Unexpectedly Enhanced Solubility of Aromatic Amino Acids and Peptides in an Aqueous Solution of Divalent Transition-Metal Cations.

Abstract

We experimentally observed considerable solubility of tryptophan (Trp) in a CuCl_{2} aqueous solution, which could reach 2-5 times the solubility of Trp in pure water. Theoretical studies show that the strong cation-π interaction between Cu^{2+} and the aromatic ring in Trp modifies the electronic distribution of the aromatic ring to enhance significantly the water affinity of Trp. Similar solubility enhancement has also been observed for other divalent transition-metal cations (e.g., Zn^{2+} and Ni^{2+}), another aromatic amino acid (phenylalanine), and three aromatic peptides (Trp-Phe, Phe-Phe, and Trp-Ala-Phe).

Cite this paper

@article{Shi2016UnexpectedlyES, title={Unexpectedly Enhanced Solubility of Aromatic Amino Acids and Peptides in an Aqueous Solution of Divalent Transition-Metal Cations.}, author={Guosheng Shi and Yaru Dang and Tingting Pan and Xing Liu and Hui Liu and Shaoxian Li and Li Juan Zhang and Hongwei Zhao and Shaoping Li and Jiaguang Han and Renzhong Tai and Yimin Zhu and Jichen Li and Qing Ji and Richard A Mole and Dehong Yu and Haiping Fang}, journal={Physical review letters}, year={2016}, volume={117 23}, pages={238102} }