Comparative Study of the Preparation of High-Molecular-Weight Fibroin by Degumming Silk with Several Neutral Proteases

Removing sericin from the periphery of silk without damage to fibroin (SF) obtain high-molecular-weight SF is a major challenge in field SF-based biomaterials. In this study, four neutral proteases, subtilisin, trypsin, bromelain and papain, were used degum silk, degumming efficiency proteases their influence on molecular weight (MW) regenerated studied. The results indicated that all could remove almost completely, they caused less fibers than Na2CO3 did. trypsin papain was strong, but relatively high SF, whereas least damage. sodium dodecyl sulfate–polyacrylamide gel electrophoresis, permeation chromatography shear viscosity showed MWs derived protease significantly higher degumming. MW highest, while low. This study provides an efficient environmentally friendly biological method for obtaining fibroin.