• Molecules and Cells
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• v.22 no.2
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• pp.141-145
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• 2006

Uric acid is the end product of the purine degradation pathway in humans. It is catabolized to allantoin by urate oxidase or uricase (E.C. 1.7.3.3.) in most vertebrates except humans, some primates, birds, and certain species of reptiles. Here we provide evidence that mouse transthyretin-related protein facilitates the hydrolysis of 5-hydroxyisourate, the end product of the uricase reaction. Mutagenesis experiments showed that the residues that are absolutely conserved across the TRP family, including His11, Arg51, His102, and the C-terminal Tyr-Arg-Gly-Ser, may constitute the active site of mTRP. Based on these results, we propose that the transthyretin-related proteins present in diverse organisms are not functionally related to transthyretin but actually function as hydroxyisourate hydrolases.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.1
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• pp.8-11
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• 2021

Transthyretin (TTR) is an important transporter protein for thyroxine (T4) and a holo-retinol protein in human. In its native state, TTR forms a tetrameric complex to construct the hydrophobic binding pocket for T4. On the other hand, this protein is also infamous for its amyloidogenic propensity, which causes various human diseases, such as senile systemic amyloidosis and familial amyloid polyneuropathy/cardiomyopathy. In this work, to investigate various structural features of TTR with solution-state nuclear magnetic resonance (NMR) spectroscopy, we conducted backbone NMR signal assignments. Except the N-terminal two residues and prolines, backbone 1H-15N signals of all residues were successfully assigned with additional chemical shift information of 13CO, 13Cα, and 13Cβ for most residues. The chemical shift information reported here will become an important basis for subsequent structural and functional studies of TTR.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.1
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• pp.1-4
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• 2023

Transthyretin (TTR) is an indispensable transporter protein of thyroxine and a retinol molecule in humans. TTR has a stable homo-tetrameric structure in its native state, while upon dissociation into monomers, it becomes aggregation-prone and can form an amyloid fibril. Although the amyloidogenic propensity of TTR has been known and investigated since the late 1990s, the structural information regarding TTR's amyloidogenic species is still elusive. Here, we employed high-pressure nuclear magnetic resonance (HP-NMR) approaches on the monomeric variant of TTR (TTR[F87M/L110M]; M-TTR) and observed that it experiences a two-step transition in response to the pressurized condition. Our study demonstrated that M-TTR in an ambient condition has heterogeneous structural features, which is likely related to the amyloidogenic propensity of TTR.

• Journal of Life Science
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• v.26 no.2
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• pp.253-258
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• 2016

In this study, nano-micelled curcumin was produced with natural sea salt with a view to comparing the in silico molecular binding affinity of pure curcumin compound to the active site of transthyretin. Using an optical light microscope and an electron microscope, it was found that the structure of the surface and the cross-section of nano-micelled curcumin was significantly different from natural sea salt. In particular, the crystal structure and nano-components in the nano-micelled curcumin were united, and the layer was more strongly stabilized than untreated salts. In the virtual 3D structure, in silico molecular docking study, the ligand binding affinity of nano-micelled curcumin to the transthyretin active site was found to be higher than that of pure curcumin. In addition, a nano-micelled curcumin formula interacted with more amino acid residues of transthyretin domains. The pharmacophore feature of the nano-micelled curcumin also showed more condensed and constrained features than normal curcumin. These results suggest that nano-micelled curcumin may effectively bind to and stabilize transthyretin, thereby regulating transthyretin-related physiological diseases. Collectively, the nano-micelled curcumin process suggests that normal curcumin can be modified more efficiently into the novel bio-functional chemical formula to stabilize the transthyretin structure. Therefore, the nano-micelled curcumin process can be applied to the field of the regulation of Alzheimer's disease.

• Journal of the Korean Magnetic Resonance Society
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• v.24 no.3
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• pp.91-95
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• 2020

Transthyretin (TTR) is an abundant protein in blood plasma and cerebrospinal fluid (CSF), working as a homo-tetrameric complex to transport thyroxine (T₄) and a holo-retinol binding protein. TTR is well-known for its amyloidogenic property; several types of systemic amyloidosis diseases are caused by aggregation of either wild-type TTR or its variants, for which more than 100 mutations were reported to increase the amyloidogenicity of TTR. The rate-limiting step of TTR aggregation is the dissociation of a monomeric subunit from a tetrameric complex. A wide range of biochemical and biophysical techniques have been employed to elucidate the TTR aggregation processes, among which nuclear magnetic resonance (NMR) spectroscopy contributed much to characterize the structural and functional features of TTR during its aggregation processes. The present review focuses on discussing the recent advances of our understanding to the amyloidosis mechanism of TTR and to the structural features of its monomeric aggregation-prone state in solution. We expect that the present review provides novel insights to appreciate the molecular basis of TTR amyloidosis and to develop novel therapeutic strategies to treat diverse TTR-related diseases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.684-692
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• 2003

The herbal extract(YMT_02) is a modified extracts from Yukmijihwang-tang(YMJ) to promote memory-enhancing. The YMJ extracts has been widely used as replenishing yin and tonifying the kidneys herbal medicine for hundred years ia Asian countries. The purpose of this study is to: 1) quantitatively evaluate the memory-enhancing effect of YMT_02 by passive avoidance test, 2) statistical evaluation of candidate gene expression (pentraxin. PEP-19, transthyretin) in rat hippocampus. The hippocampi of YMT_02 and control group were dissected and mRNA was further purified. After synthesizing cDNA using oligo-dT primer, the cDNA were applied to Real Time PCR. The results were as follows : 1) passive avoidance test showed enhancing memory retentin by YMT_02 treatment, 2) expression of pentraxin, that accelerate degenerating of neuronal cell, was significantly decreased, 3) the mRNA of genes that has been known to be associated with protecting neuronal cell degeneration, such as PEP-19 and transthyretin, were significantly increased upon YMT_02 treatment. From above results, the administration of YMT_02 which tonify the function of Kidneys could enhance the ability of memory and learning. In addition, the administration of YMT_02 enhance memory retention through modulating particular gene (pentraxin, PEP-19, transthyretin) expressions in hippocampu.

• Korean Circulation Journal
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• v.53 no.5
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• pp.347-349
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• 2023

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.621-627
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• 2017

The understanding of the mechanical properties of amyloid fibers, which induce various neurodegenerative diseases, is directly related to the amyloid growth mechanism. Diverse studies have been performed on amyloid fibers from the viewpoint of disease epidemiology. Recently, attempts have been made to use amyloid fibers as new materials because of their notable mechanical properties and self-aggregation abilities. In this study, the mechanical properties of transthyretin (TTR105-115), which induces cardiovascular disease, were evaluated using a molecular dynamics (MD) simulation. In particular, the effect of the end-terminal capping on the structural stability of TTR105-115 was evaluated. The mechanical behavior and properties of TTR105-115 were measured by steered molecular dynamics (SMD). We clarified the factors affecting the mechanical properties of these materials and suggested the possibility of utilizing them as nature inspired materials.

• Animal Bioscience
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• v.36 no.9
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• pp.1367-1375
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• 2023

Objective: Pigment production and distribution are controlled through multiple proteins, resulting in different coat color phenotypes of sheep. Methods: The expression distribution of vimentin (VIM) and transthyretin (TTR) in white and black sheep skins was detected by liquid chromatography-electrospray ionization tandem MS (LC-ESI-MS/MS), gene ontology (GO) statistics, immunohistochemistry, Western blot, and quantitative real time polymerase chain reaction (qRT-PCR) to evaluate their role in the coat color formation of sheep. Results: LC-ESI-MS/MS results showed VIM and TTR proteins in white and black skin tissues of sheep. Meanwhile, GO functional annotation analysis suggested that VIM and TTR proteins were mainly concentrated in cellular components and biological process, respectively. Further research confirmed that VIM and TTR proteins were expressed at significantly higher levels in black sheep skins than in white sheep skins by Western blot, respectively. Immunohistochemistry notably detected VIM and TTR in hair follicle, dermal papilla, and outer root sheath of white and black sheep skins. qRT-PCR results also revealed that the expression of VIM and TTR mRNAs was higher in black sheep skins than in white sheep skins. Conclusion: The expression of VIM and TTR were higher in black sheep skins than in white sheep skins and the transcription and translation were unanimous in this study. VIM and TTR proteins were expressed in hair follicles of white and black sheep skins. These results suggested that VIM and TTR were involved in the coat color formation of sheep.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.9 no.1
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• pp.27-28
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• 2009