We have synthesized and characterized a phosphoramidite derivative of 2′-deoxy-6-selenoinosine (d^6SeI) and incorporated this modification into an oligonucleotide by solid-phase synthesis. During cleavage from the solid-support and deprotection, spontaneous dimerization of this oligonucleotide occurs via formation of a diselenide cross-link between the modified nucleobases. This cross-link can be readily reduced to restore the single-stranded oligonucleotide. UV thermal denaturation and circular dichroism spectroscopy of duplexes with d^6SeI paired against all four native nucleobases revealed minor differences in stability and structure relative to 2′-deoxyinosine. This selenium containing nucleobase modification may be useful for applications in DNA nanomaterials and X-ray crystallography.

我们已经合成并表征了2'-脱氧-6-硒代肌苷的亚磷酰胺衍生物（d ^6Se I），并通过固相合成将该修饰结合到寡核苷酸中。在从固相支持物切割和脱保护期间，该寡核苷酸的自发二聚化是通过在修饰的核碱基之间形成二硒化物交联而发生的。该交联可以容易地还原以恢复单链寡核苷酸。d ^6Se的双链体的紫外热变性和圆二色谱我对所有四个天然核苷碱基配对发现，相对于2'-脱氧肌苷，在稳定性和结构上存在微小差异。这种含硒的核碱基修饰可能可用于DNA纳米材料和X射线晶体学。