The molecular structure of spider dragline silk: Folding and orientation of the protein backbone
The molecular structure of spider dragline silk: Folding and orientation of the protein backbone
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DOI：
10.1073/pnas.152162299
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发表时间：
2002-08-06
影响因子：
11.1
通讯作者：
Meier, BH
中科院分区：
文献类型：
--
作者：
van Beek, JD;Hess, S;Meier, BH
蜘蛛拖丝是自然界的高性能纤维，其设计原理在很大程度上仍然是未知的，特别是对于形成材料主体的非结晶富含甘氨酸的结构域。在这里，我们应用二维固态NMR来确定的骨干扭转角（φ，psi）的分布，以及在甘氨酸和丙氨酸残基的多肽骨架朝向纤维的方向。这些新的数据表明，牵引丝中的所有结构域都具有优选的二级结构，并且具有强烈的取向性，其中链主要平行于纤维。如前所述，丙氨酸残基主要以0折叠构象存在。甘氨酸残基部分地并入p片层中，并且以其他方式形成具有近似3重对称性的螺旋结构。
The design principles of spider dragline silk, nature's high-performance fiber, are still largely unknown, in particular for the noncrystalline glycine-rich domains, which form the bulk of the material. Here we apply two-dimensional solid-state NMR to determine the distribution of the backbone torsion angles (phi,psi) as well as the orientation of the polypeptide backbone toward the fiber at both the glycine and alanine residues. Instead of an "amorphous matrix," suggested earlier for the glycine-rich domains, these new data indicate that all domains in dragline silk have a preferred secondary structure and are strongly oriented, with the chains predominantly parallel to the fiber. As proposed previously, the alanine residues are predominantly found in a 0 sheet conformation. The glycine residues are partly incorporated into the p sheets and otherwise form helical structures with an approximate 3-fold symmetry.