Hansen J C, Skalak R, Chien S, Hoger A
Department of Bioengineering, University of California, San Diego, La Jolla 92093, USA.
Biophys J. 1997 May;72(5):2369-81. doi: 10.1016/S0006-3495(97)78882-9.
A finite-element network model is used to investigate the influence of the topology of the red blood cell membrane skeleton on its macroscopic mechanical properties. Network topology is characterized by the number of spectrin oligomers per actin junction (phi a) and the number of spectrin dimers per self-association junction (phi s). If it is assumed that all associated spectrin is in tetrameric form, with six tetramers per actin junction (i.e., phi a = 6.0 and phi s = 2.0), then the topology of the skeleton may be modeled by a random Delaunay triangular network. Recent images of the RBC membrane skeleton suggest that the values for these topological parameters are in the range of 4.2 < phi a < 5.5 and 2.1 < phi s < 2.3. Model networks that simulate these realistic topologies exhibit values of the shear modulus that vary by more than an order of magnitude relative to triangular networks. This indicates that networks with relatively sparse nontriangular topologies may be needed to model the RBC membrane skeleton accurately. The model is also used to simulate skeletal alterations associated with hereditary spherocytosis and Southeast Asian ovalocytosis.
一个有限元网络模型被用于研究红细胞膜骨架拓扑结构对其宏观力学性能的影响。网络拓扑结构由每个肌动蛋白连接点处血影蛋白寡聚体的数量（φa）和每个自缔合连接点处血影蛋白二聚体的数量（φs）来表征。如果假设所有相关的血影蛋白均为四聚体形式，即每个肌动蛋白连接点有六个四聚体（即φa = 6.0且φs = 2.0），那么骨架的拓扑结构可以用随机德劳内三角网络来建模。红细胞膜骨架的近期图像表明，这些拓扑参数的值在4.2 < φa < 5.5和2.1 < φs < 2.3范围内。模拟这些实际拓扑结构的模型网络所呈现的剪切模量值相对于三角网络有超过一个数量级的变化。这表明可能需要具有相对稀疏非三角形拓扑结构的网络来准确模拟红细胞膜骨架。该模型还用于模拟与遗传性球形红细胞增多症和东南亚椭圆形红细胞增多症相关的骨架改变。
