https://repository.kopri.re.kr/handle/201206/14824 Sat, 18 Apr 2026 22:24:19 GMT 2026-04-18T22:24:19Z https://repository.kopri.re.kr/handle/201206/14891 Title: Feruloyl Esterase (LaFae) from Lactobacillus acidophilus: Structural Insights and Functional Characterization for Application in Ferulic Acid Production Authors: Sangeun Jeon; Hwang, Jisub; Do, Hackwon; Ly Thi Huong Luu Le; Lee, Chang Woo; Wanki Yoo; 이민주; Shin, Seung Chul; Kyeong Kyu Kim; Kim, Han-Woo; Lee, Jun Hyuck Abstract: Ferulic acid and related hydroxycinnamic acids, used as antioxidants and preservatives in the food, cosmetic, pharmaceutical and biotechnology industries, are among the most abun-dant phenolic compounds present in plant biomass. Identification of novel compounds that can produce ferulic acid and hydroxycinnamic acids, that are safe and can be mass-produced, is criti-cal for the sustainability of these industries. In this study, we aimed to obtain and characterize a feruloyl esterase (LaFae) from Lactobacillus acidophilus. Our results demonstrated that LaFae reacts with ethyl ferulate and can be used to effectively produce ferulic acid from wheat bran, rice bran and corn stalks. In addition, xylanase supplementation was found to enhance LaFae enzymatic hydrolysis, thereby augmenting ferulic acid production. To further investigate the active site configuration of LaFae, crystal structures of unliganded and ethyl ferulate-bound LaFae were determined at 2.3 and 2.19 A resolutions, respectively. Structural analysis shows that a Phe34 residue, located at the active site entrance, acts as a gatekeeper residue and controls substrate binding. Mutating this Phe34 to Ala produced an approximately 1.6-fold increase in LaFae activ-ity against p-nitrophenyl butyrate. Our results highlight the considerable application potential of LaFae to produce ferulic acid from plant biomass and agricultural by-products. Sun, 01 Jan 2023 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/14891 2023-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/14850 Title: Structural and biochemical insights into PsEst3, a new GHSR-type esterase obtained from Paenibacillus sp. R4 Authors: Kim, Hyun; 손종현; Choi, Woong; 김민서; Lee, Jun Hyuck; Shin, Seung Chul; Kim, Han-Woo Abstract: PsEst3, a psychrophilic esterase obtained from Paenibacillus sp. R4, which was isolated from the permafrost of Alaska, exhibits relatively high activity at low temperatures. Here, crystal structures of PsEst3 complexed with various ligands were generated and studied at atomic resolution, and biochemical studies were performed to analyze the structure-function relationship of PsEst3. Certain unique characteristics of PsEst3 distinct from those of other classes of lipases/ esterases were identified. Firstly, PsEst3 contains a conserved GHSRA/G pentapeptide sequence in the GxSxG motif around the nucleophilic serine. Additionally, it contains a conserved HGFR/K consensus sequence in the oxyanion hole, which is distinct from that in other lipase/esterase families, as well as a specific domain composition (for example a helix-turn-helix motif) and a degenerative lid domain that exposes the active site to the solvent. Secondly, the electrostatic potential of the active site in PsEst3 is positive, which may cause unintended binding of negatively charged chemicals in the active site. Thirdly, the last residue of the oxyanion hole-forming sequence, Arg44, separates the active site from the solvent by sealing the acyl-binding pocket, suggesting that PsEst3 is an enzyme that is customized to sense an unidentified substrate that is distinct from those of classical lipases/esterases. Collectively, this evidence strongly suggests that PsEst3 belongs to a distinct family of esterases. Sun, 01 Jan 2023 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/14850 2023-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/14845 Title: Crystal structure and biochemical analysis of acetylesterase (LgEstI) from Lactococcus garvieae Authors: Do, Hackwon; Yoo Wanki; Wang Ying; 남예원; Shin, Seung Chul; Kim, Han-Woo; Kim Kyeong Kyu; Lee, Jun Hyuck Abstract: Esterase, a member of the serine hydrolase family, catalyzes the cleavage and formation of ester bonds with high regio- and stereospecificity, making them attractive biocatalysts for the synthesis of optically pure molecules. In this study, we performed an in-depth biochemical and structural characterization of a novel microbial acetylesterase, LgEstI, from the bacterial fish pathogen Lactococcus garvieae. The dimeric LgEstI displayed substrate preference for the short acyl chain of p-nitrophenyl esters and exhibited increased activity with F207A mutation. Comparative analysis with other esterases indicated that LgEstI has a narrow and shallow active site that may exhibit substrate specificity to short acyl chains. Unlike other esterases, LgEstI contains bulky residues such as Trp89, Phe194, and Trp217, which block the acyl chain channel. Furthermore, immobilized LgEstI retained approximately 90% of its initial activity, indicating its potential in industrial applications. This study expands our understanding of LgEstI and proposes novel ideas for improving its catalytic efficiency and substrate specificity for various applications. Sun, 01 Jan 2023 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/14845 2023-01-01T00:00:00Z