Preferred conformation and dynamics of the glycerol backbone in phospholipids. An NMR and X-ray single-crystal analysis

Journal Article · Tue Dec 27 00:00:00 EST 1988 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00426a014· OSTI ID:5563126

Hauser, H; Pascher, I; Sundell, S ^[1]

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1. Eidgenoessische Technische Hochschule Zuerich (Switzerland)

The conformation of the glycerol group of a number of diacyl and monoacyl (lyso) phospholipids differing in the chemical nature of the head group was studied by {sup 1}H high-resolution NMR and X-ray crystallography. The NMR measurements were carried out with solutions or micellar dispersions of the lipids in deuteriated organic solvents or {sup 2}H{sub 2}O. Both solutions, in which the lipid is present as monomers, and lipid micelles give rise to good high-resolution NMR spectra exhibiting spin coupling hyperfine interactions. From {sup 1}H spin coupling it is concluded that there are two stable conformations about the glycerol C(2)-C(3) bond of phospholipids. By comparison of NMR and single-crystal X-ray data it is obvious that both conformations are minimum free energy conformations. Rotamer A is the conformation prevailing in phospholipid single-crystal structures. The conformation of rotamer B is also found in phospholipid single-crystal structures though to a lesser extent. NMR measurements indicate that in liquid crystals the diacylglycerol part of phospholipids fluctuates between the two stable staggered conformations of rotamers A and B. The transition between rotamers A and B is fast on the NMR time scale and must be accompanied by appropriate changes in the torsion angles {beta}{sub 1} to {beta}{sub 4} and {gamma}{sub 1} to {gamma}{sub 4} of the two fatty acyl chains. It is clear from the data presented that the parallel alignment of the hydrocarbon chains or chain stacking in phospholipid aggregates such as bilayers or micelles is the fundamental principle governing the conformation of the C(2)-C(3) glycerol bond.

• OSTI ID: 5563126
• Journal Information: Biochemistry; (USA), Vol. 27:26; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GLYCEROL
NUCLEAR MAGNETIC RESONANCE
PHOSPHOLIPIDS
MOLECULAR STRUCTURE
HEAVY WATER
NMR SPECTRA
PROTONS
X-RAY DIFFRACTION
ALCOHOLS
BARYONS
COHERENT SCATTERING
DIFFRACTION
ELEMENTARY PARTICLES
ESTERS
FERMIONS
HADRONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIPIDS
MAGNETIC RESONANCE
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXYGEN COMPOUNDS
RESONANCE
SCATTERING
SPECTRA
WATER
550601* - Medicine- Unsealed Radionuclides in Diagnostics