摘要
以铜超氧化物歧化酶（CuZnSOD，n=1～4）作为野生型CuZnSOD突变体的一种模型，研究了其在二价金属离子（Mg^2＋，Mn^2＋）存在下由非氧化途径断裂DNA的活性，并与CuZnSOD和脱辅基SOD（apoSOD）进行了比较．结果表明，在Mg^2＋或Mn^2＋存在下，CunSOD断裂DNA的活性高于CuZnSOD和apoSOD，并且DNA的断裂活性受二价金属离子浓度、pH及酶浓度等因素影响．相对活性及动力学参数的测定结果表明，CunSOD断裂DNA的相对能力按Cu1SOD〈Cu2SOD≈Cu4SOD〈Cu3SOD的顺序变化．
The study examined the DNA cleavage activity mediated by each member of the Cu^2＋ -containing forms of CuZnSOD（ CunSOD, n = 1-4） in the presence of exogenous Mg^2＋ or Mn^2＋. The result indicates that upon addition of Mg^2＋ or Mn^2＋ , CunSOD can more efficiently cleave DNA via a hydrolytic pathway compared with its holo- and apo-forms. The factors, such as exogenous divalent metal concentration, pH and enzyme concentration, can affect the DNA cleavage activity. We also measured the relative enzyme activity and the steady state kinetic parameters of the DNA cleavage reaction, indicating that the DNA cleavage activity is independent of Cu^2＋ number in CunSOD, and increased in an order of Cu1SOD 〈 Cu2SOD ≈ Cu4SOD 〈 Cu3SOD.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第2期212-216,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20571028)资助
