• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.16-21
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• 2011

Immobilization of biosorbent is very important for application to real wastewater treatment process because biosorbent itself does not have enough tough structure. Therefore, resent research on heavy metal biosorption using biomass has been focused on its efficient immobilization method. To improve the mechanical strength of freely biosorbent, many immobilization methods have been suggested for applications to the biosorbent such as microorganisms or polysaccharides. In this study, various immobilization methods such as adsorption, covalent binding, entrapment, encapsulation, and crosslinking will be introduced.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.3
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• pp.39-44
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• 2021

The CRISPR-Cas system provides adaptive immunity for bacteria and archaea against invading phages and foreign plasmids. In the Class 1 CRISPR-Cas system, multi-subunit Cas proteins assemble with crRNA to bind to DNA targets. To disarm the bacterial defense system, bacteriophages evolved anti-CRISPR (Acr) proteins that actively inhibit the host CRISPR-Cas function. Here we report the backbone resonance assignments of AcrIF7 protein that inhibits the type I-F CRISPR-Cas system of Pseudomonas aeruginosa using triple-resonance nuclear magnetic resonance spectroscopy. We employed various computational methods to predict the structure and binding interface of AcrIF7, and assessed the model with experimental data. AcrIF7 binds to Cas8f protein via flexible loop regions to inhibit target DNA binding, suggesting that conformational heterogeneity is important for the Cas-Acr interaction.

• Advances in nano research
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• v.15 no.2
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• pp.105-111
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• 2023

Integrin αvβ3 is one of the receptors expressed in cancer cells. RGD peptides have the potential to target integrin αvβ3 (receptor), which can increase drug delivery efficiency. In this study, 55 different RGD dimer motifs were investigated. At first, the binding energy between RGD peptides and the receptor was calculated using molecular docking. Then, three RGD peptides with the strongest binding energy with the receptor were selected, and their dynamic adsorption on the receptor was simulated by molecular dynamics (MD). The obtained results showed that a sequence that has RGD at the beginning and end with tryptophan (TRP) has strong Lennard-Jones (LJ) and electrostatic interactions with Integrin αvβ3 and has changed the conformation of receptor significantly, which analyzed by root mean square deviation (RMSD) and radius of gyration.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.57-65
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• 2008

are nanometer or micrometer scale vesicles that can be used as drug delivery carriers. However, plain liposomes are plagued by rapid opsonization, making their circulation time in bloodstream be shortened. In this study, model protein, bovine serum albumin (BSA)-coated liposomes were prepared by coating cationic liposomes with BSA molecules at higher pH than isoelectric point of BSA. The BSA molecules coated on the liposomal surface were denatured by thermal treatment at above 60oC. While both plain and cationic liposomes had about mean particle diameter of 1041 nm, BSA-coated cationic liposomes (BCL) had mean particle diameter of 1091 nm. Encapsulation of model drug, doxorubicin (DOX), in liposomes were carried out by using remote loading method and the loading efficiency of DOX to liposomes was about 90%. The mean particle diameter of BCL did not increase in blood plasma and adsorption of plasma protein was much less than plain or cationic liposomes. These results suggest that BCL can be used as a long-circulating liposomes in bloodstream.

• the MEAT Journal
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• s.34 winter
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• pp.26-39
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• 2007

This study investigated the effect of salt and glucono-$\delta$-lactone (GdL) on the cold-set binding of restructured pork washed and pressurized at 200 MPa. Binding strength, pH, water holding capacity (WHC) and color were determined. NaCl improved pH, WHC and binding strength. GdL also increased binding strength while decreased WHC and pH significantly (p<0.05). However, low GdL level combined with NaCl showed high pH and WHC, compared to control. In color, NaCl decreased L*-value with increasing a*-value significantly (p<0.05). In contrast to NaCl, GdL increased L*-value and decreased a*-value. GdL tended to decrease b*-value and significant differences were found when GdL was added above 1%. Pearson’s correlation coefficients presented that NaCl had a significant effect on binding strength (0.6632) and lightness (?0.7330) while GdL had a significant correlation with all parameters barring binding strength. The results indicated that under washing and pressure treatments, GdL had a potential effect on cold-set binding with reducing NaCl concentration, especially when low GdL concentration combined with NaCl was added.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.2
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• pp.26-33
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• 2009

A new testing method to evaluate the deposition potential of white pitch was developed. The new method involves depositing the potential white pitch particles on the air bubble covered plastic film in the pitch deposit tester (PDT) developed by KRICT and analysing the deposited area of white pitch using an image analyzer. In addition, the effect of two important factors (pH and calcium hardness) on white pitch deposition potential was elucidated. When pH of the coated broke stock was increased from neutral to alkali or the calcium hardness of the stock was decreased, the pitch deposit area was decreased, implying that these two factors have to be controlled during the evaluation of pitch deposition potential. It was found that hydrophobicity of the surface of latex binding films repulped is a key factor influencing white pitch deposition.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3322-3326
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• 2013

A series of hybrid molecules between (${\alpha}$)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE ($IC_{50}=2.3{\pm}0.7{\mu}M$) and AChE ($IC_{50}=30.31{\pm}0.64{\mu}M$). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity ($K_i$) value to BuChE is $2.91{\pm}0.15{\mu}M$.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2897-2902
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• 2010

Seven fully optimized geometries of 3,6-dihydrazino-1,2,4,5-tetrazine (DHT) dimers have been obtained with density functional theory (DFT) method at the B3LYP/$6-311++G^{**}$ level. The intermolecular interaction energy was calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction energy of the dimers is $-23.69\;kJ{\cdot}mol^{-1}$. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. Based on the vibrational analysis, the changes of thermodynamic properties from the monomers to dimer with the temperature ranging from 200.0 K to 800.0 K have been obtained using the statistical thermodynamic method. It was found that the hydrogen bonds dominantly contribute to the dimers, while the binding energies are not only determined by hydrogen bonding. The dimerization process can not occur spontaneously at given temperatures.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1505-1509
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• 2008

Comparative molecular simulations were performed to establish molecular interaction and inhibitory effect of flavonoid myricetin on formation of amyloid fibris. For computational comparison, the conformational stability of myricetin with amyloid $\beta$ -peptide (A$\beta$ ) and $\beta$ -amyloid fibrils (fA$\beta$) were traced with multiple molecular dynamics simulations (MD) using the CHARMM program from Monte Carlo docked structures. Simulations showed that the inhibition by myricetin involves binding of the flavonoid to fA$\beta$ rather than A$\beta$ . Even in MD simulations over 5 ns at 300 K, myricetin/fA$\beta$ complex remained stable in compact conformation for multiple trajectories. In contrast, myricetin/A$\beta$ complex mostly turned into the dissociated conformation during the MD simulations at 300 K. These multiple MD simulations provide a theoretical basis for the higher inhibitory effect of myricetin on fibrillogenesis of fA$\beta$ relative to A$\beta$ . Significant binding between myricetin and fA$\beta$ observed from the computational simulations clearly reflects the previous experimental results in which only fA$\beta$ had bound to the myricetin molecules.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1427-1430
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• 2008

Decursinol, found in the roots of Angelica gigas Nakai, has been traditionally used to treat anemia and other various diseases. Recently, numerous biological activities such as cytotoxic effect on leukemia cells, and antitumor, neuroprotection, and antibacterial activities have been reported for this compound. Although a number of proteins including protein kinase C, androgen receptor, and acetylcholinesterase were proposed as molecular targets responsible for the activities of decursinol, they are not enough to explain such a diverse biological activity mentioned above. In this study, we employed a chemical proteomic approach, leading to identification of seven proteins as potential proteins interacting with decursinol. Most of the proteins contain a defined ATP or nucleic acid binding domain and have been implied to be involved in the pathogenesis and progression of various human diseases including cancer, autoimmune disorders, or neurodegenerative diseases. The present results may provide clues to understand the molecular mechanism of the biological activities shown by decursinol, an anticancer natural product.