|Cote, Gregory - Greg|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2005
Publication Date: 12/20/2005
Citation: Biely, P., Kremnicky, L., Cote, G.L. 2005. Unique acetylation of oligosaccharides by trichoderma reesei acetyl esterase in water - vinyl acetate mixture [abstract]. International Chemical Congress of Pacific Basin Societies. Program No. 464. Interpretive Summary:
Technical Abstract: Purified T. reesei RUT C-30 acetyl esterase catalyzes acetyl transfer to a variety of carbohydrates in water in the presence of vinyl acetate as the acetyl group donor. The degree of conversion and the number of formed acetates depended on the acceptor used. With some acceptors, such as methyl or 4-nitrophenyl beta-D-glucopyranoside, only 3-O-acetyl derivative was formed in 50-70% yield. In this work three series of oligosaccharides were examined as acetyl group acceptors in this unique enzymatic transacetylation. Regardless of their polymerization degree, beta-1,4-xylooligosaccharides and beta-1,4-glucooligosaccharides (cellooligosaccharides) were transformed in good yields mainly to monoacetates and partially to diacetates, suggesting that only terminal sugar residues are acetylated. When methyl beta-glycosides of oligosaccharides or reduced oligosaccharides were used as glycosyl acceptors, only monoacetates were formed. The formation of diacetates was never significant with beta-1,4-mannooligosaccharides, indicating that the acetyl esterase does not recognize the anomeric configuration of the reducing end mannose residue. The exo-mode acetylation of oligosaccharides can be used for protection of oligosaccharides against hydrolytic action of glycosidases.