Campus Units
Chemistry
Document Type
Article
Publication Version
Published Version
Publication Date
5-2012
Journal or Book Title
Langmuir
Volume
28
Issue
21
First Page
8165
Last Page
8173
DOI
10.1021/la301090t
Abstract
A macrocyclic and a linear trimer of a facially amphiphilic cholate building block were labeled with a fluorescent dansyl group. The environmentally sensitive fluorophore enabled the aggregation of the two oligocholates in lipid membranes to be studied by fluorescence spectroscopy. Concentration-dependent emission wavelength and intensity revealed a higher concentration of water for the cyclic compound. Both compounds were shown by the red-edge excitation shift (REES) to be located near the membrane/water interface at low concentrations, but the cyclic trimer was better able to migrate into the hydrophobic core of the membrane than the linear trimer. Fluorescent quenching by a water-soluble (NaI) and a lipid-soluble (TEMPO) quencher indicated that the cyclic trimer penetrated into the hydrophobic region of the membrane more readily than the linear trimer, which preferred to stay close to the membrane surface. The fluorescent data corroborated with the previous leakage assays that suggested the stacking of the macrocyclic cholate trimer into transmembrane nanopores, driven by the strong associative interactions of water molecules inside the macrocycles in a nonpolar environment.
Copyright Owner
American Chemical Society
Copyright Date
2012
Language
en
File Format
application/pdf
Recommended Citation
Widanapathirana, Lakmini Sandachaya and Zhao, Yan, "Effects of Amphiphile Topology on the Aggregation of Oligocholates in Lipid Membranes: Macrocyclic versus Linear Amphiphiles" (2012). Chemistry Publications. 183.
https://lib.dr.iastate.edu/chem_pubs/183
Comments
Reprinted (adapted) with permission from Langmuir 28 (2012): 8165, doi:10.1021/la301090t. Copyright 2012 American Chemical Society.