不同磁场对过氧化氢酶活性及酶促反应的影响

在不同的磁场条件下研究了Nu—Fe—B静磁场对过氧化氢酶活性和反应动力学参数及二级结构的影响．采用磁场强度为0．15T、0．30T、0．45T的静磁场分别处理过氧化氢酶溶液，以曝磁时间为参数，对酶的活性、反应动力学参数、二级结构分别进行测定．结果表明，与对照样相比，处理过的过氧化氢酶活性增大，当作用时间为1h时，活性最大．3个磁场下酶的活性分别增加了18．2％、23．5％和25．8％；用不同的磁场对过氧化氢酶溶液分别作用1h，与对照样相比，随着磁场强度的增加，Km值从0．02785mol／L增加到0．08724mol／L，Vm值从0．03597mol／（L·min）增加到0．09511mol／（L·min）；同时，圆二色光谱测定结果表明磁场处理过的过氧化氢酶的二级结构也发生变化，这可能是由于磁场对过氧化氢酶辅酶中的Fe^3＋影响而引起的．

Effects of Different Magnetic Fields on Activity of Catalase and Enzymatic Reaction

The influence of Nu-Fe-B static magnetic field on catalase has been studied. Under the experimental conditions, catalase solution was treated with magnetic fields of 0.15 T,0.30 T and 0.45 T, respectively for a certain period of time,then the activity,kinetic parameters ,and the conformation （secondary structure）were investigated. Under the three magnetic conditions, there was an activity increase of 18.2%, 23.5%, 25.8%, respectively, compared with the control sample and the activity reached maximum when the catalase was treated for lh. It was also found that Km value increased from 0.027 85 mol/L to 0.087 24 mol/L and Vm value increased from 0.035 97 mol/（L·min） to 0.095 11 mol/（L·min） due to the increase of the magnetic field. The results measured by CD show that there are some changes in the enzyme secondary structure, possibly because of Fe^3＋ in the catalase coenzyme.