【摘要】 研究了La对烟草体内RuBPcase总活性和初活性的影响。La在 0～ 80 μmol·L- 1的浓度范围内能增强它的活性 ,酶初活性提高幅度高于总活性 ,表明La可以活化烟草体内RuBPcase。但当La浓度超过 80 μmol·L- 1时 ,活化作用下降甚至抑制酶活性。在RuBPcase的催化体系中 ,La,Ce在一定浓度范围 ( 2～ 8μmol·L- 1)内能够取代该酶的激活剂Mg而激活酶活性 ,对纯化酶液的激活效果要高于粗酶液。更多还原

【Abstract】 The effects of lanthanum on total activity and initial activity of RuBPcase in tobacco seedlings were studied. When the concentration of La is 0～80 μmol·L -1 , the activities of RuBPcase increase, and the activation effect of La on initial activity is higher than that on total activity. While the concentration of La surpasses 80 μmol·L -1 , the activities of RuBPcase are inhibited. It is found that La and Ce replace Mg 2+ to activate the activity of RuBPcase in the enzymatic reaction, and the activation effects of La and Ce on the purified enzyme is higher than that on crude enzyme. The result indicates that La activates the activity of RuBPcase in vivo as well as in vitro.更多还原