Thermodynamic comparison of the salt dependence of natural RNA hairpins and RNA hairpins with non-nucleotide spacers
Thermodynamic comparison of the salt dependence of natural RNA hairpins and RNA hairpins with non-nucleotide spacers
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DOI：
10.1021/bi961654g
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发表时间：
1996-11-19
期刊：
影响因子：
2.9
通讯作者：
Hall, KB
中科院分区：
文献类型：
--
作者：
Williams, DJ;Hall, KB
RNA发夹与环的10个或8个核苷酸，或7个核苷酸（乙二醇），间隔，已在实验中进行了比较，测量其热力学性质的NaCl依赖性。在1 M NaCl中，八核苷酸RNA发夹/环具有最有利的折叠自由能（Δ D度= -8.6 kcal/mol），而含有间隔区的RNA则相当不稳定（Δ D度= -5.2至-5.7 kcal/mol）;对于这些RNA/接头物质，螺旋-卷曲转变的有利熵和不利焓存在补偿性降低。优先相互作用系数（Δ γ（N））确定从分析的熔融转变作为NaCl浓度的函数进行比较，以确定对微分离子缔合的乙二醇的效果。虽然离子与完全RNA分子的螺旋和卷曲状态的缔合的差异遵循预测，但具有接头的RNA不遵循预测，这表明它们的天然和/或变性状态的描述已经改变。
RNA hairpins with loops of either ten or eight nucleotides, or seven nucleotides with (ethylene glycol), spacers, have been compared in experiments that measure the NaCl dependence of their thermodynamic properties. In 1 M NaCl, the eight-nucleotide RNA hairpin/loop has the most favorable folding free energy (Delta D degrees = -8.6 kcal/mol), while the RNAs containing the spacers are considerably more unstable (Delta D degrees = -5.2 to -5.7 kcal/mol); for these RNA/linker species, there are compensating reductions in favorable entropy and unfavorable enthalpy of the helix-coil transition. Preferential interaction coefficients (Delta Gamma(N)) determined from analyses of melting transitions as a function of NaCl concentration are compared to determine the effect of the ethylene glycol on differential ion association. While the difference in ion association to the helix and coil states of the fully RNA molecules follows prediction, the RNAs with linkers do not, indicating that the description of their native and/or denatured state has changed.