双孢蘑菇子实体超氧化物歧化酶(SOD)的分离纯化及部分性质

采用硫酸铵分级盐析、DEAE-Cellulose-52离子交换柱层析、Sephadex G-150分子筛柱层析分离纯化了双孢蘑菇(Agaricus bisporus)子实体超氧化物歧化酶.纯化了31倍,回收率为10.51%,纯酶比活力为5 512.6 u/mg,酶的最适作用温度为25 ℃,最适pH值为8.0,酶在25 ℃以下比较稳定,亚基分子质量为21 kD,全酶分子质量为43 kD, 该酶由2个相同的亚基组成.

Purification and Characterization of Superoxide Dismutase from Agaricus bisporus

The SOD of Agaricus bisporus was purified by salting out with ammonium sulfate ,column chromatography on DEAE-cellulose-52 , gel filtration on Sephadex G-150.The enzyme was purified with only a single band in non denaturing polyacrylamide gel electrophoresis , 31-fold purification,10.51% recovery of enzyme activity and 5 512.6 u/mg specific activity were obtained. The result showed that the enzyme was a kind of Mn-SOD composed of two equally sized subunits ,with a molecular weight of 43 kD, the subunit molecular weight was 21 kD.The optimum temperature and optimum pH for enzyme action were 25 ℃ and pH 8.0 respectively. The enzyme activity was stable under the temperature below 25 ℃,The K m and V max were 0.022 7mol/L and 66.7 mol/min respectively.