Raman spectroscopic characterization of Bombyx mori silk fibroin:: Raman spectrum of Silk I
Raman spectroscopic characterization of Bombyx mori silk fibroin:: Raman spectrum of Silk I
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DOI：
10.1002/jrs.675
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发表时间：
2001-02-01
影响因子：
2.5
通讯作者：
Tsukada, M
中科院分区：
文献类型：
--
作者：
Monti, P;Taddei, P;Tsukada, M
本研究的重点是通过拉曼光谱对不同处理的家蚕丝素蛋白样品进行构象表征。讨论了丝素蛋白膜和液体丝的拉曼光谱，并与具有 Silk I (Silk I-Cp) 和 Silk II (Silk II-Cp) 结构的家蚕丝素蛋白 (Cp，胰凝乳蛋白酶沉淀物) 的结晶部分的拉曼光谱进行了比较。首次报道Silk I-Cp完整的1800-200 cm(-1)拉曼光谱。发现酰胺 I 和酰胺 III 模式几乎不适合在存在无规卷曲构象的情况下对 Silk I 形式的丝素蛋白进行光谱表征。 Silk I 型的拉曼标记带在约 1415、950、930、865、260 和 230 cm(-1) 的其他光谱范围内被识别。在此基础上，对比薄膜、液体丝和Silk I-Cp在1000~800 cm(-1)范围内的拉曼光谱，清楚地表明薄膜和液体丝除了无规卷曲外，还含有Silk I结构的局部区域；它们在液体丝中的含量较高，如约 950、930 和 865 cm-1 处谱带的相对强度以及 I-1415/I-1455 强度比所示。还讨论了约 1275 和 1107 cm(-1) 处谱带的归属。这些条带之前被认为是由于家蚕丝中存在 α 螺旋构象，但从报告的结果来看，它们更应该归因于 Silk I 形式。版权所有 (C) 2001 John Wiley & Sons, Ltd.
This study focuses on the conformational characterization of differently processed Bombyx mori silk fibroin samples by Raman spectroscopy. The Raman spectra of silk fibroin film and liquid silk are discussed in comparison with those of the crystalline fractions of Bombyx mori silk fibroin (Cp, chymotryptic precipitate) with Silk I (Silk I-Cp) and Silk II (Silk II-Cp) structures. The complete 1800-200 cm(-1) Raman spectrum of Silk I-Cp is reported for the first time. The amide I and amide III modes were found to be scarcely suitable for the spectroscopic characterization of silk fibroin in the Silk I form in the presence of a random coil conformation. Raman marker bands for the Silk I form were identified in other spectral ranges at about 1415, 950, 930, 865, 260 and 230 cm(-1). On the basis of the above findings, the comparison of the Raman spectra of film, liquid silk and Silk I-Cp in the range 1000-800 cm(-1) clearly indicates that in addition to random coil, both film and liquid silk contain local domains of Silk I structure; their amount is higher in liquid silk, as indicated by the relative intensity of the bands at about 950, 930 and 865 cm-l and by the I-1415/I-1455 intensity ratio.The assignments of the bands at about 1275 and 1107 cm(-1) are also discussed. These bands were previously assigned to the presence of alpha -helical conformation in Bombyx mori silk but, from the results reported, they should rather be attributed to the Silk I form. Copyright (C) 2001 John Wiley & Sons, Ltd.