基于PET效应检测8-氧鸟嘌呤DNA糖基化酶的荧光传感器

Determination of 8-Oxyguanine DNA Glycosylase Using a Fluorescence Sensor Based on PET Effect

8-氧鸟嘌呤DNA糖基化酶(OGG1)是一种突变的DNA修复酶,可切除生物体内受损DNA的标志物8-氧鸟嘌呤(8-oxoG),而8-oxoG与多种癌症的病因学有关。基于光诱导电子转移(PET)效应,以1条5'末端标记羧基荧光素且含有8-oxoG的DNA链为信号探针,1条3'末端含多个G碱基的互补序列作为猝灭基团,根据加入OGG1前后体系荧光强度的变化,建立了一种简单快速、灵敏检测OGG1酶活性的荧光传感器。结果表明,该方法可对OGG1浓度进行灵敏的定量检测,且OGG1酶浓度在0~60 U/mL范围内与体系荧光强度的变化值呈良好线性关系,检出限为0.7 U/mL。利用该方法检测人类血清样品中的OGG1酶,加标回收率为99.1%~105%,相对标准偏差(RSD)为1.0%~4.3%。该传感器选择性好,简化了实验步骤,节约了实验成本。

8-Oxyguanine DNA glycosylase(OGG1)is an impotant DNA repaired enzyme,which can excise 8-oxyguanine(8-oxoG),a marker of damaged DNA.Meanwhile,it is implicated in the etiology of many kinds of cancers.Here,a fluorescence sensor based on the photo-induced electron transfer(PET)effect was constructed to detect the quantities of OGG1 which depended on the change of fluorescence intensity before and after addition of the OGG1 in the system.The carefully designed DNA signal probe contained an internal 8-oxoG site and 5'end carboxyfluorescein tag,a complementary sequence as the quenching group with 3'terminal containing multiple G base.This method was simple,sensitive and specific,and it was used for the detection of OGG1 in human serum samples.The results showed that there was a good linear relationship between the fluorescence intensity change of the system and OGG1 in the concentration range of 0-60 U/mL,with a detection limit of 0.7 U/mL.The recoveries for OGG1 in spiked human blood serum samples ranged from 99.1%to 105%,with the relative standard deviations(RSDs)of 1.0%-4.3%.The sensor has the advantages of good selectivity,simple operation and low cost.