Department of Food and Environmental Sciences, PO Box 27, FIN-00014 University of Helsinki, Finland.
Int J Biol Macromol. 2011 Dec 1;49(5):963-9. doi: 10.1016/j.ijbiomac.2011.08.020. Epub 2011 Aug 26.
Two α-L-arabinofuranosidases with different substrate specificities were used to modify the arabinose-to-xylose ratio of cereal arabinoxylans: one enzyme (AXH-m) removed the L-arabinofuranosyl substituents from the monosubstituted xylopyranosyl residues and the other (AXH-d3) the (1→3)-linked L-arabinofuranosyl units from the disubstituted xylopyranosyl residue. In this study, we noticed that not only the arabinose-to-xylose ratio but also the position of the arabinofuranosyl substituents affects the water-solubility of arabinoxylans. The AXH-d3 treatment had no significant effect on the solution conformation of arabinoxylans, but the density of the arabinoxylan molecules decreased in DMSO solution after AXH-m modification. The possible heterogeneity of arabinoxylans complicated the interpretation of data describing the macromolecular properties of the enzymatically modified samples.
两种具有不同底物特异性的α-L-阿拉伯呋喃糖苷酶被用于修饰谷物阿拉伯木聚糖的阿拉伯糖/木糖比例：一种酶（AXH-m）从单取代的木吡喃糖基残基上去除 L-阿拉伯呋喃糖基取代基，另一种酶（AXH-d3）从二取代的木吡喃糖基残基上去除（1→3）-连接的 L-阿拉伯呋喃糖基单元。在这项研究中，我们注意到不仅阿拉伯糖/木糖比例，而且阿拉伯呋喃糖基取代基的位置也会影响阿拉伯木聚糖的水溶性。AXH-d3 处理对阿拉伯木聚糖的溶液构象没有显著影响，但 AXH-m 修饰后，阿拉伯木聚糖分子在 DMSO 溶液中的密度降低。阿拉伯木聚糖的可能异质性使描述酶修饰样品的大分子性质的数据的解释变得复杂。
