以来源于不动杆菌Acinetobacter sp.SM04的过氧化物酶A4-Prx的毕赤酵母工程表达菌株GS115/pPIC9K-A4-Prx为研究对象，从培养液中纯化重组过氧化物酶A4-Prx，分析其ZEA降解活力，并研究过氧化物酶A4-Prx的酶学特性。本论文首先研究了蛋白的纯化方法，通过一系列分离纯化手段得到纯的过氧化物酶A4-Prx，最终纯化倍数约为12，HPLC实验结果表明纯化后的过氧化物酶A4-Prx具有ZEA降解能力，且ZEA降解率达到63%。对过氧化物酶A4-Prx进行酶学特性研究，结果表明，pH和温度均对A4-Prx的过氧化物酶酶活有显著影响，pH 9.0和反应温度60 ℃时酶活最高，A4-Prx的最大酶活是204.1 U，此时过氧化氢浓度为9.7 mM。A4-Prx过氧化物酶反应受EDTA的抑制作用明显。本研究为过氧化物酶的酶学研究奠定了基础,为后续的A4-Prx降解机理研究提供先决条件，推动生物降解ZEA研究的进展。

Recombinant peroxidase A4-Prx derived from Acinetobacter sp. SM04 and expressed by genetically-engineered recombinant Pichia pastoris GS115/pPIC9K-A4-Prx was purified to analyze its enzymatic characteristics and ability to degrade zearalenone (ZEA). Ammonium sulfate precipitation and dextran column elution were used to purify A4-Prx, with a final purification factor of 12. High-performance liquid chromatography (HPLC) showed that purified A4-Prx degraded ZEA at a rate of 63%. Further analysis of A4-Prx enzymatic characteristics showed that pH and temperature had significant effects on peroxidase activity; enzymatic activity peaked at pH 9.0 and 60 ℃. Lineweaver-Burk plots of A4-Prx peroxidase reaction showed that when H2O2 concentration was 9.7 mM, Km was 4.85 mM and Vmax was 204.1 U. A4-Prx also showed significant inhibitory effect on ethylenediaminetetraacetic acid (EDTA). These results provide preset conditions for subsequent research on the degradation mechanisms of A4-Prx and further research on ZEA biodegradation.

国家自然基金项目（31201330）；广州市科技攻关项目（20130000202）；粮食公益性行业科研专项（201313005）