单链DNA稳定的金纳米簇合成及其检测核酸外切酶Ⅰ活性研究

摘要

核酸外切酶Ⅰ在基因组活动和稳定性中起着重要作用,因此,快速检测核酸外切酶Ⅰ的活性对疾病诊断和药物开发具有深远的意义.设计一个高效的DNA模板合成荧光金纳米团簇(Au NCs),以其作为荧光探针,用于简单、灵敏和无标记的方式检测核酸外切酶Ⅰ(ExoⅠ)的活性.试验结果表明:随着核酸外切酶Ⅰ的加入,单链DNA将从3'端至5'端被消化,金纳米团簇失去了单链DNA模板的保护出现团聚,导致其荧光强度下降,可用于核酸外切酶Ⅰ活性测定.该方法不需要任何基团的修饰和特殊DNA序列的设计,提高了核酸外切酶I活性测定效率.%Exonuclease Ⅰ (Exo Ⅰ) plays an important role in genome activities and stability. So the rapidly detection of Exo Ⅰ has a profound significance in disease diagnosis and drug development. In this paper, we predict to design an efficient DNA template for the formation of fluorescent Au NCs. Single-strand DNA (ss DNA) -templated Au NCs was used as fluorescent probe to detect the activity of Exo Ⅰ in a simple, sensitive, cost-effective and label-free way. It proved that with the addition of Exo Ⅰ, the ss DNA templates would be digested from 3' to 5' in pieces, the Au NCs lost the protection of the template, the fluorescence intensity of Au NCs would decrease. This homogeneous Exo Ⅰ activity assay does not need any other additional modifications of DNA sequence or difficult design, increasing the efficiency of Exo Ⅰ activity assay.