Areas of monounsaturated diacylphosphatidylcholines.
We have studied the structural properties of monounsaturated diacylphosphatidylcholine lipid bilayers (i.e., diCn:1PC, where n = 14, 16, 18, 20, 22, and 24 is the number of acyl chain carbons). High-resolution x-ray scattering data were analyzed in conjunction with contrast-varied neutron scattering data using a technique we recently developed. Analyses of the data show that the manner by which bilayer thickness increases with increasing n in monounsaturated diacylphosphatidylcholines is dependent on the double bond's position. For commonly available monounsaturated diacylphosphatidylcholines, this results in the nonlinear behavior of both bilayer thickness and lipid area, whereas for diC18:1PC bilayers, lipid area assumes a maximum value. It is worthwhile to note that compared to previous data, our results indicate that lipid areas are smaller by approximately 10%. This observation highlights the need to revisit lipid areas, as they are often used in comparisons with molecular dynamics simulations. Moreover, simulators are encouraged to compare their results not only to x-ray scattering data, but to neutron data as well.
Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario, Canada.
Norbert
N
Kucerka
Jana
J
Gallová
Daniela
D
Uhríková
Pavol
P
Balgavý
Monica
M
Bulacu
Siewert-Jan
SJ
Marrink
John
J
Katsaras
D002462:Cell Membrane / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D033363:Neutron Diffraction; D010713:Phosphatidylcholines / Q000737:chemistry*; D053838:Scattering, Small Angle; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D014867:Water