Forced extension of delipidated red blood cell cytoskeleton with little indication of spectrin unfolding
Forced extension of delipidated red blood cell cytoskeleton with little indication of spectrin unfolding
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DOI：
10.1002/cm.21001
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发表时间：
2012-02-01
期刊：
影响因子：
2.9
通讯作者：
Ikai, Atsushi
中科院分区：
文献类型：
--
作者：
Afrin, Rehana;Nakaji, Masato;Ikai, Atsushi
将完整的人红细胞（RBC）与退化的红细胞（RBC）的力延伸曲线进行比较，以评估细胞骨架柔韧性对完整膜骨架延展性的贡献。首先用磷脂酶A2降解红细胞；使用原子力显微镜（AFM）测量暴露的细胞骨架结构的拉伸性能。AFM探针用带3特异性凝集素，豆蛋白A （Con A）或抗f -肌动蛋白抗体修饰，以定位探针与细胞骨架之间的相互作用点。在小于70 pN的力下，基于光谱的细胞骨架的延伸达到23 μ m，在粘合键最终破裂之前没有出现任何力峰。我们对结果的解释是，基于谱蛋白的网络足够松弛，可以在不展开四聚体谱蛋白分子的情况下允许观察到的扩展程度。在3-带锚蛋白位点和细胞骨架的连接节点上得到的力-伸曲线没有显著差异。通过计算机模拟红细胞骨架网络模型的拉扯力学，验证了实验结果。我们的实验结果也与Mirijanian和Voth [2008；科学通报[j]。(c) 2011 Wiley期刊公司
Force-extension curves obtained on intact human red blood cells (RBC) were compared with those of delipidated RBCs to assess the contribution of cytoskeletal flexibility to the extensibility of the intact membrane skeleton. The RBCs were first delipidated by treatment with phospholipase A2; tensile properties of the exposed cytoskeletal structures were measured using an atomic force microscope (AFM). The AFM probes were modified either with the Band 3 specific lectin, concanavalin A, (Con A) or anti-F-actin antibody, to localize the point of interaction between the probe and the cytoskeleton. Extension of the spectrin-based cytoskeleton reached up to 23 mu m with a force less than 70 pN without showing any force peaks before the final rupture of the adhesive bonds. Our interpretation of the result is that the spectrin-based network was slack enough to allow the observed degree of extension without unfolding the tetrameric spectrin molecules. The force-extension curves obtained either on Band 3-ankyrin loci or on junction nodes of the cytoskeleton were not significantly different. Experimental results were verified by computer simulation of pulling mechanics of a network model of the RBC cytoskeleton. Our experimental results are also in agreement with the theoretical prediction of Mirijanian and Voth [2008; Proc Natl Acad Sci USA 105:12041208]. (c) 2011 Wiley Periodicals Inc.