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Article
Environmental Effects Dominate the Folding of Oligocholates in Solution, Surfactant Micelles, and Lipid Membranes
Journal of the American Chemical Society
  • Hongkwan Cho, Iowa State University
  • Yan Zhao, Iowa State University
Document Type
Article
Disciplines
Publication Version
Published Version
Publication Date
6-1-2010
DOI
10.1021/ja103694p
Abstract
Oligocholate foldamers with different numbers and locations of guanidinium−carboxylate salt bridges were synthesized. The salt bridges were introduced by incorporating arginine and glutamic acid residues into the foldamer sequence. The conformations of these foldamers were studied by fluorescence spectroscopy in homogeneous solution, anionic and nonionic micelles, and lipid bilayers. Environmental effects instead of inherent foldability were found to dominate the folding. As different noncovalent forces become involved in the conformations of the molecules, the best folder in one environment could turn into the worst in another. Preferential solvation was the main driving force for the folding of oligocholates in solution. The molecules behaved very differently in micelles and lipid bilayers, with the most critical factors controlling the folding−unfolding equilibrium being the solvation of ionic groups and the abilities of the surfactants/lipids to compete for the salt bridge. Because of their ability to fold into helices with a nonpolar exterior and a polar interior, the oligocholates could transport large hydrophilic molecules such as carboxyfluorescein across lipid bilayers. Both the conformational properties of the oligocholates and their binding with the guest were important to the transport efficiency.
Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 132 (2010): 9890, doi:10.1021/ja103694p. Copyright 2010 American Chemical Society.

Copyright Owner
American Chemical Society
Language
en
File Format
application/pdf
Citation Information
Hongkwan Cho and Yan Zhao. "Environmental Effects Dominate the Folding of Oligocholates in Solution, Surfactant Micelles, and Lipid Membranes" Journal of the American Chemical Society Vol. 132 Iss. 28 (2010) p. 9890 - 9899
Available at: http://works.bepress.com/yan_zhao/7/