Puchart Vladimír, Vrsanská Mária, Mastihubová Mária, Topakas Evangelos, Vafiadi Christina, Faulds Craig B, Tenkanen Maija, Christakopoulos Paul, Biely Peter
Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic.
J Biotechnol. 2007 Jan 1;127(2):235-43. doi: 10.1016/j.jbiotec.2006.06.020. Epub 2006 Jul 1.
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)-feruloyl- and 2-, 3- and 4-O-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 F. 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-feruloyl-alpha-L-arabinofuranoside was comparable. In comparison with acetates, the corresponding ferulates served as poor substrates for the carbohydrate esterase family 1 feruloyl esterase from Aspergillus oryzae. The enzyme hydrolyzed all alpha-L-arabinofuranoside 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.
2-、3-和5-O-(E)-阿魏酰基-以及2-和5-O-乙酰基-α-L-阿拉伯呋喃糖苷和2-、3-和4-O-(E)-阿魏酰基-以及2-、3-和4-O-乙酰基-β-D-木吡喃糖苷的4-硝基苯基糖苷，这些模拟天然底物的化合物，被用于研究A型、B型和C型阿魏酰酯酶的底物和位置特异性。所有的阿魏酰酯酶都表现为真正的阿魏酰酯酶，对糖醋酸酯的活性可忽略不计。以黑曲霉的AnFaeA和尖孢镰刀菌的FoFaeII为代表的A型酶专门用于伯羟基的脱阿魏酰基作用，对水解5-O-阿魏酰基-α-L-阿拉伯呋喃糖苷有很强的偏好。相反，以尖孢镰刀菌的FoFaeI和嗜热栖热菌的TsFaeC为代表的B型和C型阿魏酰酯酶，除了4-和3-O-阿魏酰基-β-D-木吡喃糖苷外，几乎作用于所有的阿魏酸盐。5-O-阿魏酰基-α-L-阿拉伯呋喃糖苷是TsFaeC和FoFaeI的最佳底物，尽管后者对2-O-阿魏酰基-α-L-阿拉伯呋喃糖苷的催化效率相当。与醋酸酯相比，相应的阿魏酸盐是米曲霉碳水化合物酯酶家族1阿魏酰酯酶的较差底物。该酶水解所有的α-L-阿拉伯呋喃糖苷和β-D-木吡喃糖苷醋酸酯。它表现为一种非特异性的乙酰酯酶而不是阿魏酰酯酶，对2-O-乙酰基-β-D-木吡喃糖苷有偏好。
