Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

11-2012

Journal or Book Title

Langmuir

Volume

48

Issue

49

First Page

17071

Last Page

17078

DOI

10.1021/la303661p

Abstract

Macrocycles made of cholate building blocks were previously found to transport glucose readily across lipid bilayers. In this study, an 15N, 13Cα-labeled glycine was inserted into a cyclic cholate trimer and attached at the end of a linear trimer, respectively. The isotopic labeling allowed us to use solid-state NMR spectroscopy to study the dynamics, aggregation, and depth of insertion of these compounds in lipid membranes. The cyclic compound was found to be mostly immobilized in DLPC, POPC/POPG, and POPC/POPG/cholesterol membranes, whereas the linear trimer displayed large-amplitude motion that depended on the membrane thickness and viscosity. 13C-detected 1H spin diffusion experiments revealed the depth of insertion of the compounds in the membranes, as well as their contact with water molecules. The data support a consistent stacking model for the cholate macrocycles in lipid membranes, driven by the hydrophobic interactions of the water molecules in the interior of the macrocycles. The study also shows a strong preference of the linear trimer for the membrane surface, consistent with its lack of transport activity in earlier liposome leakage assays.

Comments

Reprinted (adapted) with permission from Langmuir 28 (2012): doi:10.1021/la303661p. Copyright 2012 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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