Zhuang Xu-Liang, Zhang Hong-Xun
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Sheng Wu Gong Cheng Xue Bao. 2002 Sep;18(5):583-7.
Levoglucosan is the main product derived from pyrolysis of cellulose. A mutant Aspergillus niger CBX-209 could grow on levoglucosan well fermenting it into citric acid with a yield comparable to that on glucose. Levoglucosan hydrolase was absent by measuring glucose formation with the glucose oxidase and peroxidase coupling system. Cell extracts were partly purified by ammonium sulfate fractionation and ion-exchange chromatograph. Direct formation of glucose 6-phosphate from levoglucosan in the presence of ATP and MgCl2 was observed when it was reacted with partly purified enzyme by a combined strategy of enzymological and fast atom bombardment mass spectrometric analysis. These data showed that the mutant used a novel enzyme, levoglucosan kinase, to convert levoglucosan into glucose 6-phosphate. Levoglucosan kinase was an inductive enzyme.
左旋葡聚糖是纤维素热解的主要产物。突变型黑曲霉CBX - 209能够在左旋葡聚糖上良好生长,并将其发酵成柠檬酸,产量与在葡萄糖上的产量相当。通过葡萄糖氧化酶和过氧化物酶偶联系统测量葡萄糖生成量,发现不存在左旋葡聚糖水解酶。细胞提取物通过硫酸铵分级分离和离子交换色谱进行部分纯化。当通过酶学和快原子轰击质谱分析相结合的策略,使左旋葡聚糖与部分纯化的酶反应时,观察到在ATP和MgCl₂存在的情况下,左旋葡聚糖直接形成6 - 磷酸葡萄糖。这些数据表明,该突变体使用一种新型酶——左旋葡聚糖激酶,将左旋葡聚糖转化为6 - 磷酸葡萄糖。左旋葡聚糖激酶是一种诱导酶。