https://repository.kopri.re.kr/handle/201206/11897 2026-04-21T10:58:40Z 2026-04-21T10:58:40Z Chang Min Kim Hyunseok Jang Eunmi Hong Lee, Jun Hyuck Hyun Ho Park https://repository.kopri.re.kr/handle/201206/16404 2025-11-06T08:13:57Z 2023-01-01T00:00:00Z

Title: Structure of fish TRAF4 and its implication in TRAF4-mediated immune cell and platelet signaling Authors: Chang Min Kim; Hyunseok Jang; Eunmi Hong; Lee, Jun Hyuck; Hyun Ho Park Abstract: Due to an increasing interest in immunity and signal transduction in teleost fish, important key signaling molecules associated with the immune response, including TRAF molecules, have been recently cloned and characterized. To better understand the role of TRAF4 in fish immune signaling and compare it with the human system, our study cloned the TRAF4 gene from the Antarctic yellowbelly rockcod Notothenia coriiceps (ncTRAF4) and purified the protein. Here, we report the first crystal structure of teleost fish TRAF4. Based on biochemical characterization, our findings elucidated the mechanisms through which signaling molecules gain cold adaptivity. Additionally, we identified a platelet receptor GPIbβ homolog in N. coriiceps (ncGPIbβ) and found that the “RRFERLFKEARRTS” region of this homolog directly binds to ncTRAF4, indicating that ncTRAF4 also recognizes the “RLXA” motif for receptor interactions and further TARF4-mediated cellular signaling. Collectively, our findings provide novel insights into the mechanisms of TRAF4-mediated immune cell and platelet signaling in fish and the structural flexibility-mediated cold adaptiveness of signaling molecules.

2023-01-01T00:00:00Z Ahn, Yong-Yoon Kim, Jungwon Kim, Kitae https://repository.kopri.re.kr/handle/201206/13825 2022-09-07T02:05:24Z 2022-02-15T00:00:00Z

Title: Frozen Hydrogen Peroxide and Nitrite Solution: The Acceleration of Benzoic Acid Oxidation via the Decreased pH in Ice Authors: Ahn, Yong-Yoon; Kim, Jungwon; Kim, Kitae Abstract: We investigated benzoic acid oxidation via the reaction of hydrogen peroxide (H2O2) and nitrite (NO2 -). The oxidation of benzoic acid by reactive nitrous acid (HONO) was negligible, and the reactivity of the H2O2/NO2- system decreased with a decrease in temperature under aqueous conditions. However, freezing markedly accelerated the chemical reaction. Based on Raman microscope measurements, concentrated species were confirmed in certain regions of the ice. We proposed that the change in nitrite speciation (accordingly, a decrease in the pH below pKa), derived from the freezing concentration effect, was the reason for the accelerated reactions. The oxidation characteristics of the system were monitored under varying conditions, such as initial pH, dosage ratio, benzoic acid concentration, and reaction with various benzene derivatives. The ultrahigh-performance liquid chromatography/electrospray ionization/mass spectrometry (UHPLC/ESI/MS) measurement showed that peroxynitrous acid (HOONO)-mediated oxidation generated hydroxylated and nitrated byproducts. Additionally, decarboxylated products were detected, indicating direct electron transfer from the organic compounds to HOONO. As freezing is a global phenomenon, and H2O2 and NO2- are ubiquitous in the environment, the transformation of aromatic compounds with H2O2/NO2- in cold environments must be considered in environmental chemistry.

2022-02-15T00:00:00Z Lee, Seulah Jeong, Se Yun NGUYEN, Dieu Linh So, Jae Eun Kim, Ki Hyun Kim, Ji Hee Han, Se Jong Suh, Sung-Suk Lee, Jun Hyuck Youn, Ui Joung https://repository.kopri.re.kr/handle/201206/13301 2022-04-14T05:20:40Z 2022-02-01T00:00:00Z

Title: Stereocalpin B, a New Cyclic Depsipeptide from the Antarctic Lichen Ramalina terebrata Authors: Lee, Seulah; Jeong, Se Yun; NGUYEN, Dieu Linh; So, Jae Eun; Kim, Ki Hyun; Kim, Ji Hee; Han, Se Jong; Suh, Sung-Suk; Lee, Jun Hyuck; Youn, Ui Joung Abstract: Stereocalpin B, a new cyclic depsipeptide (1), and a new dibenzofuran derivative (3), were isolated from the Antarctic lichen, Ramalina terebrata (Ramalinaceae), along with a known cyclic depsipeptide (2). The structures of new compounds were characterized by comprehensive spectrometric analyses; high-resolution fast atom bombardment mass spectrometry (HR-FABMS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Stereocalpin B (1) existed in a rotameric equilibrium, which was confirmed using nuclear Overhauser effect spectroscopy (NOESY)/exchange spectroscopy (EXSY) spectrum. Absolute configurations of the amino acid units in 1 were assigned using the advanced Marfey's method and subsequent NOESY analysis of the 5-hydroxy-2,4-dimethyl-3-oxo-decanoic acid residue confirmed the complete stereochemistry of 1. Compounds 1-3 exhibited moderate antimicrobial activities against E. coli, with the IC50 values ranging from 18-30 mu g/mL. Compound 2 exhibited cell growth inhibition against HCT116 cell lines, with the IC50 value of 20 +/- 1.20 mu M, and compounds 1 and 2 also showed potent anti-inflammatory activities against lipopolysaccharide (LPS)-induced RAW264.7 macrophages with the IC50 values ranging from 5-7 mu M.

2022-02-01T00:00:00Z Kim, Kitae Nhat Thi Hong Le Anh Quoc Khuong Nguyen 안용윤 Kim, Bomi 신관용 최원용 김정원 https://repository.kopri.re.kr/handle/201206/13821 2022-09-05T16:36:42Z 2022-01-01T00:00:00Z

Title: Freezing-induced activation of the binary chloride-Oxone system to free chlorine and its application in water treatment Authors: Kim, Kitae; Nhat Thi Hong Le; Anh Quoc Khuong Nguyen; 안용윤; Kim, Bomi; 신관용; 최원용; 김정원 Abstract: Accelerated chemical reactions in frozen solutions can be applied in the degradation of organic pollutants in water. Herein we propose a novel freezing system that enables the degradation of various organic compounds in a frozen solution. Although the degradation of 4-chlorophenol (4-CP) by Oxone as the sole primary oxidant did not take place in aqueous solutions (25 °C) regardless of the presence of chloride ions (Cl？, micromolar levels) and only took place to a minor extent in frozen solutions (？20 °C) in the absence of Cl？, the addition of Cl？ (micromolar levels) to the freezing/Oxone system significantly accelerated the degradation of 4-CP. Various analytical characterizations and pH measurements of the frozen solution suggested that the enhanced degradation of 4-CP in the freezing/Oxone/Cl？ system could be because Cl？, Oxone, and protons are concentrated in the liquid brine upon freezing. This process subsequently facilitates the formation of hypochlorous acid (HOCl) as a secondary oxidant. The positive effect of Cl？ was observed under widely varying conditions (i.e., [Cl？] = 25？1000 μM, pHi = 3？11, and freezing temperature = from ？10 to ？30 °C), and the freezing/Oxone/Cl？ system described herein successfully degraded all 12 tested organic pollutants. In addition, outdoor freezing experiments carried out on winter days confirmed the successful performance of the freezing/Oxone/Cl？ system without the requirement for electrical energy.

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