X-ray diffraction measurement of the monolayer spontaneous curvature of dioleoylphosphatidylglycerol.
Phosphatidylglycerol (PG) is an anionic lipid commonly found in large proportions in the cell membranes of bacteria and plants and, to a lesser extent, in animal cells. PG plays an important role in the regulation and determination of the elastic properties of the membrane. Using small angle X-ray scattering experiments, we obtain that the monolayer spontaneous curvature of dioleoylphosphatidylglycerol (DOPG) is -1/150+/-0.021 nm(-1) when measured in 150 mM NaCl. When the experiments are carried out in 150 mM NaCl and 20mM MgCl(2), the value obtained for the monolayer spontaneous curvature is -1/8.7+/-0.037 nm(-1). These values are of importance in modelling the effects of curvature elastic stress in membrane lipid homeostasis in the bacterium Acholeplasma laidlawii [Alley, S.H., Barahona, M., Ces, O., Templer, R.H., in press. Biophysical regulation of lipid biosynthesis in the plasma membrane. Biophys. J.] and indicate that divalent cations can play a significant role in altering curvature elastic stress.
Alley
Stephen H
SH
Department of Bioengineering, Imperial College London, United Kingdom.
Ces
Oscar
O
Barahona
Mauricio
M
Templer
Richard H
RH
D004548:Elasticity; D008051:Lipid Bilayers / Q000737:chemistry*; D015636:Magnesium Chloride / Q000737:chemistry; D008560:Membrane Fluidity; D010715:Phosphatidylglycerols / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013314:Stress, Mechanical; D014961:X-Ray Diffraction / Q000379:methods*
D008051:Lipid Bilayers; D010715:Phosphatidylglycerols; D012996:Solutions; D015636:Magnesium Chloride; D012965:Sodium Chloride; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol