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Article
Aggregation and Dynamics of Oligocholate Transporters in Phospholipid Bilayers Revealed by Solid-State NMR Spectroscopy
Langmuir
  • Tuo Wang, Iowa State University
  • Lakmini Sandachaya Widanapathirana, Iowa State University
  • Yan Zhao, Iowa State University
Document Type
Article
Disciplines
Publication Version
Published Version
Publication Date
11-1-2012
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
Citation Information
Tuo Wang, Lakmini Sandachaya Widanapathirana and Yan Zhao. "Aggregation and Dynamics of Oligocholate Transporters in Phospholipid Bilayers Revealed by Solid-State NMR Spectroscopy" Langmuir Vol. 48 Iss. 49 (2012) p. 17071 - 17078
Available at: http://works.bepress.com/yan_zhao/14/