EC 3.2.1.8 From rumen microorganism. Single band on SDS-gel electrophoresis (MW 21,000). Specific activity: 380 U/mg (40°C, pH 6.0, wheat flour arabinoxylan as substrate). Contaminants: α-L-arabinofuranosidase < 0.001%, cellulase < 0.001%. Stable at 4°C for > 4 years.