Tanaka M, Abe A, Uchida T
Biochim Biophys Acta. 1981 Apr 14;658(2):377-86. doi: 10.1016/0005-2744(81)90308-9.
Substrate specificity of alpha-L-arabinofuranosidase from plant Scopolia japonica was examined using three kinds of arabinodisaccharides prepared from natural sources of synthetically. This enzyme hydrolyzed arabinofuranosyl-arabinoses which had either an alpha-(1 leads to 3) or a alpha-(1 leads to 5) linkage, but hydrolyzed arabinopyranosyl-arabinose having a alpha-(1 leads to 5) linkage to a lesser degree. alpha-L-Arabinofuranosidase (alpha-L-arabinofuranoside arabinofuranohydrolase, EC 3.2.1.55), which was shown by us to be an exo-enzyme, degraded beet araban incompletely. Arabinose oligomers and galactose-containing fragments, isolated following acid hydrolysis of araban, were both incompletely degraded by the enzyme. The reasons for the incomplete degradation were explained by the novel finding of (1 leads to 2) linkages and arabinopyranosides and the inclusion of trace amounts of galactose into the carbohydrate chain of araban. This enzyme was practically non-reacting with the hydroxyprolyl-arabinose linkage of glycopeptides from plant cell walls.
利用从天然来源或合成制备的三种阿拉伯二糖，对植物日本东莨菪中α-L-阿拉伯呋喃糖苷酶的底物特异性进行了研究。该酶可水解具有α-(1→3)或α-(1→5)连接的阿拉伯呋喃糖基阿拉伯糖，但对具有α-(1→5)连接的阿拉伯吡喃糖基阿拉伯糖的水解程度较低。我们发现α-L-阿拉伯呋喃糖苷酶（α-L-阿拉伯呋喃糖苷阿拉伯呋喃糖水解酶，EC 3.2.1.55）是一种外切酶，它对甜菜阿拉伯聚糖的降解不完全。阿拉伯聚糖酸水解后分离得到的阿拉伯糖低聚物和含半乳糖的片段，均被该酶不完全降解。降解不完全的原因可通过新发现的(1→2)连接、阿拉伯吡喃糖苷以及阿拉伯聚糖碳水化合物链中包含痕量半乳糖来解释。该酶实际上不作用于植物细胞壁糖肽的羟脯氨酰-阿拉伯糖连接。
