4-Nitrophenyl glycosides of 2-, 3-, and 5-O-(E)-feruloyl- and 2- and 5-O-acetyl-alpha-L-arabinofuranosides and of 2, 3-, and 4-O-(E)-fer-uloyl- and 2, 3- and 4-0-acetyl-beta-D-xylopyranosides, compounds mimicking natural substrates, were used to investigate substrate and positional specificity of type-A, -B, and -C feruloyl esterases. All the feruloyl esterases behave as true feruloyl esterases showing negligible activity on sugar acetates. Type-A enzymes, represented by AnFaeA from Aspergillus niger and FoFaeII from Fusarium oxysporum, are specialized for deferuloylation of primary hydroxyl groups, with a very strong preference for hydrolyzing 5-O-feruloyl-alpha-L-arabinofuranoside. On the contrary, type-B and -C feruloyl esterases, represented by FoFaeI from E oxysporum and TsFaeC from Talaromyces stipitatus, acted on almost all ferulates with exception of 4- and 3-O-feruloyl-beta-D-xylopyranoside. 5-O-Feruloyl-alpha-L-arabinofuranoside was the best substrate for both TsFaeC and FoFaeI, although catalytic efficiency of the latter enzyme toward 2-O-fer-uloyl-alpha-L-arabinofuranoside was comparable. In comparison with acetates, the corresponding ferulates served as poor substrates for the carbohydrate esterase family I feruloyl esterase from Aspergillus oryzae. The enzyme hydrolyzed all alpha-L-arabinofurano side and beta-D-xylopyranoside acetates. It behaved as a non-specific acetyl esterase rather than a feruloyl esterase, with a preference for 2-O-acetyl-beta-D-xylopyranoside. (c) 2006 Elsevier B.V. All rights reserved.
Puchart, V., Vrsanska, M., Mastihubova, M., Topakas, E., Vafiadi, C., Faulds, C. B., ... Biely, P. (2007). Substrate and positional specificity of feruloyl esterases for monoferuloylated and monoacetylated 4-nitrophenyl glycosides. Journal of Biotechnology, 127, 235-243. https://doi.org/10.1016/j.jbiotec.2006.06.020