Viscoelasticity of F-actin measured with magnetic microparticles.
Viscoelasticity of F-actin measured with magnetic microparticles.
复制标题
DOI：
10.1083/jcb.109.5.2233
复制
发表时间：
1989-11
期刊：
影响因子：
--
通讯作者：
Valberg PA
中科院分区：
文献类型：
--
作者：
Zaner KS;Valberg PA
利用分散的亚微观磁性颗粒对细胞质及其纯化组分的粘弹性进行了研究。外部施加的磁场对细胞中、丝状肌动蛋白（F-肌动蛋白）溶液中或通过加入肌动蛋白凝胶化因子、肌动蛋白结合蛋白（ABP）形成的F-肌动蛋白凝胶中的颗粒施加力。颗粒对磁力矩的响应与流体的粘弹性有关。我们比较了F-肌动蛋白的磁性颗粒方法获得的数据与F-肌动蛋白的滑动平面粘弹性仪的装置上获得的数据。F-肌动蛋白的解决方案有一个显着的弹性，增加了20倍，当凝胶形成ABP添加。这两种方法得到一致的结果，但分散的磁性颗粒表明定量更大的刚性比粘弹性仪（两个和六倍以上的F-肌动蛋白的解决方案和F-肌动蛋白加ABP凝胶，分别）。这些差异可能是由于这样的事实，即与传统的显微流变仪相比，分散颗粒测量受长程不均匀性或域状结构的影响较小。磁力测量方法被用来检查完整的巨噬细胞内的细胞质的机械性能;相同的磁力测量技术的细胞和定义明确的，纯化的蛋白质系统的应用程序是第一步解释活细胞在分子方面获得的结果。磁性粒子探针系统是一种有效的非光学技术，用于测定细胞的运动和力学性质在体外和体内。
Dispersed submicroscopic magnetic particles were used to probe viscoelasticity for cytoplasm and purified components of cytoplasm. An externally applied magnetic field exerted force on particles in cells, in filamentous actin (F-actin) solutions, or in F-actin gels formed by the addition of the actin gelation factor, actin-binding protein (ABP). The particle response to magnetic torque can be related to the viscoelastic properties of the fluids. We compared data obtained on F- actin by the magnetic particle method with data obtained on F-actin by means of a sliding plane viscoelastometer. F-actin solutions had a significant elasticity, which increased by 20-fold when gels were formed by ABP addition. Both methods gave consistent results, but the dispersed magnetic particles indicated quantitatively greater rigidity than the viscoelastometer (two and six times greater for F-actin solutions and for F-actin plus ABP gels, respectively). These differences may be due to the fact that, compared with traditional microrheometers, dispersed particle measurements are less affected by long-range heterogeneity or domain-like structure. The magnetometric method was used to examine the mechanical properties of cytoplasm within intact macrophages; the application of the same magnetometric technique to both cells and well-defined, purified protein systems is a first step toward interpreting the results obtained for living cells in molecular terms. The magnetic particle probe system is an effective nonoptical technique for determining the motile and mechanical properties of cells in vitro and in vivo.