Identification and Biochemical Characterization of a Novel Hormone-Sensitive Lipase Family Esterase Est19 from the Antarctic Bacterium <i>Pseudomonas</i> sp. E2-15
Esterases represent an important class of enzymes with a wide variety of industrial applications. A novel hormone-sensitive lipase (HSL) family esterase, Est19, from the Antarctic bacterium <i>Pseudomonas</i> sp. E2-15 is identified, cloned, and expressed. The enzyme possesses a GESAG mo...
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| Autores principales: | , , , , , , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
MDPI AG
2021
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/26af0279e2d143e193f8ad781c2465ab |
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| Sumario: | Esterases represent an important class of enzymes with a wide variety of industrial applications. A novel hormone-sensitive lipase (HSL) family esterase, Est19, from the Antarctic bacterium <i>Pseudomonas</i> sp. E2-15 is identified, cloned, and expressed. The enzyme possesses a GESAG motif containing an active serine (S) located within a highly conserved catalytic triad of Ser<sup>155</sup>, Asp<sup>253</sup>, and His<sup>282</sup> residues. The catalytic efficiency (<i>k</i><sub>cat</sub>/<i>K</i><sub>m</sub>) of Est19 for the <i>p</i>NPC6 substrate is 148.68 s<sup>−1</sup>mM<sup>−1</sup> at 40 °C. Replacing Glu<sup>154</sup> juxtaposed to the critical catalytic serine with Asp (E154→D substitution) reduced the activity and catalytic efficiency of the enzyme two-fold, with little change in the substrate affinity. The wild-type enzyme retained near complete activity over a temperature range of 10–60 °C, while ~50% of its activity was retained at 0 °C. A phylogenetic analysis suggested that Est19 and its homologs may represent a new subfamily of HSL. The thermal stability and stereo-specificity suggest that the Est19 esterase may be useful for cold and chiral catalyses. |
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