• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.803-808
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• 2012

We have implemented two-component spin-orbit relativistic effective core potential (SOREP) methods in an all-electron relativistic program DIRAC. This extends the capacity of the two-component SOREP method to many ground and excited state calculations in a single program. As the test cases, geometries and energies of the small halogen molecules were studied. Several two-component methods are compared by using spin-orbit and scalar relativistic effective core potentials. For the $I_2$ molecule, excitation energies of low-lying excited states agree well with those from corresponding all-electron methods. Efficiencies in SOREP calculations enhanced by using symmetries are also discussed briefly.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.57-60
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• 2001

The characterization of organic Metal/Insulator/Metal(MIM) devices were investigated from LB films. The physicochemical properties of the LB films were by UV absorption spectrum and AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 2, 10, 30[mN/ml The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it.

• Journal of Photoscience
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• 제12권2호
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• pp.57-61
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• 2005

The ground and excited state dipole moments of Coumarin 450 (C 450) laser dye were measured at room temperature in several solvents of varying dipole moments. The ground state dipole moment (${\mu}_g$) is estimated by using the modified Onsagar model and the excited state dipole moments (${\mu}_e$) were estimated by the method of solvatochromism as well as by utilizing the microscopic solvent polarity parameter ($E^N_T$). Further, the deviation of some of the points from the linearity of the $E^N_T$ versus Stokes shift indicates the existence of specific type of solute-solvent interaction. The excited state dipole moment of C 450 were found to be higher than those of the ground state and is interpreted in terms of the resonance structure of the molecule. A reasonable agreement has been observed between the values obtained by the method of solvatochromism and modified Onsagar model. It is observed that, corresponding to cyclohexane solution, the fluorescence maxima shift towards the red region with increasing the polarity of the solvents, hence the transition involved are of ${\pi}-{\pi}^*$ type.

• Journal of Photoscience
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• 제10권3호
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• pp.237-240
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• 2003

The tetradecameric peptide (K47-K60) near the NH$_2$-terminal region of epithelial-cell adhesion molecule (Ep-CAM) was chosen as antigenic site and a polyclonal antibody was generated, which could recognize Ep-CAM from the mouse colon tissue or the colon cancer cell, CT-26, in Western blot analysis. Then, the fluorescein isothiocyanate (FITC), a fluorescence dye, was conjugated with the affinity purified Ep-CAM antibody using thiocyanate and the amino groups of FITC and antibody, respectively. The molar ratio of FITC to antibody was estimated approximately 1.86 to 1.00 by measuring the optical densities at 492 nm and 280 nm. Ep-CAM antibody-FITC conjugate was then used for immunohistochemistry of the CT-26 cells. Judging from the shapes formed by fluorescence, the Ep-CAM antibody could delivered FITC to the surface of cells in which Ep-CAM was expressed. This result implies that Ep-CAM antibody could be also used for the tissue-specific delivery of the photosensitizer to the target protein via antigen-antibody interaction.

• 한국자기공명학회논문지
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• 제18권1호
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• pp.36-40
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• 2014

Predicting secondary structure of protein through assigned backbone chemical shifts has been used widely because of its convenience and flexibility. In spite of its usefulness, chemical shift based analysis has some defects including isotopic shifts and solvent interaction. Here, it is shown that corrected chemical shift analysis for secondary structure of protein. It is included chemical shift correction through consideration of deuterium isotopic effect and calculate chemical shift index using probability-based methods. Enhanced method was applied successfully to one of the proteins from Mycobacterium tuberculosis. It is suggested that correction of chemical shift analysis could increase accuracy of secondary structure prediction of protein and small molecule in solution.

• Journal of Photoscience
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• 제7권3호
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• pp.79-86
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• 2000

Phytochromes are red and far-red light absorbing photoreceptors for photomorphogenesis in plants. The red/far wavelength reversible biliproteins are made up of two structural domains. The light-perceiving function of the photoreceptor resides in the N-terminal domain, whereas the signal transducing regulatory function is located within the C-terminal domain. The characteristic role of the phytochromes as phtosensory molecular switches is derived from the phototransformation between two distinct spectral forms, the red light absorbing Pr and the far-red light absorbing Pfr forms. The photoinduced Pr Pfr phototransformation accompanies subtle conformational changes throughout the phytochrome molecule. The conformational signals are subsequently transmitted to the C-terminal domain through various inter-domain crosstalks and induce the interaction of the activated C-terminal domain with phytochrome interacting factors. Thus the inter-domain crosstalks play critical roles in the photoactivation of the phytochromes. Posttranslational modifications, such as the phosphorylation of Ser-598, are also involved in this process through conformational changes and by modulating inter-domain signaling.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.791-794
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• 2006

Cyclosophoraose (cyclic $\beta-(1,2)-glucan$, Cys) isolated from Rhizobium meliloti, a soil microorganism, was used as a solubility enhancer for flavonoids. The complexes of the cyclic oligosaccharide with flavonoids were confirmed through $^1H$ nuclear magnetic resonance (NMR) spectroscopic analysis. Flavonoids solubilized by Cys were quantitatively analyzed through high-performance liquid chromatography (HPLC). Among the flavonoids tested, the solubility of naringenin was greatly enhanced by Cys, compared with other compounds. The solubility of naringenin was enhanced about 7.1-fold by adding 10 mM Cys, compared with a control. $^1H$ NMR spectroscopic analysis indicated that the H-6 and H-8 protons, which are located on the A ring of naringenin, were greatly shifted upfield upon the complexation with Cys. This result suggested that Cys showed a regioselective interaction with the naringenin molecule upon the complexation, resulting in the solubility enhancement of naringenin.

• Archives of Pharmacal Research
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• 제27권9호
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• pp.978-983
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• 2004

The effects of glycyrrhizic acid (GLZ) on protein binding of diltiazem, verapamil, and nifedipine were investigated. Protein binding studies (human serum, human serum albumin (HSA) and (X1-acid glycoprotein (AAG)) were conducted using the equilibrium dialysis method with and without addition of GLZ. The binding parameters, such as the number of moles of bound drug per mole of protein, the number of binding sites per protein molecule, and the association con-stant, were estimated using the Scatchard plot. The serum binding of nifedipine, verapamil, and diltiazem was displaced with addition of GLZ, and the decreases of Ks for serum were observed. GLZ decreased the association constants of three drugs for HSA and AAG, while the binding capacity remained similar with addition of GLZ. Although the characteristics of interaction were not clear, GLZ seemed to mainly affect HSA binding of nifedipine rather than AAG binding, while GLZ seemed to affect both AAG- and HSA-bindings of verapamil and dilt-iazem resulting in a serum binding displacement.

• Interaction and multiscale mechanics
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• 제4권3호
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• pp.219-237
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• 2011

Recent advances in scientific computing enable the full atomistic simulation of DNA molecules. However, there exists length and time scale limitations in molecular dynamics (MD) simulation for large DNA molecules. In this work, a two-level homogenization of DNA molecules is proposed. A wavelet projection method is first introduced to form a coarse-grained DNA molecule represented with superatoms. The coarsened MD model offers a simplified molecular structure for the continuum description of DNA molecules. The coarsened DNA molecular structure is then homogenized into a three-dimensional beam with embedded molecular properties. The methods to determine the elasticity constants in the continuum model are also presented. The proposed continuum model is adopted for the study of mechanical behavior of DNA loop.

• Journal of Ginseng Research
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• 제20권1호
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• pp.23-29
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• 1996

The effect of ginseng glycosides and their aglycones on the thermodynamic characteristics of membranes from dipalmitoylphosphatidylcholine (DPPC) was investigated. Total saponins (TS) from Korean red ginseng, Panax ginseng C.A. Meyer, interacted with the Eel Phase of lipid in the Polar region and did not penetrate the deeper glycerol backbone of lipid molecule. From the all investigated components of TS (aglycons and ginsenosides), only 20-(S)-panaxadiol (PD) had an effect similar to TS. High concentration of TS penetrated in hydrophobic Cl-C8 region. The presence of cholesterol did not influence the interaction of TS with DPPC. An elimination of transition, however, took place at 10~100 $\mu\textrm{g}$/ml of TS. DPPC had a low ability to interact with cholesterol (CHL) as compared with other lecithins except ethanolamine. From our results, only TS and PD, at high concentrations (100 mol%), influenced the phase transition of mixture of DPPC:CHL.