含胆固醇的SOPC膜的弯曲刚度。
Bending rigidity of SOPC membranes containing cholesterol.
作者信息
Song J, Waugh R E
机构信息
Department of Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642.
出版信息
Biophys J. 1993 Jun;64(6):1967-70. doi: 10.1016/S0006-3495(93)81566-2.
Bilayer membranes in the fluid state exhibit a large resistance to changes in surface area, negligible resistance to surface shear deformation, and a small but finite resistance to bending. The presence of cholesterol in the membrane is known to increase its resistance to area dilation. In this report, a new method for measuring bilayer membrane bending stiffness has been used to investigate the effect of cholesterol on the bending rigidity of SOPC (1,stearoyl-2,oleoyl-phosphatidylcholine) membranes. The curvature elasticity (kc) for membranes saturated with cholesterol was measured to be 3.3 x 10(-19) J, approximately 3-fold larger than that the modulus for cholesterol-free SOPC membrane. These findings are consistent with previous measurements of bending stiffness based on thermal fluctuations, which showed a similar approximately 3-fold increase in the modulus with cholesterol addition (Evans and Rawicz, 1990, Phys. Rev. Lett. 64:2094) and provide further substantiation of the important contribution that cholesterol makes to membrane cohesion and stability.
处于流体状态的双层膜对表面积变化表现出很大的阻力，对表面剪切变形的阻力可忽略不计，而对弯曲的阻力虽小但有限。已知膜中胆固醇的存在会增加其对面积扩张的阻力。在本报告中，一种测量双层膜弯曲刚度的新方法被用于研究胆固醇对1, 硬脂酰 - 2, 油酰 - 磷脂酰胆碱（SOPC）膜弯曲刚度的影响。测得胆固醇饱和的膜的曲率弹性（kc）为3.3×10⁻¹⁹ J，约为不含胆固醇的SOPC膜模量的3倍。这些发现与先前基于热涨落的弯曲刚度测量结果一致，后者表明添加胆固醇后模量也有类似的约3倍增加（Evans和Rawicz，1990年，《物理评论快报》64:2094），并进一步证实了胆固醇对膜凝聚和稳定性的重要贡献。
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