稀土离子(La3+、Ce3+、Nd3+)对超氧化物歧化酶活性的影响

摘要

The effects of rare earth ions (La3+、Ce3+、Nd3+) on pyrogallol and copper-zinc superoxide dismutase(Cu,Zn-SOD)were studied with the pyrogallol autoxidation method under the condition of 25 ℃,0.1 mol/L Tris-HCl buffer solution(pH 8.2).The possible inhibition mechanism was presumed.The results showed that La3+、Nd3+ had an inhibiting action on pyrogallol autoxidation.While the rate of pyrogallol autoxidation demonstrated a decreasing trend first,then an increading trend in response to the increasing Ce3+.Three rare earth ions all could inhibit the activity of Cu,Zn-SOD.And with the increasing of La3+、Ce3+、Nd3+ concentrations,the inhibition degree became strong.When the concentration of rare earth ion was more than 2.22×10-5 mol/L,the activity of Cu,Zn-SOD was inhibited absolutely.%利用微量邻苯三酚自氧化法(320 nm)研究了25℃下,0.1 mol/L Tris-HCl缓冲体系中(pH 8.2)不同稀土离子(La3+、Ce3+、Nd3+)对邻苯三酚自氧化和铜锌超氧化物歧化酶(Cu,Zn-SOD)活性的影响,并对可能的抑制作用机理进行了讨论.结果表明,稀土离子La3+、Nd3+对邻苯三酚自氧化有抑制作用,Ce3+对邻苯三酚自氧化表现出先抑制后促进的作用；3种稀土离子对Cu,Zn-SOD酶活性均存在抑制作用,并随稀土离子浓度的增加抑制程度不断增强,而当加入的稀土离子浓度大于2.22× 10-5 mol/L时,Cu,Zn-SOD完全失活.