中文摘要：

以红薯块根为材料,对红薯中的过氧化物酶进行提取、分离、纯化并测定其性质。结果表明：经40%～80%饱和度的硫酸铵分级分离、Sephadex G-100凝胶过滤、Concanavalin A亲和层析三个步骤,获得纯化的红薯过氧化物酶,酶纯化倍数为26.56倍,回收率0.92%,比活性3841.80 U/mg,SDS-PAGE电泳显示酶分子量为23 kDa。红薯过氧化物酶以愈创木酚为底物时λmax=470 nm,Km=3.031 mmol/L,酶的最适pH值为5.0,最适温度是35℃。酶的热稳定性较高,60℃保温20 min,残存相对活性为72.40%;酶的低温贮存稳定性很高,0～4℃冰箱中贮存20 d后,残存相对活性为97.28%。

英文摘要：

The tuber of sweet potato was used as material.The peroxidase in sweet potato was extracted,separated and purified and its properties were determined.The results indicated that by means of 40~80% ammonium sulfate precipitation,Sephadex G-100 gel filtration and affinity chromatography with concanavalin A,the purified peroxidase were obtained from sweet potato.Its purification fold,recovery rate and specific activity were 26.56,0.92% and 3 841.80 U/mg,respectively.SDS-PAGE electrophoresis showed the molecular mass of the peroxidase was 23 kDa.With guaiacol as substrate,λmax=470 nm,Km=3.031 mmol/L,the optimum conditions for the peroxidase were temperature of 35℃ and pH of 5.0.The peroxidase showed a high thermal stability,it remained 72.40% of the original activity after it had been treated at 60℃ for 20 min.It also showed very high storage stability at low temperature,and it remained 97.28% of the original activity after it had been treated at 0-4℃ for 20 days.