Solvation in protein (un)folding of melittin tetramer-monomer transition

Christina M. Othon, Oh Hoon Kwon, Milo M. Lin, Ahmed H. Zewail

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

Protein structural integrity and flexibility are intimately tied to solvation. Here, we examine the effect that changes in bulk and local solvent properties have on protein structure and stability. We observe the change in solvation of an unfolding of the protein model, melittin, in the presence of a denaturant, trifluoroethanol. The peptide system displays a well defined transition in that the tetramer unfolds without disrupting the secondary or tertiary structure. In the absence of local structural perturbation, we are able to reveal exclusively the role of solvation dynamics in protein structure stabilization and the (un)folding pathway. A sudden retardation in solvent dynamics, which is coupled to the change in protein structure, is observed at a critical trifluoroethanol concentration. The large amplitude conformational changes are regulated by the local solvent hydrophobicity and bulk solvent viscosity.

Original languageEnglish (US)
Pages (from-to)12593-12598
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume106
Issue number31
DOIs
Publication statusPublished - Aug 4 2009

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Keywords

  • Fluoresence spectroscopy
  • Preferential solvation
  • Protein folding
  • Ultrafast hydration

ASJC Scopus subject areas

  • General

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