Oligonucleotides incorporating 8-aza-7-deazapurines: synthesis and base pairing of nucleosides with nitrogen-8 as a glycosylation positionElectronic supplementary information (ESI) available: The molecular weight of oligonucleotides measured by MALDI-TOF. See http://www.rsc.org/suppdata/ob/b3/b301608k/
作者:Junlin He、Frank Seela
DOI:10.1039/b301608k
日期:——
the base pairing motifs of the universal nucleoside 8-aza-7-deazapurin-6-amine N8-(2'-deoxyribofuranoside) 2 (adenine analogue) and that of the 2,6-diamino compound 1. Owing to the absence of an amino group on the nucleoside 3a the low stability of oligonucleotide duplexes incorporating this compound opposite to the four canonical DNA-constituents indicate hydrogen bonding and base pairing for the universal
掺入异常连接的8-氮杂-7-脱氮嘌呤N8-(2'-脱氧核糖核苷)3a,b(嘌呤和6-氨基-2-氯嘌呤类似物)的寡核苷酸用作化学探针,以研究通用核苷的碱基配对基序8-氮杂-7-脱氮嘌呤-6-胺N8-(2'-脱氧核糖呋喃糖苷)2(腺嘌呤类似物)和2,6-二氨基化合物1的氨基酸。由于在核苷3a上不存在氨基,因此低掺入该化合物的与四个规范DNA成分相反的寡核苷酸双链体的稳定性表明,形成更稳定双链体的通用核苷1和2的氢键和碱基配对。当6-氨基-2-氯-8-氮杂-7-脱氮嘌呤核苷3b取代1并位于相同位置时,形成两组双链体(i)具有3b与dA或dC相对的高Tm双链,以及(ii)具有3b与dG或dT相对的低Tm双链。这些结果是由于3b的2-氯取代基与dT的2-氧代基或dG的6-氧代基发生空间冲突,而2-卤代取代基很好地容纳在与dA或dC形成的碱基对中。为了比较,研究了掺入规则连接的核苷4-6a,b的双链体