Thiazole orange-conjugated peptide nucleic acid for fluorescent detection of specific DNA sequences and site-selective photodamage
Thiazole orange-conjugated peptide nucleic acid for fluorescent detection of specific DNA sequences and site-selective photodamage
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用于荧光检测特定 DNA 序列和位点选择性光损伤的噻唑橙缀合肽核酸
作者：
Tanaka;M;et al.
将噻唑橙子（TO）与假互补肽核酸（pcPNA）偶联，合成了一种检测双链DNA（dsDNA）中特异性序列的荧光探针。一对TO-缀合的pcPNA通过双链侵入结合到dsDNA中的靶位点，并促进TO部分的嵌入，从而显著增强其荧光。检测的位点特异性高到足以区分DNA中仅一个碱基对的差异。这些TO-pcPNA偶联物还起到位点选择性光损伤诱导剂的作用。在可见光照射下，染料通过能量转移在侵入位点产生单线态氧，从而在该处选择性地形成8-oxo-7，8-dihydro-2′-deoxyguanosine（8-oxoG）。
A fluorescent probe to detect specific sequences in double-stranded DNA (dsDNA) has been synthesized by conjugating thiazole orange (TO) with pseudo-complementary peptide nucleic acid (pcPNA). A pair of TO-conjugated pcPNAs bound to the target site in dsDNA through double-duplex invasion, and promoted intercalation of the TO moieties for notable enhancement of their fluorescence. Site-specificity of the detection is high enough to differentiate only one base-pair difference in DNA. These TO-pcPNA conjugates also function as site-selective photo-damage inducers. Upon irradiation with visible light, singlet oxygen was generated by energy transfer from the dyes at the invasion site, resulting in the site-selective formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxoG) there.