin A. In addition, because vitamin A is correlated with reproductive performance, we measured CRBP II mRNA abundance in erlang mountainous chickens by real-time PCR using the relative quantification method. The expression of CRBP II showed a tissue-specific pattern and egg production rate-dependent changes. The expression was very high (p<0.05) in jejunum and liver, intermediate in kidney, ovary, and oviduct, and lowest (p<0.05) in heart, hypothalamus, and pituitary. In the hypothalamus, oviduct, ovary, and pituitary, CRBP II mRNA abundance were correlated to egg production rate, which increased from 12 wk to 32 wk, peaked at 32 wk relative to the other time points, and then decreased from 32 wk to 45 wk. In contrast, the expression of CRBP II mRNA in heart, jejunum, kidney, and liver was not different at any of the ages evaluated in this study. These data may help to understand the genetic basis of vitamin A metabolism, and suggest that CRBP II may be a candidate gene to affect egg production traits in chickens.

No Relevance of NF-${\kappa}B$ in the Transcriptional Regulation of Human Nanog Gene in Embryonic Carcinoma Cells

  • Seok, Hyun-Jeong;Kim, Young-Eun;Park, Jeong-A;Lee, Young-Hee
    • Development and Reproduction
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    • v.15 no.1
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    • pp.25-30
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    • 2011
  • Embryonic stem (ES) cells can self-renew maintaining the undifferentiated state. Self renewal requires many factors such as Oct4, Sox2, FoxD3, and Nanog. NF-${\kappa}B$ is a transcription factor involved in many biological activities. Expression and activity of NF-${\kappa}B$ increase upon differentiation of ES cells. Reportedly, Nanog protein directly binds to NF-${\kappa}B$ protein and inhibits its activity in ES cells. Here, we found a potential binding site of NF-${\kappa}B$ in the human Nanog promoter and postulated that NF-${\kappa}B$ protein may regulate expression of the Nanog gene. We used human embryonic carcinoma (EC) cells as a model system of ES cells and confirmed decrease of Nanog and increase of NF-${\kappa}B$ upon differentiation induced by retinoic acid. Although deletion analysis on the DNA fragment including NF-${\kappa}B$ binding site suggested involvement of NF-${\kappa}B$ in the negative regulation of the promoter, site-directed mutation of NF-${\kappa}B$ binding site had no effect on the Nanog promoter activity. Furthermore, no direct association of NF-${\kappa}B$ with the Nanog promoter was detected during differentiation. Therefore, we conclude that NF-${\kappa}B$ protein may not be involved in transcriptional regulation of Nanog gene expression in EC cells and possibly in ES cells.

Potency and plasma protein binding of drugs in vitro-a potentially misleading pair for predicting in vivo efficacious concentrations in humans

  • Yim, Dong-Seok
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.4
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    • pp.231-236
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    • 2019
  • In drug discovery or preclinical stages of development, potency parameters such as $IC_{50}$, $K_i$, or $K_d$ in vitro have been routinely used to predict the parameters of efficacious exposure (AUC, $C_{min}$, etc.) in humans. However, to our knowledge, the fundamental assumption that the potency in vitro is correlated with the efficacious concentration in vivo in humans has not been investigated extensively. Thus, the present review examined this assumption by comparing a wide range of published pharmacokinetic (PK) and potency data. If the drug potency in vitro and its in vivo effectiveness in humans are well correlated, the steady-state average unbound concentrations in humans [$C_{u_-ss.avg}=f_u{\cdot}F{\cdot}Dose/(CL{\cdot}{\tau})=f_u{\cdot}AUCss/{\tau}$] after treatment with approved dosage regimens should be higher than, or at least comparable to, the potency parameters assessed in vitro. We reviewed the ratios of $C_{u_-ss.avg}$/potency in vitro for a total of 54 drug entities (13 major therapeutic classes) using the dosage, PK, and in vitro potency reported in the published literature. For 54 drugs, the $C_{u_-ss.avg}$/in vitro potency ratios were < 1 for 38 (69%) and < 0.1 for 22 (34%) drugs. When the ratios were plotted against $f_u$ (unbound fraction), "ratio < 1" was predominant for drugs with high protein binding (90% of drugs with $f_u{\leq}5%$; i.e., 28 of 31 drugs). Thus, predicting the in vivo efficacious unbound concentrations in humans using only in vitro potency data and $f_u$ should be avoided, especially for molecules with high protein binding.

Research and development of a three-stage door binder to improve the fire resistance of fire doors (방화문의 내화성능 향상을 위한 3단 문 결속기 연구개발)

  • Lim, Bo-Hyeok;Lee, Joo-Won;Cho, Dong-Hwan;Lee, Hae-Yeol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.157-158
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    • 2023
  • Doors that are opened and closed when entering or exiting a general building are connected to the door frame and open and close. They are equipped with door locking devices of various structures, and are either locked to the door frame for the closing operation or released from the door frame for the opening and closing operation. Here, a single-stage door binding device having a door latch that is independently disposed at the center of one axis of the door is commonly used. On the other hand, if the size of the door is over a certain size or if the door is medium to large, the opening and closing operation may not be performed smoothly with only a single stage binder, or the closing state may not be achieved stably during the closing operation. In particular, in the case of the single-stage binding device provided in medium to large fire doors, the door is fixed to the door frame unstable, causing fatal errors in the fire prevention function of the fire door. Accordingly, in order to fundamentally solve these problems, we researched and developed a three-stage door binding machine that combines a top and bottom fastening structure with a single-stage fastening structure. This 3-stage door binder not only has the fire resistance performance of a fire door, but also has a T-shaped terminal in its fastening method, so if you eliminate the upper and lower fastening, it is a 1-stage binder like a regular product, but if you remove the door latch of the 1st-stage binder, it functions as an upper and lower 2-stage binder and forms a single mold. We researched and developed a three-stage door binder that can manufacture and produce three products at the same time, satisfying both product performance and price.

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Rhodopsin Chromophore Formation and Thermal Stabilities in the Opsin Mutant E134Q/M257Y (옵신 mutant E134Q/M257Y의 로돕신 형성과 열안정성 분석)

  • Kim, Jong-Myoung
    • Journal of Life Science
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    • v.22 no.7
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    • pp.863-870
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    • 2012
  • Rhodopsin, a dim light photoreceptor, has been regarded as one of the model systems for the structural and functional study of G protein-coupled receptors (GPCRs). Constitutively active mutant GPCRs leading to the activation of heterotrimeric GDP/GTP-binding protein signaling in the absence of ligand binding are of interest for the study of the activation mechanism in GPCRs. The present study focused on the opsin mutant E134Q/M257Y, which showed a moderate level of constitutive activity and the formation of two distinct rhodopsin chromophores with absorption maxima of 500 nm and 380 nm, depending on the presence of an inverse agonist, 11-cis-retinal, and an agonist, all-trans-retinal, respectively. Reconstitution of the mutant rhodopsin upon incubation with different ratios of 11-cis-retinal and the all-trans-retinal, as well as upon sequential binding of the two retinals, indicated its preferential binding to 11-cis-retinal. The thermal stability of the 11-cis-retinal-bound form of the E134Q/M257Y mutant was lower than that of the mutants containing a single replacement but higher than that of the all-trans-retinal-bound forms. The mutant also showed a lower stability in its opsin state as compared with that of the wild-type opsin but had little effects on the binding affinity to 11-cis-retinal. Information obtained in this study will be helpful for analyzing the structural changes associated with the activation of rhodopsin and GPCRs.

Effects of Ginseng Total Saponin on The Altered Glutamatergic Nervous Systems by AF64A in Brain of Rats

  • Ma, Young;Yi, Eun Young;Choi, Woo Jung;Lim, Dong-Koo
    • Biomolecules & Therapeutics
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    • v.5 no.1
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    • pp.36-42
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    • 1997
  • To investigate effects of ginseng total saponin (GTS) on the ethylcholine aziridnium ion (AF64A) -induced glutamatergic nervous system, rats were pretreated with the infusion of AF64A (3 nmole) into lateral ventricle and were posttreated with 50 mg/kg of GTS, i.p., for 1 week. Twenty four hours after the last administration, rats were sacrificed and the levels of glutamate and taurine, [$^3$H]dizocilpine ([$^3$H]MK801) binding sites and glutamine synthetase activity were assessed in striatum, hippocampus and frontal cortex. The levels of striatal glutamate after GTS treatment in rats were decreased. And the levels of glutamate were decreased in striatum and frontal cortex and increased in hippocampus by the infusion of AF64A. However, the AF64A-induced changes of glutamate were returned to the control level by the administration of GTS in striatum, frontal cortex and hippocampus. After the infusion of AF64A, the level of taurine was decreased in striatum and increased in hippocampus. GTS administrations in the AF64A-treated rats restored to the control level of taurine in the decreased striatal level of taurine, but not in the elevated level of hippocampal taurine. The specific [$^3$H]MK801 binding sites in hippocampus was significantly decreased but not in striatum and frontal cortex after the administration of AF64A. Although GTS itself did not affect the specific [$^3$H]MK801 binding sites, GTS administrations in the AF64A-treated rats did decrease the binding sites of (\`H)Mk801 in all examined regions. The activities of striatal glutamine synthetase were decreased after GTS treatment. The activities of striatal glutamine synthetase (GS) were decreased in AF64A-treated groups. However, the decreased striatal GS activities by AF64A were returned to the control level by GTS treatment. Furthermore, GTS administrations in the AF64A-treated rats increased the hippocampal GS activities. The results indicatethat GTS may adjust the levels of glutamate and taurine constantly and may induce increase in AF64A-induced decrease of GS activity. Thus, it suggests that GTS may antagonize changes in central glutamatergic nervous system induced by AF64A. Also it suggests that the actions of GTS may differently affect in the disease state.

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Transcriptional Regulation of Human Nanog Gene by OCT4 and SOX2 (OCT4와 SOX2에 의한 인간 Nanog 유전자의 전사 조절)

  • Seok, Hyun-Jeong;Kim, Young-Eun;Park, Jeong-A;Lee, Young-Hee
    • Development and Reproduction
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    • v.14 no.2
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    • pp.123-129
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    • 2010
  • Embryonic stem (ES) cells can self-renew maintaining the undifferentiated state. Self-renewal requires many factors such as OCT4, SOX2, and NANOG. It is previously known that OCT4 and SOX2 can bind to NANOG promoter and support Nanog gene expression in mouse ES cells by the detailed studies using the mouse Nanog promoter. Here, we constructed serial deletion mutant promoter-reporter constructs to investigate the human Nanog gene promoter in detail. The highest promoter activity was obtained in the 0.6 kb (-253/+365) promoter-reporter construct which includes the binding sites of OCT4 and SOX2. To further confirm contribution of OCT4 and SOX2 in Nanog gene expression, we introduced site- directed mutation(s) in the OCT4 and/or SOX2 binding sites of the human Nanog promoter 0.6 kb (-253/+365) and checked the influence of the mutation on the promoter activity using human EC cell line NCCIT. Mutation either in OCT4 binding site or SOX2 binding site significantly reduced the activity of Nanog promoter which directly confirmed that OCT4 and SOX2 binding is essential in human Nanog gene expression.

Cloning and characterization of the cardiac-specific Lrrc10 promoter

  • Fan, Xiongwei;Yang, Qing;Wang, Youliang;Zhang, Yan;Wang, Jian;Yuan, Jiajia;Li, Yongqing;Wang, Yuequn;Deng, Yun;Yuan, Wuzhou;Mo, Xiaoyang;Wan, Yongqi;Ocorr, Karen;Yang, Xiao;Wu, Xiushan
    • BMB Reports
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    • v.44 no.2
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    • pp.123-128
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    • 2011
  • Leucine-rich repeat containing protein 10 (LRRC10) is characterized as a cardiac-specific gene, suggesting a role in heart development and disease. A severe cardiac morphogenic defect in zebrafish morphants was recently reported but a contradictory result was found in mice, suggesting a more complicated molecular mechanism exists during mouse embryonic development. To elucidate how LRRC10 is regulated, we analyzed the 5'enhancer region approximately 3 kilo bases (kb) upstream of the Lrrc10 start site using luciferase reporter gene assays. Our characterization of the Lrrc10 promoter indicates it possesses complicated cis-and trans-acting elements. We show that GATA4 and MEF2C could both increase transcriptional activity of Lrrc10 promoter individually but that they do not act synergistically, suggesting that there exists a more complex regulation pattern. Surprisingly, knockout of Gata4 and Mef2c binding sites in the 5’enhancer region (-2,894/-2,889) didn't change the transcriptional activity of the Lrrc10 promoter and the likely GATA4 binding site identified was located in a region only 100 base pair (bp) upstream of the promoter. Our data provides insight into the molecular regulation of Lrrc10 expression, which probably also contributes to its tissue-specific expression.

Natural and synthetic pathogen associated molecular patterns modulate galectin expression in cow blood

  • Asiamah, Emmanuel Kwaku;Ekwemalor, Kingsley;Adjei-Fremah, Sarah;Osei, Bertha;Newman, Robert;Worku, Mulumebet
    • Journal of Animal Science and Technology
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    • v.61 no.5
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    • pp.245-253
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    • 2019
  • Pathogen-associated Molecular Patterns (PAMPs) are highly conserved structural motifs that are recognized by Pathogen Recognition receptors (PRRs) to initiate immune responses. Infection by these pathogens and the immune response to PAMPS such as lipopolysaccharide (LPS), Peptidoglycan (PGN), bacterial oligodeoxynucleotides [CpG oligodeoxynucleotides 2006 (CpG ODN2006) and CpG oligodeoxynucleotides 2216 (CpG ODN2216)], and viral RNA Polyinosinic-Polycytidylic Acid (Poly I:C), are associated with infectious and metabolic diseases in animals impacting health and production. It is established that PAMPs mediate the production of cytokines by binding to PRRs such as Toll-like receptors (TLR) on immune cells. Galectins (Gal) are carbohydrate-binding proteins that when expressed play essential roles in the resolution of infectious and metabolic diseases. Thus it is important to determine if the expression of galectin gene (LGALS) and Gal secretion in blood are affected by exposure to LPS and PGN, PolyI:C and bacterial CpG ODNs. LPS increased transcription of LGALS4 and 12 (2.5 and 2.02 folds respectively) and decreased secretion of Gal 4 (p < 0.05). PGN increased transcription of LGALS-1, -2, -3, -4, -7, and -12 (3.0, 2.3, 2.0, 4.1, 3.3, and 2.4 folds respectively) and secretion of Gal-8 and Gal-9 (p < 0.05). Poly I:C tended to increase the transcription of LGALS1, LGALS4, and LGALS8 (1.78, 1.88, and 1.73 folds respectively). Secretion of Gal-1, -3, -8 and nine were significantly increased in treated samples compared to control (p < 0.05). CpG ODN2006 did not cause any significant fold changes in LGALS transcription (FC < 2) but increased secretion of Gal-1, and-3 (p < 0.05) in plasma compared to control. Gal-4 was however reduced in plasma (p < 0.05). CpG ODN2216 increased transcription of LGALS1 and LGALS3 (3.8 and 1.6 folds respectively), but reduced LGALS2, LGALS4, LGALS7, and LGALS12 (-1.9, -2.0, -2.0 and; -2.7 folds respectively). Secretion of Gal-2 and -3 in plasma was increased compared to control (p < 0.05). Gal-4 secretion was reduced in plasma (p < 0.05). The results demonstrate that PAMPs differentially modulate galectin transcription and translation of galectins in cow blood.