Small angle neutron scattering of native and reconstituted silk fibroin

Silks spun by spiders and insects are independently evolved proteinaceous biomaterials with fascinating physical properties attracting scientists from a wide range of disciplines using a wide range of analytical tools. Here we demonstrate the suitability of neutron small angle scattering (SANS) to investigate the morphology and structure of native silk fibroin at near in vivo conditions. Comparing native and reconstituted silk we observed significant differences in sizes, molecular weights, refolding and interactions. These observations question the validity of a presently widespread approach in silk analysis i.e. studying reconstituted silk with the goal to gain important insights into the mechanisms involved in the formation (storage and spinning) of native silks.