Single-particle tracking offers a method to interrogate the organization of transmembrane proteins by measuring their mobilities within a cell's plasma membrane. Using this technique, the diffusion characteristics of the Duffy antigen (DARC), glycophorin A, band 3, and GLUT1 were compared under analogous conditions on intact human erythrocyte membranes. Microscopic diffusion coefficients revealed that the vast majority of all four transmembrane proteins exhibit very restricted movement but are not completely immobile. In fact, only 12% of GLUT1 resolved into a highly mobile subpopulation. Macroscopic diffusion coefficients and compartment sizes were also similar for all four proteins, with movements confined to the approximate dimensions of the "corrals" of the cortical spectrin cytoskeleton. Taken together, these data suggest that almost the entire populations of all four transmembrane proteins are immobilized by either the incorporation within large multiprotein complexes or entrapment within the protein network of the cortical spectrin cytoskeleton.

中文翻译：

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Duffy 抗原、血型糖蛋白 A、Band 3 和 GLUT1 在红细胞中的扩散：深入了解膜复合物

单粒子追踪提供了一种通过测量跨膜蛋白在细胞质膜内的流动性来询问其组织的方法。使用这种技术，在类似条件下，在完整的人红细胞膜上比较了 Duffy 抗原 (DARC)、血型糖蛋白 A、带 3 和 GLUT1 的扩散特性。微观扩散系数显示，所有四种跨膜蛋白中的绝大多数表现出非常有限的运动，但并非完全不动。事实上，只有 12% 的 GLUT1 分解为高度移动的亚群。所有四种蛋白质的宏观扩散系数和隔室大小也相似，运动仅限于皮质血影细胞骨架的“畜栏”的近似尺寸。综合起来，