STUDY OF BINDING ABILITY OF PHOSPHOROTHIOATE OLIGONUCLEOTIDES WITH PROTEIN

硫代磷酸寡核苷酸与蛋白质结合能力的研究

基本信息

批准号：
08670540
负责人：
SHOJI Yoko
金额：
$ 1.6万
依托单位：
St.Marianna University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

We've recognized that phosphorothioate oligonucleotides (S-ODN) showed potent anti-herpetic activities when target site was limited near the splicing site. It was implied that S-ODN interfered the conservative structure which could be essential for the splicing, thus showed potent anti-herpetic activities. This was one explanation why S-ODN targeted splicing site showed potent anti-herpetic activities. However, it has been reported that G rich sequences reveal sequence non-specific biological activities. S-ODN may reveal another mechanism which might be based on strong protein binding activities. S-ODN strongly bound to serum protein at the ratio of 86.6%, while 21.6% for phosphodiester oligonucleotides (D-ODN). Binding activities which directly bound to the virus was more than 50% for S-ODN, on the other hand it was less than 5% for D-ODN.Thirteen mer S-ODN showed inhibitory effect on virus entry into the cell at the early stage of infection, while D-ODN did not. CD spectrum of S-ODN implied G-quartet structure, however, the relation between biological activities and higher dimension structure could not be clear.Moreover, we tried to enhance the anti-herpetic activities of S-ODN by using cationic liposomes. Cationic liposomes is useful tool to enhance the anti-herpetic activities of D-ODN, while it was not the case for SOD.One of the reason might be strong protein binding activities of S-ODN.From this study, the caution is proposed when S-ODN containing G-rich sequences might involve another mechanism other than antisense manner. We should carefully select the drug delivery system to enhance the biological activities of S-ODN.

我们已经认识到，当靶位点限制在剪接位点附近时，硫代磷酸寡核苷酸 (S-ODN) 显示出有效的抗疱疹活性。这表明S-ODN干扰了剪接所必需的保守结构，从而显示出有效的抗疱疹活性。这就是为什么 S-ODN 靶向剪接位点显示出有效的抗疱疹活性的一种解释。然而，据报道，富含G的序列揭示了序列非特异性生物活性。 S-ODN 可能揭示另一种基于强蛋白质结合活性的机制。 S-ODN 与血清蛋白的结合率为 86.6%，而磷酸二酯寡核苷酸 (D-ODN) 的结合率为 21.6%。 S-ODN与病毒直接结合的结合活性超过50%，而D-ODN则低于5%。13聚体S-ODN在病毒进入细胞的早期就表现出抑制作用。感染阶段，而D-ODN则没有。 S-ODN的CD谱暗示G-四重体结构，但生物活性与高维结构之间的关系尚不清楚。此外，我们尝试利用阳离子脂质体增强S-ODN的抗疱疹活性。阳离子脂质体是增强 D-ODN 抗疱疹活性的有用工具，而 SOD 则不然。原因之一可能是 S-ODN 较强的蛋白质结合活性。从本研究中，建议谨慎使用含有富含G序列的S-ODN可能涉及除反义方式之外的另一种机制。应谨慎选择药物递送系统以增强S-ODN的生物活性。