Vitkova Victoria, Méléard Philippe, Pott Tanja, Bivas Isak
Liquid Crystal Laboratory, Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria.
Eur Biophys J. 2006 Feb;35(3):281-6. doi: 10.1007/s00249-005-0019-5. Epub 2005 Oct 7.
We investigate the bending elasticity of lipid membranes with the increase of the alamethicin concentrations in the membrane via analysis of the thermally induced shape fluctuations of quasi-spherical giant vesicles. Our experimental results prove the strong influence of alamethicin molecules on the bending elasticity of diphytanoyl phosphatidylcholine and dilauroyl phosphatidylcholine membranes even in the range of very low peptide concentrations (less than 10(-3) mol/mol in the membrane). The results presented in this work, testify to the peripheral orientation of alamethicin molecules at low peptide concentrations in the membrane for both types of lipid bilayers. An upper limit of the concentration of the peptide in the membrane is determined below which the system behaves as an ideal two-dimensional solution and the peptide molecules have a planar orientation in the membrane.
我们通过分析准球形巨型囊泡热诱导的形状波动，研究了随着膜中短杆菌肽浓度增加时脂质膜的弯曲弹性。我们的实验结果证明，即使在非常低的肽浓度范围内（膜中小于10⁻³摩尔/摩尔），短杆菌肽分子对二植烷酰磷脂酰胆碱和二月桂酰磷脂酰胆碱膜的弯曲弹性也有很强的影响。这项工作中呈现的结果表明，对于这两种类型的脂质双层，在膜中低肽浓度下短杆菌肽分子呈周边取向。确定了膜中肽浓度的上限，低于该上限时系统表现为理想的二维溶液，且肽分子在膜中呈平面取向。
