Purification, Characterization of GH11 Endo-[beta]-1,4-xylanase from Thermotolerant Streptomyces sp. SWU10 and Overexpression in Pichia pastoris KM71H

• Published in: Molecular biotechnology 2013-05, Vol.54 (1), p.37
• Main Authors: Deesukon, Warin, Nishimura, Yuichi, Sakamoto, Tatsuji, Sukhumsirichart, Wasana
• Format: Article
• Language: English
• Subjects: Amino acids; Bacteria; Biofuels; Cloning; Enzymes; Filtrate; Gene expression; Molecular biology; Physicochemical properties; Waste treatment; Yeast
• ISSN: 1073-6085; 1559-0305
• DOI: 10.1007/s12033-012-9541-8

We have previously described two forms of an endo-[beta]-1,4-xylanase (XynSW2A and XynSW2B) synthesized by thermotolerant Streptomyces sp. SWU10. Here, we describe another xylanolytic enzyme, designated XynSW1. The enzyme was purified to homogeneity from 2Â L of culture filtrate. Its apparent molecular mass was 24Â kDa. The optimal pH and temperature were pH 5.0 and 40Â °C, respectively. The enzyme was stable in a wide pH ranges (pH 1â[euro]"11), more than 80Â % of initial activity remained at pH 2â[euro]"11 after 16Â h of incubation at 4Â °C and stable up to 50Â °C for 1Â h. Xylobiose and xylotriose were the major xylooligosaccharides released from oat spelt xylan by the action of XynSW1, indicating of endo-type xylanase. The complete xynSW1 gene contains 1,011Â bp in length and encode a polypeptide of 336 with 41 amino acids of signal peptide. The amino acid sequence analysis revealed that it belongs to glycoside hydrolase family 11 (GH11). The mature xynSW1 gene without signal peptide sequence was overexpressed in Pichia pastoris KM71H. The recombinant XynSW1 protein showed higher molecular mass due to the differences in glycosylation levels at the six N-glycosylation sites in the amino acid sequence and exhibited better physicochemical properties than those of the native enzyme including higher optimal temperature (60Â °C), and specific activity, but lower optimal pH (4.0). Because of their stability in a wide pH ranges, both of native and recombinant enzymes of XynSW1, may have potential application in several industries including food, textile, biofuel, and also waste treatment.[PUBLICATION ABSTRACT]