Isenberg G, Goldmann W H
Biophysics Department E-22, Technical University of Munich, Garching, Germany.
FEBS Lett. 1998 Apr 17;426(2):165-70. doi: 10.1016/s0014-5793(98)00336-6.
Using ultrastructural analysis and labeling with polyclonal antibodies that recognize peptide sequences specific for phospholipid binding, we mapped the functional domain structure of intact platelet talin and its proteolytic fragments. The talin dimer, which is crucial for actin and lipid binding, is built of a backbone containing the 200 kDa rod portions, at both ends of which a 47 kDa globular domain is attached. Peptide-specific polyclonal antibodies were raised against three potential lipid binding sequences residing within the N-terminal 47 kDa domain (i.e. S19, amino acids 21-39; H18, amino acids 287-304; and H17, amino acids 385-406). Antibodies H17 and H18 localize these lipid binding sequences within the N-terminal 47 kDa globular talin subdomains opposed at the outer 200 kDa rod domains within talin dimers. Hence, we conclude that in its dimeric form, which is used in actin and lipid binding, talin is a dumbbell-shaped molecule built of two antiparallel subunits.
我们运用超微结构分析，并使用识别磷脂结合特异性肽序列的多克隆抗体进行标记，绘制了完整血小板踝蛋白及其蛋白水解片段的功能域结构。对肌动蛋白和脂质结合至关重要的踝蛋白二聚体，由包含200 kDa杆状部分的主干构成，在其两端连接着一个47 kDa的球状结构域。针对位于N端47 kDa结构域内的三个潜在脂质结合序列（即S19，氨基酸21 - 39；H18，氨基酸287 - 304；以及H17，氨基酸385 - 406）制备了肽特异性多克隆抗体。抗体H17和H18将这些脂质结合序列定位在踝蛋白二聚体内与外部200 kDa杆状结构域相对的N端47 kDa球状踝蛋白亚结构域内。因此，我们得出结论，在用于肌动蛋白和脂质结合的二聚体形式中，踝蛋白是由两个反平行亚基构成的哑铃状分子。
