Membrane-mediated assembly of annexins studied by site-directed spin labeling
Membrane-mediated assembly of annexins studied by site-directed spin labeling
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DOI：
10.1074/jbc.273.35.22453
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发表时间：
1998-08-28
影响因子：
4.8
通讯作者：
Hubbell, WL
中科院分区：
文献类型：
--
作者：
Langen, R;Isas, JM;Hubbell, WL
膜联蛋白是在Ca 2+存在下结合于膜的可溶性蛋白质。晶体结构已被确定为一些可溶性形式，但鲜为人知的是重要的膜结合状态。我们采用定点自旋标记来证明：1）膜联蛋白XII在生理条件下与双层结合时呈现类似于晶体结构的三聚体构型; 2）双层上的三聚体组装非常迅速，发生在毫秒级的时间尺度上，而亚基交换需要数小时; 3）不同的膜联蛋白可以混合形成异源三聚体。膜联蛋白的快速组装和异源三聚体的形成对膜联蛋白的细胞功能具有重要意义。
Annexins are soluble proteins that bind to membranes in the presence of Ca2+. Crystal structures have been determined for some soluble forms, but little is known about the important membrane-bound state. We employed site-directed spin labeling to demonstrate that 1) annexin XII assumes a trimer configuration similar to the crystal structure when bound to bilayers under physiological conditions; 2) trimer assembly on bilayers is remarkably rapid, occurring on a millisecond time scale, whereas subunit exchange requires hours; and 3) different annexins can mix to form heterotrimers. The rapid assembly and heterotrimer formation have important implications concerning the cellular functions of annexins.