Aqueous viscosity is the primary source of friction in lipidic pore dynamics.
Aqueous viscosity is the primary source of friction in lipidic pore dynamics.
复制标题
水粘度是脂质孔隙动力学中摩擦的主要来源。
DOI：
10.1016/j.bpj.2011.11.009
复制
发表时间：
2011
影响因子：
3.4
通讯作者：
Cohen,FredricS
中科院分区：
文献类型：
--
作者：
Ryham,Rolf;Berezovik,Irina;Cohen,FredricS
据我们所知，开发了一种新理论来描述脂质体中脂质孔的动力学。该理论方程捕捉了实验观察到的孔隙半径随时间变化的三阶段函数形式——第一阶段，孔隙快速扩大；第二阶段，缓慢收缩毛孔；第三阶段，毛孔快速闭合。他们还表明，脂质流动在动力学上受到膜和水粘度值的限制；因此，孔隙演化受到两种粘度的影响。该理论预测，对于半径为数十微米的巨型脂质体，水粘度的影响超过膜粘度的影响。通过使用该理论来计算脂质孔的边缘张力，以定量地解释第三阶段（快速孔闭合）中的孔动力学。该边缘张力值与从缓慢孔闭合阶段（第 2 阶段）标准计算的值一致。对于小的亚微米脂质体，膜粘度影响孔动力学，但前提是水溶液的粘度与蒸馏水的粘度相当。由水粘度引起的摩擦的第一原理流体力学计算与通过将新理论应用于先前发表的实验结果的数据而获得的摩擦非常一致。
A new theory, to our knowledge, is developed that describes the dynamics of a lipidic pore in a liposome. The equations of the theory capture the experimentally observed three-stage functional form of pore radius over time—stage 1, rapid pore enlargement; stage 2, slow pore shrinkage; and stage 3, rapid pore closure. They also show that lipid flow is kinetically limited by the values of both membrane and aqueous viscosity; therefore, pore evolution is affected by both viscosities. The theory predicts that for a giant liposome, tens of microns in radius, water viscosity dominates over the effects of membrane viscosity. The edge tension of a lipidic pore is calculated by using the theory to quantitatively account for pore kinetics in stage 3, rapid pore closing. This value of edge tension agrees with the value as standardly calculated from the stage of slow pore closure, stage 2. For small, submicron liposomes, membrane viscosity affects pore kinetics, but only if the viscosity of the aqueous solution is comparable to that of distilled water. A first-principle fluid-mechanics calculation of the friction due to aqueous viscosity is in excellent agreement with the friction obtained by applying the new theory to data of previously published experimental results.