Introduction - This script shows some properties of the silk protein. Scroll down until the text corresponding to the view is visible. (Based on 1slk.pdb, S.A.Fossey et al., Biopolymers 31 1529 (1991)).
Silk fibroin is spun by silkworms and some spiders and is composed of stacked antiparallel b-sheets. The b-sheet is composed of the repeating sequence [Gly-Ala-Gly-Ala-Gly-Ser-Gly..]. This sequence allows the sheets to stack on each other with the Ser or Ala residues opposite a Gly residue.