Enzymatic synthesis of β-xylosyl-oligosaccharides by transxylosylation using two β-xylosidases of glycoside hydrolase family 3 from Aspergillus nidulans FGSC A4
作者:Adiphol Dilokpimol、Hiroyuki Nakai、Charlotte H. Gotfredsen、Maaike Appeldoorn、Martin J. Baumann、Natsuko Nakai、Henk A. Schols、Maher Abou Hachem、Birte Svensson
DOI:10.1016/j.carres.2010.12.010
日期:2011.2
gave inferior yields on these acceptors. The regioselectivity was acceptor dependent and primarily involved beta-1,4 or 1,6 product linkage formation although minor products with different linkages were also obtained. Five of the 18 transxylosylation products obtained from D-lyxose, D-galactose, turanose and sucrose (two products) as acceptors were novel xylosyl-oligosaccharides, beta-D-Xylp-(1-->4)-D-Lyxp
来自构巢曲霉FGSCA4,BxlA和BxlB的构巢曲霉糖苷水解酶家族3(GH 3)的两个β-木糖苷酶在巴斯德毕赤酵母中重组产生,并分别以16和118mg / L的产率分泌到培养上清液中。BxlA表现出比BxlB高约六倍的催化效率(k(cat)/ K(m))(对聚硝基苯基β-D-木吡喃糖苷(pNPX)和β-1,4-木糖寡糖(聚合度2-6)) 。对于这两种酶,k(cat)/ K(m)随着β-1,4-木糖寡糖链长的增加而降低。使用pNPX作为供体,以9种单糖,7种二糖和两种糖醇作为受体,通过反式木糖基化反应合成了18种不同的β-木糖基-低聚糖,收率为2-36%(BxlA)和6-66%(BxlB)。BxlA使用了单糖D-甘露糖,D-lyxose,D-talose,D-木糖,D-阿拉伯糖,L-岩藻糖,D-葡萄糖,D-半乳糖和D-果糖为受体,而BxlB使用相同的物质,除了D-糖,D-阿拉伯糖和L-岩藻