Guanosine monophosphate (GMP) is a nucleotide that can self-assemble in aqueous solution under certain conditions. An understanding of the process at the molecular level is an essential step to comprehend the involvement of DNA substructures in transcription and replication, as well as their relationship to genetic diseases such as cancer. We present the temperature-dependent terahertz (1.5–12 THz, 50–400 cm) absorptivity spectra of aqueous Na GMP solution in comparison with the aqueous solutions of other RNA nucleotides. Distinct absorption features were observed in the spectrum of GMP, which we attribute to the intramolecular modes of the self-assemblies (i.e., G-complexes) that, at 1 M, start to form at 313 K and below. Changes in broad-band features of the terahertz spectrum were also observed, which we associate with the release of hydration water in the temperature-dependent formation of guanine quadruplexes. Using a state-of-the-art THz calorimetry approach correlating spectroscopic to thermodynamic changes, we propose a molecular mechanism of hydrophilic hydration driving GMP self-assembly as a function of temperature. The free energy contribution of hydrophilic hydration is shown as a decisive factor in guanine-quadruplex formation. Our findings spotlight the role of hydration in the formation of macromolecular structures and suggest the potential of hydration tuning for regulating DNA transcription and replication.

中文翻译：

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水合水驱动单磷酸鸟苷的自组装

单磷酸鸟苷（GMP）是一种在一定条件下可以在水溶液中自组装的核苷酸。在分子水平上理解这一过程是理解 DNA 亚结构在转录和复制中的参与及其与癌症等遗传疾病的关系的重要一步。我们展示了 Na GMP 水溶液与其他 RNA 核苷酸水溶液的温度依赖性太赫兹（1.5-12 THz，50-400 cm）吸收光谱。在 GMP 光谱中观察到明显的吸收特征，我们将其归因于自组装体（即 G 复合物）的分子内模式，自组装体（即 G 复合物）在 1 M 时开始在 313 K 及以下形成。还观察到太赫兹光谱宽带特征的变化，我们将其与鸟嘌呤四链体的温度依赖性形成中水合水的释放相关联。使用最先进的太赫兹量热方法将光谱与热力学变化相关联，我们提出了一种亲水水合驱动 GMP 自组装作为温度函数的分子机制。亲水性水合的自由能贡献被证明是鸟嘌呤四链体形成的决定性因素。我们的研究结果强调了水合在大分子结构形成中的作用，并表明水合调节在调节 DNA 转录和复制方面的潜力。