A novel esterase from a soil metagenomic library displaying a broad substrate range

• Published in: AMB Express 2021-03, Vol.11 (1), p.38-38, Article 38
• Main Authors: Yao, Jian, Gui, Lun, Yin, Shaocheng
• Format: Article
• Language: English
• Subjects: Acetic acid; Amino acid sequence; Amino acids; Biomedical and Life Sciences; Biotechnology; Carboxylesterase; Chlorogenate esterase; Conserved sequence; E coli; Enzymes; Esterase; Esters; Ferulic acid esterase; Feruloyl esterase; Gel electrophoresis; Libraries; Life Sciences; Metagenomics; Microbial Genetics and Genomics; Microbiology; Multi‐functional esterase; Original; Original Article; p-Nitrophenylacetic acid; pH effects; Phenolic compounds; Protein structure; Proteins; Sodium lauryl sulfate; Soils; Structural analysis; Substrate specificity; Substrates; Tannase
• ISSN: 2191-0855; 2191-0855
• DOI: 10.1186/s13568-021-01198-5

A novel esterase gene was isolated from a soil metagenomic library. The gene encoded a protein of 520 amino acids which contained a 21 aa signal peptide. Primary structure analysis of the protein sequence revealed that it contained a conserved active site motif (SxSxG) and a structural motif (CS-D-HC). Then the esterase gene was cloned and expressed in Escherichia c oli BL21(DE3). SDS-PAGE analysis of the purified esterase showed that it was expressed in a highly soluble form and its molecular mass was estimated to be 55 kDa. Characterization of the esterase revealed that it exhibited high activity toward p -nitrophenyl esters with short acyl chains and especially p -nitrophenyl acetate, suggesting that it was a typical carboxylesterase rather than a lipase. With p -nitrophenyl acetate as substrate, the enzyme showed its optimal activity at pH 7.0 and 30 °C, and it was stable at a broad pH range from 4.5 to 10.0 and temperature not higher than 50 °C. Furthermore, the enzyme showed different substrate specificity from known esterase, it was not only hydrolyzing against p -nitrophenyl esters, but also hydrolyzing all hydroxybenzoic esters and hydroxycinnamic ester assayed. As it was an enzyme active on a broad range of phenolic esters, simultaneously possessing feruloyl esterase, chlorogenate esterase and tannase activities, it could serve as a valuable candidate for applications in biotechnology.