Hypoxanthine riboside (HXR) is a nucleoside essential for wobble base pairs to translate the genetic code. In this work, an absorption and luminescence study showed that HXR and human serum albumin (HSA) formed a new complex through hydrogen bonds and van der Waals forces at ground state. Fluorescence probe experiments indicated that HXR entered the first subdomain of domain II in HSA and was fixed by amino acid residues in site I defined by Sudlow, and after competing with a known site marker. The recognition interaction featured negative ΔHϴ , ΔSϴ and ΔGϴ thermodynamic parameters. Fluorescence and circular dichroism spectra described the polarity of residues and α-helix and β-strand content changed because of HXR binding. The most rational structure for the HXR-HSA complex was recommended by the molecular docking method, in which the binding location, molecular orientation, adjacent amino acid residues, and hydrogen bonds were included. In addition, the influence of β-cyclodextrin and some essential metal ions on the balance of the HSA-HXR system interaction was measured. The study gained comprehensive information on the transportation mechanism for HXR in blood, and was of great significance in understanding the theory of HXR biotransformation and in discussing its clinical in vivo half-life.

中文翻译：

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次黄嘌呤核糖体与血浆白蛋白相互作用的光谱和计算探索。

次黄嘌呤核糖苷（HXR）是摆动碱基对翻译遗传密码所必需的核苷。在这项工作中，吸收和发光研究表明，HXR和人血清白蛋白（HSA）通过基态的氢键和范德华力形成了新的复合物。荧光探针实验表明，HXR进入了HSA域II的第一个子域，并被Sudlow定义的位点I中的氨基酸残基固定，并与已知的位点标记竞争。识别相互作用具有负的ΔHϴ，ΔSϴ和ΔGϴ热力学参数。荧光和圆二色性光谱描述了残基的极性以及由于HXR结合而改变的α-螺旋和β-链含量。通过分子对接方法推荐了HXR-HSA配合物最合理的结构，其中包括结合位置，分子取向，相邻的氨基酸残基和氢键。此外，还测量了β-环糊精和一些必需金属离子对HSA-HXR系统相互作用平衡的影响。该研究获得了有关HXR在血液中转运机制的全面信息，对于理解HXR生物转化的理论以及讨论其临床体内半衰期具有重要意义。