Isolation and partial characterization of an extracellular glucansucrase from Leuconostoc mesenteroides NRRL B-1355 that synthesizes an alternating (1→6), (1→3)-α-d-glucan
作者:Gregory L. Côté、John F. Robyt
DOI:10.1016/s0008-6215(00)80795-8
日期:1982.2
Because of its structural differences from dextran, its different physical characteristics, and its resistance to hydrolysis by endodextranase, we have named glucan S, alternan, and the enzyme that synthesizes it from sucrose, alternansucrase. Alternansucrase has been isolated by two different methods. The first involves removal of the fraction L glucan from the culture fluid via hydrolysis by an
mesenteroides NRRL B-1355肠球菌在蔗糖上生长,可产生两种细胞外α-D-葡聚糖。尽管两者均被称为dextrans,但它们在化学和物理上是截然不同的,并且可以通过分级乙醇沉淀分离为标为L和S的级分。级分L与B-512F葡聚糖相似,具有95%的α-(1变为6)键和5%alpha-(1进入3)分支链接,但分数S具有alpha-(1进入6)和alpha-(1进入3)链接的交替序列。由于其与右旋糖酐的结构差异,不同的物理特性以及其对内切葡聚糖酶水解的抵抗力,我们将其命名为葡聚糖S(交替糖),以及由蔗糖(交替糖)合成的酶。已通过两种不同方法分离出交替糖。首先涉及通过内切葡聚糖酶水解从培养液中去除L葡聚糖馏分,然后在Bio-Gel A5m上进行色谱分离。空隙体积级分仅合成交替糖,而迁移较慢的第二级分主要合成葡聚糖和一些交替糖。第二种方法是在O-(苯氧乙酰基)纤维素上进行疏水层析。交