Biophysical Journal 54: 373-381 (1988)
© 1988 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Siminovitch, D J Articles by Griffin, R G Search for Related Content PubMed PubMed Citation Articles by Siminovitch, D J Articles by Griffin, R G

Anisotropic 2H-nuclear magnetic resonance spin-lattice relaxation in cerebroside- and phospholipid-cholesterol bilayer membranes.

Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139.

ABSTRACT

The axially symmetric powder pattern 2H-nuclear magnetic resonance (NMR) lineshapes observed in the liquid crystalline phase of pure lipid or lipid/cholesterol bilayers are essentially invariant to temperature, or, equivalently, to variations in the correlation times characterizing C-2H bond reorientations. In either of these melted phases, where correlation times for C-2H bond motions are shorter than 10(-7) s, information on the molecular dynamics of the saturated hydrocarbon chain would be difficult to obtain using lineshape analyses alone, and one must resort to other methods, such as the measurement of 2H spin-lattice relaxation rates, in order to obtain dynamic information. In pure lipid bilayers, the full power of the spin-lattice relaxation technique has yet to be realized, since an important piece of information, namely the orientation dependence of the 2H spin-lattice relaxation rates is usually lost due to orientational averaging of T1 by rapid lateral diffusion. Under more favorable circumstances, such as those encountered in the lipid/cholesterol mixtures of this study, the effects of orientational averaging by lateral diffusion are nullified, due to either a marked reduction (by at least an order of magnitude) in the diffusion rate, or a marked increase in the radii of curvature of the liposomes. In either case, the angular dependence of 2H spin-lattice relaxation is accessible to experimental study, and can be used to test models of molecular dynamics in these systems. Simulations of the partially recovered lineshapes indicate that the observed T1 anisotropies are consistent with large amplitude molecular reorientation of the C-2H bond among a finite number of sites.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				K. K. Lehtimaki, P. K. Valonen, J. L. Griffin, T. H. Vaisanen, O. H. J. Grohn, M. I. Kettunen, J. Vepsalainen, S. Yla-Herttuala, J. Nicholson, and R. A. Kauppinen Metabolite Changes in BT4C Rat Gliomas Undergoing Ganciclovir-Thymidine Kinase Gene Therapy-induced Programmed Cell Death as Studied by 1H NMR Spectroscopy in Vivo, ex Vivo, and in Vitro J. Biol. Chem., November 14, 2003; 278(46): 45915 - 45923. [Abstract] [Full Text] [PDF]

				J. L. Griffin, K. K. Lehtimaki, P. K. Valonen, O. H. J. Grohn, M. I. Kettunen, S. Yla-Herttuala, A. Pitkanen, J. K. Nicholson, and R. A. Kauppinen Assignment of 1H Nuclear Magnetic Resonance Visible Polyunsaturated Fatty Acids in BT4C Gliomas Undergoing Ganciclovir-Thymidine Kinase Gene Therapy-induced Programmed Cell Death Cancer Res., June 15, 2003; 63(12): 3195 - 3201. [Abstract] [Full Text] [PDF]