摘要
用抗坏血酸－Ｆｅ（Ⅲ）或过氧化氢为活性氧体系分别作用于牛红细胞铜锌超氧化物歧化酶（ＣｕＺｎ－ＳＯＤ），发现酶活性降低的同时，其活性中心中Ｃｕ（Ⅱ）被还原成Ｃｕ（Ⅰ）。进一步用抗坏血酸－Ｆｅ（Ⅲ）或过氧化氢作用于马来酰亚胺标记ＣｕＺｎ－ＳＯＤ，用ＥＳＲ测定的结果表明酶分子亚基的缔合受到影响。结果提示酶的失活与活性中心中Ｃｕ（Ⅱ）的还原及酶构象的变化有关。
The effect of reactive oxygen spedes on the structure of cupro-zinc superoxide dismutase (CuZn-SOD) was studied by ESR and spin label. Hydrogen peroxide or ascorbate-Fe(Ⅲ)system were used to modal CuZn-SOD.The result showed that Cu(Ⅱ)in the active site of the enzyme was reduced to Cu(Ⅰ)as assessed by ESR,and concomitantly the enzyme lost its catalytic activity. Hydrogen peroxide or ascorbate-Fe(Ⅲ)were further used to modify the CuZn-SOD labeled by maleimido spin label. The result showed that the binding of the two subunits was influenced .It is suggested that the reduction of Cu(Ⅱ)in the active site of the enzyme and the conformational alteration might be responsible for the loss of the enzymatic activity.
出处
《生物物理学报》
CAS
CSCD
北大核心
1994年第3期497-500,共4页
Acta Biophysica Sinica
基金
国家自然科学基金
关键词
铜
锌
超氧化物歧化酶
活性氧
电子自旋共振
Cupro-zinc superoxide dismutase
Reactive oxygen species
ESR
Spin label
