羟丙基甲基纤维素诱导丝素蛋白的构象转变

制备了羟丙基甲基纤维素 (HPMC)和丝素蛋白 (SF)的共混膜 ,用FTIR ,XRD和DSC方法对共混膜的结构进行了表征 ,讨论了HPMC对SF的构象转变作用 ,结果表明 ,HPMC能够有效的诱导SF的构象转变 ,HPMC的比例是影响SF的构象转变程度的重要因素 .当混入 3%～ 10 %HPMC时 ,SF的构象存在由无规线团或SilkI向SilkII(β 折叠 )的转变 ,当加入 7%HPMC时 ,β 折叠构象的比例最大 .从红外分析可知 ,构象转变是由于适量的HPMC与SF混合形成了二者之间的分子间氢键所致 .对不同比例的共混膜测定其在水中的溶出率 ,结果显示当HPMC的比例为 7%时SF几乎不溶于水

CONFORMATION TRANSITION OF SILK FIBROIN INDUCED BY BLENDING HYDROXYPROPYL METHYLCELLULOSE

The blend membranes of silk fibroin (SF) and hydroxypropyl methylcellulose (HPMC) were made.The effect of HPMC on the conformation transition of silk fibroin membranes was analyzed by Fourier transform infrared spectrum,X-ray diffraction,and Differential scanning calorimetry.The results demonstrated that the content of blending HPMC had a great influence on the conformation of silk fibroin membranes.The conformational change from a random coil or Silk I to β-sheet structure occurred when blending 3%～10% HPMC and the β-sheet content was maximal when HPMC content was 7%.This result is due to the formation of intermolecular hydrogen bonds when some content HPMC was mixed with fibroin.The result of water-solubility showed the blend film was almost insoluble when HPMC content was 7%.