Conformational Analysis of Native Fibronectin by Means of Force Spectroscopy
Conformational Analysis of Native Fibronectin by Means of Force Spectroscopy
复制标题
利用力谱法对天然纤连蛋白进行构象分析
作者：
Y. Oberdörfer;A. Fuchs;A. Janshoff
力的测量提供了一个很好的工具来研究折叠和展开的单丝状蛋白质。特别是，肌肉蛋白质和细胞外基质蛋白质的弹性特性对于理解纤维蛋白质的结构-功能关系至关重要。在这项研究中，我们专注于天然纤连蛋白，一个模块化的细胞外基质蛋白，包括不同类型的重复单元表现出各种各样的功能展开。血浆中的天然纤连蛋白（220 - 250 kDa）是一种二聚体，由至少三类重复单元组成，即FN-I、-II和-III结构域。氨基酸数目不同的结构域都具有β-桶结构。力-延伸曲线的统计分析清楚地揭示了FN-I（45个氨基酸）、FN-II（60个氨基酸）和FN-III（90个氨基酸）的不同解折叠。除了有关长丝机械性能的数据外，分析还提供了有关绝对成分的信息。
Force measurements provide an excellent tool to study the folding and unfolding of single-filamentous proteins. In particular, elastic properties of muscle proteins and proteins of the extracellular matrix are of paramount interest for the understanding of structure−function relationships of fibrous proteins. In this study, we focused on the unfolding of native fibronectin, a modular extracellular matrix protein comprising different types of repeating units exhibiting a large variety of functions. Native fibronectin (220−250 kDa) from blood plasma is a dimer composed of at least three classes of repeating units, FN-I, -II, and -III domains. The domains differing in the number of amino acids all have a β-barrel structure. Statistical analysis of force−extension curves clearly revealed the distinct unfolding of FN-I (45 amino acids), FN-II (60 amino acids), and FN-III (90 amino acids). Besides data about mechanical properties of the filament, the analysis provided also information about the absolute composi...