Second-Order Derivation Fourier Transform Infrared Spectral Analysis of Regenerated Wool Keratin Structural Changes

Keratin is a natural biopolymer with excellent biocompatibility and biodegradability properties. It is widely used in biomaterial construction. The secondary structure of keratin is essential in its applications. This structure is associated with its regeneration. In this study, the structure of regenerated keratin from wool was analyzed using the amide I, II, and III bands from second-order derivation Fourier transform infrared spectroscopy. The results showed that the regenerated wool keratin retained its molecular backbone with the cleavage of disulfide bonds. The amide I and II bands indicated that the content ratio of alpha-helix to non-alpha-helix structure was less in the regenerated keratin than that of raw wool. The amide III band confirmed the contents of alpha-helix/beta-sheet/beta-turn/random coil for raw wool (35%/31%/22%/13%) and regenerated keratin (26%/35%/23%/15%).