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Insights Into the Role of Exposed Surface Charged Residues in the Alkali-Tolerance of GH11 Xylanase.

ABSTRACT: Thermostable and alkaline- or acid-stable xylanases are more advantageous in agricultural and industrial fields. In this study, a rational structure-based design was conducted based on a thermostable GH11 xylanase TlXynA from Thermomyces lanuginosus to improved pH-tolerance. Four mutant enzymes (P1, P2, P3, and P4) and five variants (N1, N2, N3, N4, and N5) were constructed by substituting surface charged residue combinations using site-directed mutagenesis. Compared to the native enzyme, two mutants P1 and P2 showed higher acid tolerance, especially at pH 3.0, presented 50 and 40% of their maximum activity, respectively. In addition, four mutants N1, N2, N3 and N4 had higher tolerance than the native enzyme to alkaline environments (pH 7.0-9.0). At pH 9.0, the residual activities of N1, N2, N3, and N4 were 86, 78, 77, and 66%, respectively. In summary, an improved pH-tolerance design principle is being reported.

SUBMITTER: Wu X

PROVIDER: S-EPMC7225583 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Insights Into the Role of Exposed Surface Charged Residues in the Alkali-Tolerance of GH11 Xylanase.

Wu Xiuyun X Zhang Qun Q Zhang Lanzeng L Liu Shijia S Chen Guanjun G Zhang Huaiqiang H Wang Lushan L

Frontiers in microbiology 20200508

Thermostable and alkaline- or acid-stable xylanases are more advantageous in agricultural and industrial fields. In this study, a rational structure-based design was conducted based on a thermostable GH11 xylanase TlXynA from Thermomyces lanuginosus to improved pH-tolerance. Four mutant enzymes (P1, P2, P3, and P4) and five variants (N1, N2, N3, N4, and N5) were constructed by substituting surface charged residue combinations using site-directed mutagenesis. Compared to the native ...[more]

PMID: 32457729

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