2,6-Bis(functionalized) purines as metal-ion-binding surrogate nucleobases that enhance hybridization with unmodified 2′-O-methyl oligoribonucleotides
作者:Sharmin Taherpour、Harri Lönnberg、Tuomas Lönnberg
DOI:10.1039/c2ob26885j
日期:——
bases were found to stabilize short oligonucleotide duplexes when incorporated into the 3′-termini of both strands, even in the absence of divalent metal ions but especially in the presence of Cu2+. The highest melting temperature determined for such a duplex was 71.8 °C, nearly 30 °C higher than the Tm of the respective solely Watson–Crick paired duplex. Despite the dramatic stabilizing effect of the terminal
三种不同嘌呤碱的容量,即。2,6-双(3,5-二甲基吡唑-1-基)嘌呤,2-(3,5-二甲基吡唑-1-基)腺嘌呤和2,6-双(2-乙酰基-1-甲基肼基)嘌呤已经研究了与天然核碱基形成的金属离子介导的碱基对的形成。为此,将源自这些碱基的核糖核苷掺入短2'- O-甲基寡核糖核苷酸的链内或3'-末端位置,并在不存在和存在三种不同金属离子的情况下将这些碱基修饰的寡聚物的杂交特性( Cu 2 +,Zn 2+和Pd 2+)是通过UV和CD光谱法研究的。当掺入两条链的3'-末端时,发现前两个碱基可稳定短的寡核苷酸双链体,即使在不存在二价金属离子的情况下,尤其是在Cu 2+存在的情况下也是如此。确定的这种双链体的最高熔化温度为71.8°C,比T m高近30°C各自的Watson-Crick配对双工。尽管末端金属碱基对具有显着的稳定作用,但这些短的修饰寡核苷酸仍保留了内部Watson-Crick碱基对的序列