Mishima K, Nakamae S, Ohshima H, Kondo T
Department of Physics, College of Art & Sciences, Showa University, 4562 Kamiyoshida, Fujiyoshida-shi, Yamanashi 4030005, Japan.
Chem Phys Lipids. 2001 Mar;110(1):27-33. doi: 10.1016/s0009-3084(00)00225-5.
We directly measured curvature elasticity of dipalmitoylphosphatidylcholine multilamellar bilayers close to the chain-melting transition using the method of electric-field-induced bending deformation of the cylindrical tubes. The result shows that the bending modulus, kappa(c), decreases remarkably at temperatures close to the melting transition temperature. This reflects a softening of the bilayer resulted from the area fluctuations as predicted theoretically. However, the decrease of kappa(c) near the transition is far smaller than that predicted. This is due to the experimental method and the narrow transition width of the multilamellar bilayers. Nevertheless, the result obtained gives direct evidence of the kappa(c) reduction predicted for multilamellar membranes in the transition regime. Below about 41 degrees C, almost of all cylindrical tubes cannot response to the electric field, indicating a very large bending rigidity.
我们使用圆柱管电场诱导弯曲变形的方法，直接测量了接近链熔化转变温度的二棕榈酰磷脂酰胆碱多层双分子层的曲率弹性。结果表明，弯曲模量κ(c)在接近熔化转变温度时显著降低。这反映了如理论预测的那样，由于面积波动导致双分子层变软。然而，转变附近κ(c)的降低远小于预测值。这是由于实验方法以及多层双分子层的转变宽度较窄。尽管如此，所获得的结果直接证明了在转变区域中多层膜预测的κ(c)降低。在约41摄氏度以下，几乎所有圆柱管都无法响应电场，表明弯曲刚度非常大。
