狗肝铜锌超氧化物歧化酶的纯化

Purification of Copper-zinc Superoxide Dismutase From Dog Liver

本文采用加热、硫酸铵分级沉淀和柱层析的方法,从狗肝中提纯了铜锌超氧化物歧化酶(Cu·Zn-SOD),并对其理化性质进行了鉴定。结果表明酶的纯度均一。与文献报道的不同来源的同类酶相同,狗肝Cu·Zn-SOD系由两个相同亚基组成的二聚体,每分子晦蛋白合有两个铜和两个锌原子。分子量33.6kD,N-末端氨基酸为丙氨酸。

Copper and zinc-containing superoxide dismutase (Cu·Zn-SOD) was purified from dog liver by heat treatment at 65℃ for 5min, following precipitation with ammonium sulfate and special colunm chromatographies.The enzyme was homogeneously pure. Through the investigation of its physiochemical properties,it was proved to be identical to similar enzymes reported previously as shown by its molecular weight of about 33.69 kD Containing two equally sized subunits and 2 atoms of copper and 2 atoms of zinc per molecule. The N-terminal residue of its amino acid sequence in molecule was found to be alanine.