Thermal fluctuation and elasticity of lipid vesicles interacting with pore-forming peptides.
The thermal fluctuation and elasticity of dioleoyl-phosphocholine large unilamellar vesicle interacting with pore-forming peptide, melittin, were investigated by neutron spin-echo measurements. The relaxation behavior of the membrane fluctuation with different peptide to lipid molar ratio P/L can be divided into three regions, resulting from characteristic changes of the effective bending modulus κ(˜) of the membrane which includes the effects of internal dissipation within the membrane. At low P/L, melittin is adsorbed parallel to the surface of membrane and κ(˜) decreases significantly due to perturbation of hydrocarbon chain packing. At a critical P/L, melittin forms pores in the membrane and κ(˜) starts to increase slightly due to high pore rigidity. At higher P/L where the repulsive interpore interaction becomes significant, κ(˜) increases rapidly.
Lee
Ji-Hwan
JH
Department of Nuclear and Quantum Engineering, KAIST, Daejeon, 305-701, Republic of Korea.
Choi
Sung-Min
SM
Doe
Changwoo
C
Faraone
Antonio
A
Pincus
Philip A
PA
Kline
Steven R
SR
D004548:Elasticity; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008560:Membrane Fluidity / Q000502:physiology; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry* / Q000378:metabolism; D016062:Porosity; D012542:Scattering, Radiation; D013997:Time Factors; D053835:Unilamellar Liposomes / Q000737:chemistry* / Q000378:metabolism
D008051:Lipid Bilayers; D010455:Peptides; D010713:Phosphatidylcholines; D053835:Unilamellar Liposomes; C017251:1,2-oleoylphosphatidylcholine