Nuclear magnetic resonance study of sphingomyelin bilayers

Journal Article · Tue Apr 24 00:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00468a032· OSTI ID:6071079

Bruzik, K S; Sobon, B; Salamonczyk, G M ^[1]

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1. Center of Molecular and Macromolecular Studies, Lodz (Poland)

Bilayers of D-erythro-(N-stearoylsphingosyl)-1-phosphocholine (C{sub l8}-SPM), previously characterized by differential scanning calorimetry in various phases, were studied by means of wide-line {sup 31}P, {sup 2}H, high-resolution {sup 13}C CP-MAS, and {sup 1}H MAS NMR. The fully relaxed gel phase of C{sub 18}-SPM at temperatures below 306 K displayed {sup 31}P NMR spectra characteristic of the rigid phase with frozen rotation of the phosphocholine head group. Three other gel phases existing in the temperature range 306-318 K displayed spectra with incompletely averaged axially symmetric powder line shapes and were difficult to differentiate on the basis of their {sup 31}P NMR spectra. The gel-to-gel transition at 306 K was found to be fully reversible. The main phase transition at 318 K resulted in the formation of the liquid-crystalline phase for which spectra with axially symmetric line shapes of uniform width were obtained, regardless of the nature of the starting gel phase. {sup 13}C CP-MAS NMR spectra revealed significant differences in the molecular dynamics of sphingomyelin in various phases. All carbon atoms of the polar head group in the liquid-crystalline phase gave rise to a separate resonance lines. Numerous carbon atom signals were doubled in the stable phase, demonstrating the existence of two slowly interconverting conformers.

• OSTI ID: 6071079
• Journal Information: Biochemistry; (USA), Vol. 29:15; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
MEMBRANES
PHASE STUDIES
SPHINGOMYELINS
NUCLEAR MAGNETIC RESONANCE
CARBON 13
DEUTERIUM COMPOUNDS
NMR SPECTRA
PHOSPHORUS 31
TEMPERATURE EFFECTS
CARBON ISOTOPES
ESTERS
EVEN-ODD NUCLEI
HYDROGEN COMPOUNDS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
PHOSPHORUS ISOTOPES
RESONANCE
SPECTRA
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics