5-Aza-7-deaza-2′-deoxyguanosine: Oligonucleotide Duplexes with Novel Base Pairs, Parallel Chain Orientation and Protonation Sites in the Core of a Double Helix
作者:Frank Seela、Alexander Melenewski
DOI:10.1002/(sici)1099-0690(199902)1999:2<485::aid-ejoc485>3.0.co;2-j
日期:1999.2
chains a stable “purine-purine” base pair was observed between 5-aza-7-deazaguanine and guanine or 7-deazaguanine. Antiparallel stranded duplexes are formed when 5-aza-7-deazaguanine pairs with cytosine. This base pair has only two hydrogen bonds under neutral conditions but is stabilized by a third one in acidic medium. A new base pair is also detected between the base of 1 and isoguanine (neutral medium)
合成了含有5-氮杂-7-脱氮-2'-脱氧鸟苷(1)的寡核苷酸。用膦酸酯15或亚磷酰胺5进行固相合成。还使用了氨基未保护的膦酸酯4。含有1个寡核苷酸的杂交研究导致新的碱基对导致双链具有平行(ps)或反平行(aps)链取向。在具有平行链的那些中,在5-氮杂-7-脱氮鸟嘌呤和鸟嘌呤或7-脱氮鸟嘌呤之间观察到稳定的“嘌呤-嘌呤”碱基对。当5-氮杂-7-脱氮鸟嘌呤与胞嘧啶配对时,会形成反平行链双链体。该碱基对在中性条件下仅具有两个氢键,但在酸性介质中被第三个氢键稳定。在1的碱基和异鸟嘌呤(中性培养基)之间也检测到新的碱基对。