• Animal cells and systems
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• v.11 no.2
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• pp.93-98
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• 2007

Gonadotropin-releasing hormone (GnRH), synthesized in the hypothalamus, plays a pivotal role in the regulation of vertebrate reproduction. Since molecular isoforms of GnRH and their receptors (GnRHR) have been isolated in a broad range of vertebrate species, GnRH and GnRHR provide an excellent model for understanding the molecular co-evolution of a peptide ligand-receptor pair. Vertebrate species possess multiple forms of GnRH, which have been created through evolutionary mechanisms such as gene/chromosome duplication, gene deletion and modification. Similar to GnRHs, GnRH receptors (GnRHR) have also been diversified evolutionarily. Comparative ligand-receptor interaction studies for non-mammalian and mammalian GnRHRs combined with mutational mapping studies of GnRHRs have aided the identification of domains or motifs responsible for ligand binding and receptor activation. Here we discuss the molecular basis of GnRH-GnRHR co-evolution, particularly the structure-function relationship regarding ligand selectivity and signal transduction of mammalian and non-mammalian GnRHRs.

• Journal of Ginseng Research
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• v.32 no.2
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• pp.99-106
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• 2008

A ligand - whether an endogenous hormone, neurotransmitter, exogenous toxin or synthetic drug - binds to plasma membrane proteins (e.g., ion channels, receptors or other functional proteins) to exert its physiological or pharmacological effects. Ligands can also have functional groups, showing stereospecificity for interaction sites on their counterpart plasma membrane proteins. Previous reports have shown that the ginsenoside Rg$_3$, a bioactive ginsenoside, meets these criteria in that: 1) an aliphatic side chain of $Rg_3$ plays a role as a functional group, 2) Rg$_3$ regulates voltage- and ligand-gated ion channels in a stereospecific manner with respect to carbon-20, and 3) $Rg_3$ regulates subsets of ligand-gated and voltage-gated ion channels through specific interactions with identified amino acid residues inside the channel pore, in the outer pore entryway, or in toxin binding sites. Rg$_3$, therefore, could be a candidate for a novel ginseng-derived glycosidic ligand regulating ion channels and receptors. This review will examine how Rg$_3$ regulates voltage-gated and ligand-gated ion channels through interactions with its target proteins in the plasma membrane. Hopefully, this review will advance understanding of ginseng pharmacology at the cellular and molecular levels.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.605-606
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• 1989

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.421-426
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• 2007

A linking ligand containing sulfur donor atoms in the terminal thiophene rings, 1,2-bis(thiophen-2-ylmethylene) hydrazine (L), was prepared by Schiff-base condensation. Ligand L reacted with [PdCl2(NCPh)2] to produce a molecular Pd compound [PdL2Cl2] (1). On the other hand, it reacted with AgNO3 and AgClO4 to produce a 2-D network [AgL0.5(NO3)] (2) and a 1-D polymer [AgL]ClO4 (3), respectively, whose structures are based on secondary intermolecular forces such as H-bonding, van der Waals interaction, and π-π stacking. Polymer 2 exhibited photoluminescence at room temperature in the solid state.

• BMB Reports
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• v.36 no.2
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• pp.207-213
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• 2003

Peroxisome proliferator-activated receptors (PPARs) are orphan nuclear hormone receptors that are known to control the expression of genes that are involved in lipid homeostasis and energy balance. PPARs activate gene transcription in response to a variety of compounds, including hypolipidemic drugs. Most of these compounds have high affinity to the ligand-binding domain (LBD) of PPARs and cause a conformational change within PPARs. As a result, the receptor is converted to an activated mode that promotes the recruitment fo co-activators such as the steroid receptor co-activator-1 (SRC-1). Based on the activation mechanism of PPARs (the ligand binding to $PPAR{\gamma}$ induces interactions of the receptor with transcriptional co-activators), we performed Western blot and ELISA. These showed that the indomethacin, a $PPAR{\gamma}$ ligand, increased the binding between $PPAR{\gamma}$ and SRC-1 in a ligand dose-dependent manner. These results suggested that the in vitro conformational change of $PPAR{\gamma}$ by ligands was also induced, and increased the levels of the ligand-dependent interaction with SRC-1. Collectively, we developed a novel and useful ELISA system for the mass screening of $PPAR{\gamma}$ ligands. This screening system (based on the interaction between $PPAR{\gamma}$ and SRC-1) may be a promising system in the development of drugs for metabolic disorders.

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.65-74
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• 1979

An effect of the spin-orbit coupling interaction of ligand orbitals on the ground state for octahedral $[Ti(Ⅲ)A_3B_3]$, $ [V(Ⅲ)A_3B_3]$, $ [Fe(Ⅲ)A_3B_3]$ and $ [Ni(Ⅱ)A_3B_3]$ type complexes has been investigated in this work, applying the degenerate perturbation theory. The wave functions are not affected but the energy level splitting for the ground state of these complexes by the spin-orbit coupling interaction of ligand orbitals. The extent of effect on the energy level splitting for the ground state is decreased in order Ti(Ⅲ) > V(Ⅲ) > Fe(Ⅲ).

• BMB Reports
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• v.49 no.3
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• pp.159-166
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• 2016

Several members of tumor necrosis factor receptor (TNFR) superfamily that these members activate caspase-8 from death-inducing signaling complex (DISC) in TNF ligand-receptor signal transduction have been identified. In the extrinsic pathway, apoptotic signal transduction is induced in death domain (DD) superfamily; it consists of a hexahelical bundle that contains 80 amino acids. The DD superfamily includes about 100 members that belong to four subfamilies: death domain (DD), caspase recruitment domain (CARD), pyrin domain (PYD), and death effector domain (DED). This superfamily contains key building blocks: with these blocks, multimeric complexes are formed through homotypic interactions. Furthermore, each DD-binding event occurs exclusively. The DD superfamily regulates the balance between death and survival of cells. In this study, the structures, functions, and unique features of DD superfamily members are compared with their complexes. By elucidating structural insights of DD superfamily members, we investigate the interaction mechanisms of DD domains; these domains are involved in TNF ligand-receptor signaling. These DD superfamily members play a pivotal role in the development of more specific treatments of cancer.

• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.14-14
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• 2003

We have crystallized and determined the structures o the Shank PDZ domain, alone and in complex with the synthetic C-terminal hexapeptide of GKAP protein at resolutions of 1.8Å and 2.5Å, respectively. The structure revealed the structural basis of the ligand recongition by Class I PDZ-ligand interaction. Moreover, dimeric structureof shank PDZ domain suggests that the βA strand is a common surface for dimerization of PDZ domains.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.125-137
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• 2013

2012년 G 단백질 연결 수용체(G-Protein Coupled Receptors ; GPCR) 연구가 노벨 화학상을 받았다. 상당히 많은 병과 관련되어 있어 잠재력이 크고, 많은 연구가 진행 중이다. 현재 리간드와 단백질간의 정전기적 포텐셜 연구를 통한 예측 연구가 진행되고 있지만, GPCR과 리간드 간의 연구에서 아직 리간드의 전하를 통한 단백질과 리간드간의 상호작용 예측 연구가 되어 있지 않다. 그렇기 때문에 이번 연구에서는 8가지 방법으로 전하(charge)를 띠게 하여서 단백질과 리간드의 상호작용을 계산을 통하여 예측하여 보았다.

• Bulletin of the Korean Chemical Society
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• v.10 no.2
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• pp.138-142
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• 1989

Three oxovanadium(IV) complexes with bidentate ligands having only oxygen donor atoms, benzohydroxamic acid (Hben), 8-hydroxyquinoline-N-oxide(Hhqno) and picolinic acid-N-oxide (Hpicn) are prepared and magnetic and spectroscopic properties are investigated for the complexes $VO(ben)_2,\;VO(hqno)_2\;and \;VO(picn)_2.$ Magnetic data together with IR results strongly indicate that dimeric intermolecular interaction is significant in $VO(ben)_2$ while the presence of polymeric V-O${\cdot}{\cdot}$V-O interaction is suggestive in $VO(picn)_2$. For all three complexes, three electronic d-d transitions were observed; extremely strong optical absorption of these bands of $VO(ben)_2$ in DMSO are supposed to be arised from a great metal-ligand covalency. Some fundamental vibration modes of oxovanadium(IV) complexes were empirically assigned from the differences in the spectrum of metal complexes with free ligand.