Red cell membranes of ankyrin-deficient nb/nb mice lack band 3 tetramers but contain normal membrane skeletons.
Red cell membranes of ankyrin-deficient nb/nb mice lack band 3 tetramers but contain normal membrane skeletons.
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DOI：
10.1021/bi9704966
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发表时间：
1997-08
期刊：
影响因子：
2.9
通讯作者：
S. J. Yi;Shih-Chun Liu;Laura H. Derick;J. Murray;J. Barker;M. Cho;J. Palek;D. Golan
中科院分区：
文献类型：
--
作者：
S. J. Yi;Shih-Chun Liu;Laura H. Derick;J. Murray;J. Barker;M. Cho;J. Palek;D. Golan
通过表征nb/nb小鼠红细胞中锚蛋白缺乏对骨骼超微结构、3-带骨架关联和3-带寡聚物状态的影响，研究了锚蛋白在基于光谱的骨骼网络和3带寡聚物形成和稳定中的作用。尽管严重的栓蛋白缺乏，nb/nb小鼠红细胞骨骼成分形成了相对均匀的二维六边形连接复合物阵列，通过谱蛋白四聚体交联。用非离子型洗涤剂C12E8（辛二醇十二烷基单醚）处理nb/nb幽灵，能带3几乎完全提取。提取的能带3只以能带3二聚体存在。荧光光漂白恢复和偏振荧光耗尽测量显示，与对照红细胞相比，完整nb/nb中波段3的横向（33% vs 10%）和旋转（90% vs 76%）移动部分增加。与对照红细胞相比，nb/nb中带3分子主要部分的旋转相关时间缩短了10倍，表明nb/nb细胞中的旋转约束明显放松。这些数据表明，尽管锚蛋白在加强骨架与膜双分子层的附着方面起着重要作用，但锚蛋白并不是形成稳定的二维光谱骨架所必需的。锚蛋白缺陷红细胞的膜中3带四聚体的缺失表明锚蛋白是形成稳定的3带四聚体所必需的。
The role of ankyrin in the formation and stabilization of the spectrin-based skeletal meshwork and of band 3 oligomers was studied by characterizing, in nb/nb mouse red cells, the effect of ankyrin deficiency on skeletal ultrastructure, band 3-skeleton associations, and band 3 oligomeric states. Despite severe ankyrin deficiency, nb/nb mouse red cell skeletal components formed a relatively uniform two-dimensional hexagonal array of junctional complexes cross-linked by spectrin tetramers. Treatment of nb/nb ghosts with the nonionic detergent C12E8 (octaethylene glycol n-dodecyl monoether) resulted in nearly complete extraction of band 3. The extracted band 3 was present exclusively as band 3 dimers. Fluorescence photobleaching recovery and polarized fluorescence depletion measurements showed increases in the laterally (33% vs 10%) and rotationally (90% vs 76%) mobile fractions of band 3 in intact nb/nb compared to control red cells. The rotational correlation time of the major fraction of band 3 molecules was 10-fold shorter in nb/nb compared to control red cells, indicating a significant relaxation of rotational constraints in nb/nb cells. These data suggest that, although ankyrin plays a major role in strengthening the attachment of the skeleton to the membrane bilayer, ankyrin is not required for the formation of a stable two-dimensional spectrin-based skeleton. The absence of band 3 tetramers in the membrane of ankyrin-deficient red cells suggests that ankyrin is required for the formation of stable band 3 tetramers.