Entrapment of Immature Amyloid Protofilaments in the Hydrophobic Domain of Schizophyllan
Entrapment of Immature Amyloid Protofilaments in the Hydrophobic Domain of Schizophyllan
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DOI：
10.1007/s00289-008-0927-5
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发表时间：
2008-03
期刊：
影响因子：
3.2
通讯作者：
M. Sakuragi;Y. Takeda;Naohiko Shimada;K. Sakurai
中科院分区：
文献类型：
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作者：
M. Sakuragi;Y. Takeda;Naohiko Shimada;K. Sakurai
已知β-1,3-葡聚糖裂褶多糖（SPG）在自然界中采用三螺旋结构，在碱性溶液中采用无规卷曲构象，当其无规卷曲复性时形成疏水域。本文介绍了淀粉样蛋白与 SPG 的络合，推测是由于 β-折叠和 SPG 疏水结构域之间的疏水相互作用。圆二色性 (CD) 显示复合物在 225 nm 处有负带，表明存在堆叠的 β-折叠。 然而，广角 X 射线散射 (WAXS) 没有显示出通常在成熟淀粉样蛋白中在 1.0 nm 处观察到的清晰的 β 片层间衍射。结合WAXS和CD，可以得出结论，复合物中的溶菌酶具有β-折叠，但β-折叠不能很好地堆叠以产生衍射。 可以使用横截面 Gunier 和 Debye-Bueche 函数的组合来再现复合体的小角度 X 射线散射 (SAXS) 剖面。
β-1,3-glucan schizophyllan (SPG) is known to adopt a triple helical structure in nature and a random coil conformation in alkaline solutions which forms a hydrophobic domain when its random coil is renatured. This paper presents the complexation of amyloid with SPG, presumably owing to hydrophobic interactions between the β-sheets and the SPG hydrophobic domain. Circular dichroism (CD) showed that complex had a negative band at 225 nm, indicating the presence of the stacked β-sheets. However, wide angle X-ray scattering (WAXS) showed no clear inter β-sheet diffractions that are generally observed at 1.0 nm in matured amyloid. Combining WAXS and CD, it can be concluded that lysozyme in complex has β-sheets but the β-sheets are not well stacked to give diffraction. Small angle X-ray scattering (SAXS) profile from complex can be reproduced using a combination of the cross-sectional Gunier and Debye-Bueche functions.