Interaction of electric dipoles with phospholipid head groups. A sup 2 H and sup 31 P NMR study of phloretin and phloretin analogues in phosphatidylcholine membranes

Journal Article · Tue Apr 23 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00230a017· OSTI ID:5596804

Bechinger, B; Seelig, J ^[1]

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1. Univ. of Basel (Switzerland)

Phloretin, 4-hydroxyvalerophenone, and 2-hydroxy-{omega}-phenylpropiophenone are lipophilic dipolar substances that modify ionic conductances of bilayer membranes. The structural changes at the level of the head groups and the hydrocarbon chains as induced by the incorporation of phloretin and its analogues were investigated with deuterium and phosphorus nuclear magnetic resonance. Membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were selectively deuterated at the choline head group and at the hydrocarbon chains, and {sup 2}H and {sup 31}P NMR spectra were recorded with varying concentrations of dipolar agents. Incorporation of phloretin leaves the bilayer structure intact, induces only a small disordering of the hydrocarbon chains and has no significant effect on the head-group dynamics. On the other hand, quite distinct structural changes are observed for the phosphocholine head group. In addition to this structural change, phloretin also modifies the hydration layer at the lipid-water interface. Much less {sup 2}H{sub 2} is adsorbed to the membrane surface when the bilayer contains phloretin, 4-hydroxyvalerophenone, or 2-hydroxy-{omega}-phenylpropiophenone. Moreover, a rather large change in the residual phosphorus chemical shielding anisotropy argues in favor of hydrogen-bond formation between the phosphate segment and the phloretin hydroxyl groups.

• OSTI ID: 5596804
• Journal Information: Biochemistry; (United States), Vol. 30:16; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ELECTRIC DIPOLES
BIOLOGICAL EFFECTS
MEMBRANES
MOLECULAR STRUCTURE
PHOSPHOLIPIDS
NUCLEAR MAGNETIC RESONANCE
CHOLESTEROL
CHOLINE
DEUTERIUM COMPOUNDS
NMR SPECTRA
PHOSPHORUS 31
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
DIPOLES
DRUGS
ESTERS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
LIPIDS
LIPOTROPIC FACTORS
MAGNETIC RESONANCE
MULTIPOLES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
QUATERNARY COMPOUNDS
RESONANCE
SPECTRA
STABLE ISOTOPES
STEROIDS
STEROLS
550201* - Biochemistry- Tracer Techniques