韭菜过氧化物酶的分离纯化及性质

经匀浆、抽提、硫酸铵分级沉淀、CM-Sepharose 离子交换层析、Superdex-200凝胶过滤层析，获得电泳纯的韭菜过氧化物酶(POD)。该酶比活力达到14031.41U/mg，纯化倍数为102.96，回收率为10.85%。该酶分子质量约为28.4kD，最适温度40℃、最适pH值为4.6。该酶在20～40℃以及pH 4.0～8.0有较好的稳定性，在最适条件下测得其Km值为18.15mmol/L。低浓度草酸、Zn2+、Mg2+等对该酶有较强激活作用；甲醇、乙醇、异丙醇、SDS、抗坏血酸(AsA)以及Mn2+、Fe3+等对该酶有较强的抑制作用。

Isolation, Purification and Characterization of Peroxidase from Chinese Chives

Electrophoresis-pure peroxidase (POD) from Chinese chives was obtained after sample homogenization, extraction, ammonium sulfate precipitation, CM-Sepharose chromatography and Superdex-200 gel filtration. The purified POD had an activity of 14031.41U/mg. The purification factor was 102.96 and the recovery rate was 10.85% . The molecular weight of this enzyme was 28.4 kD, the optimum temperature and pH were 40 ℃ and 4.6, respectively. The POD enzyme was stable under 20－40℃ and pH 4－8. The Km of this enzyme was determined to be 18.15 mmol/L under optimum conditions. Its activity could be strongly activated by low concentrations of oxalic acid, Zn2+ and Mg2+, but inhibited by methanol, ethanol, isopropanol, SDS, ascorbic acid, Mn2+ and Fe3+.