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Hwang J, Yoo W, Shin SC, Kim KK, Kim HW, Do H, Lee JH. Structural and Biochemical Insights into Bis(2-hydroxyethyl) Terephthalate Degrading Carboxylesterase Isolated from Psychrotrophic Bacterium Exiguobacterium antarcticum. Int J Mol Sci 2023; 24:12022. [PMID: 37569396 PMCID: PMC10418727 DOI: 10.3390/ijms241512022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
This study aimed to elucidate the crystal structure and biochemically characterize the carboxylesterase EaEst2, a thermotolerant biocatalyst derived from Exiguobacterium antarcticum, a psychrotrophic bacterium. Sequence and phylogenetic analyses showed that EaEst2 belongs to the Family XIII group of carboxylesterases. EaEst2 has a broad range of substrate specificities for short-chain p-nitrophenyl (pNP) esters, 1-naphthyl acetate (1-NA), and 1-naphthyl butyrate (1-NB). Its optimal pH is 7.0, losing its enzymatic activity at temperatures above 50 °C. EaEst2 showed degradation activity toward bis(2-hydroxyethyl) terephthalate (BHET), a polyethylene terephthalate degradation intermediate. We determined the crystal structure of EaEst2 at a 1.74 Å resolution in the ligand-free form to investigate BHET degradation at a molecular level. Finally, the biochemical stability and immobilization of a crosslinked enzyme aggregate (CLEA) were assessed to examine its potential for industrial application. Overall, the structural and biochemical characterization of EaEst2 demonstrates its industrial potency as a biocatalyst.
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Affiliation(s)
- Jisub Hwang
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea;
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Wanki Yoo
- Department of Chemistry, Graduate School of General Studies, Sookmyung Women’s University, Seoul 04310, Republic of Korea;
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea; (K.K.K.); (H.-W.K.)
| | - Seung Chul Shin
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea;
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea; (K.K.K.); (H.-W.K.)
| | - Han-Woo Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea; (K.K.K.); (H.-W.K.)
| | - Hackwon Do
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea;
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Jun Hyuck Lee
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea;
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
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