Transxylosylation of β-Xylosidase from Aspergillus awamori K4

• Published in: Bioscience, biotechnology, and biochemistry Vol. 61; no. 12; pp. 2010 - 2014
• Main Authors: Kurakake, Masahiro, Osada, Shinji, Komaki, Toshiaki
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis 1997; Japan Society for Bioscience Biotechnology and Agrochemistry
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrolases; Mission oriented research; Physiology and metabolism; sugar alcohol; transxylosylation; trehalose; xylooligosaccharide; β-xylosidase; Sorbitol; Temperature; Trehalose; Enzyme; Molecular weight determination; Environmental factor; Xylan 1,4-β-xylosidase; Fungi; Transglycosylation; Enzymatic activity; Glycosidases; Substrate specificity; Mannitol; pH; Hydrolases; Fungi Imperfecti; O-Glycosidases; Physicochemical properties; Thallophyta; Aspergillus awamori; β-xylosidase; trehalose; xylooligosaccharide; transxylosylation; sugar alcohol
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.61.2010

β-Xylosidase from Aspergillus awamori K4 was purified. The optimum pH and temperature were around pH 4 and 70°C, and the molecular weight was estimated to be 117,000 on SDS-PAGE analysis. The enzyme has broad acceptor specificity in transxylosylation. Especially, its acceptor accessibility for sorbitol and mannitol of sugar alcohols were higher than that for monosaccharides. Trehalose was a much more effective acceptor than maltose and lactose of other disaccharides. In the reaction with 13-14% xylooligosaccharides (consisting of 3.4% xylose, 67.9% xylobiose, and 28.7% xylotriose) and 9-13% acceptors (sorbitol, mannitol, and trehalose), the amount of transfer products for each acceptor was 7-11% in 24 h. On 1 H- and 13 C-NMR analysis, main transfer products with sorbitol and mannitol were 6-O-β-xylosyl sorbitol (77.3%) and l(6)-O-β-xylosyl mannitol (73.7%), respectively. Two products with trehalose were 6 (6′)-O-β-xylosyl trehalose (52.1%) and 6,6′-O-β-di-xylosyl trehalose (47.9%).