BENDING ELASTIC-MODULI OF LIPID BILAYERS - MODULATION BY SOLUTES
BENDING ELASTIC-MODULI OF LIPID BILAYERS - MODULATION BY SOLUTES
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DOI：
10.1051/jphys:019900051010094500
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发表时间：
1990-05-15
期刊：
影响因子：
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通讯作者：
SACKMANN, E
中科院分区：
文献类型：
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作者：
DUWE, HP;KAES, J;SACKMANN, E
我们提出了高精度测量的弯曲弹性模量的各种不同的脂质和溶质的抗弯刚度的修改的双层。的测量是基于傅立叶分析的热激发膜起伏（囊泡形状波动），使用最近开发的动态图像处理方法。作为波动波矢量的函数的弯曲模量的测量提供的信息的限制的激励有限的膜面积（表面张力效应）的约束和瞬态的横向张力在每个单层中产生的限制扩散在高波矢量。测量的波动幅度的自相关函数提供了进一步的测试的理论模型。对溶质效应的研究表明，胆固醇使二肉豆蔻酰磷脂酰胆碱的弯曲模量从Kc= 1.1× 10^-12尔格增加到4.2 × 10^-12尔格（30摩尔%时）。掺入约2摩尔%的短双极脂质将Kc降低至kT的量级。建立了这些超弹性囊泡的投影回转半径Rg与R2 g/A 0.94±0.02的表面积A（或脂质分子数N）之间的标度律。
We present high precision measurements of the bending elastic moduli for bilayers of a variety of different lipids and of modifications of the flexural rigidity by solutes. The measurements are based on the Fourier analysis of thermally excited membrane undulations (vesicle shape fluctuations) using a recently developed dynamic image processing method. Measurements of the bending modulus as a function of the undulation wave vector provide information on the limitation of the excitations by the constraint of finite membrane area (surface tension effects) and by transient lateral tensions arising in each monolayer by restricted diffusion at high wavevectors. Measurements of the autocorrelation function of the undulation amplitudes provide a further test of the theoretical models. Studies of the effect of solutes show that cholesterol increases the bending modulus of dimyristoylphosphatidylcholine from Kc= 1.1× 10^-12 ergs to 4.2 x 10^-12 ergs (at 30 mole%). Incorporation of about 2 mole% of a short bipolar lipid reduces Kc to the order of kT. A scaling law between the projected radius of gyration, Rg, of these hyperelastic vesicles and the surface area, A (or number of lipid molecules N) of R2g∝ A 0.94±0.02 was established.