초록 |
The spinning mechanism of silk is of interest due to superior properties of silk fiber and its mild spinning conditions. The secret of silk spinning is still unsolved, but extensive works were done with silk fibroin, which is the main protein of silk fiber. There is another protein in silkworm gland, named sericin. Even though sericin is in contact with fibroin at least 5 days in the silkworm gland, the role of sericin were never elucidated extensively. We previously reported that the presence of sericin might retard the crystallization of silk fibroin and thereby stabilize the highly concentrated fibroin. However, the previous study used hot water extracted sericin which has lower molecular weight than orginal sericin. In this study, we extracted sericin using urea-mercaptoethanol solution which prevents degradation of sericin during extraction procedure. The structural transition of fibroin were observed in the presence of non-degraded sericin. |