help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Originally published as Biophys J. BioFAST on October 8, 2004.
doi:10.1529/biophysj.104.043620
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
biophysj.104.043620v1
88/1/255    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Soong, R.
Right arrow Articles by Macdonald, P. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Soong, R.
Right arrow Articles by Macdonald, P. M.
Biophysical Journal 88:255-268 (2005)
© 2005 The Biophysical Society

Lateral Diffusion of PEG-Lipid in Magnetically Aligned Bicelles Measured Using Stimulated Echo Pulsed Field Gradient 1H NMR

Ronald Soong and Peter M. Macdonald

Department of Chemistry, University of Toronto, Ontario, Canada; and Department of Chemical and Physical Sciences, University of Toronto at Mississauga, Ontario, Canada

Correspondence: Address reprint requests to Peter M. Macdonald, 3359 Mississauga Rd., Mississauga, ON L5L 1C6, Canada. Tel: 905-828-3805; Fax: 905-828-5425; E-mail: pmacdona{at}utm.utoronto.ca.

Lateral diffusion measurements of PEG-lipid incorporated into magnetically aligned bicelles are demonstrated using stimulated echo (STE) pulsed field gradient (PFG) proton (1H) nuclear magnetic resonance (NMR) spectroscopy. Bicelles were composed of dimyristoyl phosphatidylcholine (DMPC) plus dihexanoyl phosphatidylcholine (DHPC) (q = DMPC/DHPC molar ratio = 4.5) plus 1 mol % (relative to DMPC) dimyristoyl phosphatidylethanolamine-N-[methoxy(polyethylene glycol)-2000] (DMPE-PEG 2000) at 25 wt % lipid. 1H NMR STE spectra of perpendicular aligned bicelles contained only resonances assigned to residual HDO and to overlapping contributions from a DMPE-PEG 2000 ethoxy headgroup plus DHPC choline methyl protons. Decay of the latter's STE intensity in the STE PFG 1H NMR experiment (gz = 244 G cm–1) yielded a DMPE-PEG 2000 (1 mol %, 35°C) lateral diffusion coefficient D = 1.35 x 10–11 m2 s–1. Hence, below the "mushroom-to-brush" transition, DMPE-PEG 2000 lateral diffusion is dictated by its DMPE hydrophobic anchor. D was independent of the diffusion time, indicating unrestricted lateral diffusion over root mean-square diffusion distances of microns, supporting the "perforated lamellae" model of bicelle structure under these conditions. Overall, the results demonstrate the feasibility of lateral diffusion measurements in magnetically aligned bicelles using the STE PFG NMR technique.




This article has been cited by other articles:


Home page
 Biophys. JHome page
C. Loudet, S. Manet, S. Gineste, R. Oda, M.-F. Achard, and E. J. Dufourc
Biphenyl Bicelle Disks Align Perpendicular to Magnetic Fields on Large Temperature Scales: A Study Combining Synthesis, Solid-State NMR, TEM, and SAXS
Biophys. J., June 1, 2007; 92(11): 3949 - 3959.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
M. N. Triba, P. F. Devaux, and D. E. Warschawski
Effects of Lipid Chain Length and Unsaturation on Bicelles Stability. A Phosphorus NMR Study
Biophys. J., August 15, 2006; 91(4): 1357 - 1367.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
R. Soong and P. M. Macdonald
Influence of the Long-Chain/Short-Chain Amphiphile Ratio on Lateral Diffusion of PEG-Lipid in Magnetically Aligned Lipid Bilayers as Measured via Pulsed-Field-Gradient NMR
Biophys. J., September 1, 2005; 89(3): 1850 - 1860.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2005 by the Biophysical Society.