THE mystery of how silkworms and spiders prevent their glands from clogging up as they spin silk has been solved. The trick is to make sure the fibroin proteins that form the silk remain moist.
David Kaplan and Hyoung-Joon Jin at Tufts University in Medford, Massachusetts, found that the raw fibroin proteins made by silkworms form zigzagging strands. As water is withdrawn, the strands fuse into globules called micelles, which then lose more water to cluster into a thick, globular gel (Nature, vol 424, p 1057). This elongates into a strand of silk when stretched.
Critical hydrophilic regions of…
