不同溶解体系的丝素蛋白分子质量及对再生丝素膜性能的影响

为了便于根据不同丝素蛋白制品开发要求控制丝素蛋白的分子质量,用SDS-PAGE电泳方法检测不同溶解体系制取丝素蛋白的分子质量,并对不同分子质量丝素蛋白制备的再生丝素膜进行傅里叶红外光谱(FTIR)、热重(TGA)、微商热重(DTG)和热水溶失率等结构与性能的测试。SDS-PAGE检测结果显示,在LiBr-CH3CH2OH-H2O、Ca(NO3)2-CH3OH-H2O和Na-SCN-H2O溶解体系中的丝素蛋白分子质量较高且分布广;在CaCl2-CH3CH2OH-H2O和LiBr-H2O溶解体系中的丝素蛋白分子质量较低。FTIR、TGA、DTG和热水溶失率测试结果显示,低分子质量丝素蛋白溶液在成膜时较难形成α-结构和β折叠结构;而高分子质量丝素蛋白溶液在成膜时则较容易转变形成这2种结构。

Effects of Different Solvent Systems on Molecular Mass of Silk Fibroin and Properties of the Regenerated Silk Fibroin Membranes

In order to facilitate the control of molecular mass of silk fibroin according to the needs of various products in the utilization of silk proteins,several different solvent systems were used to dissolve Bombyx mori silk fibroins to prepare silk fibroin solution and regenerated silk fibroin membranes.The molecular mass of liquefied silk fibroin was measured by SDS-PAGE and the structure and properties of the regenerated fibroin membranes were characterized through FTIR, TGA,DTG,and hot water-solubility tests.SDS-PAGE results showed that the molecular masses of liquefied silk fibroin dissolved by LiBr-CH3CH2OH-H2O,Ca(NO3)2-CH3OH-H2O and NaSCN-H2O were higher and varied greater,and those dissolved by CaCl2-CH3CH2OH-H2O and LiBr-H2O were relatively lower.FTIR,TGA,DTG and hot water-solubility measurement indicated that,during membrane formation,the silk fibroin solution with low molecular mass was difficult to form α-structure and β-sheet,while that with high molecular mass was easier to form these two structures.