Ultrafast hydration dynamics in melittin folding and aggregation: Helix formation and tetramer self-assembly

The hydration dynamics in different conformations of melittin from a random coil, to a folded alpha-helix, and to self-assembled tetramer is studied using intrinsic tryptophan as a molecular probe. It is observed that the solvation dynamics occurs in 0.62 and 14.7 ps in a random-coiled primary structure, which indicates critical role of hydration dynamics in peptide conformational transitions and protein structural stability and integrity.