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Biochemical characteristics and gene cloning of a novel thermostable feruloyl esterase from Chaetomium sp.

Yang, Shao-Qing, Tang, Luo, Yan, Qiao-Juan, Zhou, Peng, Xu, Hai-Bo, Jiang, Zheng-Qiang, Zhang, Pan
Journal of Molecular Catalysis. B, Enzymatic 2013 v.97 pp. 328-336
Chaetomium, Magnaporthe oryzae, amino acid sequences, amino acids, catalytic activity, feruloyl esterase, gel chromatography, genes, molecular cloning, molecular weight, open reading frames, pH, polyacrylamide gel electrophoresis, substrate specificity, temperature, thermal stability
A feruloyl esterase from Chaetomium sp. CQ31 was purified and biochemically characterized. The purified feruloyl esterase had a specific activity of 38.6U/mg. The molecular mass of the enzyme was estimated to be 30.2kDa by SDS-PAGE, and 29.6kDa by gel filtration, indicating that the enzyme was a monomer. The optimum pH and temperature of the enzyme were pH 7.5 and 60°C, respectively. It was stable over a broad pH range of 4.0–10.0, and also exhibited good thermostability. The enzyme displayed strict substrate specificity. The Km and Vmax values for methyl ferulate were 0.98μmol/min/mg and 42.6U/mg, respectively. Furthermore, the feruloyl esterase gene was cloned and sequenced. Open reading frame (ORF) of the feruloyl esterase gene (879-bp) encodes 274 amino acids. The deduced amino acid sequence of the feruloyl esterase gene exhibited the highest identity (79%) with that of type B feruloyl esterase from Magnaporthe oryzae.