Analysis of esterification properties of esterase from Thermoascus aurantiacus QH-1 by molecular docking

To ascertain the esterification characteristics of Thermoascus aurantiacus, the high-yield esterase strain was selected from 6 strains (number as QH-1~QH-4, FH-5~FH-7) of T. aurantiacus by determining the esterase activity. On the basis of genome sequence, the physicochemical properties of esterases...

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Bibliographic Details
Main Author: LU Tong, ZHAO Wei, CUI Meilin, WANG Jiali, ZHANG Xiuhong
Format: Article
Language:English
Published: Editorial Department of China Brewing 2025-01-01
Series:Zhongguo niangzao
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Online Access:https://manu61.magtech.com.cn/zgnz/fileup/0254-5071/PDF/0254-5071-2025-44-1-85.pdf
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Summary:To ascertain the esterification characteristics of Thermoascus aurantiacus, the high-yield esterase strain was selected from 6 strains (number as QH-1~QH-4, FH-5~FH-7) of T. aurantiacus by determining the esterase activity. On the basis of genome sequence, the physicochemical properties of esterases were predicted, and the homology modeling, molecule docking and interaction of esterase model with fatty acid were conducted by online software. At the meanwhile, the esterification validation experiments with different fatty acids as substrates were performed to study its substrate specificity. The results showed that the esterase activity of T. aurantiacus QH-1 was the highest (16.10 U/g). Its genome encoded 12 esterases, and 6 of which with stable molecular structure were homologously modeled. Among them, the constructed models for esterases scaffold 198.t7, scaffold 360.t9 and scaffold 64.t20 had high reliability, with all amino acids>90% in the Ramachandran Plot permissive region and Global Model Quality Evaluation (GMQE) values close to 1. When the 3 esterases molecules were docked with common fatty acids, the free energies were all negative, which indicated that T. aurantiacus QH-1 was able to synthesize corresponding ethyl esters from ethanol and fatty acids, and its esterases had low substrate specificity. The corresponding ethyl esters were detected in validation reactions of solid T. aurantiacus QH-1 cultures esterified with different fatty acids, and the highest esterification activity (152 mg/50 g·7 d) was obtained when the substrata was octanoic acid. When the 3 esterases were docked with different fatty acid molecules, the esterase scaffold 64. t20 docked with octanoic acid had the lowest free energy, so it was hypothesized to be the main esterase of T. aurantiacus QH-1, which bound with substrates mainly by hydrophobic force, hydrogen bonding and salt bonding.
ISSN:0254-5071