Quadruplex-to-Duplex Transition of G-Rich Oligonucleotides Probed by Cationic Water-Soluble Conjugated Polyelectrolytes

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• 作者：Fang He ; Yanli Tang ; Minghui Yu ; Fude Feng ; Lingling An ; Huan Sun ; Shu Wang ; Yuliang Li ; Daoben Zhu ; and Guillermo C. Bazan
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：May 31, 2006
• 年：2006
• 卷：128
• 期：21
• 页码：6764 - 6765
• 全文大小：76K
• 年卷期：v.128,no.21(May 31, 2006)
• ISSN：1520-5126

文摘

G-quartet DNA converts to duplex form in the presence of its complementary strand. This conformational change can be detected in real time by a homogeneous assay method based on the signal amplification of conjugated polyelectrolytes and the specific interaction of intercalating dyes with double-stranded DNA (dsDNA). The probe solution contains a cationic, conjugated polymer (CCP), G-quadruplex labeled with a fluorescein at the 5'-terminus (G-quadruplex-Fl), and ethidium bromide (EB). The addition of a complementary target results in the transition from G-quadruplex to duplex (dsDNA-Fl) and EB intercalation within the duplex structure. Excitation of the CCP leads to energy transfer from CCP to dsDNA-Fl (FRET-1) and then energy transfer from dsDNA-Fl to EB (FRET-2). Increasing the number of mismatched bases discourages dsDNA formation, which is detected in the assay.