Effects of chain length modification and bis(ethyl) substitution of spermine analogs on purine-purine-pyrimidine triplex DNA stabilization, aggregation, and conformational transitions.
Effects of chain length modification and bis(ethyl) substitution of spermine analogs on purine-purine-pyrimidine triplex DNA stabilization, aggregation, and conformational transitions.
复制标题
精胺类似物的链长修饰和双（乙基）取代对嘌呤-嘌呤-嘧啶三链体 DNA 稳定、聚集和构象转变的影响。
DOI：
10.1021/bi9624494
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Thomas,TJ
中科院分区：
文献类型：
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作者：
Musso,M;Thomas,T;Shirahata,A;Sigal,LH;VanDyke,MW;Thomas,TJ
天然的多胺腐胺、亚精胺和精胺已知可以稳定嘧啶-嘌呤-嘧啶和嘌呤-嘌呤-嘧啶三链体DNA的形成。我们研究了精胺的两种四胺和两种五胺类似物及其双（乙基）衍生物稳定5 '-TG 3 TG 4 TG 4 TG 3 T-3'与其靶双链体探针（由寡核苷酸5 '-TCGAAG 3AG 4AG 4AG 3A-3'和5 '-TCGATC 3 TC 4 TC 4 TC 3 T-3'组成）之间三链DNA形成的能力。我们使用电泳迁移率变动分析（EMSA），熔融温度（Tm）的测量，和圆二色性（CD）光谱，以评估这些新的多胺类似物对三链体DNA的稳定性，解离常数，聚集和构象的影响。在一般情况下，五胺比四胺更有效地稳定三链体DNA，虽然大多数的多胺与悬垂的游离氨基导致DNA聚集低于50%转化为三链体DNA。乙基取代这些悬垂氨基降低其效力约2倍，在稳定三链体DNA，然而，这种效果是超过补偿缺乏DNA聚集在双（乙基）多胺的存在下。在多胺存在下观察到三链DNA的Tm浓度依赖性增加。CD光谱测量表明，在多胺的存在下稳定的三链体DNA的构象相比，单独的寡核苷酸的CD光谱的明显差异。三链体DNA的温度依赖性CD谱显示，在不存在和存在多胺的情况下，双链体/三链体→单链DNA转变为双相熔融。这些结果表明，多胺的结构修饰是一种有效的策略，开发三链DNA稳定配体，在抗基因治疗的潜在应用。
The natural polyaminesputrescine, spermidine, and spermineare known to stabilize pyrimidine−purine−pyrimidine and purine−purine−pyrimidine triplex DNA formation. We studied the ability of two tetramine and two pentamine analogs of spermine and their bis(ethyl) derivatives to stabilize triplex DNA formation between 5‘-TG3TG4TG4TG3T-3‘ and its target duplex probe, consisting of the oligonucleotides 5‘-TCGAAG3AG4AG4AG3A-3‘ and 5‘-TCGATC3TC4TC4TC3T-3‘. We used electrophoretic mobility shift assay (EMSA), melting temperature (Tm) measurements, and circular dichroism (CD) spectroscopy to evaluate the effects of these novel polyamine analogs on triplex DNA stability, dissociation constants, aggregation, and conformation. In general, pentamines were more efficacious than tetramines in stabilizing triplex DNA, although most of the polyamines with pendant free amino groups caused DNA aggregation below 50% conversion to triplex DNA. Ethyl substitution of these pendant amino groups lowered their efficacy approximately 2-fold in stabilizing triplex DNA; however, this effect was more than compensated for by the lack of DNA aggregation in the presence of bis(ethyl)polyamines. A concentration-dependent increase in theTmof triplex DNA was observed in the presence of polyamines. CD spectral measurements showed distinct differences in the conformation of triplex DNA stabilized in the presence of polyamines compared to the CD spectra of the oligonucleotides alone. Temperature-dependent CD spectra of triplex DNA showed monophasic melting in the absence and presence of polyamines, suggesting duplex/triplex → single-stranded DNA transition. These results indicate that structural modifications of polyamines is an effective strategy to develop triplex DNA-stabilizing ligands, with potential applications in antigene therapeutics.