title: Altered substrate specificity of the gluco-oligosaccharide oxidase from Acremonium strictum.
abstract: 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 kcat 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.
authors: Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, Canada M5S 3E5; telephone: +1-416-946-7861; fax: +1-416-978-8605.
authors: Maryam
authors: M
authors: Foumani
authors: Thu V
authors: TV
authors: Vuong
authors: Emma R
authors: ER
authors: Master
mesh_terms: D000164:Acremonium / Q000201:enzymology* / Q000235:genetics; D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019943:Amino Acid Substitution; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D020125:Mutation, Missense; D009844:Oligosaccharides; D010843:Pichia; D013379:Substrate Specificity / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D009844:Oligosaccharides; D000429:Alcohol Oxidoreductases; C072250:glucooligosaccharide oxidase