CHEMICAL SYNTHESIS OF OLIGONUCLEOTIDE ANALOGUES

与mRNA或双链DNA互补的人工合成寡核苷酸AS 一种在活细胞中削弱基因表达的方法提供了动力 设计和开发用于治疗目的的寡核苷酸类似物。 与天然寡核苷酸不同，α，β-寡核苷酸 具有可替代的(3‘到3’)和(5‘到5’)-核苷酸间磷酸二酯 连接不容易被核酸酶识别，因此， 这种固有的核溶解稳定性，可能会在反义应用中找到应用 实验。 发展了一种简化的化学方法来合成α-二氢呋喃。 核苷前体。α，β-α，β-的固相合成 具有交替的(3‘至3’)-和(5‘至5’)-的寡核苷酸 核苷酸间磷酸二酯键(24-mer)，补充a 与第二外显子编码的剪接受体位点重叠的区域 HIV-1Tat基因产物已经完成。这种齐聚物 与其互补的未经修饰的DNA链杂交并形成复合体 Tm(53摄氏度)可与类似的 由相应的β-寡核苷硫代硫酸酯组成的杂交物 及其互补的未修饰DNA链(Tm=56℃)，但较低 比在天然DNA双链(TM=66摄氏度)下观察到的 同样的条件。因此，α，β-寡脱氧核苷酸应该 表现出与经过充分研究的贝塔相似的序列特异性- 硫代低聚脱氧核糖核苷。 为了更好地抵抗核酸酶，α，β- 具有唯一硫代硫键的寡核苷酸或 在每个末端也只合成了两个这样的连杆。这个 这些寡核苷酸类似物抑制血管紧张素转换酶的效力和有效性 HIVIIIb在人类T细胞系中的复制正在研究中。 同时对细胞系的细胞毒作用进行了评估。

Synthetic oligonucleotides complementary to mRNA or double-stranded DNA as a means to impair gene expression in living cells has provided the impetus to design and develop oligonucleotide analogues for therapeutic purposes. Unlike natural oligonucleotides, alpha,beta-oligodeoxyribonucleotides having alternative (3'to 3')-and (5'to 5')-internucleotidic phosphodiester linkages are not readily recognized by nucleases and, as a consequence of this inherent nucleolytic stability, may find application in antisense experiments. A simplified chemistry has been developed for the synthesis of alpha- nucleoside precursors. The solid-phase synthesis of an alpha,beta- oligodeoxyribonucleotide having alternating (3'to 3')-and (5'to 5')- internucleotidic phosphodiester linkages (24-mer), complementary to a region overlapping the splice acceptor site of the second exon encoding the HIV-1 Tat gene product, has been accomplished. This oligomer hybridized to its complementary unmodified DNA strand and formed a complex having a Tm (53 degrees C) comparable to that obtained with a similar hybrid composed of the corresponding beta-oligonucleoside phosphorothioate and its complementary unmodified DNA strand (Tm=56 degrees C) but lower than that observed with the native DNA duplex (Tm=66 degrees C) under the same conditions. Thus, alpha,beta-oligodeoxyribonucleotides should exhibit similar sequence-specificity as the well-studied beta- oligodeoxyribonucleoside phosphorothioates. To provide better resistance against nucleases, alpha,beta- oligodeoxyribonucleotides having exclusively phosphorothioate linkages or only two these linkages at each terminus have also been synthesized. The potency and efficacy of these oligonucleotide analogues at inhibiting the replication of HIVIIIb in a human T-cell line are under investigation. Cytotoxic effects on the cell line are simultaneously assessed.