Structure and\nDynamics of ATP and the ATP–Zn<sup>2+</sup> Complex in Solution

Despite the crucial role of ATP in life and artificial\nlife-like\napplications, fundamental aspects relevant to its function, such as\nits conformational properties and its interaction with water and ions,\nremain unclear. Here, by integrating linear and two-dimensional infrared\nspectroscopy with <i>ab initio</i> molecular dynamics, we\nprovide a detailed characterization of the vibrational spectra of\nthe phosphate groups in ATP and in its complex with Zn<sup>2+</sup> in water. Our study highlights the role of conformational disorder\nand solvation dynamics, beyond the harmonic normal-mode analysis,\nand reveals a complex scenario in which electronic and environmental\neffects tune the coupling between phosphate vibrations. We identify\nβγ-bidentate and αβγ-tridentate modes\nas the preferential coordination modes of Zn<sup>2+</sup>, as was\nproposed in the literature for Mg<sup>2+</sup>, although this conclusion\nis reached by a different spectral interpretation.