论文标题
通过过渡金属离子增强组氨酸的水亲和力
Enhanced water affinity of histidine by transition metal ions
论文作者
论文摘要
过渡金属离子在生物学环境中广泛存在，对于许多维持生命的生理过程至关重要。最近，已经显示出过渡金属离子，例如Cu $^{2+} $，Zn $^{2+} $，Ni $^{2+} $，可以增加芳族生物分子的溶解度。与Cu $^{2+} $相比，Zn $^{2+} $对诸如色氨酸（TRP）等生物分子的溶解度的增强较少。另一方面，Zn $^{2+} $在人类血浆中的浓度更高，并且在蛋白质中最多，它在过渡金属离子中最多，阐明Zn $^{2+} $是否可以增强其他芳族氨基酸的溶解度非常重要。在此，我们观察到芳族氨基酸组氨酸（HIS）的溶解度在Zncl $ _2 $溶液中大大增强。基于第一个原则计算，这种溶解度的增强归因于阳离子 - $π$之间的相互作用与Zn $^{2+} $之间的相互作用。我们的结果对于芳香药物的生物利用度非常重要，并为理解Zn $^{2+} $的生理功能提供了新的见解。
Transitional metal ions widely exist in biological environments and are crucial to many life-sustaining physiological processes. Recently, transition metal ion such as Cu$^{2+}$, Zn$^{2+}$, Ni$^{2+}$, have been shown can increase the solubilities of aromatic biomolecules. Comparing with Cu$^{2+}$, Zn$^{2+}$ shows less enhancement to the solubilities of biomolecules such as tryptophan (Trp). On the other hand, Zn$^{2+}$ has a higher concentration in human blood plasma and appears in protein the most among transition metal ions, clarifying whether Zn$^{2+}$ can enhance the solubilities of other aromatic amino acids is significantly important. Herein, we observed that the solubility of aromatic amino acid histidine (His) is greatly enhanced in ZnCl$_2$ solution. Based on first principle calculations, this enhancement of solubility is attributed to cation-$π$ interaction between His and Zn$^{2+}$. Our results here are of great importance for the bioavailability of aromatic drugs and provide new insights for the understanding of physiological functions of Zn$^{2+}$.
