Liu Xueping, Huang Qian, Pan Peng, Fang Mengqi, Zhang Yadong, Yang Shanlong, Li Mingzhong, Liu Yu
National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China.
Polymers (Basel). 2023 Aug 12;15(16):3383. doi: 10.3390/polym15163383.
Removing sericin from the periphery of silk without damage to silk fibroin (SF) to obtain high-molecular-weight SF is a major challenge in the field of SF-based biomaterials. In this study, four neutral proteases, subtilisin, trypsin, bromelain and papain, were used to degum silk, and the degumming efficiency of the proteases and their influence on the molecular weight (MW) of regenerated silk fibroin were studied. The results indicated that all four neutral proteases could remove sericin from silk almost completely, and they caused less damage to SF fibers than NaCO degumming did. The degumming efficiency of trypsin and papain was strong, but they caused relatively high damage to SF, whereas bromelain caused the least damage. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel permeation chromatography and shear viscosity showed that the MWs of regenerated SF derived from neutral protease degumming were significantly higher than that of SF derived from NaCO degumming. The MW of regenerated SF derived from bromelain degumming was the highest, while the MWs of regenerated SF derived from papain and trypsin degumming were relatively low. This study provides an efficient and environmentally friendly biological degumming method for obtaining high-molecular-weight silk fibroin.
在不损伤丝素蛋白（SF）的前提下从蚕丝外围去除丝胶以获得高分子量的SF是基于SF的生物材料领域的一项重大挑战。在本研究中，使用了四种中性蛋白酶，即枯草杆菌蛋白酶、胰蛋白酶、菠萝蛋白酶和木瓜蛋白酶对蚕丝进行脱胶，并研究了这些蛋白酶的脱胶效率及其对再生丝素蛋白分子量（MW）的影响。结果表明，所有四种中性蛋白酶都能几乎完全从蚕丝中去除丝胶，并且与碳酸钠脱胶相比，它们对SF纤维造成的损伤更小。胰蛋白酶和木瓜蛋白酶的脱胶效率较高，但它们对SF造成的损伤相对较大，而菠萝蛋白酶造成的损伤最小。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、凝胶渗透色谱和剪切粘度的结果表明，中性蛋白酶脱胶得到的再生SF的分子量显著高于碳酸钠脱胶得到的SF的分子量。菠萝蛋白酶脱胶得到的再生SF的分子量最高，而木瓜蛋白酶和胰蛋白酶脱胶得到的再生SF的分子量相对较低。本研究为获得高分子量丝素蛋白提供了一种高效且环保的生物脱胶方法。
