Triple-helix formation in the antiparallel binding motif of oligodeoxynucleotides containing N9- and N7-2-aminopurine deoxynucleosides
Triple-helix formation in the antiparallel binding motif of oligodeoxynucleotides containing N9- and N7-2-aminopurine deoxynucleosides
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DOI：
10.1093/nar/29.11.2260
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发表时间：
2001-06-01
影响因子：
14.9
通讯作者：
Leumann, CJ
中科院分区：
文献类型：
--
作者：
Parel, SP;Leumann, CJ
合成了含有Alphan(7)-、Betan(7)-、Alphan(9)-和Betan(9)-2-氨基嘌呤(AP)-脱氧核糖核苷四种异构体(Z)的反平行三螺旋结合基序的形成三聚体的寡核苷酸15聚体。在没有单价金属阳离子存在的情况下，用定量DNase I足迹滴定法测定了它们与含有与氨基嘌呤残基相对的4个天然碱基对(X-Y)的双链DNA靶标的结合，相应的结合常数在1.0×10(6)~1.3×10(8)M~(-1)之间。Z=Alphan(7)AP：T-A>；A-T>；C-G类似于G-C；Z=Betan(7)AP：A-T>；C-G>；G-C>；T-A；Z=Alphan(9)AP：A-T=G-C>；T-A；C-G；Z=Betan(9)AP：G-C>；A-T>；C-G>；T-A。
Tripler-forming oligodeoxynucleotide 15mers, designed to bind in the antiparallel triple-helical binding motif, containing single substitutions (Z) of the four isomeric alphaN(7)-, betaN(7)-, alphaN(9)- and betaN(9)-2-amino-purine (ap)-deoxyribonucleosides were prepared. Their association with double-stranded DNA targets containing all four natural base pairs (X-Y) opposite the aminopurine residues was determined by quantitative DNase I footprint titration in the absence of monovalent metal cations, The corresponding association constants were found to be in a rather narrow range between 1.0 x 10(6) and 1.3 x 10(8) M-1. The following relative order in Z x X-Y base-triple stabilities was found: Z = alphaN(7)ap: T-A > A-T > C-G similar to G-C; Z = betaN(7)ap: A-T > C-G > G-C > T-A; Z = alphaN(9)ap: A-T = G-C > T-A > C-G; and Z = betaN(9)ap: G-C > A-T > C-G > T-A.