Doluca Osman, Hale Tracy K, Edwards Patrick J B, González Carlos, Filichev Vyacheslav V
College of Sciences, Institute of Fundamental Sciences, Massey University, Private Bag 11-222, 4442 Palmerston North (New Zealand), Fax: (+64) 6-3505682.
International Burch University, Francuske Revolucije, 71210 Sarajevo (Bosnia and Herzegovina).
Chempluschem. 2014 Jan;79(1):58-66. doi: 10.1002/cplu.201300310. Epub 2013 Dec 2.
In this study the position of the thiazole orange derivative in triplex-forming oligonucleotides (TFOs) is varied and the fluorescence of the resulting complexes with DNA duplexes, single-stranded DNAs and RNAs are evaluated. Under similar conditions single attachment of the TO-dye to 2'-O-propargyl nucleotides in the TFOs (assembly dependent fluorescence enhancing nucleic acids, AFENA) led to probes with low fluorescent intensity in the single-stranded state with fluorescence quantum yield (Φ ) of 0.9 %-1.5 %. Significant increase in fluorescence intensity was detected after formation of DNA triplexes (Φ =23.5 %-34.9 %). Under similar conditions, Watson-Crick-type duplexes formed by the probes with single stranded (ss) RNA and ssDNA showed lower fluorescence intensities. Bugle insertions of twisted intercalating nucleic acid (TINA) monomers were shown to improve the fluorescent characteristics of GT/GA-containing antiparallel AFENA-TFOs. Self-aggregation of TFOs caused by guanosines was eliminated by TINA insertion which also promoted DNA triplex formation at pH 7.2. Importantly these AFENA-TINA-TFOs can bind to the duplex in the presence of complementary RNA at 37 °C.
在本研究中，噻唑橙衍生物在三链形成寡核苷酸（TFOs）中的位置是变化的，并评估了所得与DNA双链体、单链DNA和RNA形成的复合物的荧光。在相似条件下，将TO染料单连接到TFOs中的2'-O-炔丙基核苷酸上（组装依赖性荧光增强核酸，AFENA），导致单链状态下荧光强度较低的探针，其荧光量子产率（Φ）为0.9% - 1.5%。形成DNA三链体后检测到荧光强度显著增加（Φ = 23.5% - 34.9%）。在相似条件下，由探针与单链（ss）RNA和ssDNA形成的沃森-克里克型双链体显示出较低的荧光强度。扭曲插入核酸（TINA）单体的小号插入显示可改善含GT/GA的反平行AFENA-TFOs的荧光特性。鸟苷引起的TFOs自聚集通过TINA插入得以消除，这也促进了在pH 7.2时DNA三链体的形成。重要的是，这些AFENA-TINA-TFOs在37°C下存在互补RNA时可与双链体结合。
