2018 Volume 26 Pages 13-20
Gel-like liquid silk separated from the middle division of the middle silk gland was immersed in room temperature water for various time periods, and the subsequent dissolved fractions of the liquid silk were used to produce aerogels with different fibroin and sericin contents. Then, the re-dissolvability of the aerogels in water at 50 °C was measured. The aerogels rich in sericin showed poor re-dissolvability. Alternately, the re-dissolvable fraction showed a peculiar amino acid composition that was quite different from fibroin, sericin, and other functional minor protein fractions. This unknown silk protein fraction could promote the dispersion of fibroin into water.