Functionalization of oligonucleotides capable to form alternate-stranded triplex containing stereoisomeric nucleotide units

合成了一种新型的二核苷磷酸三酯亚磷酰胺衍生物，并成功地将其插入到α-β嵌合寡聚DNA的中间部分。所得立体异构嵌合体DNA之一强烈增强嵌合体和双链DNA之间形成的交替链三链体的热稳定性。另一方面，含有携带相同单元的低聚物的双链体未能显示出任何Tm增加（稳定化）效果，而不管携带嵌入部分的磷原子的立体化学。合成了一种新型的蒽醌衍生物，它与2，2-二（羟甲基）丙酸偶联，作为一种新的非核苷组分，并成功地通过掺入14-mer三链体形成寡核苷酸（TFO）的内部区域， ...更多信息 亚磷酰胺法。合成了一种新型的TFO，并对其热稳定性进行了研究.修饰后的嵌合体DNA与双链DNA形成的三螺旋DNA具有显著的热稳定性，但嵌入剂共轭核碱基的位置对其稳定性影响不大。在所研究的嵌合DNA中，在相邻位置上带有两个嵌入剂共轭核碱基的修饰嵌合DNA表现出最高的稳定性。与双链DNA杂交后，修饰的嵌合体DNA即使在接近生理pH的条件下也能形成基本稳定的交替链三链体。此外，引入衍生物所带来的三链体稳定效果几乎与衍生物的立体化学无关。该偶联物与二价金属离子如Fe^<2+>、Cu^<2+>、Zn^<2+>等形成络合物。其中，Fe^<2+>络合物有效地切割双链DNA。目前正在进行一项研究，利用带有该复合物的功能性嵌合DNA作为序列特异性基因调节剂。少

A novel phosphoramidite derivative of a dinucleoside phosphotriester unit bearing an intercalative moiety at its internucleotide linkage in a stereospecific manner was prepared and successfully incorporated into the middle portion of α-β chimeric oligoDNA. One of the resulting stereoisomeric chimera DNAs strongly enhances the thermal stability of an alternate-stranded triplex formed between the chimera and a double-stranded DNA. On the other hand, the duplexes containing the oligomers bearing the same unit failed to show any Tm increment (stabilization) effect regardless of the stereochemistry of the phosphorous atom bearing the intercalative moiety. Thus, the stabilizing effect of the current dinucleoside unit seems to be specific to the DNA triplex.An anthraquinone derivative conjugated with 2,2-bis(hydroxymethyl)propionic acid as a novel non-nucleosidic component was synthesized and successfully incorporated into an internal region of 14-mer triplex-forming oligonucleotide (TFO) via … More the phosphoramidite method. The resulted novel TFO exhibits remarkable enhancement effect on the thermal stability of a DNA triplex upon binding to a pyrimidine-gap containing polypurine sequence.Novel α-β chimeric oligodeoxynucleotides bearing an intercalator-conjugated nucleobase located at the internal 4-nt linker region were synthesized, and their triplex-stabilizing property was examined. The triple helical DNA formed between the modified chimera DNA and double-stranded DNA exhibited remarkable thermal stability ; however, the position of the intercalator-conjugated nucleobase had little influence on the stability. Among the examined, modified chimera DNA bearing the two intercalator-conjugated nucleobases at adjacent positions exhibited the highest stability.Novel diastereomeric α-β chimeric oligodeoxynucleotides bearing a propionic acid derivative of an anthraquinone-polyamine conjugate in the "linker" region were synthesized. Upon hybridization with double-stranded DNA, the modified chimera DNAs formed substantially stable alternate-stranded triplex even at near physiological pH. Furthermore, the triplex-stabilizing effect brought about by the incorporation of the derivative was almost regardless of the stereochemistry of the derivative.Novel conjugate composed of an intercalator-metal ligand-2,2-bis(hydroxymethyl)propionic acid was prepared. The conjugate forms complexes with divalent metal ions such as Fe^<2+>, Cu^<2+>, Zn^<2+>, etc. Among them, the Fe^<2+> complex cleaves double-stranded DNA, efficiently. A study to utilize a functional chimera DNA bearing the complex as a sequence specific gene regulator is now under way. Less