Raj K C, Chandra T S
Department of Chemistry, Indian Institute of Technology, Madras, India.
FEMS Microbiol Lett. 1996 Dec 15;145(3):457-61. doi: 10.1111/j.1574-6968.1996.tb08616.x.
Alkali-tolerant Aspergillus fischeri Fxn1 produced two extracellular xylanases. The major xylanase (M(r) 31,000) was purified to electrophoretic homogeneity by ammonium sulfate precipitation, anion exchange chromatography and preparatory PAGE. Xylose was the major hydrolysis product from oat spelt and birch wood xylans. It was completely free of cellulolytic activities. The optimum pH and temperature were 6.0 and 60 degrees C, respectively. pH stability ranged from 5 to 9.5 and the t1/2 at 50 degrees C was 490 min. It had a Km of 4.88 mg ml-1 and a Vmax of 588 mumol min-1 mg-1. The activity was inhibited (95%) by AlCl3 (10 mM). This enzyme appears to be novel and will be useful for studies on the mechanism of hydrolysis of xylan by xylanolytic enzymes.
耐碱费氏曲霉Fxn1产生两种胞外木聚糖酶。通过硫酸铵沉淀、阴离子交换色谱和制备型聚丙烯酰胺凝胶电泳将主要木聚糖酶（分子量31,000）纯化至电泳纯。木糖是燕麦spel和桦木木聚糖的主要水解产物。它完全没有纤维素分解活性。最适pH和温度分别为6.0和60℃。pH稳定性范围为5至9.5，50℃下的半衰期为490分钟。其Km为4.88 mg ml-1，Vmax为588 μmol min-1 mg-1。该活性被10 mM的AlCl3抑制（95%）。这种酶似乎是新的，将有助于研究木聚糖分解酶水解木聚糖的机制。
