【摘要】 探讨了 Bal31核酸酶在无 Ca( )体系中能否依赖稀土离子 L a( )从两端降解线性 DNA分子 .发现了 1mmol/ L的 L a( )能激活 Bal31核酸酶 ,从而快速酶解线性 DNA.表明了 Ca( )并不是文献中所说的唯一能激活 Bal31核酸酶的离子 .用液相色谱 (HPL C)分别检测 Ca( )、L a( )体系的酶解产物 ,结果表明 :虽然后者酶解 CG碱基对的速率只约为前者的 60 % .但两体系对AT碱基对的酶解速度相近更多还原

【Abstract】 We studied the possibility of Bal31 nuclease’s degrading double stranded DNA from both 5’ and 3’ with La(III) in existence. The result of experiment showed: 1×10 -3 mol La(III) can react with Bal31 nuclease degrades DNA very quickly from both 3’ and 5’ termini. The fact proved that the enzyme is not absolutely dependent on calcium. In addition, using HPLC, we determined the terminal produce of Bal31 degrading DNA with La(III) or Ca(II),we found that though La(III) system in degrading A T base pair is 60 % than that Ca(II) system, it is very close to the Ca(II) system in degrading C G base pair.更多还原