• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.305-308
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• 2008

We performed coupled-cluster calculations to determine the intermolecular interaction energy between two TiAu4 clusters. Our ab initio calculations predict that the binding energy is 2.89 eV, which is somewhat larger than the known binding energy of 2.0 eV for TiH4-TiH4. The intermolecular binding energy is relatively high, despite TiAu4 having all the attributes of a magic cluster. The favorable orbital interaction between occupied Au(6s) and unoccupied Ti(3d) orbitals leads to the strong dimeric interaction for TiAu4-TiAu4.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.749-752
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• 2013

Trehalose-tethered monomeric and dimeric berberines were synthesized in 50% and 30% from the reaction of berberrubine with 6-tosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose and 6,6'-ditosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose, respectively, and fully characterized by MS (HR and ESI) and NMR ($^1H$, $^{13}C$, COSY and HSQC). Spectrophotometric and spectrofluorimetric titrations indicated that compared with berberine, trehalose-tethered monomeric berberine had comparable DNA-binding affinity toward calf-thymus DNA, whereas trehalose-spaced dimeric berberine exhibited higher DNA-binding affinity. The potential application of these conjugates is also briefly discussed.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1711-1716
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• 2008

The reaction of copper(II) chloride with phenyl-N-[(pyridine-2-yl)methylene]methaneamide (ppmma) leads to a new $\mu$ -chloro bridged dimeric [Cu(ppmma)$Cl_2$]$_2$ complex, whereas a reaction of copper(II) bromide with ppmma affords a monomeric Cu(ppmma)$Br_2$ complex. Both complexes have been characterized by X-ray crystallography and electronic absorption spectroscopy. The crystal structural analysis of [Cu(ppmma)$Cl_2$]$_2$ shows that the two Cu(II) atoms are bridged by two chloride ligands, forming a dimeric copper(II) complex and the copper ion has a distorted square-pyramidal geometry ($\tau$ = 0.2). The dimer units are held through a strong intermolecular $\pi-\pi$ interactions between the nearest benzyl rings. On the other hand, Cu(ppmma)Br2 displayed a distorted square planar geometry with two types of strong intermolecular π-π interaction. EPR spectrum of [Cu(ppmma)$Cl_2$]$_2$ in frozen glas s at 77 K revealed an equilibrium between the mononuclear and binuclear species. The magnetic susceptibilities data of [Cu(ppmma)$Cl_2$]$_2$ and Cu(ppmma)$Br_2$ follow the Curie-Weiss law. No significant intermolecular magnetic interactions were examined in both complexes, and magnetic exchange interactions are discussed on the basis of the structural features.

• Applied Microscopy
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• v.35 no.4
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• pp.16-23
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• 2005

Peroxiredoxins (Prxs) are a superfamily of thiol-specific antioxidant proteins present in all organism and involved in the hydroperoxide detoxification of the cell. To determine the structural organization of yeast-Prx, electron microscopic analysis was performed. The average images of yeast-Prxs revealed three different structure, i.e. spherical-shaped structure, ring-shaped structure and irregularly-shaped small particles. In order to analyze the conformational change of yeast-Prx by reduction and oxidation, Prxs were subjected to DTT and $H_2O_2$. In presence of DTT, yeast-Prx showed a high tendency to form a decamer. However, they changed into dimeric or spherical structure in the oxidized state. Here we also show ionic interaction between dimeric subunits is primarily responsible for yeast-Prx oligomerization.

• Bulletin of the Korean Chemical Society
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• v.10 no.4
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• pp.346-348
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• 1989

Interactions between Tl atoms for the Tl dimer are studied by relativistic and nonrelativistic EHT methods. Relativistic bond weakening for the Tl dimer is qualitatively explained by comparing orbital energies from relativistic and nonrelativistic calculations. It is also shown that significant overlap exists, especially for 6p orbitals, at the internuclear distance larger than 4 ${\AA}$, implying that Tl-Tl interaction is not just the electrostatic interaction in the recently discovered dimeric thallacarborane.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1231-1236
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• 2011

Chiral discrimination is the ability to distinguish one enantiomeric form over another. The differential binding interaction between two molecules with the same helicity and those with the opposite helicity was investigated by using dispersion-corrected density functional theory. [5]helicene, tetrahydro[5]helicene and the polar D-${\pi}$-A compounds, 3,12-dimethoxy-7,8-dicyano-[5]helicene and 3,12-dimethoxy-7,8-dicyano-tetrahydro[5]helicene were the monomers considered in this study. In gas phase, the dimeric interaction from two helical molecules with the opposite handedness is greater than from those with the same handedness. The stable configurations of such dimers were identified. The most stable configuration tends to be the one with maximum contact between monomers.

• 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.

• 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.

• Journal of the Korean Applied Science and Technology
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• v.38 no.4
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• pp.1003-1009
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• 2021

A study on the associative properties of sodium hyaluronate (NaHA) and Alkane-bis (dimethylalkylammonium bromide) surfactants in aqueous solution was investigated in relation to the chemical structure of surfactants. As a result of measuring the interfacial tension, a parabolic graph showing the minimum value (c_min) at a specific concentration was shown. Above this minimum concentration the increase in interfacial tension is thought to be related to the formation of aggregates of NaHA chains and dimeric surfactants. The plot of viscosity vs surfactant concentration shows a slight maxium at c_min and a viscosity decrease at high surfactant concentrations. Viscosity nonlinear behavior is related to the size increase due to the complex growth and to the size shrinkage following from the interaction with electrolyte ions and free micelles. The results of surface tension measurements show a broad region of surface tension decrease, indicating the NaHA-surfactant interaction. The increase in surface tension above c_min may be related to the adsorption of clusters, consisting of free NaHA chains and dimeric surfactant. The strong adsorption of surfactant is observed at high concentrations.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1183-1189
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• 2021

Autodisplay of a multimeric protein complex on a cell surface is limited by intrinsic factors such as the types and orientations of anchor modules. Moreover, improper folding of proteins to be displayed often hinders functional cell surface display. While overcoming these drawbacks, we ultimately extended the applicability of the autodisplay platform to the display of a protein complex. We designed and constructed a cell surface attachment (CSA) system that uses a non-covalent protein-protein interaction. We employed the high-affinity interaction mediated by an orthogonal cohesin-dockerin (Coh-Doc) pair from Archaeoglobus fulgidus to build the CSA system. Then, we validated the orthogonal Coh-Doc binding by attaching a monomeric red fluorescent protein to the cell surface. In addition, we evaluated the functional anchoring of proteins fused with the Doc module to the autodisplayed Coh module on the surface of Escherichia coli. The designed CSA system was applied to create a functional attachment of dimeric α-neoagarobiose hydrolase to the surface of E. coli cells.