Altered Substrate Specificity of the Gluco-Oligosaccharide Oxidase From Acremonium strictum

作者：Foumani Maryam; Vuong Thu V; Master Emma R^*

来源：Biotechnology and Bioengineering, 2011, 108(10): 2261-2269.

DOI：10.1002/bit.23149

• gluco-oligosaccharide oxidase
• Acremonium strictum
• substrate specificity
• carbohydrate docking
• protein engineering

A gluco-oligosaccharide oxidase (GOOX) from Acremonium strictum type strain CBS 346.70 was cloned and expressed in Pichia pastoris. The recombinant protein, GOOX-VN, contained fifteen amino acid substitutions compared with the previously reported A. strictum GOOX. These two enzymes share 97% sequence identity; however, only GOOX-VN oxidized xylose, galactose, and N-acetylglucosamine. Besides monosaccharides, GOOX-VN oxidized xylo-oligosaccharides, including xylobiose and xylotriose with similar catalytic efficiency as for cello-oligosaccharides. Of three mutant enzymes that were created in GOOX-VN to improve substrate specificity, Y300A and Y300N doubled k(cat) values for monosaccharide and oligosaccharide substrates. With this novel substrate specificity, GOOX-VN and its variants are particularly valuable for oxidative modification of cello-and xylo-oligosaccharides. Biotechnol. Bioeng. 2011; 108: 2261-2269.

• 出版日期2011-10