Anisotropic sup 2 H NMR spin-lattice relaxation in L sub. alpha. -phase cerebroside bilayers

Journal Article · Tue Dec 12 00:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00451a003· OSTI ID:6921151

Speyer, J B; Weber, R T; Gupta, S K.D.; Griffin, R G ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

A series of {sup 2}H NMR inversion recovery experiments in the L{sub {alpha}} phase of the cerebroside N-palmitoylgalactosylsphingosine (NPGS) have been performed. In these liquid crystalline lipid bilayers the authors have observed substantial anisotropy in the spin-lattice relaxation of the CD{sub 2} groups in the acyl chains. The form and magnitude of the anisotropy varies with position in the chain, being positive in the upper region, decreasing to zero at the 4-position, and reversing sign at the lower chain positions. It is also shown that addition of cholesterol to the bilayer results in profound changes in the anisotropy. These observations are accounted for by a simple motional model of discrete hops among nine sites, which result from the coupling of two modes of motion - long-axis rotational diffusion and guache-trans isomerization. This model is employed in quantitative simulations of the spectral line shapes and permits determination of site populations and motional rates. These results, plus preliminary results in sphingomyelin and lecithin bilayers,illustrate the utility of T{sub 1} anisotropy measurements as a probe of dynamics in L{sub {alpha}}-phase bilayers.

• OSTI ID: 6921151
• Journal Information: Biochemistry; (USA), Vol. 28:25; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CEREBROSIDES
NUCLEAR MAGNETIC RESONANCE
MEMBRANES
MOLECULAR STRUCTURE
ANISOTROPY
CHOLESTEROL
DEUTERIUM COMPOUNDS
PHOSPHOLIPIDS
SPIN-LATTICE RELAXATION
CARBOHYDRATES
ESTERS
GLYCOLIPIDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIPIDS
MAGNETIC RESONANCE
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
RELAXATION
RESONANCE
SACCHARIDES
STEROIDS
STEROLS
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