Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon, Korea.
Department of Polar Sciences, University of Science and Technology, Incheon, Korea.
PLoS One. 2023 Feb 6;18(2):e0280988. doi: 10.1371/journal.pone.0280988. eCollection 2023.
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.
酯酶是丝氨酸水解酶家族的一员，具有高度区域和立体特异性催化酯键的断裂和形成，使其成为合成光学纯分子的有吸引力的生物催化剂。在这项研究中，我们对来自细菌鱼病原体乳球菌的新型微生物乙酰酯酶 LgEstI 进行了深入的生化和结构表征。二聚体 LgEstI 对 p-硝基苯酯的短酰基链表现出底物偏好，并显示出 F207A 突变的活性增加。与其他酯酶的比较分析表明，LgEstI 具有狭窄而浅的活性位点，可能表现出对短酰基链的底物特异性。与其他酯酶不同，LgEstI 含有较大的残基，如色氨酸 89、苯丙氨酸 194 和色氨酸 217，这些残基阻止了酰基链通道。此外，固定化 LgEstI 保留了初始活性的约 90%，表明其在工业应用中的潜力。这项研究扩展了我们对 LgEstI 的理解，并为提高其催化效率和针对各种应用的底物特异性提出了新的思路。
