Experimental study of triplex-forming oligonucleotide targeted to the initiator of S gene of HBV labeled with ^(125)I

This study is used to investigate the feasibility of employing the Iodogen method to label triplex-forming oligonucleotide (TFO) targeted to the initiator of the S gene of HBV with 125I. A 17-mer oligonucleotides sequence was synthesized and grafted at the 5′ terminal with a tyramine group. Radioiodination of the tyramine-TFO with 125I was then performed using the Iodogen method. After TFO was labeled with 125I using the Iodogen method, the label- ing rate, the radiochemical purity, stability and bioactivity were determined, respectively. The results show that the radiolabeling rate and the radiochemical purity were 93% and 99%, respectively; and the radiochemical purity is more than 90% in vitro at -20°C on the 5th day after labeling; and the rate of 125I-tyramine-TFO binding to HepG2.2.15 cells was (37.2 ± 1.4)% and statistically different from the rate of HepG2 (p < 0.5). Hence, it is concluded that the labeling of oligonucleotides conjugated with tyramine using the Iodogen method is successful and is characterized with a high labeling rate, high stability, and a low loss of bioactivity of the labeled agent.

^(125)I标记免疫球蛋白重链V1家族框架区反义寡核苷酸

用DNA合成仪将含酪胺的单体连接在18聚体寡核苷酸的5′端,并用氯胺-T法进行125I标记。该标记方法的标记率为80.7%,标记物放化纯度为98.7%,体外放置24h放化纯度仍高于90%。聚丙烯酰胺凝胶电泳(PAGE)显示各时间点的条带与未保温的对照组平行,均未见异常条带。