Brown D M, Lin P K
M.R.C. Laboratory of Molecular Biology, Cambridge, Great Britain.
Carbohydr Res. 1991 Sep 2;216:129-39. doi: 10.1016/0008-6215(92)84156-m.
The nucleosides N6-methoxy-2'-deoxyadenosine (dZ) and 2-amino-9-(2-deoxy-beta-ribofuranosyl)-6-methoxyaminopurine (dK) have been synthesised and converted into 5'-O-dimethoxytrityl 3'-(2-cyanoethyl N,N-diisopropylphosphoramidites). These monomers have been used in machine DNA synthesis to give a set of heptadecanucleotides containing up to three analogue nucleotides. The melting transitions (Tm) show that the 17-mer duplexes containing Z.T and Z.C base-pairs have closely similar stabilities, as have those containing K.T and K.C pairs. They are less stable than the corresponding fully complementary duplexes, but more stable than those containing mismatched pairs. This, in the case of dZ, is in accord with the amino-imino tautomeric ratio of approximately 1:4 observed for the nucleoside in methyl sulfoxide. The application of oligomers containing such "degenerate" bases in oligonucleotide probes and primers is discussed.
已合成核苷N6-甲氧基-2'-脱氧腺苷（dZ）和2-氨基-9-(2-脱氧-β-D-呋喃核糖基)-6-甲氧基氨基嘌呤（dK），并将其转化为5'-O-二甲氧基三苯甲基-3'-(2-氰基乙基-N,N-二异丙基磷酰胺酯)。这些单体已用于机器DNA合成，以得到一组含有多达三个类似核苷酸的十七聚核苷酸。熔解转变温度（Tm）表明，含有Z.T和Z.C碱基对的17聚体双链体具有非常相似的稳定性，含有K.T和K.C碱基对的双链体也是如此。它们比相应的完全互补双链体稳定性低，但比含有错配碱基对的双链体更稳定。就dZ而言，这与在二甲亚砜中观察到的该核苷约为1:4的氨基-亚氨基互变异构体比例一致。讨论了含有此类“简并”碱基的寡聚物在寡核苷酸探针和引物中的应用。
