Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity
Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity
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DOI：
10.1073/pnas.1014280108
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发表时间：
2011-03-15
影响因子：
11.1
通讯作者：
Weiss, Anthony S.
中科院分区：
文献类型：
--
作者：
Baldock, Clair;Oberhauser, Andres F.;Weiss, Anthony S.
弹性蛋白能够使弹性组织可逆变形，并能承受数十年的重复力。原弹性蛋白是弹性蛋白的可溶性前体，弹性蛋白是哺乳动物中发现的主要弹性蛋白。弹性蛋白原的形状和组装机制知之甚少，因为其独特的组成和自缔合倾向阻碍了结构研究。在这项研究中，我们使用小角度X射线和中子散射解决了原弹性蛋白全长和相应重叠片段的纳米结构，使我们能够识别分子的离散区域。弹性蛋白原是一种不对称的卷曲，具有一个突出的足，包含C-末端细胞相互作用基序。我们表明，个别原弹性蛋白分子是高度可扩展的，但没有滞后弹性，作为高效的分子纳米弹簧。我们的发现揭示了生物学如何使用这种单一蛋白质来构建持久的弹性结构，使细胞附着在附加的脚上。我们提出了一个独特的模型头到尾组件，它允许通过堆叠弹簧设计的分子的不对称线圈的传播。
Elastin enables the reversible deformation of elastic tissues and can withstand decades of repetitive forces. Tropoelastin is the soluble precursor to elastin, the main elastic protein found in mammals. Little is known of the shape and mechanism of assembly of tropoelastin as its unique composition and propensity to self-associate has hampered structural studies. In this study, we solve the nanostructure of full-length and corresponding overlapping fragments of tropoelastin using small angle X-ray and neutron scattering, allowing us to identify discrete regions of the molecule. Tropoelastin is an asymmetric coil, with a protruding foot that encompasses the C-terminal cell interaction motif. We show that individual tropoelastin molecules are highly extensible yet elastic without hysteresis to perform as highly efficient molecular nanosprings. Our findings shed light on how biology uses this single protein to build durable elastic structures that allow for cell attachment to an appended foot. We present a unique model for head-to-tail assembly which allows for the propagation of the molecule's asymmetric coil through a stacked spring design.