Abstract
Each xylanase shows a unique aglycone specificity in transglycosylation, though most xylanases are classified under only two families based on the amino acid sequence and the structure of the protein. We investigated the aglycone specificity of a xylanase from Hypsizigus marmoreus using many kinds of aromatic compounds as acceptors. Xylanase was stable in the presence of the aromatic compounds (-100 mM) used in this experiment except for phenol. Some compounds such as vanillyl alcohol accelerated the degradation of xylan by xylanase and in the presence of them xylanase produced more reducing sugars in addition to β-glycosides than in the absence of those acceptors. Among the aromatic compounds having alcoholic hydroxyl groups, cinnamyl alcohol-having a double bond was the best acceptor and the amount of transglycosyl product was 30.8% against the whole product. Xylanase also catalyzed the transglycosylation in the presence of diphenol compounds and aromatic compounds that have both the phenolic and the alcoholic hydroxyl group. Xylanase could catalyze the transglycosylation to the alcoholic-OH of the acceptor rather than to the phenolic-OH.
