Vibrational spectroscopy studies on the blend films of silk fibroin and silk-protein like polymers

Vibrational spectroscopy (ATR-FTIR and Raman) was used to investigate the interaction and conformation transition in the blend films of silk fibroin(SF) and silk-protein like polymers(P1, P2) containing the oligopeptide segments[(Ala)(4), GlyAlaGlyAla] which derived from the crystal region of spider dragline silk and silkworm(Bombyx mori) silk. The results revealed that the intermolecular hydrogen-bond interaction, which was formed between the molecular chains of SF and the oligopeptide segments in P1 and P2, induced a partial random coil/alpha-helix conformation transfer to beta-sheet conformation after blending. And beta-sheet and random coil/alpha-helix conformation coexisted in the SF/P1 and SF/P2 blend films, while the predominant conformations in the pure SF and P1 films were random coil/alpha-helix. These conclusions would be significant for artificial spinning of the regenerated silk fibroin.