relative to the natural system. (ii) bcd(A10) discriminates between a complementary oligodeoxynucleotide with a mismatch in the center in the same way as d(A10), indicating equal base-pairing selectivity. (iii) bcd(A10) forms more stable triplexes with d(T10) of the pyrimidine-purine-pyrimidine (py · pu · py) motif than d(A10). (iv) The stability of duplexes containing a bicyclic strand is more sensitive
描述了一种新型寡核苷酸('bicyclooligodeoxynucleotide'= bcd(X n))的合成,该寡核苷酸在其糖-
磷酸骨架中显示出较小的构象柔性,并描述了十聚体bcd(T 10)和给出了bcd(A 10)相互之间以及通过紫外光谱和量热技术获得的互补RNA和DNA序列。结果可总结如下:(i)bcd(T 10)与互补的RNA和DNA的配对较弱,而bcd(A 10)相对于天然系统形成更强的双链体。(ii)bcd(A 10)以与d(A 10)相同的方式区分中心错配的互补寡聚脱氧核苷酸,表明碱基配对选择性相等。(III)BCD(A 10)形成与d更稳定的三螺旋(T 10
嘧啶-
嘌呤-
嘧啶)(
吡啶·プ·PY)基序比d(A 10)。(iv)含双环链的双链体的稳定性对盐浓度更敏感。包含bcd(A 10)的双链体具有较高的灵敏度,这是由于较高的差异阳离子摄取引起的。(v)双相形成焓的差示扫描量热法(
DSC)分析显示ΔH