【摘要】 L68菌株中的邻苯二酚 2 ,3 双加氧酶经硫酸铵分级沉淀、DEAE SepharoseFastFlow柱层析、Hydroxyapatite柱层析、Sephadex G15 0凝胶过滤分离 ,并经SDS 聚丙烯酰胺凝胶电泳检测 ,达到了电泳纯 .提纯倍数为 2 34 .1倍 ,收率为 2 0 .2 % .酶相对分子质量为 (132± 10 )kDa ,由 4个相对分子质量相同的亚基组成 .最适反应温度 35℃ ,且酶活力在 15～ 65℃比较稳定 ;最适 pH为 8.0 ,在 pH 7.0～ 10 .5酶活力较高且比较稳定 .某些金属离子尤其是Fe3+ 对酶活力有强烈的抑制作用 .以邻苯二酚为底物 ,Km 为 2 0 .63μmol/L ,Vmax为 2 .82 μmol/ (min·mg)更多还原

【Abstract】 Catechol 2,3 Dioxygenase was purified from strain L68 by (NH 4) 2SO 4 precipitation, DEAE Sepharose Fast Flow chromatography, Hydroxyapatite chromatography, Sephadex G 150 gel filtration with 234.1 fold purification, and a recovery of 20.2%. The purified enzyme was homogeneous on SDS PAGE. The enzyme with a molecular mass of (132±10)kDa contained four same subunits. The optimal conditions for activity of enzyme were pH 8.0, temperature 35 ℃. The enzyme was stable over the range of pH 7.0～10.5 and below 65 ℃. The activity was greatly inhibited by Fe 3+ ,etc. The K m for catechol of the enzyme was 20.63 μmol/L, V max was 2.82 μmol/(min·mg).更多还原