title: The effects of cryosolvents on DOPC-β-sitosterol bilayers determined from molecular dynamics simulations.
abstract: Polyhydroxylated alcohols and DMSO are common cryosolvents that can damage cell membranes at sufficiently high concentrations. The interaction of representative plant cell membranes composed of mixed 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)-β-sitosterol bilayers, at a range of compositions, with a variety of cryosolvent molecules (DMSO, propylene glycol, ethylene glycol, glycerol, and methanol) has been investigated using molecular dynamics simulations. All the cryosolvents cause the bilayers to thin and become disordered; however, DMSO and propylene glycol have a greater disordering effect on the bilayer. Propylene glycol is shown to have the ability to cause the formation of pores in pure DOPC bilayers in a manner similar to that previously shown for DMSO. As the concentration of β-sitosterol within the bilayer increases, the membranes become more resistant to the deleterious effects of the cryosolvents. All three polyhydroxylated species are observed to form hydrogen bonds to multiple phospholipid molecules, effectively acting as cross-linkers, with glycerol being the most effective cross-linker. Increases in the concentration of β-sitosterol reduce overall hydrogen bonding of the bilayer with the cryosolvents as well as cross-linking, with glycerol and ethylene glycol being the most affected. The ability of all of these cryosolvents to affect the integrity of cell membranes appears to be the result of the balance of their ability to disorder lipid bilayers, to diffuse across them, and to interact with the lipid head groups.
authors: Western Australian Biomedical Research Institute, Curtin Health Innovation Research Institute, School of Biomedical Sciences, Curtin University, P.O. Box U1987, Perth WA, 6845, Australia.
authors: Zak E
authors: ZE
authors: Hughes
authors: Chris J
authors: CJ
authors: Malajczuk
authors: Ricardo L
authors: RL
authors: Mancera
mesh_terms: D004121:Dimethyl Sulfoxide / Q000737:chemistry; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D010713:Phosphatidylcholines / Q000737:chemistry*; D019946:Propylene Glycol / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D014867:Water; D019946:Propylene Glycol; C017251:1,2-oleoylphosphatidylcholine; D004121:Dimethyl Sulfoxide