The phenanthridine biguanides efficiently differentiate between dGdC, dAdT and rArU sequences by two independent, sensitive spectroscopic methods
作者:Marijana Radić Stojković、Snežana Miljanić、Katarina Mišković、Ljubica Glavaš-Obrovac、Ivo Piantanida
DOI:10.1039/c1mb05030c
日期:——
At submicromolar concentrations two novel phenanthridine biguanides exhibit distinctly different spectroscopic signals for dGdC and dAdT sequences, respectively, by opposite fluorimetric changes (quenching for dGdC and increase for dAdT) and especially the bis-biguanide derivative gives an opposite ICD response (negative ICD for dGC and strong positive for dAdT). This specific signalling was explained by the ability of compounds to switch the binding mode from intercalation into dGdC to minor groove binding into dAdT sequences. Both compounds bind to rArU by intercalation, yielding different fluorimetric and CD response in comparison to any of aforementioned ds-DNA. Moreover, both compounds revealed significantly higher affinity toward ds-polynucleotides in comparison to previously studied alkylamine- and urea-analogues. Furthermore, DNA/RNA binding properties of novel compounds could be controlled by pH, due to the protonation of heterocyclic nitrogen. Low in vitro cytotoxicity of both compounds against human cell lines makes them interesting spectrophotometric probes.
在亚摩尔浓度下,两种新型菲啶双胍对 dGdC 和 dAdT 序列分别显示出截然不同的光谱信号,其荧光变化相反(dGdC 为淬灭,dAdT 为增加),尤其是双胍衍生物给出了相反的 ICD 反应(dGC 为负 ICD,dAdT 为强正 ICD)。这种特殊信号的原因是化合物能够将结合模式从插入 dGdC 转换为结合 dAdT 序列的小沟。这两种化合物都通过插层与 rArU 结合,与上述任何 ds-DNA 相比,都产生了不同的荧光和 CD 反应。此外,与之前研究的烷基胺和脲类似物相比,这两种化合物对ds-多核苷酸的亲和力明显更高。此外,由于杂环氮的质子化作用,新型化合物的 DNA/RNA 结合特性可受 pH 值的控制。这两种化合物对人类细胞株的体外细胞毒性较低,因此是有趣的分光光度计探针。