Hydroxyl-Rich β-Sheet Adhesion to the Gold Surface in Water by First-Principle Simulations

摘要

Proteins able to recognize inorganic surfaces are of paramount importance for living organisms.nMimicking nature, surface-recognizing proteins and peptides have also been man-made by combinatorialnbiochemistry. However, to date the recognition mechanisms remain elusive, and the underlying physicochemicalnprinciples are still unknown. Selectivity of gold-binding peptides (cysteine-free and rich in hydroxylnamino acids) is particularly puzzling, since the most relevant gold surface, Au(111), is known to be chemicallyninert and atomically flat. Using atomistic first-principle simulations we show that weak chemical interactionsnof dative-bond character confer to a prototype secondary structure (an antiparallel u0001-sheet made of hydroxylnamino acids) and its hydration layer the capability of discriminating among gold surface sites. Our resultsnhighlight the unexpected role of hydration water in this process, suggesting that hydrophilic amino acidsnand their hydration shell cooperate to contribute to protein-gold surface recognition.