Chabanel A, Sung K L, Rapiejko J, Prchal J T, Palek J, Liu S C, Chien S
Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York.
Blood. 1989 Feb;73(2):592-5.
The viscoelastic properties of the RBC membrane are in part determined by a submembrane network of proteins consisting of spectrin alpha beta heterodimers (SpD) assembled head-to-head to form spectrin tetramers (SpT) and spectrin oligomers (SpO). SpT, in turn, are connected into a two-dimensional network by the linkage of distal ends of SpT to protein 4.1 and actin. With the micropipette technique, we determined the membrane viscoelastic properties of RBCs from a subset of patients with hereditary elliptocytosis (HE); these RBCs exhibit membrane skeletal instability, defective SpD self-association, and a molecular defect in the alpha I domain of spectrin, which is involved in the SpD-SpD contact (HE SpD alpha-SpD). The elastic modulus and viscosity of the membrane were significantly higher for the HE RBCs than for the control cells. Incubation of normal cells with N-ethyl-maleimide (NEM) produced a similar defective SpD self-association and a significant increase in the viscoelastic parameters of the membrane. The data provide evidence that the mode of assembly of membrane spectrin in the cytoskeletal protein network plays a major role in determining the rheologic behavior of erythrocyte membrane.
红细胞膜的粘弹性部分由蛋白质的亚膜网络决定，该网络由血影蛋白αβ异二聚体（SpD）头对头组装形成血影蛋白四聚体（SpT）和血影蛋白寡聚体（SpO）组成。反过来，SpT通过SpT远端与蛋白4.1和肌动蛋白的连接而连接成二维网络。我们使用微量移液器技术测定了一组遗传性椭圆形红细胞增多症（HE）患者红细胞的膜粘弹性特性；这些红细胞表现出膜骨架不稳定、SpD自我缔合缺陷以及血影蛋白αI结构域的分子缺陷，该结构域参与SpD-SpD接触（HE SpDα-SpD）。HE红细胞膜的弹性模量和粘度显著高于对照细胞。用N-乙基马来酰亚胺（NEM）孵育正常细胞会产生类似的SpD自我缔合缺陷，并使膜的粘弹性参数显著增加。数据表明，细胞骨架蛋白网络中膜血影蛋白的组装模式在决定红细胞膜的流变行为中起主要作用。
