Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

11-2005

Journal or Book Title

Journal of the American Chemical Society

Volume

127

Issue

50

First Page

17894

Last Page

17901

DOI

10.1021/ja056151p

Abstract

The hydroxyl at the C-3 of cholic acid was converted to an amino group, and the resulting amino-functionalized cholic acid was used as a monomer to prepare amide-linked oligomeric cholates. These cholate oligomers fold into helical structures with nanometer-sized hydrophilic internal cavities in solvent mixtures consisting of mostly nonpolar solvents such as carbon tetrachloride or ethyl acetate/hexane and 2−5% of a polar solvent such as methanol or DMSO. The conformations of the foldamers were studied by UV, fluorescence, fluorescence quenching, and fluorescence resonance energy transfer. The nature of the polar/nonpolar solvents and their miscibility strongly influenced the folding reaction. Folding was cooperative, as evidenced by the sigmoidal curves in solvent denaturation experiments. The folded conformers became more stable with an increase in the chain length. The folding/unfolding equilibrium was highly sensitive toward the amount of polar solvent. One percent variation in the solvent composition could change the folding free energies by 0.5−1.4 kcal/mol.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 127 (2005): 17894, doi:10.1021/ja056151p. Copyright 2005 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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