Acid-base chemistry of frustrated water at protein interfaces

作者：Fernandez Ariel^*

来源：FEBS LETTERS, 2016, 590(2): 215-223.

DOI：10.1002/1873-3468.12047

• anticontacts
• hydrogen-bond frustration
• interfacial physics
• molecular biophysics
• protein-water interface
• structural biology

Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts.

• 出版日期2016-1