米 Structure Fibroin protein polymer Pack well: lots of h-bonds small number of ionic bonds No cystine: no S-s bonds Configuration: pleated B-sheet Degree of polymerization of silk DP Silk >Dp woolStructure Fibroin protein polymer Pack well: lots of H-bonds, small number of ionic bonds No cystine: no S-S bonds Configuration: pleated b-sheet Degree of polymerization of silk DPsilk > DPwool