Abstract
Substrate specificity of purified acetylxylan esterase (AcXE) from Trichoderma reesei was investigated on partially and fully acetylated methyl glycopyranosides. Methyl 2,3,4-tri-O-acetyl-β-d-xylopyranoside was deacetylated at positions 2 and 3, yielding methyl 4-O-acetyl-β-d-xylopyranoside in almost 90% yield. Methyl 2,3-di-O-acetyl β-d-xylopyranoside was deacetylated at a rate similar to the fully acetylated derivative. The other two diacetates (2,4- and 3,4-), which have a free hydroxyl group at either position 3 or 2, were deacetylated one order of magnitude more rapidly. Thus the second acetyl group is rapidly released from position 3 or 2 after the first acetyl group is removed from position 2 or 3. The results strongly imply that in degradation of partially acetylated β-1,4-linked xylans, the enzyme deacetylates monoacetylated xylopyranosyl residues more readily than di-O-acetylated residues. The T. reesei AcXE attacked acetylated methyl β-d-glucopyranosides and β-d-mannopyranosides in a manner similar to the xylopyranosides.
Original language | English |
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Pages (from-to) | 121-124 |
Journal | FEBS Letters |
Volume | 420 |
Issue number | 2-3 |
DOIs | |
Publication status | Published - 1997 |
MoE publication type | A1 Journal article-refereed |