https://repository.kopri.re.kr/handle/201206/11928 Wed, 22 Apr 2026 08:02:18 GMT 2026-04-22T08:02:18Z https://repository.kopri.re.kr/handle/201206/16002 Title: Synthesis of Short-Chain Alkyl Butyrate through Esterification Reaction Using Immobilized Rhodococcus Cutinase and Analysis of Substrate Specificity through Molecular Docking Authors: Seok-Jae Won; Yim, Joung Han; Hyung Kwoun Kim Abstract: Alkyl butyrate with fruity flavor is known as an important additive in the food industry. We synthesized various alkyl butyrates from various fatty alcohol and butyric acid using immobilized Rhodococcus cutinase (Rcut). Esterification reaction was performed in a non-aqueous system including heptane, isooctane, hexane, and cyclohexane. As a result of performing the alkyl butyrate synthesis reaction using alcohols of various chain lengths, it was found that the preference for the alcohol substrate had the following order: C6 > C4 > C8 > C10 > C2. Through molecular docking analysis, it was found that the greater the hydrophobicity of alcohol, the higher the accessibility to the active site of the enzyme. However, since the number of torsions increased as the chain length increased, it became difficult for the hydroxyl oxygen of the alcohol to access the γO of serine at the enzyme active site. These molecular docking results were consistent with substrate preference results of the Rcut enzyme. The Rcut maintained the synthesis efficiency at least for 5 days in isooctane solvent. We synthesized as much as 452 mM butyl butyrate by adding 100 mM substrate daily for 5 days and performing the reaction. These results show that Rcut is an efficient enzyme for producing alkyl butyrate used in the food industry. Sun, 01 Jan 2023 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/16002 2023-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/13559 Title: Purification and characterization of a new cold-active cellulolytic enzyme produced by Pseudoalteromonas sp. ArcC09 from the Arctic Beaufort Sea Authors: Kim, Min Ju; Park, Ha Ju; Kang, Pilsung; Kim, Il Chan; Yim, Joung Han; Han, Se Jong Abstract: A cold-active endoglucanase-producing bacterium was isolated from the Beaufort Sea of the Arctic Ocean and identified as Pseudoalteromonas sp. ArcC09. Cellulolytic activity of ArcC09 reached a maximum of 60 U/mg when cultivated in ZoBell medium for 72 h at 15 °C. This purified endoglucanase, with a molecular mass of 28 kDa, exhibited maximum activity at pH 7.0 and 55 °C. The ArcC09 endoglucanase exhibited 10% and 36% of its maximal activity even at low temperatures of 5 °C and 15 °C, respectively. However, it showed lower thermal stability than a mesophilic cellulase, which is characteristic of a psychrophilic enzyme. The activity was inhibited by CuSO4, and linear alkylbenzene sulfonate (LAS). These findings supplement the understanding of cold-active endoglucanases and may have commercial applications in enzymatic digestion of cellulosic biomass to fermentable sugars. Sun, 01 May 2022 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/13559 2022-05-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16181 Title: Functional production, characterization, and immobilization of a cold-adapted cutinase from Antarctic Rhodococcus sp. Authors: Won, Seok-Jae; Yim, Joung Han; Kim, Hyung-Kwoun Abstract: A lipolytic enzyme (Rcut) was discovered from the Rhodococcusstrain (RosL12) isolated from the Antarctic Ross Sea. The corresponding gene composed of 651 bases encoding 216 amino acids. It was found to be a cutinase gene through BLAST search. Rcut has a signal sequence consisting of 29 amino acids. An active Rcut was produced after the intact gene containing the signal sequence was transformed into Escherichia coli Rosetta-gami™ 2(DE3) pLysS. Rcut was purified through a nickel-nitrilotriacetic acid purification system and a carboxymethyl Sepharose column chromatography. Its specific activity was 2190 U/mg. Rcut showed the highest activity at 40 and had a low activation energy of 3.16 kcal/mol. This means that it is a typical cold-adapted enzyme. Rcut showed high activity towards medium chain fatty acids (C4-C10). Rcut degraded polycaprolactone and polyethylene terephthalate, suggesting that it could be used for decomposition of synthetic plastics causing environmental pollution. Rcut was immobilized on methacrylate-divinyl benzene bead. This immobilized Rcut (immRcut) showed higher thermal stability than the free enzyme. ImmRcut performed transesterification of various esters and ethanol in a non-polar solvent, suggesting that it could be used for the synthesis of industrially useful ester compounds. Sat, 01 Jan 2022 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/16181 2022-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/13271 Title: A new α-pyrone from Arthrinium pseudosinense culture medium and its estrogenic activity in MCF-7 cells Authors: Kwon, Haeun; Nguyen, Quynh Nhu; Na, Myung Woo; Kim, Ki Hyun; Guo, Yuanqiang; Yim, Joung Han; Shim, Sang Hee; Kim, Jae-Jin; Kang, Ki Sung; Lee, Dongho Abstract: A new α-pyrone analog, arthrifuranone A (1) was isolated from an EtOAc-extract of Arthrinium pseudosinense culture medium. The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structure of the new compound was elucidated using MS and NMR spectroscopic techniques, and the absolute configuration was established by the Mosher’s method and gauge-including atomic orbital NMR chemical shift calculations, followed by DP4 + analysis. The isolated compound was evaluated for its estrogenic activity using the MCF-7 estrogen responsive human breast cancer cells. Compound 1 showed estrogenic activity by increasing the proliferation of MCF-7 cells at the concentration of 3.125 μM via phosphorylation of estrogen receptor-α. Wed, 01 Dec 2021 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/13271 2021-12-01T00:00:00Z