Silk Fibroin/Montmorillonite Nanocomposites: Effect of pH on the Conformational Transition and Clay Dispersion
Silk Fibroin/Montmorillonite Nanocomposites: Effect of pH on the Conformational Transition and Clay Dispersion
复制标题
丝素蛋白/蒙脱土纳米复合材料：pH 对构象转变和粘土分散的影响
DOI：
10.1021/bm1002398
复制
发表时间：
2010-07-12
影响因子：
6.2
通讯作者：
Yuan, Zhi
中科院分区：
文献类型：
--
作者：
Dang, Qinqin;Lu, Shoudong;Yuan, Zhi
By adjusting the solution pH value below the isoelectric point (pl) of silk fibroin (SF) protein, the SF was in the cation state and it could interact strongly with unmodified anionic montmorillonite (MMT) surface. In this way, novel SF-MMT nanocomposites with good clay dispersion were successfully obtained, which were confirmed by X-ray diffraction and transmission electron microscopy. Further H-1 CRAMPS and C-13 CP/MAS NMR experimental results revealed that beta-sheet content of SF was remarkably enhanced for nanocomposite prepared below the pl of SF (SF-MMTA) due to the strong interaction between MMT and SF. In SF-MMTA nanocomposite, clay layers acting as an efficient nucleator could efficiently enhance the beta-sheet crystallization. On the contrary, SF preserved the native random coil conformation in SF-MMTN nanocomposites due to the weak interaction between MMT and SF. A tentative model was suggested and used to explain the mechanism of clay dispersion and conformational transition of silk protein.
