https://repository.kopri.re.kr/handle/201206/5189 Tue, 21 Apr 2026 10:00:26 GMT 2026-04-21T10:00:26Z https://repository.kopri.re.kr/handle/201206/10402 Title: Increased Productivity and Antifreeze Activity of Ice-binding Protein from Flavobacterium frigoris PS1 Produced using Escherichia coli as Bioreactor Authors: Kim, Eun Jae; Kim, Jung Eun; Hwang, J. S.; Kim, Il-Chan; Lee, Sung Gu; Kim, Sanghee; Lee, Jun Hyuck; Han, Se Jong Abstract: Ice-binding proteins (IBPs) inhibit the growth and recrystallization of intracellular ice, enabling polar organisms to survive at subzero temperatures. IBPs are promising materials in biomedical applications such as cryopreservation and the hypothermic storage of cells, tissues, and organs. In this study, recombinant IBP from the antarctic bacterium Flavobacterium frigoris PS1 (FfIBP) was produced by Escherichia coli used as bioreactor, to examine the feasibility of scale-up. Oxygen transfer was the most important factor influencing cell growth and FfIBP production during pilot-scale fermentation. The final yield of recombinant FfIBP produced by E. coli harboring the pET28a-FfIBP vector system was 1.6 g/L, 3.8-fold higher than that from the previously published report using pCold I-FfIBP vector system, and its thermal hysteresis activity was 2.5°C at 9.7 μM. This study demonstrates the successful pilot-scale production of FfIBP. Sun, 01 Sep 2019 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/10402 2019-09-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/10403 Title: Characterization of two steroid hydroxylases from different Streptomyces spp. and their ligand­bound and ­unbound crystal structures Authors: Dangi, Bikash; Lee, Chang Woo; Kim, Ki-Hwa; Park, Sun-Ha; Yu, Eun-Ji; Jeong, Chang-Sook; Park, Hyun; Lee, Jun Hyuck; Oh, Tae-Jin Abstract: Bacterial cytochrome P450 (CYP) enzymes are involved in the hydroxylation of various endogenous substrates while using a heme molecule as a cofactor. CYPs have gained biotechnological interest as useful biocatalysts capable of altering chemical structures by adding a hydroxyl group in a regiospecific manner. Here, we identified, purified, and characterized two CYP154C4 proteins from Streptomyces sp. W2061 (StCYP154C4-1) and Streptomyces sp. ATCC 11861 (StCYP154C4-2). Activity assays showed that both StCYP154C4-1 and StCYP154C4-2 can produce 2？-hydroxylated testosterone, which differs from the activity of a previously described NfCYP154C5 from Nocardia farcinica in terms of its 16α-hydroxylation of testosterone. To better understand the molecular basis of the regioselectivity of these two CYP154C4 proteins, two crystal structures of the ligand-unbound form of StCYP154C4-1 and the testosterone-bound form of StCYP154C4-2 were determined. Comparison with the previously determined NfCYP154C5 structure revealed differences in the substrate-binding residues, suggesting a likely explanation for the different patterns of testosterone hydroxylation, despite the high sequence similarities between the enzymes (54% identity). These findings provide valuable insights that will enable protein engineering for the development of artificial steroid-related CYPs exhibiting different regiospecificity. Wed, 01 May 2019 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/10403 2019-05-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/9623 Title: Structure determination of enzyme and interaction analysis of antibiotics Authors: 박현호 Tue, 05 Feb 2019 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/9623 2019-02-05T00:00:00Z https://repository.kopri.re.kr/handle/201206/9627 Title: Discovery of bioactive secondary metabolites from polar resources Authors: 나민균 Fri, 01 Feb 2019 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/9627 2019-02-01T00:00:00Z