Cholesterol perturbs lipid bilayers nonuniversally.
Cholesterol is well known to modulate the physical properties of biomembranes. Using modern x-ray scattering methods, we have studied the effects of cholesterol on the bending modulus K(C), the thickness D(HH), and the orientational order parameter S(xray) of lipid bilayers. We find that the effects are different for at least three classes of phospholipids characterized by different numbers of saturated hydrocarbon chains. Most strikingly, cholesterol strongly increases K(C) when both chains of the phospholipid are fully saturated but not at all when there are two monounsaturated chains.
Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Jianjun
J
Pan
Thalia T
TT
Mills
Stephanie
S
Tristram-Nagle
John F
JF
Nagle
D002784:Cholesterol / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D012542:Scattering, Radiation; D013816:Thermodynamics; D014965:X-Rays
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; C027891:1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine; D002784:Cholesterol; C017251:1,2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine