Bilayer thickness and thermal response of dimyristoylphosphatidylcholine unilamellar vesicles containing cholesterol, ergosterol and lanosterol: a small-angle neutron scattering study.
Small-angle neutron scattering (SANS) measurements are performed on pure dimyristoyl phosphatidylcholine (DMPC) unilamellar vesicles (ULV) and those containing either 20 or 47 mol% cholesterol, ergosterol or lanosterol. From the SANS data, we were able to determine the influence of these sterols on ULV bilayer thickness and vesicle area expansion coefficients. While these parameters have been determined previously for membranes containing cholesterol, to the best of our knowledge, this is the first time such results have been presented for membranes containing the structurally related sterols, ergosterol and lanosterol. At both molar concentrations and at temperatures ranging from 10 to 45 degrees C, the addition of the different sterols leads to increases in bilayer thickness, relative to pure DMPC. We observe large differences in the influence of these sterols on the membrane thermal area expansion coefficient. All three sterols, however, produce very similar changes to membrane thickness.
Pencer
Jeremy
J
NRC, Canadian Neutron Beam Centre, Chalk River Labs, Chalk River, ON, Canada K0J 1J0. Jeremy.Pencer@nrc.gc.ca
Nieh
Mu-Ping
MP
Harroun
Thad A
TA
Krueger
Susan
S
Adams
Carl
C
Katsaras
John
J
D002784:Cholesterol / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D004875:Ergosterol / Q000737:chemistry*; D006358:Hot Temperature; D007810:Lanosterol / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D033363:Neutron Diffraction / Q000379:methods; D012542:Scattering, Radiation
D008051:Lipid Bilayers; D008081:Liposomes; D007810:Lanosterol; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine; D004875:Ergosterol