Spider dragline silk is a semicrystalline protein polymer in which alanine-rich crystalline regions are connected by soft glycine-rich linkers that, in dry fibers are quiescent but become motionally active when plasticized by water. Using solid-state NMR to probe molecular motion and orientation of selectively C-13-labeled glycine residues, we observe a collapse of amino acid chains in hydration-induced local phase transitions and find that the relative abundance of the static and mobile phases can be controlled by fiber strain. Our results suggest a molecular mechanism for silk's mechanical properties based on latent entropic springs that are drawn in preformed extended structures, stabilized by interchain hydrogen bonding, and collapsed by hydration.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据