• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3650-3654
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• 2011

Two new unusual soyasaponins named 6"-O-methyldehydrosoyasaponin I(7) and desglucosylsoyasaponin $A_1$ (10) along with eight known saponins, dehydrosoyasaponin IV (1), dehydrosoyasaponin III (= impatienoside A) (2), soyasaponin III (3), dehydrosoyasaponin II (= soyasaponin Bg) (4), soyasaponin II (5), dehydrosoyasaponin I (= soyasaponin Be) (6), soyasaponin I (8), and kudzusaponin $SA_3$ (9), were isolated as their methyl esters and identified from the liquid culture of G. applanatum. Their structures were determined by chemical and spectroscopic analyses including 1D- and 2D-NMR as well as by comparison of their spectroscopic data with those of the reported in literatures. Although dehydrosoyasaponin IV was identified by LC-MS/MS method from soy protein isolate, this is the first report of the isolation of this compound. Dehydrosoyasaponin III (2) and kudzusaponin $SA_3$ (9) were also isolated for the first time from soybean. The presence of soyasaponins in Ganoderma species seems to be unusual feature. Thus, we presumed that compounds 1-10 might all be derived from the defatted soybean flour which was added to the culture medium as a nitrogen source.

• Korean Journal of Biological Psychiatry
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• v.17 no.4
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• pp.177-193
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• 2010

Significant advances have been made in understanding the biological underpinnings of post-traumatic stress disorder(PTSD), particularly in the field of genetics and neuroimaging. Association studies in candidate genes related with hypothalamic-pituitary-adrenal axis, monoamines including serotonin, dopamine and noradrenaline, and proteins including FK506-binding protein 5 and brain-derived neurotrophic factor have provided important insights with regard to the vulnerability factors in PTSD. Genome-wide association studies and epigenetic studies may provide further information for the role of genes in the pathophysiology of PTSD. Hippocampus, medial prefrontal cortex, anterior cingulated cortex and amygdala have been considered as key structures that underlie PTSD pathophysiology. Future research that combines genetic and neuroimaging information may provide an opportunity for a more comprehensive understanding of PTSD.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.545-548
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• 2013

It has been shown that calculating atomic charges using quantum mechanical level theory greatly improves the accuracy of docking. A protocol was developed and shown to be effective. That this protocol works is just a manifestation of the fact that electrostatic interactions are important in protein-ligand binding. In order to investigate how the same protocol helps in prediction of binding affinities, we took a series of known cocrystal structures of influenza neuraminidase inhibitors with the receptor and performed docking with Glide SP, Glide XP, and QPLD, the last being a workflow that incorporates QM/MM calculations to replace the fixed atomic charges of force fields with quantum mechanically recalculated ones at a given docking pose, and predicted the binding affinities of each cocrystal. The correlation with experimental binding affinities considerably improved with QPLD compared to Glide SP/XP yielding $r^2$ = 0.83. The results suggest that for binding sites, such as that of neuraminidase, which are laden with hydrophilic residues, protocols such as QPLD which utilizes QM-based atomic charges can better predict the binding affinities.

• Genomics & Informatics
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• v.11 no.4
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• pp.289-291
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• 2013

Human papillomavirus (HPV) infection is the leading cause of cancer mortality among women worldwide. The molecular understanding of HPV proteins has significant connotation for understanding their intrusion in the host and designing novel protein vaccines and anti-viral agents, etc. Genomic, proteomic, structural, and disease-related information on HPV is available on the web; yet, with trivial annotations and more so, it is not well customized for data analysis, host-pathogen interaction, strain-disease association, drug designing, and sequence analysis, etc. We attempted to design an online reserve with comprehensive information on HPV for the end users desiring the same. The Human Papillomavirus Proteome Database (hpvPDB) domiciles proteomic and genomic information on 150 HPV strains sequenced to date. Simultaneous easy expandability and retrieval of the strain-specific data, with a provision for sequence analysis and exploration potential of predicted structures, and easy access for curation and annotation through a range of search options at one platform are a few of its important features. Affluent information in this reserve could be of help for researchers involved in structural virology, cancer research, drug discovery, and vaccine design.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1361-1370
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• 2015

A blue laccase was purified from a white rot fungus of Trametes trogii, which was a monomeric protein of 64 kDa as determined by SDS-PAGE. The enzyme acted optimally at a pH of 2.2 to 4.5 and a temperature of 70℃ and showed high thermal stability, with a half-life of 1.6 h at 60℃. A broad range of substrates, including the non-phenolic azo dye methyl red, was oxidized by the laccase, and the laccase exhibited high affinity towards ABTS and syringaldazine. Moreover, the laccase was fairly metal-tolerant. A high-molecular-weight kraft lignin was effectively polymerized by the laccase, with a maximum of 6.4-fold increase in weight-average molecular weight, as demonstrated by gel permeation chromatography. Notable structural changes in the polymerized lignin were detected by Fourier transform infrared spectroscopy and ¹H NMR spectroscopy. This revealed an increase in condensed structures as well as carbonyl and aliphatic hydroxyl groups. Simultaneously, phenolic hydroxyl and methoxy groups decreased. These results suggested the potential use of the laccase in lignin modification.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.539-548
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• 2010

Potassium ($K^+$) is one of the most abundant cations in higher plant. It comprises about 10% of plant dry weight and it plays roles in numerous functions such as osmo- and turgor regulation, charge balance of plasma membrane and control of stomata and organ movement. Several potassium transporters and potassium channels regulate $K^+$ homeostasis in response to $K^+$ uptake systems. In this review, we describe the biological, biochemical and physiological characteristics of shaker like potassium channels in higher plant. Especially, we searched the rice genome databases and analysized expressed genes, genome structures and protein domain characteristics of shaker like potassium channels.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.2
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• pp.172-184
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• 2012

The prokaryotic molecular chaperone Hsp33 achieves its holdase activity upon response to oxidative stress particularly at elevated temperature. Despite many structural studies of Hsp33, which were conducted mainly by X-ray crystallography, the actual structures of the Hsp33 in solution remains controversial. Thus, we have initiated NMR study of the reduced, inactive Hsp33 monomer and backbone NMR assignments were obtained in the present study. Based on a series of triple resonance spectra measured on a triply isotope-[$^2H/^{13}C/^{15}N$]-labeled protein, sequence-specific assignments of the backbone amide signals observed in the 2D-[$^1H/^{15}N$]TROSY spectrum could be completed up to more than 96%. However, even considering the small portion of non-assigned resonances due to the lack of sequential connectivity, we confirmed that the total number of observed signals was quite smaller than that expected from the number of amino acid residues in Hsp33. Thus, it is postulated that peculiar dynamic properties would be involved in the solution structure of the inactive Hsp33 monomer. We expect that the present assignment data would eventually provide the most fundamental and important data for the progressing studies on the 3-dimensional structure and molecular dynamics of Hsp33, which are critical for understanding its activation process.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.77-81
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• 2014

Hyaluronic acid is a disaccharide polymer that consists of glucuronic acid and N-acetylglucosamine, and is a glycosaminoglycan. It is widely distributed in animal connective tissue, coexisting with chondroitin sulfate. It forms viscous secretions or gel by bonding to protein in the body, and thus maintains and lubricates tissue structures. In addition, its antibiotic properties are applied to cosmetics and pharmaceuticals. Therefore, it has recently been an object of great interest at cosmetic and pharmaceutical companies. $^{125}I$ has a longer half-life (59.4 days) than many other radioisotopes, and is therefore useful to long-term studies. In this study, a facile and efficient procedure for the synthesis of $^{125}I$-labeled hyaluronic acid has been designed for in vivo imaging and pharmacokinetic studies of hyaluronic acid, which are required for the development of new drugs.

• Food Science and Industry
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• v.50 no.1
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• pp.26-35
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• 2017

Obesity is a worldwide problem that is associated with metabolic disorders. Obesity is caused by the accumulation of an abnormal amount of body fat in adipose tissue. Adipose tissue is a major metabolic organ, and it has been classified as either white adipose tissue (WAT) or brown adipose tissue (BAT). WAT and BAT are characterized by different anatomical locations, morphological structures, functions, and gene expression patterns. WAT is mainly involved in the storage and mobilization of energy in the form of triglycerides. On the other hand, BAT specializes in dissipating energy as heat through uncoupling protein-1 (UCP-1)-mediated non-shivering thermogenesis. Novel type of brown-like adipocyte within WAT called beige/brite cells was recently discovered, and this transdifferentiation process is referred to as the "browning" or "britening" of WAT. Recently, Brown fat and/or browning of WAT have been highlights as a new therapeutic target for treatment of obesity and its related metabolic disorders. Here, we describe recent advances in the study of BAT and browning of WAT, focusing on proteomic approaches.

• Smart Structures and Systems
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• v.26 no.6
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• pp.809-817
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• 2020

In cells, the microtubules are surrounded by viscoelastic medium. Microtubules, though very small in size, perform a vital role in transportation of protein and in maintaining the cell shape. During performing these functions waves propagate and this propagation of waves has been investigated using nonlocal elastic theory. But the effect of surrounding medium was not taken into account. To fill this gap, this study considers the viscoelastic medium along with nonlocal elastic theory. The analytical formulas of the velocity of waves, and the results reveal that the presence of medium reduces the velocity. The axisymmetric and nonaxisymmetric waves are separately discussed. Furthermore, the results are compared with the results gained from the studies of free microtubules. The presence of medium around microtubules results in the increase of the flexural rigidity causing a significant decrease in radial wave velocity as compared to axial and circumferential wave velocities. The effect of viscoelastic medium is more obvious on radial wave velocity, to a lesser extent on torsional wave velocity and least on longitudinal wave velocity.