Lederman S, Sullivan G, Benimetskaya L, Lowy I, Land K, Khaled Z, Cleary A M, Yakubov L, Stein C A
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Antisense Nucleic Acid Drug Dev. 1996 Winter;6(4):281-9. doi: 10.1089/oli.1.1996.6.281.
Phosphorothioate oligodeoxynucleotides belong to a class of polyanions that bind to the third variable domain (v3) of HIV-1 gp120 and inhibit infectivity of a wide variety of HIV-1 isolates. This potent v3 binding of phosphorothioate oligodeoxynucleotides, which is relatively independent of the nucleotide sequence of the oligodeoxynucleotides, decreases with chain length (below 18-mers) and is low for 8-mers. However, recent studies have observed a nucleotide sequence-dependent augmentation of phosphorothioate oligodeoxynucleotide binding to v3 for 8-mers that contain the S-dG4 motif (e.g., SdT2G4T2) and have suggested that formation of quadruple helical tetraplexes (G-tetrads) is associated with the acquisition of v3 binding ability by small phosphorothioate oligodeoxynucleotides. In the current study, a series of SdG4-containing oligodeoxynucleotides were synthesized with varying tandem length (including the 8-mer SdT2G4T2, the 12-mer SdG4T4G4, and the 28-mer SdG4(T4G4)3) and compared with phosphorothioate oligodeoxynucleotides (with similar lengths or related sequences) for (1) their inhibition of the binding of mAb 9284, which binds to the N-terminal portion of the v3 loop, (2) the values of Kc when these compounds are used as competitors of the rgp120-binding of an alkylating phosphodiester oligodeoxynucleotide probe, and (3) inhibition of HIV-1 infectivity in a cell-cell transmission model. The presence of S-dG4 motifs and the number of tandem motifs augmented v3 binding and anti-HIV-1 infectivity for small (8-mer or 12-mer oligodeoxynucleotides) but did not significantly augment the potency of 28-mers. Whereas tetraplex formation of SdT2G4T2 may contribute to its v3 binding, the 12-mer SdG4T4G4 does not migrate as the tetraplex on nonreducing gels, suggesting that S-dG4 motifs may augment anti-HIV activity by multiple mechanisms.
硫代磷酸酯寡脱氧核苷酸属于一类多阴离子，它们与HIV-1 gp120的第三个可变结构域（v3）结合，并抑制多种HIV-1分离株的感染性。硫代磷酸酯寡脱氧核苷酸这种强大的v3结合能力相对独立于寡脱氧核苷酸的核苷酸序列，随链长（低于18聚体）而降低，对于8聚体来说较低。然而，最近的研究观察到，对于含有S-dG4基序（例如SdT2G4T2）的8聚体，硫代磷酸酯寡脱氧核苷酸与v3的结合存在核苷酸序列依赖性增强，并且表明四重螺旋四链体（G-四联体）的形成与小硫代磷酸酯寡脱氧核苷酸获得v3结合能力有关。在本研究中，合成了一系列具有不同串联长度的含SdG4的寡脱氧核苷酸（包括8聚体SdT2G4T2、12聚体SdG4T4G4和28聚体SdG4(T4G4)3），并与硫代磷酸酯寡脱氧核苷酸（具有相似长度或相关序列）比较，以研究（1）它们对与v3环N端部分结合的单克隆抗体9284结合的抑制作用，（2）当这些化合物用作烷基化磷酸二酯寡脱氧核苷酸探针rgp120结合的竞争剂时的Kc值，以及（3）在细胞-细胞传播模型中对HIV-1感染性的抑制作用。S-dG4基序的存在和串联基序的数量增强了小（8聚体或12聚体寡脱氧核苷酸）的v3结合和抗HIV-1感染性，但对28聚体的效力没有显著增强。虽然SdT2G4T2的四链体形成可能有助于其v3结合，但12聚体SdG4T4G4在非还原凝胶上不会以四链体形式迁移，这表明S-dG4基序可能通过多种机制增强抗HIV活性。
